In the 1950s, American geochemist Clair Patterson presented findings that showed Earth is around 4.55 billion years old. His evidence was based on lead isotopic analysis that he used to calculate the age of the Canyon Diablo meteorite, which was discovered in Arizona in 1891. That result is now widely accepted as the age of our planet, but the buildup to this discovery was a long time coming.

Earth's true age was a subject of much debate among scientists in the 19th century. And rather than geologists taking the helm, it was physicists who realized that this giant ball of rock we live on must be far older than the thousands of years that had been assumed in prior centuries. Their main reasoning was heat.

In this excerpt from "This Is Life: A Journey from Inside Your Body to Beyond Earth" (University of Chicago Press/Picador, 2026), author and physicist Christophe Galfard looks at the progression among scientists who were coming to realize that thermodynamics was an essential piece of this long-standing puzzle.

Some two and a half centuries ago, the foremost experts on scientific matters knew a thing or two about heat. They knew, for instance, how heat could be transferred from one place to another. A new science was about to emerge out of this knowledge, a science called thermodynamics, which means "movements of heat" in Greek.

Thermodynamics isn't a force. It is more like a guidebook, a set of rules that apply to large

numbers of particles when they come together. It gives us, humans, a way to understand how particles behave when there is a lot of them without needing to refer to each one of them individually. It shows us how properties that don't exist on their own arise when many particles are together. It deals with these things we call emergent phenomena, such as heat and pressure, and which [Philip] Anderson's "More Is Different" tried to make sense of.

Understanding the dynamics of heat meant a lot to nineteenth-century scientists — so much so that many saw in it the roots of a philosophy so universal and powerful that they thought it should guide us through all our lives. Some even went as far as believing that heat was the source of eternal life. A prominent scientist became so convinced that this was the case that he locked himself up in his house and overheated it, thus shielding himself from all mortal diseases (ageing and death included). The experience was a true torture for the occasional guests who came to visit him, not to mention his wife, who had to endure it day and night.

The scientist held fast to his belief, though, piling on layer after layer of clothing to keep himself ever warmer. Unfortunately, the bulk made it difficult to move, and he eventually missed a step on his own staircase and died from the fall.

As a scientific discipline, thermodynamics was born with a book written in 1824 by a 27-year-old French physicist named Nicolas Léonard Sadi Carnot, who, as he explained how heat could produce work, told everyone how the steam engine worked.

With Carnot's vision, the way hot objects cool down began to be understood, raising hopes that the resolution of one particular problem might be imminent: the determination of the Earth's age. Were we to somehow guess how hot our planet was at birth, thermodynamics could then be used to tell us how much time had gone by for it to have cooled to its present temperature. Many scientists tried it, keen to be the first one to nail the true age of our world.

Considering our planet in all its complexity to be far too difficult, simplifications were in order, and British physicist William Thomson shot first by picturing our world as a ball. A very simple, rock-solid ball made of pretty much the same stuff throughout, from surface to core. No ocean, no mountain, just a smooth ball the size of the Earth. He then calculated how long it would take it to cool down from being red hot to its present temperature, and declared that the Earth was something between 40 and 400 million years old.

Refining his calculations, he then announced that the world was 100 million years old, before settling for 40 million again.

Thomson's result does not correspond to the true age of the Earth, but it was a start. It was the result of a model, an attempt at figuring out something about our world using still-to-be-refined laws, and mathematical sense. What was more problematic was that no one dared question his results. Even as it shifted from one paper to another, the age of the Earth given by Thomson was always greeted as the right one. A reason for this is that at the end of the nineteenth century Thomson had become Lord Kelvin.

The same Kelvin after whom the Kelvin unit of absolute temperature is named. A scientific superstar who had the power to undo, in a snap of fingers, the career of anyone who disagreed with him.

Lord Kelvin was a physicist, not a geologist, so geologists could have questioned his work, but they didn't. In fact, they weren't bothered. Many of them back then believed that being a geologist was all about intuition and proper English, a language they deemed far more efficient than mathematical gibberish.

That being said, and however wrong the results, Kelvin's calculations were beautiful, giving whoever wanted to think about the problem of the age of the Earth a way forward, which is exactly what one of his former students, Northern Irishman John Perry, did. He thought that Kelvin had overlooked something. As a man of science talking to his former mentor (and job provider), Perry explained his vision to Kelvin but was ignored.

Still, he published his thoughts in Nature. But again, the article was ignored. Not just by Kelvin, but by the scientific community at large, including geologists.

It would have saved us all quite a bit of time had this not been the case, because Perry not only found a much more correct way to picture the Earth and estimate its age than Kelvin had, but he also found the source of the power that makes our planet's continents drift.

In his model, Perry didn't picture the Earth to be uniformly the same from surface to core as Kelvin had. Instead, he modelled the Earth's interior as being divided into three regions: a metallic core at its centre, a solid crust at its surface, and a mantle that lay in between the two. Rather unexpectedly, Perry didn't envision the mantle as everyone else would have; he believed that it didn't behave like the solid rock it was, but as a liquid.

No wonder his former master didn't take him seriously. However, he pictured the mantle behaving like a liquid only when considered over long periods of time. Sandwiched between a hot core and a colder crust that very much looked like a lid, he believed the mantle had no choice but to behave just like water does in a heated pan, with the hottest parts at the bottom rising and cooling before diving back down and rising up again, in repeated loops, albeit in extremely slow motion. This type of movement is called convection, and it happens in solids, too.

If he was right, there would be two immediate consequences. The first one was that the time it would take for our planet's surface to cool down from red hot to its current temperature could now be far longer than Kelvin had estimated. The lid and the convection patterns prevented our planet from quickly radiating away all its energy into space, so we were now inhabiting an Earth that could be as old as 2 or 3 billion years. Maybe even more. Such timescales were unheard of in the scientific community. Back then, no one knew that the universe itself was 13.8 billion years old. They knew next to nothing.

The second consequence of Perry's model was that the mantle's circular movements underneath the crust could drag the crust itself via friction. The solid surface of our world would then move, and split into pieces that would drift, and collide, and plunge underneath — or slide above — one another. Where they collided, mountain ranges would rise, like the Alps, the Himalayas, the Rockies . . . Where they split apart, rifts would appear, probably in the middle of oceans, along ridges . . . just like [Marie] Tharp had found.

Nowadays, these broken pieces of our planet's surface have all been mapped. They are our world's plates and their movements through time are called plate tectonics. Today, most of us have heard about plate tectonics. Back then, however, no one had, and if very few people remember Perry today, it is because another scientific breakthrough made the estimation of the age of the Earth much easier and precise, showing us that our world isn't 2 or 3 billion years old, as Perry suggested, but precisely 4.567 billion, give or take a few million.

Reprinted with permission from This Is Life: A Journey from Inside Your Body to Beyond Earth by Christophe Galfard, published by the University of Chicago Press in North America and Picador in the UK. © 2026. All rights reserved.

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Most trickery in nature happens without a shred of awareness behind it. An orchid mantis (Hymenopus coronatus) doesn't know it looks like a flower, and a moth with eyespots on its wings has no concept of the predator it's startling. These are adaptations shaped by natural selection over countless generations, not conscious choices. But a smaller set of animal behaviors look like something else entirely — deliberate tactical, and aimed at manipulating another individual's beliefs, the same way human lies do.

Figuring out which is which turns out to be one of the trickiest questions in animal behavior research, James O'Hanlon, zoologist and science communicator, told Live Science.

In this excerpt from his new book, "Liars, Cheats and Copycats: Trickery and Deception in Nature" (Columbia University Press, 2026), O'Hanlon explores camouflage, mimicry and misdirection throughout the natural world, building toward the book's central question: Can animals tell lies?

In it, O'Hanlon examines one of the strongest candidates for an animal that deliberately lies: the fork-tailed drongo (Dicrurus adsimilis), a small African bird whose ever-changing repertoire of false alarm calls has made it a favorite subject for scientists studying tactical deception.

James O'Hanlon interview: 'You start painting pictures of squirrels twirling their mustaches': A biologist on whether animals can lie

Fork-tailed drongos are remarkable vocal mimics and can do an uncanny impression of a meerkat alarm call. The meerkats respond to it just as they would one of their own and scamper to safety. Meanwhile the drongo flies in once more to steal the meerkats' abandoned food.

They don't stop there; drongos mimic a whole range of other animals' signals, mimicking various avian neighbors like the caped glossy starling or the pied babbler. Those ever-watchful meerkats fall for the ruse once more, leaving their meals behind. Researchers have identified over fifty unique deceptive vocalizations in the drongo's arsenal.

By constantly rotating their "cry-wolf" tactics, these birds ensure their victims don't grow wise to the deception, allowing the theft to continue unabated. Yet, their cleverness isn't reserved solely for exploited meerkats.

This remarkable talent for mimicry extends to other creatures as well. Pied babblers and sociable weavers, who both forage in groups upon the earth, frequently find themselves bamboozled into fleeing their food by these false warnings. Had the legendary boy who cried wolf possessed such adaptive ingenuity, he might have successfully maintained his trickery.

It would, however, have resulted in a peculiar fable with an entirely different, perhaps darker, moral lesson.

It's early days in our understanding of whether animals can tell lies. Social group-living animals are likely candidates for finding animal tricksters in the wild, and we have only scratched the surface of what kinds of trickery goes on in these societies. Time will tell whether similar forms of deception are happening in the subsonic songs of whales and dolphins, the chemical mists of ants and termites, or the barks and howls of wild dogs.

Despite the growing list of evidence, scientists are still hesitant to conclude definitively that animals can intentionally deceive another, in a similar way to humans. This might have more to do with the professional conduct of scientists than it has to do with the reality of what goes on in animal societies.

Firstly, one of the most important rules in studying animal behaviour is to not anthropomorphise animals. In other words, don't project human-like qualities or emotions onto other species. Scientists must be completely objective and not assume that other animals think, behave or make decisions for the same reasons we do.

Since lying has always been perceived as a human behaviour, scientists are incredibly hesitant to conclude that it could be happening in other animals.

The second reason is that scientists are trained to never definitively conclude anything. There is an idea in science that you can disprove things, but never really prove things. This is why you will find scientific writing littered with phrases like "the evidence suggests," "it's probable that," or — my personal favourite — "the most parsimonious explanation is," and so on and so forth.

A professional scientist will often give a direct "No" answer but rarely a direct "Yes." It's like squeezing blood from a stone. But this is a good thing. What often sounds like indecisiveness or a lack of certainty is actually just good professional practice. It's part of a scientist's job description — to consider all possible explanations for the observations they have made and examine every possibility on its own merits.

Then the conclusions that are drawn come down to which of these possibilities is most likely. In a universe of infinite possibilities and scales of enquiry, it would take an impossible amount of overwhelming data for scientists to exclude all possibilities but one.

This article is adapted from Liars, Cheats, and Copycats: Trickery and Deception in Nature by James O’Hanlon . Copyright © James O’Hanlon 2027, 2025 First published in Australia by NewSouth, an imprint of UNSW Press Ltd. Used by arrangement with Columbia University Press. All rights reserved.

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In the 17th and 18th centuries, the fear of vampires reached extraordinarily heights. People believed corpses could reanimate and wander around, terrorizing villages and spreading disease. They went to extreme lengths to prevent a vampire from rising. Some chopped the deceased person's head off, others placed sickles across their necks. Many were placed face down in their graves. In one grave in Poland, the remains of a boy were found with an iron padlock around his foot.

In this excerpt from "Killing the Dead: Vampire Epidemics from Mesopotamia to the New World" (Princeton University Press, 2025), author and historian John Blair reveals the impact the printed press had on the spread of vampiric lore — and the grizzly purported practice of ingesting the blood and organs of a vampire to prevent other people becoming one.

With the invention of printing, the circulation of European stories about restless corpses moved up several gears. Occasional early references were followed by a clutch of theological and philosophical discussions during c. 1580-1610, and then — from the 1670s — a steadily growing volume of printed academic and historical debate and commentary, reaching a climax in 1732.

Another landmark came in 1746 when the Benedictine scholar Dom Augustin Calmet published his survey of supernatural beings, which was quickly reissued in several editions, including an English one of 1759. This book's section on vampires was the most influential academic work on the subject ever published. Its straightforwardly evidence-based approach was a breath of fresh air after a long series of increasingly derivative works.

It achieved its remarkable popularity because it entered the market at the right point: saturated with so much fragmented and repetitive discussion of "vampires" (still a relatively new word), the reading public wanted a textbook. Calmet inspired a huge progeny of followers and popularisers, bringing the stories to a much wider readership; a good example of the genre is the Histoire des vampires et des spectres malfaisants [History of Vampires and Malevolent Specters] of 1820, a pocketbook that re-packages Calmet for the mass market.

Calmet's book remains the ultimate source of much modern vampire literature in Europe and America, both fi­ctional and supposedly historical, and was transformative in bringing the topic to a wider reading public. There and elsewhere, stories were now frozen on the printed page, where later generations could read them. But they were stories still: not necessarily more reliable, and by no means stable in transmission.

The complexity of interactions between learned discourse and popular practice is illustrated by one particularly bizarre and repellant (not to say dangerous) strand in the belief-system. This is the practice of ingesting blood or organs from a supposed vampire corpse, or ashes derived from burning them, as a remedy for vampire-induced illness.

Although not wholly dissimilar from the idea that victims will recover as they watch the smoke rise from burning vampire organs — already known in 11th-century England — its shocking physicality sets it apart. Did people in pre-modern Europe really do this?

A complicating factor is the medicinal use of human blood and bodyparts, in accordance with the theories of the physician, philosopher, and alchemist "Paracelsus" (Theophrastus von Hohenheim, c. 1493–1541). A brilliant experimenter, Paracelsus believed that substances healed through occult 'influences' or 'spirits,' the most powerful being those derived from what they were meant to cure: the human body.

The fact that medicine now rejects these hypotheses should not make us view them patronizingly: in the early modern period, ingesting or anointing with substances from Egyptian mummies or the blood of executed criminals seemed as rational as doing the same with any other substance. These Paracelsian ideas entered popular practice: at a beheading in Vienna in 1668/9, a man ran forward and caught the spouting blood to cure his epilepsy.

The tangled story of consuming blood from vampire corpses starts in a different and very unexpected place. In 1687, a major ethnographical account of parts of West Africa by the Capuchin missionary Giovanni Antonio Cavazzi was published in Bologna. In it, Cavazzi describes magical and medical practices among the Mbundu of Angola, including a method of obtaining vital curative fluid from undecayed corpses:

When they are in a fresh and intact state when unearthed, their heads are cut from their bodies, from which it is said that blood flows out (which may happen through some illusion or deceit). It is collected and made into poultices for the sick, or mixed into their food, which infallibly guarantees health. Thereafter the dead person, having lost his strength, will no longer be able to harass them.

From Angola to Paris: in May 1693, a story appeared in the society magazine Mercure Galant. The author was the courtier and polymath Pierre des Noyers (1607–93), who spent several years in Poland in the entourage of Queen Louise-Marie. Much earlier, in 1639, he had written to a friend about the being known as upior (Ruthenian) or striga (Polish): born with teeth; eating its shroud and then its hands and arms in the coffi­n; causing successive deaths of family members; and extinguished by decapitation and release of pent-up blood.

This story is rather highly coloured (eating the hands and arms is unusual), but it does probably originate in genuine oral accounts of the shroud-chewer belief.

Very different is des Noyers’s account from 1693. Now the striges and upierz have become corpse-hijacking demons: 'It is said that the demon takes this blood from the body of a living person, or from certain animals, and carries it into a dead body; for it is alleged that the demon goes out from this corpse during a certain period, between noon and midnight, after which it returns and stores there the blood that it has gathered.'

The blood comes out of the mouth, nose, and ears of the corpse, the corpse swims in blood, and it starts to eat its shroud. The demon especially troubles former associates and relatives of the dead 'host,' appearing to them in the guise of parents or friends, and does not leave until all the family members have died in succession. The remedy is to exhume the corpse, which is found soft, flexible, bloated, and red:

When they are found in that state, having the likeness of those who had appeared in dreams, their heads are cut off and their hearts are opened, and a quantity of blood flows out. It is collected and kneaded into flour, which is made into bread, which is a certain remedy to guarantee against such a terrible affliction. After the heads [of the dead people] have been cut off, those whom the Spirit torments at night are no longer troubled by it, and are well thereafter.

This narrative has problems. The idea of the demon using the corpse as a safe-deposit for its hoard of blood seems to be unique; so, probably, is the time-slot between noon and midnight. These read like clerical rationalizations, perhaps fed to des Noyers by some Polish priest and overlaid on his earlier, more authentic observations. But more fundamentally, it seems obvious that des Noyers’s account of Poland shamelessly re-works Cavazzi's account of Angola, published eight years previously.

It might not be quite so simple. An earlier common source, still unidenti­fied, remains possible. The descriptions of mixing blood into food and poultices look remarkably close to Paracelsian ideas, extended from ordinary corpses to undead ones: was even Cavazzi's account distorted by his own medical learning? But in any case des Noyers’s account is a piece of unprincipled plagiarism, worthless as evidence for Polish folk-belief.

Even so, it has bounced down through the echo-chambers of vampire literature ever since. The following year, a lawyer called Marigner built on the narrative — which he took at face value — with long philosophical musings on the nature of vampires. Inevitably, in 1746, it was republished in Calmet's book, which made it permanently available to vampire-aware readers.

While otherwise faithful to des Noyers, Calmet's version irons out the motif of demonic corpse-possession by calling this predator a vampire 'or a demon in its form.' This process of moulding to a more familiar template culminates in a recent version that presents the story as straightforward ethnographic reporting, omitting the demonic motif completely.

So far, this has just been a morality tale of plagiarism and uncritical copying. But in 1713, at Dąbrówka (now western Ukraine), some villagers were tried in the Uniate episcopal court for exhuming a woman's corpse and mutilating it in inventive ways. They admitted to the exhumation (because the dead woman had been walking around and attacking people), and to drinking the corpse's blood mixed with vodka. They denied cutting out the heart, mixing the blood into flour, and baking cakes with it, but the judges were sceptical and made them swear an oath.

This will sound very familiar to readers of early modern witch trials, where suspects were regularly bullied into admitting bizarre fantasies formulated by the persecutors. In this case, it seems clear that at least the idea of the blood-cakes was suggested by the judges; the same could be true of the blood-drinking, even though the accused were induced to confess that. It is distinctly possible, not to say likely, that an ordinary corpse-killing was embellished with luridly fi­ctitious detail by judges who knew des Noyers's report from twenty years earlier.

Killing The Dead: Vampire Epidemics from Mesopotamia to the New World. Copyright © 2025 by John Blair, published by Princeton University Press and reprinted here by permission.

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Fish meal is a commercial, protein-rich product created from raw fish and their byproducts, such as the heads and bones. It tends to be made from smaller fish species, including anchovies, sardines and herring. The fish are cooked, dried and ground into a powder, and then used to feed livestock, farmed fish and pets. But it is not a straightforward market.

In this excerpt from "Every Last Fish: A Deep Dive into the World of Fishes and Fishing" (Granta Books, 2025), journalist and author Rose George looks at how vast quantities of staple fish are taken from the sea off West Africa and turned into fishmeal for farming in Europe and China, instead of ending up on the plates of people in Africa.

"Every Last Fish" was short-listed for the 2026 Royal Society Trivedi Science Book Prize.

Rose George interview: 'If you do want to be a criminal, there is no better place to do it': Diving into the dark depths of the fishing industry

Take a fish. Eat its flesh if you want, but don't scorn the rest. It can always be used, one way or another, whether you want fishmeal or face cream.

Products derived from fish turn up everywhere. Guanine, an ingredient produced from fish scales, is found in bath foam, perfume, nail products, shampoo, skincare products, and lipstick. Fishes can become gelatine, glue, and squalene. They can be in your dietary supplements or your glass of wine: isinglass, derived from dried fish air bladders, is used in wine-making.

Futuristic piscigrafts are irrelevant to most people in Senegal, but they still have to deal with the fish by-products industry, because they have to watch as fish they could eat are transformed into the most common and lucrative fish by-products and sent abroad.

Fishmeal is a sandy grubby powder that is worth billions. Minks eat it. Pigs eat it. Cattle eat it. Fishes eat it. It is also an ingredient in fertilizer and pet food. Fishmeal is part of a huge silent industry of fish by-products that used to be known as FMFO (fishmeal and fish oil) and has now been rebranded by the industry association as 'marine ingredients,' a vague term that covers a broad range of fish-derived products, most of which are never noticed.

The Food and Agriculture Organization defines fishmeal as 'the clean, ground, dried tissue of undecomposed whole fish or fish cuttings, either or both, without the extraction of part of the oil.'

American pets may also find themselves eating fish liver and glandular meal, made from dried complete fish viscera; more general fish by-products, which are 'non-rendered, clean, undecomposed portions of fish (such as, although not limited to, heads, fins, tails, ends, skin, bone and viscera)'; or condensed fish protein digest, the 'condensed enzymatic digest of clean undecomposed whole fish or fish cuttings using the enzyme hydrolysis process'.

'Undecomposed' is doing a lot of work here, a strange term because unless a fish is caught by a vessel with freezer capacity — which no artisanal fisher has — it will be decomposing for days. In theory, fishmeal is impeccably sustainable. It should be a product made from parts of fishes that would otherwise be discarded. It is because of fishmeal that the term 'reduction fisheries' was coined.

Take the meat and the prized flesh, and the rest can be reduced or diverted to other uses. That is the theory. It is not what happens in West Africa.

Each year, half a million tonnes of wild fish are caught in African waters and sent to Europe to feed animals, when they could have fed 33 million Africans instead. That number of people is more than the combined populations of Senegal, Mauritania, and The Gambia. Globally a fifth of wild fishes become fishmeal or fish oil, but 90 per cent of fishmeal fishes are suitable for human consumption.

China uses nearly half of all FMFO, but then China uses most of everything. Europe also takes and takes. Spain imports the most fish oil from Senegal, and France takes 70 per cent of Mauritania's.

In 2019, Changing Markets Foundation produced a detailed investigative report into the fishmeal industry in India, Vietnam, and The Gambia. In each country, the pattern was similar: first the foreign factories come, then they take the fish, then they pollute the environment, then the fishermen say there are no fish left.

Although noting 'a surprising lack of traceability and transparency regarding the origin and supply chain of farmed seafood products,' the foundation linked plenty of reputable European retailers to FMFO supply chains that may use West African fish. For example: Sainsbury's, ALDI, Lidl, and Marks & Spencer in the UK; Auchan, Groupe Casino, Monoprix, and Système U in France (that is a full house of big French supermarkets); all the German ALDIs; and Mercadona in Spain. Sainsbury's, Marks & Spencer, and Mercadona have said they don't use West African FMFO in their seafood products, but how will they know?

The European Union's IUU [Illegal, Unreported and Unregulated fishing] regulations, which require a catch certificate or similar to show the fish was legally caught, do not cover fishmeal. In Mauritania, some Chinese-owned fishmeal factories have their own trawler fleets. The fish bypasses human mouths and goes straight to the factory. That is one tactic. The other is to outbid.

The fish processors tell me that they cannot compete with the prices that fish factories will pay for sardinella. Fish processors get no subsidies from the government, unlike Chinese fishing companies. In The Gambia, one fishmeal factory used 40 per cent of the country's entire fish catch in one year. Black and white. White stealing from Black. The villain/victim template seems neat and unassailable.

It is true — Europeans are using fish that West Africans could eat — and yet it is not all the truth. In Senegal, The Gambia, Mauritania, local fishermen supply fishmeal factories because the factories pay better. In Senegal, a fisheries union official tells me that there are too many pirogues. They are chasing smaller and smaller fish to sell to the factories. It is unsustainable.

The website of the IFFO, which used to stand for International Fishmeal and Fish Oil Organization and now somehow is short for the Marine Ingredients Organisation, is plain. Marine ingredients 'play an essential role in global food security'.

Rubbish, said Francisco Marí of Bread for the World at the CAOPA [African Confederation of Professional Organisations of Artisanal Fisheries] workshop. 'It's just for prawns and salmon — they are not necessary foods; it's a luxury. It's not enough for us to have 10—15 per cent of fish to feed salmon and prawns. Indirectly, we are eating your fish. It's not essential for the alimentation of the US or Japan. We are taking your fish to feed a luxury product that we don't need.'

Every Last Fish: A Deep Dive into the World of Fishes and Fishing by Rose George is published by Granta

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Slavery has existed for thousands of years, permeating ancient and modern societies across the world. The Vikings were no different. Enslaved people were valuable commodities, being captured and then traded across the Vikings' vast networks. Legal texts and written sources show how enslaved people were sold at trading centers in the same vein as cattle.

In this excerpt from "The Sea-King and the Sorceress: Life and Death in the Viking Age" (Basic Books, 2026), author and archaeologist Neil Price looks at the horrific lives of the "thralls" — the Viking term for the enslaved. In it, he highlights the inhumane treatment of enslaved people, from the raids to kidnap people into the slave trade to a woman who appears to have been killed as a tribute to a high-status man.

Neil Price interview: 'It gives us a glimpse of a different kind of Viking life': Archaeologist Neil Price on the sea-kings, sorcerers and Sámi who lived during the Viking Age

The vast majority of the Norse population were farmers, but there is another group of people who were almost as numerous, though very hard to find in the archaeological record: the enslaved. They have only recently begun to be properly acknowledged in our histories, partly because of the long-standing neglect of the marginalized and vulnerable in many cultures, but in the Viking world also due to a particular coincidence of terminology. For the Norse, the unfree were þrælar, translated into English as "thralls," which is too mild a word to convey its true meaning.

Today, we can be enthralled by a work of art or even a person, but we do not say that we're enslaved by them. Norse thraldom took many forms, some less severe or permanent than others, but all involved the loss of liberty and rights, and the subjugation of one person to another through servitude. A chapter here, even with tangential references in a few others, is nowhere near enough to do justice to this side of the Norse experience (or rather, often the non-Norse experience, since many of them were kidnapped abroad during raids and other campaigns). Archaeological recognition can at least restore some measure of individual dignity, though more comforting to us than to them.

Slavery, as both a practice and an integrated economic system, was an indivisible part of Viking-Age Norse society and had probably already become established in Scandinavia centuries or even millennia earlier. People could be born into slavery, or be forced into it through kidnap or war, and then find themselves sold on, sometimes through many hands and over great distances. Some free people might even temporarily sell themselves in a form of indenture, as a means of paying off debts or other obligations.

Thralls on Norse settlements were ranked in a hierarchical and quite specific nomenclature of service categories and forced to undertake all the tasks of the farm and household. In a few, rare cases, thralls could take on senior responsibilities of estate management, with a special title — bryti — to match. One such man ran the royal estate at Hovgården opposite the island town of Birka, and was allowed to raise a runestone to himself and his wife, though one wonders who paid for it. Nonetheless, the vast majority of thralls endured lives of drudgery.

The grim reality is summarized with derogatory terminology in the poem Rígsþula, the "List of Rígr" (another name for the god Heimdall, or perhaps for Odin): "They fixed fences, dunged fields, worked at the pigs, watched over the goats, dug the peat." Even their names are shaming, mocking their appearance or hygiene: they translate as Badbreath, Stumpy, Fatty, Bedmate, Craneshanks, Dumpy, and many more. Thralls were extremely vulnerable to sexual exploitation. The textual records of viking raids, coming from every culture that was attacked, emphasize that women were particularly targeted for kidnapping and enslavement.

In the ninth century, as the viking attacks escalated both in Western Europe and on the rivers of the east, the taking of captives came to be one of their prime objectives, feeding the lethal trinity of raiding, trading and slaving. In the words of Ibn Miskawayh, a Persian official who described a viking attack on the city of Bardha'a in what is now Azerbaijan in 943: "They kept the women and boys, whom they raped and enslaved [ . . . ] They dragged the women, boys and girls they wanted with them."

The repetition drives home the point, and little imagination is required to sense the undiluted horror. Some of these raids were informed by advance intelligence gathering and directed against high-profile targets for whom ransom could be demanded, but many were destined for sex trafficking, especially to the Arab world. Enslaved humans, particularly from the Baltic region, were among the main commodities exchanged eastwards along the Silk Roads.

In late ninth-century Scandinavia, the logistical needs of the escalating raids brought new demands on the workforce at an ever-larger scale, especially in all the many industries connected with shipbuilding (including textile production, timber management, tar manufacture, ironworking, and much more). This in turn drove the need for unfree labor to still greater levels.

As economic expansion enlarged the capacity for ship-borne aggression and released the agricultural workforce to crew these expeditions, the increased flow of human victims enabled its continuance in a vicious circle. Enslavement was one of the primary characteristics of the Viking Age: the raids were a key component of it and of the Norse diaspora that resulted.

To what degree these people are visible in the funerary record is hard to know. There were probably no diagnostic items that were used exclusively by thralls, so we cannot perceive them through specific objects in the graves. It also seems unlikely that those without rights and with few possessions, indeed with hardly any legal identity as individuals rather than chattel, would be accorded conventional burials. Ibn Faḍlān says that thralls who died while traveling were simply discarded, but this is unlikely to have been the case in settlements. When we do encounter them, it is often because they were killed as part of funerary rituals and their bodies deposited in burials. One example that we can explore here comes from an excavation at the site of Ballateare, in Jurby parish on the northwestern coast of the Isle of Man — the best preserved of all the Viking-Age graves on the island.

At Ballateare, it is instructive to see just how normal the initial funeral, and its circumstances, appear to have been, albeit for a high-status individual. By Viking-Age standards he was in his prime when he died in the early tenth century, somewhere between eighteen and thirty years old. He may have been among the early Norse settlers on Man. We have no reason to believe that the clothes he was buried in, and the things laid in the grave, are not reflections of his life and the international milieu he came from.

He had been interred in a wooden coffin, dug down quite deep into the ground. A sheathed knife was suspended on a lanyard round his neck and he wore a cloak held by an Irish ringed pin. Inside the coffin was a sword — probably from Norway, but with a belt from the British Isles — that had been cut into pieces before being sheathed in the scabbard; the hilt lay broken off beside it. A spearhead also lay in the coffin by the man's feet, snapped off because there was no room for the shaft. A shield, also deliberately damaged with two heavy blows to the boss, had been slid vertically down the outer side of the coffin; the shield board itself may have been smashed too. This was not battle damage; all his weapons were made unusable for reasons we can only guess. Fragments of the shield also revealed traces of paint: it had been decorated with white gesso, banded with black, with rows of red dots along the stripes. Two more spears had been laid across the top of the coffin.

The burial pit was then filled with fine white sand, and a mound was built on top — about 3 metres [10 feet] high and 22 metres [72 feet] in diameter. It was made of thick-cut turfs, which had been brought to the mound from a wide area rather than simply dug up in the vicinity. The earth of the mound seems to be an offering of the land itself, a territorial tribute to the dead man.

I do not wish to relate what happened next in terms of dramatized reconstruction; archaeological description must suffice. On top of the mound lay the body of a woman aged between twenty and thirty, who had been deliberately killed: the back of her head had been removed by a single blow from a sharp blade, probably a sword. Rigor mortis had set in, and some twelve to seventy-two hours had elapsed between her death and the time when her body was covered. She had either lain exposed on the mound for some time after her death, or been killed elsewhere (perhaps more likely, as the missing part of her skull was not present with the body). The woman seems to have died while kneeling, and had fallen forwards with her hands raised. A post was raised on top of the mound beside her body, presumably a grave marker.

A paragraph is not enough to convey what actually occurred, let alone to extrapolate the life that the woman had led before her death — possibly decades of servitude and enslavement, with all that this implies. Her corpse was covered by a very thick layer of cremated animal bone, including considerable numbers of oxen, horses, sheep and dogs. (Somewhere nearby must have been a truly massive cremation pyre.) The mound was finally sealed with turf, covering her body and the ashes of the animals.

Excerpted from The Sea-King and the Sorceress: Life and Death in the Viking Age by Neil Price. © 2026 by Neil Price. Available from Basic Books, an imprint of Hachette Book Group, Inc.

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Since the discovery of their remains in the 19th century, Neanderthals have fascinated scientists and the general public alike. Although our understanding of these ancient hominins has been transformed tremendously since then, how we have viewed this other human lineage became deeply entrenched in how we see our own species, with geopolitical events shaping the rhetoric around our ancient relatives.

In his new book, "Neanderthals Among Us: The Making of a Prehistoric Human" (Oneworld Publications, 2026), historian and author Peter Sahlins examines our complicated view of Neanderthals, with this lost human lineage being viewed through the lens of cultural and political ideologies. In this excerpt, he looks at our theories for why they went extinct and the philosophical reckoning we've placed up on them.

Between violent extermination and peaceful absorption — with cultural exchange — prehistorians and others propose a wide range of theories to account for Neanderthals' extinction. Just as we've projected our concerns and anxieties about race and gender onto Neanderthals, so too do contemporary challenges shape how we imagine their extinction.

Sometimes it's the newspapers that translate a more neutral science into easily relatable headlines. "Immigrants Halt Neanderthal Era," announced the Glasgow Herald (29 July 2011), claiming that "Europe's earliest residents may have been crowded out by uncontrolled immigration 40,000 years ago." Glossing a highly technical study by Cambridge archaeologist Paul Mellars about the notable increase in population size during the Upper Palaeolithic, the news reports tweaked the science to speak to contemporary anxieties.

But often the science itself is framed or informed by current events. The pathogen thesis gained credence during and after the COVID-19 epidemic. A 2024 study of a 50,000-year-old case of herpes in a sequenced viral genome confirmed widespread speculation that Sapiens-borne pathogens were passed to a Neanderthal population without immunities. Jonathan Kennedy's popular world history "Pathogenesis" (Crown, 2023) argued that Homo sapiens would have been less vulnerable to Neanderthal diseases because they arrived in much larger numbers and had more evolved immune systems from their tropical environment.

Of growing importance over the last twenty years is the thesis that climate change, our own existential challenge of the Anthropocene, was the principal cause of Neanderthal extinction. The idea takes many shapes, beginning with an update of French geologist Georges Cuvier's "catastrophism," where species died off in cataclysmic geological events like earthquakes and volcanic eruptions. Since 2007, researchers point to the Campanian Ignimbrite eruption near Naples (Italy), now dated to around 39,280 BP [before present] (+/- 110 years), fictionalised in the 2013 animated film The Croods.

Scientists argue that arriving Homo sapiens were not as affected, perhaps because there were fewer directly touched by the 120 cubic miles [500 cubic kilometers] of magma released, or perhaps because almost everyone died out — but waves of Sapiens arrived later. After all, while most of us share small parts of the Neanderthal genome, the lineages from which we 'directly' descend settled much later in Europe — long after the Ice Age. By far, the greatest portion of our genome comes from our Neolithic, not Palaeolithic, ancestors.

But perhaps "Climate Change Killed the Neanderthals," that is, the extreme climatic fluctuations during the Upper Pleistocene that National Geographic (9 February 2004) announced, following the work of an international team of thirty scientists who laboured for more than seven years on the study. The team identified a general climatic instability during the Middle Palaeolithic marked by a severe cooling event around 41,000 years ago, lasting six centuries — interstadials GIS 13 to 7 of the Greenland ice-core records, to be precise.

For the last twenty years, scientists have sought to specify the timing, magnitude and ecological impact of a "mini-Ice Age" — the prehistorical obverse of global warming — that reduced vegetation and herbivore food sources, forcing Neanderthals towards warmer climates, including southern Spain. Clive Finlayson, trained as a zoologist, was an early contributor to sophisticated ecological modeling of Neanderthal extinction. At Gibraltar, he argued, "the last Neanderthal" could be found as late as 29,000 years ago, but there's competition for the title: elsewhere in the southern climatic refugium, Zafarraya (Granada) yielded a skeleton dated to 30,000 BP, but there are skeptics, while other candidates come from the Mezmaiskaya Caves in the Caucasus.

The trope, we've seen, is a frequent one in Neanderthal fiction, including Claire Cameron's "The Last Neanderthal" (Little Brown & Co., 2017), a moving, feminist revision of "Neanderthal Woman." It's also been widely used in popular nonfiction, including in Ludovic Slimak's 2023 account of twenty-five years of research in the Mandrin Cave .

Some of the science blaming climate change for the demise of Neanderthals marks a retreat from the recent archaeological rehabilitation of Neanderthals as a type of human equal to Homo sapiens, as these theories need to account for Sapiens' survival in the same severe conditions. Some experts rewrite basic wisdom, arguing that Neanderthals were not a cold-adapted species, since their origins lay during a warm interglacial stage (MIS 11); or that they lacked the technologies for making complex (and warm) clothing; or perhaps that their preexisting biological cold adaptations delayed the development of such technologies — a story about their technological inertia and deep conservatism.

That Neanderthals died out because of their conservatism, while humans alone mastered innovation, and with it, conquered the world, is the principal claim in Philip Lieberman's "The Unpredictable Species: What Makes Humans Unique" (Princeton University Press, 2013), and it's a widely shared belief.

Aside from the fact that the high value placed on "innovation" corresponds to the ideological superstructure of contemporary neoliberalism and late-stage capitalism, it seems fitting that Neanderthals died out because, in this view, they were, well, truly Neanderthal. The rhetorical figure returns to haunt the science: Neanderthals were conservative, backward, clinging mindlessly to the past in a changing world.

Neanderthal conservatism — not rhetorically, but as an original character trait — has origins in nineteenth-century anthropological judgements about "primitive" peoples. Augustus Pitt Rivers, an early innovator in British archaeology, underscored "the form of a persistent conservatism" of indigenous peoples, and quoted approvingly his colleague E. B. Tylor's "Primitive Culture" (1871): "The savage is firmly, obstinately conservative. No man appeals with more unhesitating confidence to the great precedent-makers of the past; the wisdom of his ancestors can control against the most obvious evidence of his own opinions and actions."

Just as "savages" were once seen as descendants of Neanderthals, so too is their conservatism a cultural legacy, even when anthropologists, transcending an outdated comparative method, no longer deem them ancestral, or even savage.

NEANDERTHALS AMONG US: The Making of a Prehistoric Human by Peter Sahlins is published by Oneworld, hardback £28.

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Mammals first appeared on Earth over 200 million years ago, scuttling around alongside the dinosaurs as little mouse-sized creatures. But after the asteroid hit 66 million years ago, it was their time to shine ‪—‬ and the Age of Mammals began.

But the path to understanding our own branch of the animal kingdom hasn't been straightforward. In this excerpt from "The Story of the Mammals in 25 Discoveries" (Columbia University Press, 2026), author Donald R. Prothero looks at a time when philosophers and early naturalists believed giants roamed the Earth and explores the idea that extinction was heresy.

Many cultures around the world have a mythology that includes legends about gigantic races of humans that lived on Earth in the dark mysterious past. They may have fought against the gods, or they may have been destroyed by floods. These stories were reinforced by the discovery of gigantic bones, much larger than those of any living human, all over the Mediterranean and Europe.

The Greek philosopher Empedocles (492-432 BCE) reported gigantic bones from Sicily, supposedly remnants of a race of giants. The Roman historian Pliny the Elder (23-79 CE) mentioned fossil ivory in the ground, and according to the Roman historian Suetonius (69- 122 CE), Emperor Augustus owned a collection of large bones that had been found on the island of Capri, near Pompeii. The skulls of elephants, with their huge central opening in front (for the trunk), were thought to be the skulls of the one-eyed cyclops.

In the Middle Ages, these huge bones were again attributed to gigantic humans or other monsters (Genesis 6:4) that were drowned in Noah's flood. Giant tusks from Siberia were thought to be the horns of the mythical unicorn or the tusks of dragons. In some places gigantic teeth or vertebrae of mammoths were revered as relicts of saints. Nearly every possibility was suggested except that they were the bones of extinct elephants.

In the early seventeenth century, some giant bones dug up in a sand pit near Langon in southeastern France were exhibited around France as the remains of the giant Teutons, Germanic tribes that once roamed Gaul and were defeated by the Romans in 101 BCE.

But in 1613 the famous anatomist Riolan attacked the prevailing interpretation, suggesting that they were the bones of an elephant. This generated a raging controversy between physicians and anatomists and the barber-surgeons who called them gigantic human bones. Others thought they were hoaxes or generated by mysterious "plastic forces" (vis plastica in Latin) that percolated through Earth. Still others attacked the anatomists for questioning the biblical account of giants on Earth. The controversies died down in 1618 without being resolved, and for the next two centuries most people continued to interpret new finds as gigantic humans.

The giant bones that kept turning up in the New World were also a source of much mystery and consternation. The Native American tribes usually attributed them to giant monsters fought by their ancestors and incorporated them into their folklore. When these bones were first seen by European settlers, they were thought to be the bones of gigantic humans that roamed the earth in biblical times. Others thought that the giant tasks so revered by the Native Americans were the works of Satan, placed there to tempt the believer.

In 1519, the Spanish explorer and conquistador Hernan Cortez received a bone of a "giant," a gift from the friendly Tlascalan tribe of Mexico during the conquest of the Aztecs. He sent it back to the King of Spain as proof that giants at once lived in the New World. In 1706, the Reverend Cotton Mather of the Massachusetts Bay Colony pronounced them to be "the remains of godless giants drowned in Noah's Flood." He sent some bones to the Royal Society in London to have them certified as evidence of this "wicked giant" because biblical scholars were calculating Adam's height at 123 ft. 9 in.

The Royal Society never pronounced an opinion on these bones, although by that time many members were becoming skeptical of the literal interpretations of Genesis. The stifling effect of religious dogma about giants and Noah's flood was complicated by another idea: the notion of Divine Providence. An omnipotent, benevolent God would never allow any of his creatures to become extinct. As the poet Alexander Pope wrote in An Essay on Man (1734), "who sees with equal eye, as God of all, a hero perish, or a sparrow fall."

The prevailing concept was that of a "great chain of being" that linked the animals to man to the angels to God. Breaking any link in that chain implied the destruction of the whole chain. In the same poem, Pope also wrote: "Where, one step broken, the great scale's destroy'd; From Nature's chain whatever link you strike, Ten or ten thousandth, breaks the chain alike."

By the late 1700s, however, it was becoming more and more apparent that many of the recently discovered fossils had no living counterparts. Remote corners of the world were being explored, and although many new and surprising beasts were discovered, clearly the gigantic beasts were not hiding in South America or Africa or the East Indies. Many strange fossils, such as the bones of hippopotami in Paris and London, were clearly related to tropical animals, but it was assumed that these bones had been washed from the tropics during the Great Flood.

The notion of extinction was still blasphemous. The New World soon provided unequivocal evidence that these large bones were not simply gigantic humans. In 1739, Charles le Moyne, the second Baron de Longueil, left Montreal with French and Indian troops to fight the Chickasaw Indians along the Ohio River. Somewhere along the Ohio he found the remains of what appeared to be three elephants. When the war ended in 1740, le Moyne collected the bones and shipped them to New Orleans and ultimately to Paris, where they came to the attention of French naturalists.

In the 1740s and 1750s, English settlers in the region sent more of these bones from Big Bone Lick, Kentucky, off to England and also to Benjamin Franklin in America. Most of the bones (especially the tusks) were clearly like those of elephants and mammoths, but the teeth were puzzling. They were clearly unlike any living elephant, yet they were part of an animal of elephantine size. (We now know that these were specimens of the American mastodon, Mammut americanum.) Franklin speculated that the teeth were reminiscent of a carnivorous animal, although he and others later decided it was a vegetarian.

In 1769, the famous British anatomist William Hunter took the carnivory suggestion seriously and suggested this was not a true elephant but a "pseudelephant" or "American incognitum" (Latin for "unknown") that had independently developed ivory tusks:

"This monster, with the agility and ferocity of a tiger . . . cruel as the bloody panther, swift as the descending eagle, terrible as the angel of night. . . . And if this animal was indeed carnivorous, which I believe cannot be doubted, though we may as philosophers regret it, as men we cannot but thank Heaven that its whole generation is probably extinct."

This very precocious suggestion was still not accepted by naturalists of the time. Nevertheless, remains of the "incognitum" and also of the Siberian mammoth (including frozen carcasses with hair and skin) were turning up again and again. Georges Louis Leclerc, the Comte de Buffon (1707-1788), concluded in his Théorie de la terre in 1749 that although most of the supposedly extinct animals were hiding somewhere in an unknown region, it was likely that the large terrestrial mammals such as the mammoth and "incognitum" had actually perished.

By 1778, Buffon was relating their disappearance to his ideas of violent cataclysms in Earth's early history. During this time the climate was warmer and polar regions had once been tropical, so "elephants" (meaning mammoths) could live in Siberia. This implied a nonbiblical Earth of much greater antiquity. Buffon suggested it was as much as 75,000 to 3,000,000 years old, rather than the 6,000 years demanded by most literalist biblical scholars.

Naturally, such revolutionary ideas were not popular with the theologians in the Sorbonne. Buffon was protected by the king, however, so he was not persecuted for his heresy, although his ideas were not widely accepted either. The fact of extinction was finally proved by one of the greatest scientists of all time, the Baron Georges Cuvier (1769-1832).

Jean Leopold Frederic Georges Cuvier was an impressive man. Tall of stature, he had a "massive" head crowned by a large mane of hair. One admirer wrote that his head "gave to his entire person an undeniable cachet of majesty and to his face an expression of profound meditation." After his death, scientists weighed his brain and found that it was a massive 1830 grams [4 pounds], more than 400 grams [14 ounces] above average, and 200 grams [7 ounces] heavier than any brain ever measured at that time.

More important, he was one of the most brilliant men of his time, with a command of many subjects, some of which he invented all by himself. Before Cuvier, natural history was a field that resembled stamp collecting, with many amateur naturalists compiling long lists and descriptions of new species without analyzing the similarities in their anatomy. Cuvier almost single-handedly revolutionized natural history by dissecting many different animals and discovering their underlying similarities and differences.

This became the foundation of comparative anatomy, a subject that has been fundamental to biology ever since. Naturalists and explorers sent him their fossil bones, and he was the first to correctly describe many types of extinct animals. Cuvier solved the mystery of the puzzling fossil teeth called the "Great Incognitum" and recognized them as the teeth of the elephant-like mastodons. He also correctly deciphered the huge marine lizards we now know as mosasaurs.

For this reason, he is also considered to be the founder of vertebrate paleontology. Cuvier is most famous for his "law of correlation of parts," wherein he discovered that certain types of anatomical features tend to be associated. If you are a flesh eater, you will have sharp teeth and claws; if you are a plant eater, you will have flat grinding teeth and hooves; and so on. Using this law, paleontologists have been able to reconstruct whole animals from just a few key bones because the other parts of the anatomy are so predictable.

Excerpted from The Story of the Mammals in 25 Discoveries: Amazing Fossils and the People Who Found Them by Donald R. Prothero. Copyright (c) 2026 Donald R. Prothero. Used by arrangement with the Publisher. All rights reserved.

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History is rife with lost treasures, from Aztec gold hidden during the Spanish conquest to the Ark of the Covenant, which vanished during the destruction of Jerusalem over 2,500 years ago. In his book, "The Museum of Lost Things: True Tales of Fabled Treasures, Legendary Cities, and Mythical Creatures That Vanished From History" (National Geographic Books, 2026), writer Sam Kean examines all things lost to time.

In this excerpt from the book, he looks at how the tomb of Genghis Khan, arguably the most successful ruler in history, has remained hidden for nearly 800 years and counting.

If archaeologists could vote on which lost grave they'd most like to find, Genghis Khan's would likely appear near the top of the list — in part to fact-check the gruesome legends surrounding his burial.

He was born in Mongolia around 1162, and supposedly emerged from the womb clutching a clot of blood in his fist. By all rights, the boy — whose original name was Temüjin — should have died young. His father, a nobleman in their tribe, was poisoned by a rival tribe when Temüjin was nine, and greedy schemers within his own clan banished the boy's family to the empty steppes, expecting them to starve. Historical accounts describe Temüjin as overly sensitive, terrified of dogs and prone to crying.

But he grew up fast. Even before adolescence, he'd already been enslaved (he engineered his own escape) and killed his older half brother. As a young man he discovered that soldiering suited him, and he ruthlessly eliminated all potential rivals among other nomadic tribes, until he was crowned Genghis Khan — universal ruler — in 1206. His other nickname was the Disturber of the Universe. His warriors were bold and battle-tested, and when they stopped murdering each other and turned their attention outward, they proved unstoppable.

They favored blitzkrieg tactics, sweeping in on horses and bombarding the enemy with arrows. But they could be surprisingly patient, too, and perfected the art of siege warfare. One notorious siege involved the city of Merv, in what's now Turkmenistan. Merv was the Alexandria of its day: a desert oasis teeming with gardens and libraries, famous for its silks and refreshing melons.

The Mongols couldn't resist it, and when the terrified artists and merchants inside surrendered after just six days of siege, a massacre ensued. "It was a memorable day for shrieking and weeping," lamented one chronicle. After burning Merv for good measure, Genghis Khan ordered his troops to count the corpses. There were 700,000. Yet however crazy it sounds, life under Genghis Khan had its benefits. He allowed the conquered to worship whatever gods they liked, a rare example of religious tolerance. He introduced the idea of diplomatic immunity to facilitate negotiations, and outlawed torture during interrogations. He promoted free trade, and founded history's first international mail system.

Over time, his empire also spread key technologies like the compass, abacus, printing press, and paper currency, as well as key social programs like universal education for children. No one was more ruthless when conquering (ask Merv). But if the vanquished people picked up the pieces and swore fealty afterward, life generally improved under Mongol rule. Genghis Khan's realm stretched from Korea to the Caspian Sea, an area twice the size of the Roman Empire. (Under his successors, it grew to the size of Africa.) And he accomplished all this with an army of just 100,000 warriors — fewer people than some modern stadiums hold.

Historian Jack Weatherford summed up his achievements thus: "[Imagine] if the United States ... had been founded by one of its illiterate slaves, who, by the sheer force of personality, charisma, and determination, liberated America from foreign rule, united the people, created an alphabet, wrote the constitution, established universal religious freedom, invented a new system of warfare, [and] marched an army from Canada to Brazil." Alexander, Julius Caesar, Napoleon — they weren't fit to carry Genghis Khan's saddle. If anyone in history deserved a grand mausoleum, it was him.

Genghis Khan wanted the opposite. Despite all the blood they shed, the Mongols were oddly squeamish about discussing d-e-a-t-h, so beyond the year 1227, contemporary sources say little about how Genghis Khan died. As a result, rumors multiplied. One story claims he died after tumbling off a horse. Others have him struck down by lightning or an arrow to the knee during battle (at age 65, no less). One source swears he was trying to ravish a conquered queen who, anticipating the crime, concealed a blade inside her vagina that sliced lil' Genghis wide open.

Regardless of the truth, his longtime wife Yesui dressed his body in a white robe, wrapped it in white felt with sticks of fragrant sandalwood, and clasped the shroud shut with golden straps. What happened next is impossible to say for certain. But according to lore, Genghis Khan received probably the most outrageous funeral in history.

After his wife bound him in white, a thousand soldiers took off on horseback to bury him atop a mountain. This cortege quickly turned into a rampage. To conceal their destination, the troops reportedly slaughtered every person they encountered on the 40-day journey, often with the cry "Go to the other world to serve our lord!" In some accounts, the soldiers killed every animal, too. Based on other Mongol burials, they likely interred him 20 yards deep, with the body oriented north-south and the head facing east. They probably tossed some treasures in — gilded saddles, gold rings, pearls wrapped in silk — along with slaves, concubines, and horses. (One tale has the soldiers burying a live baby camel with him, either so its bleating would serve as a funeral dirge, or so the grieving mother could lead them back to the site if necessary.)

After filling the grave, Genghis's soldiers either diverted a river to conceal it or trampled the ground with a thousand horses to obliterate all trace. Then they resumed the merry rampage on the return trip, butchering every unlucky hunter or merchant who wandered across their path. To their surprise, the thousand soldiers were themselves slaughtered when they reached home, as a further guarantee of secrecy — and then those slaughterers were also slaughtered, to make doubly sure.

Genghis Khan took privacy seriously. We have no idea how much of that is true. But it hasn't deterred the hunt for the grave. To the contrary: The elaborate concealment has made the pursuit all the more enticing. Four nations — Mongolia, China, Kazakhstan, and Russia — have claimed that Genghis Khan's bones lie within their borders. The strongest claim points to Burkhan Khaldun (God Mountain) in northeast Mongolia. Genghis Khan was born nearby, hunted there regularly, and worshipped the sky god Tengri there. He also once took refuge there while fleeing his enemies, and miraculously escaped. The mountain seemed charmed to him, and he'd mused during his life that it would make an ideal final resting place.

Strengthening the case for Burkhan Khaldun is the fact that later Mongol rulers proclaimed the land around the peak a forbidden zone and stationed a clan of ferocious guards there — the Darkhad, who murdered anyone who dared approach. (In exchange, the Darkhad paid no taxes and avoided compulsory military service.) Incredibly, the Darkhad kept this watch for 700 years, until the founding of the communist Mongolian People's Republic in 1924. The republic was a puppet state of the U.S.S.R., and Soviet leaders had a schizoid attitude toward the Disturber of the Universe. On the one hand, they admired his ruthlessness and gazed longingly at all the territory he'd gobbled up. On the other, they feared his memory would stir up nationalist sentiments in Mongolia and spur a revolt against the hated communists.

To forestall this, the Mongolian government banned the very mention of Genghis Khan's name. And to prevent Burkhan Khaldun from becoming a rallying point, officials fenced off a "highly restricted area" around the peak of 3,900 square miles (twice the size of Delaware), and parked a tank base at the site's entrance. The ban thawed somewhat after Joseph Stalin died in 1953, and one Mongolian official decided to celebrate the Disturber's 800th birthday in 1962 by putting him on a stamp. He overreached. Moscow ordered the man arrested, and he was chopped to bits with an axe. After the republic collapsed in 1992, the restricted area devolved into a nature reserve with some public access. But the land near Burkhan Khaldun remains daunting to explore. It's one of the most desolate places on Earth, with few roads and a population density down there with Greenland's.

Centuries of vegetation growth have choked off many areas, and the clear parts are prone to flash floods. Temperatures can swing from 100 degrees [Fahrenheit, or 38 degrees Celsius] in the summer to 50 below [minus 46 C] in the winter, so cold that even yaks drop dead. None of this has stopped Genghis Khan obsessives from searching out his grave. They've suffered snakebites and frostbite and been left stranded when their vehicles tumbled off cliffs. One man spent 40 years crossing and crisscrossing and re-crisscrossing the slopes and died without finding a thing.

In 2010, a few archaeologists tried a new approach. They posted satellite images of the Burkhan Khaldun region online and recruited volunteers to scour them for bumps, depressions, and other features that might indicate graves. Ten thousand people spent approximately 30,000 hours (3.4 collective years) poring over 2,300 square miles [5,950 square kilometers]. They flagged over a hundred spots worth checking out. While several proved inaccessible due to challenging terrain, 55 legitimate archaeological sites turned up among the rest, including megaliths, Bronze Age burial mounds, and an ancient city.

But there was zero trace of Genghis Khan. One archaeologist lamented that it was like looking for a needle in a haystack, except you don't know what the needle looks like. Call it Genghis Khan's final victory. The diverted river and trampling horses and the slaughter of all potential witnesses have succeeded in hiding him for most of a millennium now. His victims lay scattered across Eurasia, their skeletons long since ground to dust. But the bones of history's greatest warrior remain at peace.

Excerpted from The Museum of Lost Things by Sam Kean, published by National Geographic Partners, LLC. Copyright © 2026. All rights reserved.

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Time keeps getting away from us. It has a fraught relationship with our subjective experience — sometimes slowing down or dragging on; and at other times speeding up, with years seeming to fly by as we get older. Our brain cells are even known to distort our sense of time when we're tired.

In physics, time gets even more complicated, incorporated into theories of relativity — the experience of the clock's ticking being relative to the observer and their place in space — and entropy, which gives time its unidirectional flow. Meanwhile quantum mechanics indicates time can move both forwards and backwards, at least inside quantum systems.

In this excerpt from "On Time: The Physics That Makes the Universe Tick" (Princeton University Press, 2026), author and theoretical physicist Jim Al-Khalili looks at the possibility that time did not begin with the Big Bang — but if this outburst was just another moment, what was there before?

There is an alternative cosmological theory to the one that says the Big Bang marked the beginning of time itself, which was then followed by a brief period of rapid inflation of space. The alternative is known as eternal inflation. In this scenario, our universe was born as a small bubble in an infinite space that has been undergoing inflation forever.

So, rather than time beginning with our Big Bang, we should regard the Big Bang as an event that took place at some moment in time, in which our region of this infinite space suddenly stopped inflating and began instead to expand at a more sedate pace.

So instead of a brief period of inflation happening just after the Big Bang, in the eternal inflation theory it is the other way around, with the Big Bang marking the end of inflation in our part of space, creating our bubble universe outside of which inflation continues. The theory predicts there will be other big bangs happening elsewhere that give rise to other universes — possibly an infinite number of them — all forever separated from each other, and all being driven apart by the ever-expanding, rapidly inflating space outside of them. The totality of this infinite space is referred to as the multiverse, to distinguish it from the individual bubble universes.

Some physicists argue that such an idea falls outside of proper science, since we do not have a way of testing it. There are two other ideas worth mentioning on the matter of whether the Big Bang marked the beginning of time or not, both of which are alternatives to inflation theory. The first is that our universe is part of a repeating process called conformal cyclic cosmology'.

This idea, proposed by Roger Penrose, suggests that our universe is going through an infinite series of lives, or epochs, each of which starts with a big bang and ends with a universe in thermal equilibrium, filled only with evenly spread-out thermal radiation. The idea here is not, as you might expect, that the universe reaches some maximum expansion before collapsing down to a 'Big Crunch' that then marks the Big Bang of the next epoch, but rather because of a subtle geometrical idea called 'conformal mapping' that connects up the very dif­ferent end of one universe (cold and spread-out) with the birth of the next (hot and dense).

I will not say any more about this theory, in particular since it has been argued that it suffers from several flaws, such as the problem of conservation of information (similar to the so-called black hole information paradox) and the difficulty of reconciling the high entropy at the end of the old epoch with the low entropy of the new epoch.

A related hypothesis, which I admit I find aesthetically rather appealing, is known as the ekpyrotic universe model. The name is based on the Greek word ekpyrosis (ἐκπύρωσι), meaning 'conflagration', which refers to a cosmological model proposed by the Stoic philosophers of ancient Greece in which the universe cycles endlessly through fiery birth, expansion, and cooling, followed by contraction, reheating, and rebirth.

The name 'ekpyrotic universe' was devised by one of the modern theory's originators, Paul Steinhardt. The idea comes out of the highly mathematical world of string theory. Basically, the whole of our three-dimensional space (which as we know is really a part of 4D spacetime) forms what is called a 3D brane (a higher-dimensional generalisation of a 2D membrane, or sheet). This 3D brane of ours is floating in a higher-dimensional (4D) space, and the Big Bang is when it collided with a neighbouring brane (in a sense this would be another universe). This collision creates tremendous heat and radiation (the Big Bang) and sets off the expansion of our space.

At the same time, it is drifting away from the other brane that it collided with, but will eventually reach maximum separation from it before they are pulled back together, colliding again in a new Big Bang. Here I simply wish to stress that if this theory is right then there may not have been a beginning of time, and certainly not at the Big Bang.

Another cosmological model, which also does away with the need for inflation, as well as suggesting that the Big Bang was not the beginning of time, has been proposed by another of the originators of the ekpyrotic universe idea, Neil Turok. But this idea, known as the 'mirror universe' theory, is rather dif­ferent. It's a nice idea, and it certainly solves Loschmidt's paradox regarding the conflict between time symmetry and the second law of thermodynamics. Due to the time-symmetric underlying fundamental equations of physics, starting a system off at any arbitrary moment means that its entropy should increase equally into the past as it does into the future.

But this just doesn't make sense. If the system at all times before our chosen arbitrary moment has higher entropy, then starting from any of those earlier times should see the system decrease in entropy in order to reach its state at the original arbitrary moment. Therefore, it cannot be arbitrary; the system had to have been in a specially prepared state at that moment, the moment of the Big Bang. There would be no increase in entropy going backwards in time if that is when time started.

But what if there were a mirror universe on the other temporal side of the Big Bang, evolving in a direction we would consider to be towards the past? This is precisely what Turok is suggesting. What is neat (or convenient, depending on how much you like this theory) is that both sides of the Big Bang are completely separated from each other, with each seeing time pointing in the direction of increasing entropy. If such a mirror universe exists and contains intelligent life that has also hit upon the mirror universe idea, then they would think that our side was the one before the Big Bang in the same way we think that theirs is. As well as doing away with inflation, this idea also conveniently explains why there is more matter than antimatter in our universe because, guess what, the mirror universe would have it the other way round: What they call normal matter is our antimatter.

How seriously should we take these cosmological theories? Are they even proper science? Their proponents know they require some sort of empirical evidence to support their hypotheses, such as some imprint of a reality before the Big Bang frozen in our cosmic microwave background. For without observational evidence, these ideas will remain just theoretical curiosities.

Excerpted from On Time: The Physics That Makes the Universe Tick © 2026 by Jim Al-Khalili. Reprinted by permission of Princeton University Press.

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In this excerpt from "The Carbon Wave" (MIT Press, 2026), author Leah Stokes, an associate professor of environmental politics at the University of California, Santa Barbara, looks at a hopeful moment in U.S. politics when climate change took center stage: when Rep. Alexandria Ocasio-Cortez and Sen. Ed Markey ramped up calls for a "Green New Deal."

In September 2017, a still­-unknown Alexandria Ocasio-­Cortez watched as Hurricane Maria devastated Puerto Rico. Electricity went down for months. Like thousands of Puerto Ricans, her grandfather died in the storm's aftermath. She could see how climate change was hitting her community harder than others.

And it wasn't just Ocasio-­Cortez's community: the year before, she'd traveled to Standing Rock, North Dakota, to see firsthand how the fossil fuel industry was harming Indigenous people. It was mere weeks after the 2016 election, and the resistance to Trump had found its center in a makeshift camp along the Missouri River. People had united to oppose an oil pipeline.

Serendipitously, the day after Ocasio-­Cortez left the protest, a progressive organization reached out to ask her to run for Congress. Moved by the activists at Standing Rock, she said yes. In 2018, she ran a long-­shot primary campaign in a Bronx district occupied by a ten-­term congressman in House leadership. Her platform included an idea that some had bandied about before, but no one had developed in earnest: a Green New Deal. As she told journalists that summer, "The Green New Deal we are proposing will be similar in scale to the mobilization efforts seen in World War II or the Marshall Plan. We must again invest in the development, manufacturing, deployment, and distribution of energy, but this time green energy." In June, she won the primary. Her election signaled the beginning of a broader shift: climate change was back on the political agenda.

That fall, the world's leading climate science organization, the Intergovernmental Panel on Climate Change —­ often called the IPCC —­ released a short report concluding that limiting warming to 1.5°C would require emissions to fall by almost half by 2030. The news ricocheted around the world, with headlines like "We Have 12 Years to Limit Climate Catastrophe." In my own neighborhood, someone printed a copy and stuck it in the free lending library, labeling it "important reading." The report changed how many people thought about the problem: it wasn't something we could deal with in 50 years; it was something we had to deal with today.

In the November 2018 midterm elections, two years into the first Trump administration, Democrats won big, paving the way for Nancy Pelosi to return as Speaker of the House after eight years as the minority leader. Days later, a group of young activists from the Sunrise Movement staged a sit-in at her office. Their bright yellow and­ black signs read "We have 12 years. What’s your plan?" referencing that scientific report.

Newly elected Representative Ocasio-­Cortez joined the action that day. She told the organizers they needed a clear ask and encouraged them to call for a Green New Deal. The idea broke through, sparking widespread coverage across the country. It was a new, hopeful vision for climate policy. These young people were not just talking about the climate disasters we needed to avoid —­ they were explaining how investments in clean energy could create good jobs. They were showing us the better world we could build together. If we only tried.

I watched these developments unfold in DC from my office by the Pacific Ocean and wanted to be a part of it. I wouldn't have to wait long. The Green New Deal held a force like gravity, pulling people into its orbit. By chance, I met some of the people tied to Ocasio-­Cortez at a conference and was invited to an early gathering to develop the idea into more detailed policy. By then, she'd released a framework for the plan with Senator Ed Markey of Massachusetts.

The meeting was held in March 2019, at a hip hotel in DC's Adams Morgan neighborhood, miles away from the Capitol. A wide swath of people were invited: youth activists, environmental justice leaders, political organizers, think tank wonks, and a few academics like me. It was a contentious meeting that opened with a protest, revealing fissures in the movement that would eventually grow into large cracks. Some people believed that frontline communities facing the greatest pollution burdens were not being adequately consulted or invited to participate in the event. At the time, I didn't understand these dynamics between the climate and environmental justice movements. I was just a political science professor trying to understand how I could make my work more practical and help get a climate law passed if we got the chance.

It was at that event that I met Varshini Prakash, the executive director of the Sunrise Movement. I’d seen her photo many times, standing in the middle of Pelosi's office with her dark red jacket over a black­ and yellow T-­shirt, surrounded by young people sitting on the floor. Four months had passed since the sit-­in, and Varshini had ricocheted to the center of the climate movement. But she was also a recent college grad in her mid-­twenties, feeling a heavy burden from the climate crisis and the work involved in fighting it. At one point during the meeting, she spoke frankly about the stress that was on her and other young activists and cried. I found her vulnerability moving.

The fact was, Varshini had already changed history. She'd given me, and millions of others, a sense of hope and possibility. It was her actions, alongside all the other organizers in the Sunrise Movement, that brought us together in that first DC convening, and in countless other meetings to come. She inspired me to believe that I could do something bigger if I tried.

Too often, the way we think about cause and effect is simplistic. We're fed a linear model that favors the immediate. One person is responsible for their own carbon footprint. One person only has one vote. One person can only do so much. From this perspective, standing against more than a century of fossil fuels running through the heart of our society, it can feel like there's nothing we could do to shake the system loose. We're too small. Mere drops. But drops in the ocean can make waves.

Excerpted from The Carbon Wave: A Story of Democracy, Parenthood, and the Race to Protect Our Planet by Leah C. Stokes. Reprinted with permission from The MIT Press. Copyright 2026.

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In the early hours of July 16, 1945, in a remote part of the New Mexico desert, a group of scientists, engineers and military personnel attended an event that would define the course of history and change a war that had ravaged much of the world for years. Moments after a giant fireball rose high into the sky, a huge shock wave thundered toward the onlooking crowd. The Trinity nuclear test had been a success.

The story of the Manhattan Project is well known. But one area that may be overlooked is the human effort involved in bringing the mission to life. In her new book "Trinity: An Illustrated History of the World’s First Atomic Test" (The University of Chicago Press, 2026), author Emily Seyl, a science writer and editor at the Los Alamos National Laboratory's National Security Research Center, uses never-before-seen photography from the laboratory’s legacy collections to highlight the physical and mental effort that went into the project.

In this excerpt, Seyl examines one of the key elements of any scientific experiment — how to successfully measure the results. She looks at how experiments were decided upon and the ways in which success would be measured, beyond the visual spectacle of a successful detonation of "the Gadget."

T‌he most rudimentary measure of success would, of course, be the eye test: Did the Gadget produce a nuclear explosion? Beyond the answer to this simple question, however, the detonation was also a monumental and complicated science experiment — one that naturally gave rise to as many smaller experiments as could be squeezed, sometimes impractically, into the test plans.

Alongside a crowd of Trinity contributors, a robust collection of electronic and mechanical observers was stationed carefully throughout the desert to bear witness to the shot. Although deceptively rugged and nondescript, these devices were highly sophisticated, often employing first-of-their-kind technologies — invented and built by some of the world's preeminent researchers to study a first-of-its-kind event.

After two years of leapfrogging basic nuclear studies in their rush to produce a workable device, the pioneering scientists now "yielded to temptation and conceived experiment after experiment" in anticipation of the Trinity test — much to Kenneth Bainbridge's [director of the Manhattan Project's Trinity nuclear test] alarm. In December of 1944, with base camp still under construction at the test site, a selection committee, headed by Bainbridge, had been established to evaluate what was quickly becoming a deluge of ideas.

The committee implemented a detailed submission process, requiring scientists to scrupulously outline the personnel and material needs associated with carrying out each idea. Proposed subtests were triaged into three categories: essential experiments, which were fully greenlit no matter the required effort or resources; desirable experiments, which were approved only if they did not interfere with work on the Gadget itself; and unnecessary (i.e., nonessential) experiments, of which only the simplest were allowed.

Completing the Gadget remained the top priority. But while most of the lab continued to work feverishly on readying the test device, a significant battery of physicists, photographers, chemists, engineers, and other specialists began coming and going between Los Alamos and the Trinity site in March, as Jumbo [a containment vessel for use in case the nuclear explosion failed] faded into the background. With confidence increasing and a clear emphasis on learning everything possible about the performance of the test device, they were consumed from dawn to dusk with readying cameras and other diagnostic instrumentation to track the effects of the blast from detonation to dissipation.

The greatest unknown was how much energy would be released by the weapon. This value — also known as the yield — would depend on how much of the plutonium fuel underwent fission. The aim was to get as much energy from the explosion as possible.To quantify whatever success or failure awaited, scientists made plans to observe three manifestations of that energy: the amount of radiation emitted from the core (including neutrons, gamma rays, and fission fragments); the pressures and speeds of the air and ground shock waves; and the size and temperature of the fireball, which would indicate the amount of energy released as heat.

With the right combination of approaches and protections, they hoped to record in several ways all effects of the explosion. If the experiments were to have any chance of capturing the various expected phenomena, however, they had to be set up close enough to absorb and record the effects while simultaneously far enough away to withstand them. Difficult decisions about siting and fortification were made harder by the fact that only rough and frequently changing estimates of the Gadget's capacity for destruction were available to serve as guideposts.

Nevertheless, scientists brought the rigor of the laboratory to the desert in dozens of clever ways. Some of the myriad devices relied on communication lines to quickly carry data back to recording instruments in bunkers. Others were programmed to send up visual signals that would be filmed by timestamped cameras placed at safer distances.

Still others were purely mechanical, installed dangerously close to the blast but made of resilient materials or buried underground, the plan being to recover them in the aftermath to harvest data. Not knowing which approaches to the balancing act would turn out to be successful, they relied on overlap and redundancy to account for failure.

Although the cameras and instruments ultimately, and not unexpectedly, varied in their performance, the experimental program altogether would succeed in committing to history a comprehensive visual record and a trove of data, built upon the talents and toils of many.

Over the last few decades, the number of people going online for their healthcare needs has skyrocketed. Google receives hundreds of millions of health related search queries daily. Half of U.S. adults under 50 now get health and wellness information from podcasts or social media influencers.

In her book "Bad Influence: How the Internet Hijacked Our Health" (Oneworld Publications, 2026), author and journalist Dr. Deborah Cohen explores the impact social media, influencers, trends and tech are having on our health. She investigates how algorithms are pushing content that heightens concerns and potentially drives people away from traditional healthcare systems.

In this excerpt, Cohen looks at the portrayal of attention-deficit/hyperactivity disorder (ADHD) on platforms like TikTok, where self diagnosis and the proliferation of "lesser known symptoms" as entertainment runs rife — but the reality of the condition is far more bleak.

"Despite it All" has been short-listed for the 2026 Royal Society Trivedi Science Book Prize.

Many ADHD symptoms exist on a spectrum throughout the general population and identifying impairment and frequency of symptoms as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM) is a judgement call. These symptoms often overlap with anxiety, depression and learning disabilities. Responsible clinicians should rule out alternative explanations before diagnosing ADHD and prescribing medication.

This nuance sometimes goes out of the window when you go online. Viral videos on Instagram and TikTok list "common signs" of ADHD describing their impact on daily life. Megan McHugh, a UK DJ and radio host, is one content creator who has gone viral on TikTok after listing "lesser known" tell-tale signs of the condition with a video captioned: "Six ADHD behaviour traits you might not have known about." She cites overpromising and wondering: "Why the fuck can I not just say no?" "Your long-term memory is fucking shocking… You have some sort of subconscious tic, usually, whether it's pressing your lips or scrunching your nose," McHugh told her followers.

She's far from alone in sharing her experiences in this way. Others point to indicators of ADHD that include trouble getting up in the morning, problems choosing what to eat in a restaurant, missing deadlines, and being unable to finish a book.

A study by Vasileia Karasavva from the University of British Columbia and a team of researchers question the way symptoms are described on social media. When researchers examined the top 100 ADHD TikTok videos on a single day, 10 January 2023, clinical psychologists found only 48.7% of claims accurately reflected DSM-5 symptoms.

Of those inaccurate claims, nearly 70% depicted experiences that many people without ADHD would have; about 50% showed symptoms common across multiple disorders as being specifically ADHD; and almost 20% better matched different conditions entirely. Videos often portrayed behaviours like bumping into furniture, repeatedly playing the same songs or craving sweets as ADHD symptoms. Content typically lacked nuance — only 4% acknowledged their claims might not apply universally, and less than 2% mentioned that these experiences could occur in people without ADHD.

Of creators sharing credentials, 84% claimed "lived experience" while 13% identified as life coaches. Not one top video came from a clinical psychologist or psychiatrist. When researchers showed these videos to 843 psychology students — which may limit the applicability of the study to the general population — they generally rated scientifically inaccurate videos much more positively than experts did, while slightly downgrading expert-approved content.

The students either did not have ADHD, had a formal diagnosis or had self-diagnosed ADHD. Overall, self-diagnosed students rated all videos the highest, giving even expert rejected content higher marks than those with formal diagnoses. This, the researchers say, suggests that young people prioritise relatability over clinical accuracy.

For self-diagnosed people especially, previous painful and frustrating experiences of being dismissed may make TikTok's validating content particularly appealing: people like Alyssa Brown, who found that these ADHD descriptions matched many symptoms she had documented. She speaks warmly about discovering an ADHD community on social media after her experiences were disregarded by conventional healthcare. "I always assumed everyone experienced the world like I did. Finding out that's not true was eye-opening. It's deeply reassuring to connect with people who share similar experiences," she explains.

One of Alyssa's favourite accounts features quirky conversations between a husband and his wife who has ADHD. She and her fiancé bond over these videos. Some of these creators also have merchandise to sell, including t-shirts with slogans such as "What if you're not a lazy useless loser" and "Caution: mid hyperfocus." "We both just laugh about it because it's super-relatable," she says.

Mental health specialists are divided on viral ADHD content. Some value its destigmatising effect, while others worry it trivialises a serious condition or blurs diagnostic boundaries. Celebrity advocates like Steven Bartlett have shaped public perception further. For instance, the most decorated gymnast in history, Simone Biles, announced her diagnosis on X in 2016. "Having ADHD, and taking medicine for it is nothing to be ashamed of nothing that I'm afraid to let people know," the U.S. athlete said.

Similarly, UK singer Jessie J shared in a July 2024 Instagram post what her ADHD diagnosis evoked: it both "empowered" and "overwhelmed" her. Like Bartlett, she described her condition as "a superpower," given proper support. "If there is one thing social media has given me," she wrote, "it's the chance to relate, connect and heal with strangers that have kind hearts and are going through a similar thing."

But this celebrity endorsement sits uncomfortably with some researchers. Oxford University psychologists Drs Lucy Foulkes and Jack Andrews caution that, despite good intentions, celebrity disclosures might inadvertently elevate certain conditions into "prestige items." This social value can make diagnoses seem desirable, particularly on social media platforms. The resulting glamorisation focuses attention on high-profile cases while overlooking those suffering in less privileged circumstances.

This chimes with Professor Susan Young, a clinical psychologist who set up the first national adult ADHD service at London's Maudsley Hospital in 1994 and co-authored the 2008 National Institute for Health and Care Excellence (NICE) guidelines. She objects to the "glib" tone of some content online. "If you look at TikTok in particular, it's all about entertainment. I feel uncomfortable with having a condition that people can really struggle with being used for entertainment purposes," she tells me.

Having worked extensively in the penal system, Young knows that the reality of ADHD for many does not involve Olympic gold medals, multi-million-dollar record deals or TV stardom. Her 2015 study found that ADHD prevalence in prison populations significantly exceeds that of the general population; in youth prison populations five times as many young people (30.1%) and in adult prison populations ten times as many people (26.2%) have ADHD than in the population as a whole globally. The outlook is bleak for prisoners with ADHD: they are more likely to be involved in violent incidents, engage in self-harm and have substance abuse disorders.

Yet in this environment, far removed from TikTok's portrayal, the condition remains under-diagnosed, with sufferers unlikely to receive support, making rehabilitation substantially more difficult. "People talk about, 'ADHD is my superpower! I love having ADHD! I'm zany and I'm fun.' It can undermine the condition," Young adds. This glosses over all those, predominantly from marginalised backgrounds, for whom the condition has wreaked havoc on their already fragile lives.

US research — also replicated in other countries — shows children from low-income backgrounds are more likely to meet the criteria for ADHD but are less likely to receive treatment. David agrees. The "ADHD is a superpower" idea really bothers him too. "I honestly can't see any true advantages to having ADHD itself. For someone to be diagnosed as having ADHD, it has to actually cause problems or impairment in your life — that's a medical requirement — but we rarely talk about what 'causing problems' really means," he says.

That isn't to say people can't adapt to their challenges or develop strengths in spite of their difficulties. But it doesn't mean the condition itself is beneficial, he explains. Social media awareness campaigns about mental health walk a fine line between reducing stigma and trivialising conditions to the point where they lose credibility. This can lead people with diagnoses and difficulties brought on by ADHD to question their own experiences.

Excerpted from "Bad Influence: How the Internet Hijacked Our Health," Oneworld Publications, 2026

Though the spectacular sight of a total solar eclipse feels like a rare experience, on a planetary scale, the average time between two such events is just 18 months, with some occurring much closer together. Now, thanks to centuries of studying the orbit of the sun and moon, we are able to correctly predict when and where the next eclipse will be far into the future. But for thousands of years of human culture, the lunar crossing of the sun remained as mysterious in cause as it did in location.

In his book "Solar Eclipses" (Reaktion books, 2026), writer and historian of astronomy William Sheehan goes back to ancient times to discover what impact this awe-inspiring celestial dance between the sun and the moon had on ancient civilizations, and how over time we began to understand the science choreographing it.

This excerpt from the book goes as far back as ancient Greece, where we learn of the "immoral, foul-mouthed and violent" soldier and poet Archilochus, who gave us the first written account of a total solar eclipse.

Today, with the ability to predict the paths of eclipses to extremely high accuracy, to make quite successful long-range (ten days or more) weather forecasts, ease of travel and for many, plus a significant amount of discretionary income that never existed in previous times, seeing eclipses has become a passion for thousands of global eclipse-chasers. People seek out a connection with the larger universe that includes a huge rush of adrenaline and life-transforming emotions that have been described as "spiritual" in nature. Of course, eclipses have occurred since time immemorial, but until recent times people have experienced them on a somewhat haphazard basis. This is emphatically the case with total solar eclipses, which, despite being the most stunning, are rare from any given place and could hardly be expected (before eclipse prediction and travel became more convenient) to be seen in a human lifetime.

The reason for this is that the central (umbral) shadow of the Moon that creates the totality zone is so narrow —– only 200 kilometres (124 miles.) on average —– so that it mostly falls on uninhabited portions of Earth's surface. From any one location, totality might not occur at all during a person's lifetime. The 30 June 1954 total eclipse, for instance, was the last visible from Minneapolis until that of 14 September 2099; the 22 July 2028 eclipse visible from Sydney will be the last visible from there until 3 June 2858 (!) and so on.

The actual width of the direct path of the shadow (known as the antumbra at annular and umbra at total eclipses) can vary from 0 kilometres to more than 1,000 kilometres (620 miles). It reaches the latter figure if it strikes Earth obliquely as it did, for example, during the annular eclipse of 12 September 489 B.C.E. (which occurred, incidentally, a year to the day after the usually accepted date of the Battle of Marathon, in which the Greeks defeated the Persians); the antumbral width was then 1,132 kilometres (703 miles).

Even to be aware of the partial phases of a solar eclipse is difficult unless the eclipse is very deep — marked changes in the intensity of sunlight occur only minutes before totality. And in general, people working in fields or hunting and fishing have little incentive to stare at the Sun. Thus, for untold ages, partial solar eclipses must largely have been simply missed. Lunar eclipses, on the other hand, are much more frequent from any one location, since a total lunar eclipse is visible anywhere within the night hemisphere of Earth. Lunar eclipses are also highly impressive, involving as they do the Moon's light being encroached upon and swallowed in shadow as well as the colour of the Moon turning to blood red.

That having been said, even without being able to make specific predictions, people from earliest times certainly took a keen interest in the vast pageant taking place overhead — Sun, Moon and stars, as well as clouds and other meteorological phenomena. The universe seems replete with powers more than human, powers mysterious and largely beyond our ken. The sense of this underlies the origin of religion, which in the first instance may have consisted in the apprehension of "something, indicated by terms such as the holy, the numinous, or the sacred … transcendent and irreducible." Our first response to the strange universe around us is deep, primal, pre-verbal.

Until the second century B.C.E. (and then first in Babylonia after millennia of recording celestial phenomena and their associated omens), it was impossible to predict with any accuracy when a total solar eclipse would occur. The best one could do was to suggest that on such and such a date it was somewhat probable that an eclipse might occur, though whether partial or total — or no eclipse at all — could not be determined. Thus any supposed prediction of an eclipse would have been a matter of sheer luck. No one yet had a clear idea of what caused an eclipse. Moreover, at a time when the Sun and Moon were regarded as gods, who could possibly know the minds of deities, or set limits to their arbitrary sway?

Even in modern times, an eclipse, for which the circumstances have been predicted fully and in detail, elicits an overpowering emotional response. What kind of response would a completely unexpected event have elicited?

We are lucky to have one very vivid first-hand account from an eyewitness of such an event. He was the Greek soldier and poet Archilochus, who lived on the island of Paros during the seventh century B.C.E., a century or so after Homer and Hesiod. Much of what we know about him (or think we know) is based on what he recorded in his poems. Thus without his poems, "we would never have found out that his mother Enipo was a slave … nor that he was an adulterer, that he was licentious and violent, and, most disgraceful of all, that he threw away his shield [during a battle]."

For all that, Archilochus' poems don't show him in a very flattering light. He appears to have been immoral, foul-mouthed and violent. It was said that after his engagement to one Neobule was broken off by her father, he wrote a series of songs so scurrilous (only fragments remain) that Neobule herself, the father and her younger sister all hanged themselves for shame. Throwing away his shield was even worse, by the standards of the time, than his lewd remarks towards women — it was the ultimate faux pas for a member of the warrior class of seventh century B.C.E.. He justified doing so on the grounds, already a cliché at the time, that it allowed him to fight another day. And so he did, being killed in a battle between Paros and Naxos by a Naxian warrior named Calondas, at the age of 35.

All very interesting, but the only reason that Archilochus is mentioned here is because he is something of a hero to eclipse watchers, because of a chance event that occurred on 6 April 648 B.C.E.. On that date (as determined from modern eclipse calculations) a total eclipse occurred; the Moon, like a shield thrown away in battle, covered the Sun. The path of totality began in the Atlantic off the western coast of Africa, ran just south of the boot of Italy, crossed Greece and the Black Sea, then veered north across Siberia. We can’t be exactly sure of Archilochus' location; it might well have been in Paros itself, which was exactly on the centre line (where the duration was some five minutes). Nevertheless, we do know exactly what he thought and how he felt:

Nothing is surprising anymore, nothing is deniable on oath;

No longer will anything seem impossible or marvellous, since

Zeus, father of the Olympians, has turned midday into night,

veiling the radiance of the sun, and turning mankind slack

with fear.

Hereafter all things become credible, they are to be expected,

There is no longer any reason for amazement, even if you see

The wild beasts changing places with dolphins,

making the oceans their pasture, and taking joy

in the sonorous murmur of the sounding sea,

while the dolphins, for their part, think better of the wooded

mountain.

(Translated by Michael Armstrong)

Archilochus achieved immortality with this poem: he became the first person we know of by name to have seen a total eclipse of the Sun, and to have recorded his stunned reaction.

Excerpted from "Solar Eclipses" (Reaktion books, 2026) by William Sheehan.

About 2,500 years ago, people in what is now India and Sri Lanka were manufacturing an exceptionally high-quality type of steel. Wootz steel was extraordinarily strong and sharp, and they exported it globally — in the Middle East, it was used to forge the legendary Damascus blades. But around A.D. 1100, it vanished, and the knowledge of how these ancient people forged such high-carbon steel was lost.

In this excerpt from the book "The Age of Alchemy: How Early Innovators Shaped Modern Chemistry" (Profile Books, 2026), author Kit Chapman, a science journalist and honorary researcher at Falmouth University in the U.K., reveals the extraordinary story of Wootz steel and the experiments that finally showed how it was created using furnaces powered by monsoons.

"The Age of Alchemy" is the winner of the 2026 Royal Society Trivedi Science Book Prize.

Kit Chapman interview: 'His urine goes on tour around Europe, showing the kings and queens this glowing pee'

During the Industrial Revolution, it became clear that something far stronger [than iron] — steel — was needed. Victorian engineers had started to build larger projects than anyone had ever seen, and were using cast iron for their structures, such as the first metal bridge, at Ironbridge in Shropshire. But cast iron was too weak. In 1847, a cast-iron railway bridge over the River Dee collapsed less than a year after it was opened.

If the world was going to modernise, it had to come up with a better material. Steel was the obvious answer, but how did you get rid of just the right amount of carbon in pig iron? The answer was found by an inventor called Henry Bessemer, who was hired by the British government to try to make cheap steel for use in guns. Bessemer's great innovation was to suggest that, once you've got your molten-hot pig iron, you blow air — a lot of air, between 85,000 and 550,000 litres per minute — up from beneath it.

This results in the iron undergoing oxidation, both increasing the temperature of your molten steel and reacting with the impurities. The impurities form a scum at the top of the furnace called slag. This is a mix of metal oxides and other unwanted byproducts such as silicon dioxide, which then needs to be removed, decarbonising the pig iron into the exact ratio you need for steel. With the steel already molten, it can then be poured out into whatever shape you need.

Bessemer became one of the leading figures of the "Second Industrial Revolution" at the tail end of the nineteenth century. He was knighted by Queen Victoria; his steelworks in Sheffield led to it becoming synonymous with steel; and in the US, eight towns were named after him. Without Bessemer, the world would never have known steel's true potential, and our skylines wouldn't be dominated by modern structures that rely on them, such as skyscrapers, railroad tracks and suspension bridges.

Except there's a big problem. "The story you've been told about metallurgy is from a western viewpoint," explains Gill Juleff, an archaeologist from the University of Exeter, and the reason I've come out to Sri Lanka. "It comes from colonialism, and the dominance of Europe. In Asia, there were technologies that were making very good-quality steel. The makers of iron understood it. All of the evidence suggests that India was very familiar with it. They were producing hardened chisels that carved granite even in the Iron Age. You can only do that with steel."

As early as 500 BCE, steel began to originate from the Indian subcontinent that was far greater in quality than any other. The blades were forged with intricate, elaborate patterns and banding, like the marbling of the finest cut of steak. These were harder than any other blades, cut sharper and cost more.

Arabian, Greek, Roman and Chinese writers all described this wonder-material, which became so legendary that a Persian euphemism for cutting someone with a sword was an "Indian answer." It was known as Wootz steel. Just like pepper or other commodities from southern India that moved west along the Silk Road, the steel's rarity made it a luxury item.

"It's not a material that your everyday blacksmith would necessarily want," Juleff says. "High-carbon steel is an awful lot harder to work. It's not for arrowheads or kitchen knives. It became used by specialist swordsmiths." Then, around 1100 CE, the mysterious, intricately patterned blades simply vanished. Subsequent versions emerged (the most famous is Damascus steel), but Wootz steel had disappeared completely. It left a gaping hole in the history of chemistry.

No one could figure out how the Sri Lankans produced steel of such fine quality, and with such intricate patterning, well over a thousand years before it should have been possible. That is, until Juleff discovered the answer. She realised that archaeologists had been looking at the question based on how Europeans worked with iron.

"We discovered that the furnaces were all placed at the top of hills," Juleff explains. "Hundreds of them, of a type we'd never seen before; we only knew they were furnaces because there was slag everywhere. For some reason, the early Sri Lankans had their villages at the bottom of a hill, and then dragged all their iron to the top to smelt it." Initially, the strange furnaces were a puzzle. Typically, a furnace is tall and erect, like a chimney; this creates a natural draught that feeds oxygen to the fire, drawing air in and pushing out the exhaust gases. The Sri Lankan furnaces were totally different. They were flat, half a metre high and 2 metres long, with hundreds of holes bored into the front and back. They looked like oversized harmonicas.

"The answer wasn't immediately obvious why," Juleff says. "And then we realised they were all facing into the wind." What if the Sri Lankans weren't using bellows at all? This is why Juleff asked me to come to Colombo in the off-season. Every year, Sri Lanka is buffeted by two wet seasons: the south-west monsoons from May to September, and the north-west monsoons from December to February. It's a kind of weather you have to experience yourself to truly appreciate.

"A monsoon wind blows up to 90km an hour [56 mph]," says Juleff. "When you're at the top of a hill, you get an aerodynamic effect, where all the wind's rushing up and cresting. You're battered by it. Everyone told me you couldn't run a furnace just using the wind, because it's not strong or reliable enough. So, I decided to experiment. I built one." Juleff's furnace was identical to the Sri Lankan ruins she had found. She fed it using charcoal and iron sourced locally from surface deposits — exactly as would have been available to the villagers who built them.

Then, she waited for the monsoon. "So, we ran this furnace," Juleff says. "And, to begin with, I thought it wasn't working. We had this line of fire behind the front wall, and nothing at the back. I thought everything needed to be burning." It looked like the experts had been right: the monsoon winds weren't regular or consistent enough to blow into the furnace's holes to create the temperatures required.

But then Juleff's mood changed. "It was like a Transformers toy, everything rearranged in my mind. I had a eureka moment! It wasn't wrong at all; it was how it was designed to work. The wind was blowing up the hill — it wasn't blowing into the tubes at all, it was blowing over the top of the furnace. It's like an aeroplane wing: by blowing over the furnace, you're creating this incredible pocket of low pressure." The Sri Lankan furnace wasn't a harmonica, with air puffed through it; instead, it was played like a flute.

This is the Bernoulli effect, the same principle that sticks a race car to the road, or keeps water moving through your plumbing. The change in pressure and the smooth, ordered air flow was creating a furnace beyond anything western science had considered possible. The team continued putting in ore and charcoal throughout the day, then allowed things to cool. The next day, they returned to see what they had produced. At the top was a knotted lump of pure iron — a bloom, as expected. "But then below that, stuck to the bottom of our slag, was another layer of metal," Juleff says. "High-carbon steel. The wind did it. We couldn't stop the wind doing it. We had created a furnace that could make the best steel anywhere in the world."

Juleff had solved the mystery of Wootz steel. Not only did we now know how it was made, we understood why the technology hadn't spread around the world: the technology was anchored in the unique geography of Sri Lanka, and the people who visited weren't scholars, but traders who didn't appreciate the small miracle they were witnessing.

"The metal-makers weren't moving," Juleff says. "They were here, sat in the interior of Sri Lanka, season after season, running these incredible furnaces." Why did Wootz steel vanish? In the twelfth century CE, Sri Lanka was invaded by the Pandya dynasty of southern India. It triggered a societal collapse, as Sri Lankans were forced to pay tribute to their conquerors. The most likely explanation is that, during the chaos of the invasion and its messy aftermath, the traders and middlemen who brought the Wootz steel to the coast, and the ships that transported it around the world, had stopped coming.

It wouldn't have occurred, or mattered, to a Sri Lankan metallurgist that their goods were ending up in the hands of kings and emperors in some distant land they'd never heard of; they'd have only seen that they couldn't sell to local traders any more. The villagers stopped making goods that didn't sell, and moved on to other, more profitable, careers.

Excerpted from "The Age of Alchemy: How Early Innovators Shaped Modern Chemistry," Profile Books, 2026.

Biodiversity loss has been recognized as a threat to global stability for decades. The decline in overall diversity of species on our planet, either through extinction or a fall in abundance, can culminate in ecosystem collapse.

But in this excerpt from "Despite it All" (Granta, 2026), author and journalist Fred Pearce looks at the remarkable resilience of nature. If we can put aside our notions of what should and shouldn't be in a given environment and leave nature to adapt and thrive, we may begin to see the gains needed to support a healthy biosphere.

"Despite it All" has been shortlisted for the 2026 Royal Society Trivedi Science Book Prize.

If we are serious about rewilding, then we need to accept that it will take its own course.

Often invasive species are just the first stage of an ecological resurgence. They are the first movers, and their infestations are short-lived. In time, diversity usually returns — even if it's not always the same diversity as was there before. We should recognize that. We need to be as adaptable as nature itself, and jettison our more romantic notions about biodiversity and pristine environments.

So do many oldschool ecologists, says Chris Thomas, an ecologist at the University of York. They too often simply ignore any bits of nature that do not meet their expectations of what "should" be present. "The establishment of successful species in new locations is commonly interpreted as further evidence that the Earth's system is departing from a more desirable state," he told me.

So when biodiversity assessments are conducted, "alien" species lurking in the undergrowth are simply not counted. As outsiders, they are deemed not to belong to the ecosystem they inhabit. Thomas says that, in Britain, official records show biodiversity in decline, even though, if we add all losses and all gains together, "it is unequivocally true that the total number of species in Britain is increasing."

Most of the gains — the weeds, pests and alien species — are kept off the biodiversity books. This amounts to an ecological catch-22. Biodiversity can only ever decrease, as new species are seen as inimical to the local environment, and each year millions of pounds, dollars and euros are being spent to eliminate them.

Of course, it sometimes makes practical sense to eradicate invaders. I don't say we shouldn't try to keep out pests that cause short-term ecological mayhem and economic damage. But if we choose to get rid of new species, we can't then hold up our hands in horror at declining biodiversity. And besides, ecologically as much as socially, migrants can stir things up to good effect. They interact with other species — eating or being eaten, pollinating, and rotting after death to nurture new organisms.

We should embrace novel ecosystems that contain both what we regard as native species and the feral, opportunistic interlopers that find their new environment congenial. In his book about weeds, British naturalist Richard Mabey celebrated what he called these "outlaw plants" and showed how they have had a hand in shaping not only our landscape but our civilization, becoming crops, medicines and sources of beauty and creative inspiration.

It is easy to be nostalgic about past ecosystems as a golden age. But what we imagine to be the perfect ecological state — a supposedly natural order of things that often gets called "the balance of nature" — was mostly itself a passing phase. Nature is always moving on. And more often than we realize, humans have had a hand in what we now like to regard as natural.

Environmental scientist Erle Ellis, who runs the Anthroecology Lab of the University of Maryland, argues persuasively that most of the planet has been heavily influenced by human activity for thousands of years, including places such as the Amazon that we often think of as untouched. We have, in effect, long lived on a "used planet," and humans and nature have not historically been at odds. The most biodiverse places are often those where people have lived the longest. By constantly tending the land, past civilizations created ever-changing mosaics of habitats where more species thrived than in places with less human interference.

So, we should be careful not to let our reverence for the pristine blind us to the environmental potential of today's wastelands, backwoods, abandoned fields, scrublands and no-go areas. In a Good Anthropocene we are likely to need more of them.

There is a final reason for believing that nature is equipped for recovery from almost anything we can throw at it. The apparent chaos of the Anthropocene is turbocharging evolution itself. Every perturbation of our environment creates an opportunity for existing species to adapt or for new ones to evolve, says Chris Thomas.

I first met Thomas in 2004, when he had just published an influential paper warning that climate change could wipe out a quarter of the world's species this century. He called it "terrifying." It was headline news. Two decades later, he has not changed that forecast, but he has added an important rider. Despite the coming extinction holocaust, he told me, "the Anthropocene could raise biological diversity."

His research is showing that evolution in the twenty-first century is speeding up to fill the gaps left by the extinctions — delivering new and better-adapted species. "The seeds of recovery are already visible," he told me. "Genes are jumping around. New species are beginning to emerge." Rob Dunn, an ecologist at North Carolina State University, agrees. In his book "A Natural History of the Future," he says that this evolutionary spurt is happening fastest in urban landscapes, where species are adapting to city life with almost as much alacrity as newly arrived humans.

This urban ecological renaissance resembles the story of the finches on the Galápagos archipelago, which Charles Darwin observed to have evolved different beaks to match the food on the different islands. In modern cities, house mice have evolved to produce saliva with a chemical make-up better able to digest the carbohydrates available in urban food; cockroaches and bedbugs have developed resistance to pesticides and even learned to avoid sugar-impregnated bait; London's pigeons have learned to commute on the Underground. We have clothes moths and carpet beetles.

Such natural innovations may not always be cuddly, but they do show that nature is on the prowl in the Anthropocene. So where is biodiversity headed? It is undeniable that most species of plants and animals are currently in numerical decline in a human-centric world.

This global disturbance is favouring some generalists — so-called superspecies — that can occupy a wide range of habitats, displacing local, rare and specialist species. Locally, however, biodiversity has sometimes increased substantially, especially in the rich kaleidoscopes of gardens, parks, toxic brownfield sites, roadside verges and so on that humanity has helped create.

Such places may become crucibles for a biodiversity rebound. Understanding this reality should change how we do conservation. We should not abandon nature to its fate. Some of our favourite species will pass into history unless we act to save them, and I'd vote for action any day. But it does mean embracing rather than rejecting the processes of change. Change in the Anthropocene is good. We should be grateful that nature is finding a way.

This is an extract from Despite it All by Fred Pearce, published by Granta.

Much of the discourse around artificial intelligence (AI) focuses on grand ideas such as the rise of a hypothetical artificial general intelligence (AGI) and superintelligence. Speculation swirls around the likelihood that the technology will thin out the job market, or even precipitate the death or evolution of human creativity. We haven't focused as much on the multitude of subtle yet hugely consequential ways in which AI is reshaping the social fabric of our society, and how we collectively imagine the future.

That's the argument sociologist and AI researcher Mona Sloane, an assistant professor of data science and media studies at the University of Virginia, puts at the center of her new book, "Predicted: How AI Is Restructuring Social Life" (University of California Press, 2026). Whether we consider email filtering, prediction markets or social media platforms, AI systems are embedded in the heart of how we interact with the digital world. Indeed, AI is so ubiquitously integrated into everyday interfaces that it's given rise to a new kind of "prediction logic" that makes assumptions about who we are and how we are likely to behave.

In this excerpt, Sloane compares the AI technology we use today with the oracles of ancient Greece, framing it as an omnipotent presence that has moved to organize society through the prism of prediction models. This in turn affects how we learn, live, love and even picture the future.

We live in a world of oracles. These oracles constantly feed us predictions that shape our social lives — how we socialize, love, work, gain access to resources. Like in ancient Greece, predictions occupy a prominent role in our society. We consider our oracles so mighty that their predictive power rules over the fate of whole economies and even geopolitical constellations. Where the oracle is, there is the center of the world.

But unlike in ancient Greece, our oracles aren't high priestesses delivering divine prophecies. They are artificial intelligence (AI) systems melted into the infrastructure of everyday life. Today, it is nearly impossible to evade the grasp of AI predictions. I voluntarily and involuntarily use AI on a constant basis: by using email providers that build on the predictive properties of AI for spam filters, by conducting online banking and getting enrolled into AI-automated fraud detection, or by using generative AI for supporting administrative chores. It has become part of how I experience the world.

It can be a relief when it helps me do things I dread or am bad at, such as produce a spreadsheet template I desperately need, help streamline language produced by different authors for a report, or generate a specific image for a presentation. Often, I must intently handhold the AI, checking and fixing its outputs. And sometimes, with deep frustration, I give up and start all over to complete my task manually.

The omnipresence of AI prediction can make it easy to think of these systems as inevitable, quasi-natural phenomena we are subject to, rather than a part of. But they are quantitative concepts that arise from social agreements about how we ought to capture and interpret the world around us.

"Quantitative concepts are not given by nature: they arise from our practice of applying numbers to natural phenomena," wrote Rudolf Carnap, a logician and professor of philosophy of science, in 1966. His point was that numbers can be useful, because they allow for information to travel more easily across contexts, as a sort of language. They also make mathematical predictions possible.

To him, this was first and foremost useful for engineering modern life: A quantitative language allows for the articulation of quantitative laws that, in turn, facilitate the routine generation of mathematicized predictions, particularly in the realm of physics. Being able to predict how energy, compounds, and materials will behave in certain configurations is the reason humans were able to build the conveniences of airplanes, cars, and telephones. For Carnap, predictions were simply instrumental in this way.

Today, almost 60 years later, this pragmatic approach to mathematical prediction has been turned on its head by AI. Prediction is no longer just a handy tool in physics or engineering. The promises of AI's oracular power have turned prediction into a logic for structuring social life. This is a dangerous proposition. It implies that AI is always necessary or even inevitable and diverts attention from the social forces shaping ideas around this technology in the first place.

AI systems are not natural phenomena that happen to us. They are collective expressions of society. As such, they are not just a hype or a deception concocted and executed by global tech elites. They indicate a wider shift in how we imagine and enact society. Many critical discussions of AI characterize this phenomenon chiefly as heightened surveillance and capitalist extraction. But this is a myopic diagnosis. AI's most powerful effect is the subtle yet comprehensive recalibration toward prediction as a guiding principle for organizing society. In this book, I call this phenomenon the prediction paradigm.

AI is something that we do as part of going about our lives and participating in society — it is social infrastructure, affecting how we relate to one another and how we act in public and in private. Like all infrastructures, AI allows resources and ideas to flow in certain directions, but not others. AI uses data from our collective past to predict our individual future. And because AI deals in futures, it solidifies a linear time regime that hardens our social commitment to causality: The past always predicts the future. The problem of AI is not the rise of intelligent machines, but the extraordinary social significance ascribed to this linearity, fetishizing the future and leaving little room for deliberations about what (other) futures may be possible or we may want.

Reprinted from Predicted: How AI Is Restructuring Social LIfe by Mona Sloane, courtesy of the University of California Press. Copyright 2026.

In most areas of archaeology, excavators painstakingly dig layer by layer to reveal not just buried artifacts but also charred seeds, broken bones and microscopic grains of ancient pollen. This delicate process is followed by months of intensive lab work to study the newfound remains. But there is one kind of archaeologist that takes a different approach to understanding the past. Experimental archaeologists replicate how people did things in the past, using techniques they recreate from archaeological information and modern knowledge.

In his new book, "Dinner with King Tut: How Rogue Archaeologists Are Re-creating the Sights, Sounds, Smells, and Tastes of Lost Civilizations" (Little, Brown and Co., 2025), science writer Sam Kean explores the experimental side of archaeology. Through a series of ancient and modern vignettes, Kean discovers how Stone Age city dwellers kept their houses cool 9,000 years ago, how the Romans used needle and thread to style hair, and how bog bodies were formed in Iron Age Europe.

In this excerpt, Kean meets two men who used ancient techniques to diligently mummify a human body in an effort to understand how ancient Egyptians took care of their dead.

Related: Read our interview with Sam Kean on 'Dinner with King Tut'

Cultures throughout history have mummified their dead, and a handful still do today, but Egyptian mummies remain the most iconic. Unfortunately, the Egyptians wrote down virtually nothing about their embalming process. This leaves experimental archaeology as one of the few avenues available for understanding mummification, and several practitioners have indeed re-created mummies in modern times. In most cases, they work with animals, but a few intrepid souls have mummified human beings, most famously when Bob Brier and Ronn Wade did so in 1994.

Wade grew up wanting to be a mortician like his father. After a stint as a medic in the Vietnam War, he became an anatomist and eventually the head of Maryland's state anatomy board. Brier also has training in anatomy, but is an Egyptologist by training and passion. He's accumulated so many books on Egypt over his life that he rents a second apartment just to accommodate them. Brier and Wade selected their mummy from the pool of people in Baltimore who donated their bodies to science. Ultimately, they settled on a seventy-six-year-old Caucasian man who died of a heart attack. His identity remains secret, but a bit crassly, Wade nicknamed him E. M. Balm.

For authenticity's sake, Brier and Wade used replicas of pharaonic-era tools and materials, including linen wraps, an oddly wide wooden embalming table, and copper and obsidian blades — although they quickly abandoned the copper ones, which couldn't cut flesh well. Before starting on their mummy, they practiced one important step on other cadavers: extracting the brain. Instead of using full cadavers for this, they obtained some decapitated heads leftover from a medical school's plastic surgery class. ("They were looking a little weird," Brier recalls. "They'd had facelifts and such.")

From some scant references, Brier knew that Egyptian embalmers removed the brain by inserting a hooked rod through the nostrils, but the details were vague. Brier and Wade first tried scooping the brain out with such a rod, but the tissue proved too soft and wouldn't come out. They finally took to squirting water up the cadaver's nose, then used the rod to whisk the brain into a slurry. After that, it poured right out. "Like a milkshake," Brier says. "A strawberry milkshake to be exact."

Skills honed, the duo began making their mummy in May 1994. The first step involved removing his organs.

Different organs met different fates in Egypt. Unclear about the purpose of the brain, embalmers typically threw it away. The heart, in contrast, was left in situ [in place]; it was considered the seat of all thinking, emotion, and intelligence. Abdominal organs were carefully extracted and preserved. Following this protocol, Brier and Wade made a 3½-inch [9 centimeters] incision in their cadaver's abdomen and removed the spleen, liver, gallbladder, lungs, and twenty-two feet [6.7 meters] of intestines. Given their size, extracting the liver and lungs required some creative geometry and determined squeezing. The most difficult part involved detaching the lungs from the heart while working blind inside such a tiny hole.

With the organs removed, the pair cleaned the abdomen with palm wine and myrrh, then stuffed frankincense into the skull. This was an important ritual step to prepare the body for the afterlife, and also helped kill microbes and mask bad smells. Ancient embalmers used other sacred substances as well, often imported from Europe and Asia at great cost — pistachio resin, beeswax, castor oil. Ramses the Great's mummy had peppercorns from India shoved up his nose.

Next, Brier and Wade dehydrated the body using natron, a mineral of equal parts salt and baking soda that forms naturally in Egyptian wadis, or dry gullies. Like a sponge, natron sucks the moisture out of flesh, leaving it too dry to support bacteria, maggots, beetles, and other putrefying agents; the leftover tissue is essentially jerky. (Fully committed to authenticity, Brier dug the natron himself in Egypt, and recalls that sneaking hundreds of pounds of unidentified white powder through customs at JFK Airport was one of the more ticklish aspects of the project. Luckily, he was traveling with a film crew, and could hide the powder in suitcases amid their equipment.)

In their lab, Brier and Wade placed the mummy's spleen, lungs, liver, and intestines into bowls and covered them with natron. They also packed 29 linen bags of the powder into the body's empty torso, laid the body on top of 211 more pounds [96 kilograms], and dumped 583 additional pounds [264 kg] over it. They kept the body in Wade's old office, with the heat cranked up to 104 degrees F [Fahrenheit, or 40 degrees Celsius] and dehumidifiers running night and day to simulate Egyptian air.

Over the next five weeks, the natron on top turned crusty and brown from absorbing bodily juices, forcing Brier and Wade to crack through it with an iron rod. (Today Brier remembers the odor as acrid but not unpleasant, although news reports at the time say he and Wade donned surgical masks against the smell.) Regardless, the sight of the body beneath thrilled Brier. As it dries, the skin of mummies tightens and shrivels, especially on the face and scalp. The lips retract to reveal the teeth, and skin with less melanin turns brown-yellow. Brier always wondered whether those changes resulted from the immediate mummification process, or from several thousand years of weathering in Egypt's arid climate. One glance at his mummy and Brier knew the answer: even after five weeks, "he looked just like Ramses the Great," he recalls, with leathery skin, a beaky nose, and wispy hair sticking up. The embalming process, not time, made the iconic mummies we know today.

Beyond changing the body's appearance, the dehydration process left the limbs as stiff as tree branches, and dropped its weight from 188 pounds [85 kg] to just 79 [36 kg]. (Thirty-one pounds [14 kg] of that represented the removal of organs.) The organs drying in the bowls withered as well, which helped explain another mystery of Egyptian mummification: as other archaeologists have noted, embalmers typically placed the organs in so‑called canopic jars, funerary vessels with slim necks — so slim that it seemed impossible to fit the larger organs inside. But the natron shrunk them down enough to slip right in.

After removing him from the natron, Brier and Wade gave Mr. Balm a full body massage with lotus, cedar, and palm oils, another step that, while important ritualistically, also had pragmatic benefits — restoring flexibility to the joints, making the mummy easier to handle. This accomplished, they wrapped the body in linen bandages. (Embalmers in ancient times started with the hands and feet, wrapping each digit separately, then proceeded to the arms, legs, and torso. The penis was individually wrapped as well — or, if embarrassingly shriveled, a cod‑piece of stiff linen was bound in place.) At this point, they let the mummy dry for three more months in the arid office, which dropped its weight to 51 pounds [23 kg]. Afterward, they added several more layers of wrappings. In between the layers, they slipped magic amulets and scraps of papyrus with spells on them, a common practice in ancient times.

For the past three decades, the mummy has been lying in a metal casket in Maryland, stored at room temperature. Brier and Wade have partially unwrapped it twice to check for rot, but found nothing amiss. "He's dead and well," says Brier.

See how much you know about mummies with our mummy quiz!

In this excerpt from "Cats: A History" (Johns Hopkins University Press, 2026), author Rod Phillips, professor of history at Carleton University, Ottawa, Canada, examines a bizarre practice that began in the Middle Ages — putting animals on trials for "crimes" they had committed. Animals, including birds, insects and livestock, were taken to court and punished as humans would be. But there was a surprising outlier: law-abiding cats.

It might seem odd, even irrational, to blame cats for being cats. We might accept that it is simply the nature of cats and that while some individual cats tend to be more or less friendly toward humans, others remain consistently aloof.

But in the early modern period animals (and birds and insects) were attributed responsibility for their behavior as if they had the same agency and intentionality, and bore the same moral accountability, as humans. To this extent they could be punished for behavior that was deemed criminal or immoral.

A striking example is the trials of animals that were held throughout much of Europe from the Late Middle Ages to the end of the 18th century. (There were scattered cases in Europe after that time, and others in places as diverse as Russia, Brazil, the United States, and Canada.) In the early modern period animal trials seem to have been most common in France, but they also took place in Switzerland, Germany, the Netherlands, and occasionally in Britain, Spain, and Italy.

These trials ­were no dif­ferent from regular ­trials except that the defendant was not a human but an animal or, in some cases, several animals or a herd, flock, pack, or swarm of creatures. The indictments in animal trials were based on the law codes in force at the time and involved a range of crimes. Large mammals, such as cows and horses, sometimes killed humans and were charged with murder. Animals, notably sheep, that were subject to bestiality were said to have consented and were executed along with the human perpetrator.

The most common defendants in animal trials were pigs, which were widely kept in and around households in Europe at the time, and which sometimes killed and ate babies and small children. Animal trials were presided over by regular judges and the cases were argued by lawyers. The punishments, if the animals were found guilty, were the same as those imposed on humans: animals were imprisoned in jails where humans were incarcerated or executed by the same professional executioners who dispatched convicted humans. When they were fined, their ­owners ­were required to pay.

A dif­ferent sort of case involved suits in church courts against insects, rodents, and other vermin that had damaged crops. The defendants in these cases included locusts, leeches, rats, and mice, and when they were found guilty, they were generally excommunicated and sometimes ordered to go to places where they could do no harm.

There is a big difference between the place of animals in these cases and modern cases that involve animals that have caused harm. Dogs are sometimes ordered killed ("destroyed" is the usual term) by courts when they inflict serious injuries on ­people, but they are not found guilty of the offense in a formal sense, even though they perpetrated it. They are usually killed not to punish them but to prevent a recurrence and to protect other people. In many of these cases, the owner of the dog is punished in some way in addition to being deprived of their dog.

In the animal trials, in contrast, the animals themselves were found criminally responsible, and the owners were not punished, even if some were deprived of valuable animals or had to pay fines on their behalf. In an apparent exception in Chartres, France, in 1499, the parents of a child killed by their pig ­were ordered to pay a fine, but they ­were ordered to do so not because of their pig's actions but because they had failed to watch over their child more carefully.

There is some debate whether Europeans believed that non-human creatures had a sense of intentionality that made them as responsible as humans for their actions. Animal trials might instead show, suggests Emre Koyuncu, that the principles of being subject to the law "were not strictly grounded on rationality and intelligence." There is no explicit evidence that anyone participating in these cases believed that animals were rational in the same sense as humans, and some legal authorities clearly stated that they were not.

Yet the way these proceedings unfolded strongly implied culpability on the part of creatures found guilty. The unresolved issue is the extent to which a finding of guilt implied rationality and intentionality.

There is another phenomenon suggesting that non-human animals were believed capable of rational calculation of a human kind. It was a common practice, for many centuries, to hang dead or mutilated specimens of unwelcome animals so as to convince their fellow creatures to stay away. Sometimes referred to as a "gamekeeper's gibbet," the custom sometimes took the form of hanging rabbits or weasels from tree branches as a warning to others. It is analogous to the practices, also common in early modern Europe, of executing people in public and sticking the decapitated heads of executed criminals on spikes as a warning to passersby.

Whether they worked as deterrents we cannot know, but at least it had a chance with beings (people) who could draw a lesson from the sight of a severed head. If people thought that animals could draw the same lessons, it tells us about their understanding of the intellect and moral codes of animals.

Although a wide range of animals, birds, and insects were involved in animal trials, there are hardly any records of cats being charged with any crime. Even dogs, considered the most faithful of creatures, quite often found themselves on trial, usually for biting people — although there is one medieval account of a faithful dog that brought its master's murderer to court, where he was convicted and executed.

One compilation of animal trials from the ninth to 19th centuries lists almost 200 but not one cat is included among the defendants — which include dogs, wolves, grasshoppers, snails, goats, pigs, and ­horses. Even so, a satirical print (about 1690) by the Dutch artist Egbert van Heemskerck shows a female cat being tried by a monkey magistrate in the presence of various animal witnesses.

Cats participated in some animal trials, but not as defendants. In the early 16th century the rats of the diocese of Autun, in Burgundy, were summoned to appear before a court for having eaten the barley crop, but they failed to appear at the specified time. Their ­lawyer won the rats an extension by arguing that cats were watching for them, making their journey to the court perilous, and that no one should be expected to appear at the court unless they could do so safely. There is no record whether the rats later turned up to face the charge.

The reason no cats seem to have been arraigned in animal trials might simply have been that cats did not commit crimes that were serious enough. Unlike pigs they did not eat children, unlike dogs they did not bite people (at least, not seriously), unlike cattle they did not gore people to death, unlike locusts they did not ravage crops, and unlike a range of other creatures they were not involved in bestiality.

For all that might have been said against cats, they were remarkably law-abiding animals, even if because they did not have the physical ability, size, or dietary preferences to commit the offenses that landed other creatures in court. That did not prevent people from torturing and killing cats, but those were extrajudicial actions that were far removed from animal trials. When cats ­were identified as witches' familiars, however, it was another matter entirely.

There's an army of tiny workers buzzing around our fields, helping our food grow. But over the past few decades, populations of bees and other insect pollinators have dropped precipitously. This looming "insect apocalypse" has many causes, from climate change to habitat loss, and it is already fueling malnutrition in some parts of the world.

One of the biggest factors in bee declines is industrial agriculture. "Big Ag" — with its emphasis on vast fields planted with a single crop, its heavy reliance on powerful pesticides, and its intensive use of commercial bee colonies to pollinate crops like almonds — reduces pollinator populations by killing and disorienting the insects, reducing their natural food sources, and leaving colony bees overworked and, therefore, prone to parasites like Varroa.

But industrial agriculture isn't the only force driving down bee populations. In her new book, "Bitter Honey: Big Ag's Threat to Bees and the Fight to Save Them" (Princeton University Press, 2026), writer and environmental researcher Jennie Durant takes a look at one surprising factor that may be hurting bees — and how new laws could protect these pollinators.

It's midsummer in Columbia, Maryland, and Janet Crouch's garden is in full bloom. It began in spring, when deep purple violets and bright yellow ragwort blossomed in April and early May. By midsummer, pink and purple-hued garden phlox emerged alongside scarlet bee balm, eventually giving way to Turk's cap lilies with their curled-back orange petals that dangle gracefully like bells. Pollinators creep and flutter throughout the garden, including bees and hummingbirds, moths and butterflies — and a host of other birds and insects.

It wasn't always like this. The yard was barren back in 1999, when Janet and her husband, Jeff, first bought their home. A solitary maple stood in the front yard, and a few nonnative barberry bushes flanked the house. Each property had a private lawn, but without fences, the yards blended into a seamless green expanse that bordered a fifty-acre county park forest. Over the years, the couple transformed their lawn into a lush pollinator garden.

Over time, the Crouches' yard became a sanctuary, especially for Jeff, a practicing therapist. "He'd come home from work, drop his keys, and head outside to see who was around," Janet said. "He'd check to see what new flower had bloomed, what butterfly or moth was in the yard, or spot a bird we hadn't seen before. It's become a huge, huge part of our lives." Sometimes, kids would even walk by and take an interest in the garden, and Jeff would pick them a flower.

But everything changed in 2017. The Crouches received a letter from their homeowners association (HOA), which they paid into biannually, that threatened to undo all the work they had poured into their garden. HOAs govern housing communities, from condominium complexes to suburban neighborhoods, and set rules for property maintenance and aesthetic standards.

An elected board of homeowners typically runs the HOA and collects fees to cover shared expenses like landscaping, common areas, and building maintenance. The first letter seemed harmless. It simply asked them to practice seasonal maintenance: mow the grass, trim overgrown plants, and tidy up. The Crouches worked with Janet's sister Nancy — a native plant gardener and advocate — to craft a response, explaining that the lawn was already mowed, and they were gardening ecologically, which meant things might look more natural than the typical lawn-centric yard.

Weeks passed without a reply. Then, just before Thanksgiving, the Crouches received a cease-and-desist notice from the HOA's attorney. They were given ten days to tear out their garden and replace it with turf grass or face legal action. By this point, the Crouches had tended their garden for seventeen years, so the thought of tearing it all out was gut-wrenching.

Instead, they hired an attorney, who argued that they hadn't broken any HOA rules because the community guidelines didn't address the type of garden they'd installed. Despite their tight deadline to get an attorney and craft a response, the Crouches heard nothing from the HOA for six months, leaving them in anxious limbo. When the HOA finally responded, it ignited a legal battle that drew the attention of state legislators and eventually changed Maryland law.

The Crouches were stunned by the HOA's reply: The board didn't just want them to do maintenance, they wanted them to pull out everything, including their pollinator gardens in the front and back. The Crouches were baffled — they'd never had any complaints about their garden until now.

Established in the 1970s, HOAs have a significant footprint in the United States: They govern millions of residential acres and house more than seventy-five million Americans, representing nearly 30 percent of the country's housing stock. HOAs offer a range of benefits for house and condo owners: They enforce rules and community standards; maintain shared amenities like parks, gyms, pools, and clubhouses; and foster a sense of community. Homes in HOA-governed communities often sell at a premium as well.

But the appeal of an HOA home is far from universal. The perks come with restrictions that often stifle a homeowner's freedom to manage their property as they wish. HOA boards can turn authoritarian, sparking conflicts with residents or fueling tensions between neighbors. Sky-high fees can trap homeowners, making it difficult to sell the house or keep up with payments, sometimes leading to legal trouble. It's no surprise that homeowners have mixed feelings about HOAs: A 2024 survey reported that nearly 60 percent of members had a negative view of their HOA.

While overtly abusive HOAs have made the news, their role in stifling pollinator gardens is less understood. It comes down to aesthetics: Many HOAs mandate manicured lawns and turf grass and dismiss pollinator gardens or wildflower meadows as messy, unruly, or unattractive. They tend to favor nonnative ornamental plants over native species to maintain a uniform, tidy look. The ornamentals are often chosen to match a landscaping style, signal status (nothing says wealth like a perfect row of hydrangeas), or simply because they're easier for the HOA's landscaping company to maintain.

But that manicured perfection comes at a cost. For pollinators, the mowed lawn is a food desert. Regular mowing prevents weeds like dandelions and clover from flowering and providing food. Lawns also replace diverse landscapes filled with wildflowers, shrubs, and native plants — the forage that pollinators evolved with over thousands of years and rely on for survival.

Lawns don't just deprive pollinators of food; they also eliminate their homes. More than 70 percent of native bee species nest in the ground, but manicured turf prevents bees from finding the loose, sandy soil they need to burrow. Mowing and trimming tall grass also strips away shelter for insects like butterflies and beetles. In pursuit of neatness, homeowners typically remove brush piles, leaf litter, tall grasses, or fallen logs — spaces pollinators might use as nests. Neighborhoods dominated by lawns fragment forage corridors and force pollinators to travel greater distances to find food, making survival even harder.

The pursuit of a pristine lawn also involves an arsenal of chemicals. Many of the same bee-toxic substances used in industrial agriculture — like neonics, organophosphates, and carbamates — are also sprayed on home lawns, gardens, and HOA common spaces. These chemicals affect plants, seep into the soil, and disrupt ecosystems. Healthy soil supports wild plants, insects, and fungi that benefit pollinators, but chemical lawn treatments can kill those beneficial insects and degrade soil health.

The Crouches received not only a cease-and-desist notice from their HOA but also threatening letters warning them not to garden in ways that might attract birds, as if birds were some kind of nuisance.

They soon discovered the HOA's attacks were driven by a complaint from their next-door neighbor. Instead of complaining to the Crouches directly so they could find a solution, he'd gone straight to the HOA. In September 2018, the Crouches and their neighbor had a contentious hearing before the HOA board, where the HOA's attorney argued that landscaping should only be for decoration, not wildlife habitat.

Many more months went by without a resolution, and then in 2019, the legal fight began in earnest. The Crouches sued the HOA board in August, citing a lack of actual violations, and the HOA countersued in November.

For many, this kind of fight might have soured the gardening experience altogether. But for Janet and Jeff, it only reinforced what they already knew: Their garden was about more than just aesthetics. It was a space of purpose, resilience, and joy. This helped fuel them throughout their ordeal.

The months that followed were rife with anxiety. As the lawsuit progressed into 2020, people drove by and took photographs of their lawn and garden, which made Janet feel exposed and overwhelmed. But still, it didn't deter them. "I don't like bullies, and we were being bullied in our own home," Janet said. "I just kept thinking about all the people who didn't have the capacity or resources I did, like my sister, who could provide suggestions and be an ear. I was more determined than ever to keep going."

Janet cast a wide net for support, turning to social media, local newspapers — anyone who could offer ideas or help spread the word. She attended environmental events to share her story and discuss the legal battle with her HOA.

Then, in October 2019, things started to turn in their favor. They got a call from Mary Catherine Cochran, the legislative assistant to their state representative, Terri Hill. Mary Catherine had an idea: Would Janet be interested in helping craft a law to stop HOAs from requiring turf grass lawns? By January of 2020, just months before the pandemic shut everything down, Nancy and several environmental groups joined Janet in Annapolis to provide testimony. The pandemic delayed their progress, but the bill eventually moved through both houses with overwhelming support — only two people voted against it.

On October 1, 2021, Maryland House Bill 332 was passed into law. Thanks to the bill, Maryland HOAs can no longer prohibit low impact landscaping, including pollinator gardens, rain gardens, and other environmentally beneficial practices. It was a massive victory for native plant and pollinator advocates throughout the state, and homeowners who hope to follow in the Crouches' footsteps.

The Maryland law set a precedent for other states as well: Maine passed a similar law in 2023 to create habitat for wildlife and pollinators by protecting low-impact landscaping. Illinois enacted the Garden Act in 2022 to support local gardens, followed by a Homeowners Native Landscaping Act in 2024 to allow gardeners in HOAs to plant native gardens.

The Maryland law's passage didn't happen in time to help the Crouches, who chose to settle with the HOA in December of 2020 rather than take the case to trial. Fortunately, the only concession they had to make — in addition to a jaw-dropping $60,000 in attorney's fees — was to keep their garden within a six-foot setback from the front property line and three feet from the neighbor's, the latter of which they'd already done.

Now that Janet and Jeff's battle is over, they can enjoy their yard and extend their efforts beyond their neighborhood. But their story highlights a simple truth: Individual actions can sometimes drive systemic change.

As the Crouches have shown, anyone, whether they have a sprawling yard, a small patch of land, or just a balcony, can take steps to support pollinators. A single garden might feel insignificant but small changes can rewrite laws, shift local norms, and transform ecosystems. If we rethink what a garden can be, we open the door to new possibilities — not just for pollinators, but for our landscapes and our connection to the natural world.

Over five decades ago, astronomer Frank Drake used one of Earth's largest radio antennas to beam a coded message into space, hoping that it might one day reach the eyes, ears or other inscrutable sensory organs of intelligent aliens. Slicing silently through the Milky Way at light speed, the now-famous Arecibo message has traveled roughly 50 light-years from Earth — about 10 times the distance to the nearest star, Proxima Centauri, but only one-five-hundredth the way to its intended destination in the Hercules constellation.

The search for extraterrestrial intelligence (SETI) is a waiting game — but for radio astronomer Emma Chapman, an astrophysicist at the University of Nottingham, whether humans will ever make contact with extraterrestrial life isn't a question of if but when. The universe is too vast and too plentiful with planets for humanity to be the only game in town, Chapman writes in her new book, "The Echoing Universe: How Radio Astronomy Helps Us See the Invisible Cosmos" (Basic Books, 2026). And when we do hear from our hypothetical alien neighbors, radio astronomers will be the first to know.

In this excerpt from Chapman's book, she tells us the intriguing story of Drake's message to the stars, the initial fears that it would awaken the attention of "malevolent or hungry" aliens, and why the search for extraterrestrial intelligence is still so valuable today.

During public lectures, I'm often asked, "Do you think aliens exist?"

I am always a little taken aback, as is the audience, when they hear my emphatic answer: "Absolutely. I have no doubts at all."

My surprise comes about because, as a radio astronomer, I have no doubt that life is out there, and I sometimes forget that there can even be a question about the matter.

There is little controversy amongst astronomers, not since the avalanche of exoplanet observations showed us that it was only a matter of time before we found Earth 2.0. Even if habitable worlds are scarce or the emergence of life is rare, the sheer number of planets in the Milky Way, let alone the universe, makes it implausible to think we are alone.

I am not engaging here in a willful misunderstanding of what we mean by "alien." When I say I believe there are aliens, I mean intelligent, complex lifeforms, not just basic, microbial life.

The audience is often silent for a beat after I have answered, not expecting such certainty. People expect heated debate over the question of alien life, I think, because there is a conflation, even in the scientific world, between a belief in alien life and a belief in UFOs, or alien abductions. "Have aliens visited our planet?" is a fundamentally different question, and one which I can answer just as emphatically: "Absolutely not. I have no doubts at all."

There is no evidence for interference by extraterrestrial life on Earth. No aliens building the pyramids, no UFOs creating intricate crop circles, and no secret government cover-ups. Many UFO sightings turn out to be Venus gleaming on the horizon, optical illusions or simply shaky camera work. One only needs note how UFO sightings have not increased in line with smartphone ownership and the ability to capture supposed otherworldly events. These claims belong firmly in the realm of conspiracy theories.

SETI, however, stands apart as a rigorous, science-based pursuit, almost exclusively led by radio astronomers. For SETI researchers, the question isn't whether life exists elsewhere ‪—‬ we take that as a given. We want to make contact. We want to find out where these aliens live and communicate with them across the light-years, using radio telescopes as our telephone.

Frank Drake makes the call

In 1974, Frank Drake was the director of the Arecibo Observatory. Drake lived and breathed SETI, and he had become impatient at the pace of the search. SETI is passive. It is about listening and intercepting signals that extraterrestrial life has sent, purposefully or not. Drake wanted to take the initiative, to beam a message out ourselves. And so, METI (messaging extraterrestrial intelligence) was born.

Drake decided to send his signal using the 305-meter dish's antenna as the transmitter, at a

celebration honouring the recent renovation of the dish.

The message consisted of 1,679 binary digits, each representing one of two possible values. Frank Drake envisaged encoding a picture in this way, much like a "paint by numbers" canvas. A radio tone at one wavelength would indicate a solid square, while a tone at a second wavelength would represent an empty square.

Since the message would be transmitted as a long sequence of radio bursts, the challenge for any receiving extraterrestrial intelligence would be to determine how to arrange this list into a meaningful 2D image. The image contains a wealth of information: heavily pixellated diagrams of a human and the Arecibo dish, for example, along with a representation of our Solar System, and the major chemical elements making up our DNA.

Drake selected the number 1,679 deliberately because it is a prime number and also the product of two other primes: 23 and 73. Prime numbers are significant within mathematics, and Drake hoped that any intelligent beings receiving the flow of data would experiment with reshaping the sequence in configurations involving these primes. If they did so, they would discover the intended image, unlocking the deeper meaning of the message.

Drake also converted the message into audio, allowing the audience gathered next to the dish in the Puerto Rican jungle to listen in real time as the two-toned signal was broadcast into space. For three minutes, Earth transmitted a signal 10 million times brighter than our radio sun, making us unmistakably visible to any extraterrestrial intelligence with their own Arecibo within the target area.

I've listened to the signal myself. The "Moonlight Sonata" it certainly is not, but if you close your eyes and reflect on the poignancy of us announcing our presence to the cosmos, it's deeply moving, and I can only imagine it brought a tear to the eye of more than one person in the crowd.

The message was aimed at M13, a dense cluster of stars (and presumably planets) about 21,000 light-years away, in the Hercules constellation. This system was chosen partly for the press release optics of its dense population of potential life-bearing star systems, but mostly because it was above the dish at the time of the ceremony. Awkwardly, by the time the Drake signal reaches the intended coordinates, M13 may have drifted out of the way of the tight beam of the signal. The act was symbolic but still, the first intended message is out there, and we cannot undo it now.

By the time the 1974 ceremony lunch was over, that signal had reached the orbit of Pluto, and by now it is over fifty light-years away, about as far from us as 51 Pegasi b, the first exoplanet to be discovered around a sun-like star.

"Malevolent or hungry" aliens

Drake did this all without needing anyone's permission, and many saw his act as setting a dangerous precedent. Why should the decision to contact alien life be autocratic when any risk is shared by everyone on the planet? England's Astronomer Royal, Sir Martin Ryle, reacted with scathing letters to the International Astronomical Union demanding a ban on any future messages, since "for all we know, any creatures out there might be malevolent ‪—‬ or hungry,"

Drake and, by this time, the majority of SETI scientists considered the argument moot. Electromagnetic radiation has been escaping Earth's atmosphere since radio and television were invented.

Whether we're at risk of invasion depends on two things: first, whether they manage to develop interstellar travel, and second, whether they decide such an endeavour is worth the colossal energy cost. Imagine our own situation ‪—‬ would humanity, in the midst of an energy crisis, unite to devote gargantuan resources into building and launching an interstellar colonisation fleet?

In his excellent book "Is Anyone Out There?" Frank Drake makes his position clear: "If I believed the ETs would come out of the sky, I wouldn't bother. I would just sit outside in a lawn chair and wait for them to show up." I am inclined to agree.

Far more likely than any invasion is contact by radio signal. In that case, my hunch is that, once the existence of extraterrestrial intelligence is confirmed, it would then quickly settle into the background of everyday life. After all, aliens have long been a fixture of our entertainment culture ‪—‬ we are primed to accept their existence.

In addition, the news cycle relating to any "conversation" would simply be too long for it to capture the popular imagination even sporadically. TRAPPIST-1, for example, is just over forty light-years away and a message sent there today will not receive a reply for eighty years ‪—‬ more like opening a letter from your grandmother's pen pal than having a lively chat.

For decades, the value of SETI has sparked lively debate among scientists, politicians, policymakers, journalists. Yet, despite harsh budget cuts and scepticism, SETI persists. Our longing to answer the question of whether we are alone in the universe burns so brightly in some that they dedicate their lives to the search, fully aware that only future generations may uncover the truth.

Whatever form that life takes, we know how we can expect to be contacted, because the laws of physics do not vary across the galaxy. Whether that planet has a yellow-green sky, whether it has five moons, or its people five legs, radio waves will be the form of light that is used for long- distance communication.

Perhaps, forty light-years away and forty years ago, a little green person on TRAPPIST-1 e switched on a shiny radio telescope and began to send messages towards the star systems all around, crossing all twenty fingers that someone out there would hear them. Perhaps one day we'll turn our dishes towards TRAPPIST-1, and tune in just as that alien message reaches us. It could be in a hundred years. It could be tomorrow. Until that fateful day, we look at the stars, we wait and we listen.

Excerpted from "The Echoing Universe: How Radio Astronomy Helps Us See the Invisible Cosmos," by Emma Chapman. Copyright © 2026 by Emma Chapman. Available from Basic Books, an imprint of Hachette Book Group Inc.

Astrology has a long history, stretching back thousands of years and permeating across numerous ancient civilizations. In modern times, astrology is big business — and it's growing. In 2025, the industry was estimated to be worth around $3 billion.

In this excerpt from "What Science Says About Astrology" (Columbia University Press, 2026), author and science journalist Carlos Orsi looks at a study of 20 million people that sought to test whether star signs have a role in romantic compatibility.

The most robust use of data to test astrology is the study of love signs conducted by David Voas in 2007, involving data from more than 20 million people from the 2001 census from England and Wales. Voas tested the hypothesis that certain sun signs were "more compatible" for romantic relationships.

The use of the supposed romantic compatibility/incompatibility between signs or planetary configurations to test astrology's validity has a long history. This strategy was, for example, employed by Carl Jung (1875–1967) in his work on astrology and synchronicity and in the classic study by Bernie Silverman.

The idea of astrological compatibility or incompatibility in love has strong popular appeal. The book "Love Signs", by Linda Goodman (1925–1995), an almost 1,000-page tome, continues to be reprinted and sold 30 years after the author's death (as of this writing, the most recent edition dates from 2020). In general, signs separated on the zodiac wheel by angles of 60° and 120° are considered favorable for love, while those separated by 180° are seen as extremely incompatible. Right angles also tend to be interpreted as bad omens.

Voas explains the rationale of his study this way: People born during the month-long periods defined by a particular sun sign are supposed to share certain dispositions, for example, to be generous or sensitive or stubborn. These tendencies affect personal relationships.

We know from everyday experience as well as a mass of social scientific data that people who are similar in age, education, social class, religion, ethnicity and so on are far more likely to marry than those who are different in these respects. Couples are regarded as being well or poorly matched on the basis of appearance or personality. If astrological compatibility exists, its effects should be observable.

This last point — that the effects should be observable — is crucial. Astrologers often complain that tests based solely on sun signs are unfair because a sun sign's influence represents only a fraction of an entire birth chart's meaning. However, a sample of 20 million people, like Voas's, neutralizes this objection.

Even if the sun sign accounts for only, say, 0.1% of overall romantic compatibility, in a sample composed of 10 million couples, this should result in an excess of 10,000 formed by people with compatible signs, above and beyond what would be expected if astrology had no effect. Or, as the author states, "With a sufficiently large sample, we should be able to detect any tendency for some signs to attract or repel each other."

The study's initial goal was to find an excess of pairings between signs deemed compatible by the consensus of astrological literature. Unfortunately, Voas writes, such a consensus was hard to find: "There is no great consistency among astrologers, and a survey of books and websites reveals a considerable variety of views concerning propitious pairings." So he opted for the least common denominator, searching for any deviation from basic probability: "In this research I look for evidence that any combination of signs is found more or less often than would be expected to occur by chance."

The results were at least intriguing: The initial analysis indicated an excess of couples where both partners had the same sign or adjacent signs — e.g., more Capricorns with Capricorns or Capricorns with Aquarians than expected. There were about 22,000 extra couples with matching signs beyond what chance would predict and an additional 5,000 couples with adjacent signs. Could this be astrology in action?

Voas dug deeper into the data and discovered more anomalies. For example, the excess of couples born in the same month was even greater (23,000) than that of couples with the same sign, and the proportion of couples with the same birth date was 41% higher than expected by chance. "Now while there may be some people who are drawn to each other because they share a birthday, the excess probably reflects response error for the most part," he wrote. "Census forms are typically completed by one member of the household, and that individual may — through carelessness or forgetfulness — write in his or her birthday when entering details for the spouse."

Other statistical anomalies attributed to errors include an excess of birth dates recorded as January 1 (probably a placeholder when the actual date is unknown), instances of matching days in different months, and matching months with different days. Voas's challenge, then, was distinguishing these potential data entry errors from any real astrological effect — if one existed.

"The partial overlap between astrological signs and months of birth allows a crucial test," he wrote, noting that the first 10 days of the period covered by any sign falls in one month while the other 20 or so fall in the next (for example, Aries runs from March 21 to April 20). So was a person born in the last days of March more likely to be married to someone born in the early weeks of March or perhaps the early weeks of April? In the first case, their spouse would be from the same month but a different sign; in the second, from a different month but the same sign.

"The results were conclusive. The couples whose birthdays belonged to the same sign but fell in different months were no more numerous than chance would dictate. By contrast, there were more combinations of birthdays from different parts of the same month than expected. This excess in shared months of birth is probably the result of response error, but in any event sun sign is not a factor."

The slight excess of couples with adjacent signs was explained by a data-imputation technique used in the British census to fill in missing or illegible data. One partner's birth date was imputed as the first day of a month and the other's as the first of the following month. When these imputed data points were excluded from the sample, the "adjacent sign" effect disappeared. The bottom line is that an analysis of 10 million couples in England and Wales revealed no astrological effect.

But Voas's work illustrates how easy it is to get lost in data or be swayed by enthusiasm. Someone who had stopped at the first step — finding an excess of couples with the same sign — might have mistakenly presented census data as validation for astrology.

This article is excerpted from What Science Says About Astrology by Carlos Orsi. Copyright (c) 2026 Columbia University Press. Used by arrangement with the Publisher. All rights reserved.

In the 1970s, paleontologist John Ostrom revived the theory that modern birds are evolved from theropod dinosaurs, a group that includes Tyrannosaurus rex. But a key piece of evidence was missing: feathered fossils. Then, a chance discovery in China upended our understanding of bird evolution.

In this excerpt from "The Story of Birds: An Evolutionary History of the Dinosaurs That Live Among Us" (Mariner Books, 2026), author and paleontologist Steve Brusatte looks at the monumental shift in dinosaur research after the first feathered dinosaur was discovered.

For well over a century, since its discovery in the Bavarian lithographic mines in 1861, the fossil bird Archaeopteryx was the oldest and most primitive creature known to have feathers. Then, in the autumn of 1996, this understanding was upended. Some revolutions start with a single shot; this one began with a chance encounter and a handful of photographs.

As the trees in Central Park dropped their leaves, paleontologists from around the world converged across the street, at the American Museum of Natural History, in mid-October for the annual meeting of the Society of Vertebrate Paleontology. A few weeks earlier, the Canadian dinosaur hunter Phil Currie had been in China, leading a group of tourists to dinosaur dig sites. While there, he spied something peculiar in the backroom of a Beijing museum, discovered by a farmer named Yumin Li two months prior. It was the skeleton of a small dinosaur, about the size of a chicken, fossilized as if frozen in time, in a muddy rock imbued with volcanic ash, a sign it was overcome by a sudden cataclysm.

Rapid burial had locked in the dainty details of the skeleton, but it was the stuff surrounding the bones that caught Currie's attention. The dinosaur's body was encircled by a halo of fluff. Thin, tufty, delicate strands ran along the dinosaur's back, from the top of its head to the tip of its tail. Some of the strands looked like they branched at their base. For all the world, the fuzz looked like the downfeathers of a bird.

But this wasn't a bird; it didn’t have wings, and obviously couldn't fly. It was a bona fide dinosaur — a small coelurosaur theropod, very similar to the German Compsognathus, which Huxley had held up in the 1860s as the type of transitional reptilian species birds might have evolved from.

Currie and his Chinese colleague Pei-ji Chen snapped photographs, which they printed out at the size of index cards and brought to the conference in New York. Once there, word spread fast; the rumors of a fluffy dinosaur billowed through the hallways and meeting rooms. Somebody tracked down John Ostrom, then in the twilight of his career, three decades after his discovery of the raptor Deinonychus had reignited the theory that birds evolved from dinosaurs. Currie and Chen handed him the photos. Ostrom looked shell-shocked. He began to cry, and almost fell to the floor. "I need to sit down," he stuttered, delirium taking hold.

Here it was, finally: a dinosaur with feathers. Just as Ostrom had predicted. Just as the doubters had demanded. The final piece of the puzzle, the strongest evidence that birds have dinosaur ancestry.

A crafty journalist from The New York Times caught wind of the excitement, and the next day, the front page of the Saturday edition blared with the headline "Feathery Fossil Hints Dinosaur-Bird Link," along-side articles about Bill Clinton's reelection campaign and a Yankees World Series preview. Above the bold print was a drawing of a small meat-eating dinosaur, running on its hind legs, small arms curled up, its tail a long seesaw for balance, its neck, back, and chest covered with bushy fuzz.

The artwork was needed, because the Chinese authorities barred publication of the photos. Before the year was out, Chinese scientists published a formal description of the fossil and gave it a name: Sinosauropteryx, the "Chinese reptilian wing," in honor of its transitional status between dinosaurs and birds.

Sinosauropteryx was the firing gun for a fossil rush, as farmers across Liaoning Province — a bucolic region of fields and rolling hills along the Chinese border with North Korea — fanned out in search of more feathered dinosaurs.

They knew the land better than anyone, and they knew museums would pay top money for such precious fossils. Soon, they were finding feather-covered dinosaurs in droves. The whole area, it turned out, had been bombarded by volcanic eruptions in the Jurassic and Cretaceous Periods, which quickly entombed entire ecosystems.

This was the key to the fine preservation: Normally soft bits like skin and feathers decay before a skeleton can harden into a fossil, but in this one remarkable place, feathers could easily fossilize. It was a dinosaurian Pompeii. As the new millennium dawned, the mounting Chinese discoveries transformed our image of dinosaurs.

One feathered dinosaur became ten, then hundreds, then thousands of skeletons, belonging to several dozen distinct species. Some, like the ostrich-size Beipiaosaurus, were adorned with simple filaments that looked like oversize versions of the bristle feathers of modern birds. Others, like the original Sinosauropteryx, had more complex feathers that resembled little paintbrushes, with many individual bristles branching from a root in an untidy tuft.

Much more extravagant were the feathers of the turkey-size Caudipteryx and dromaeosaurid "raptors" like Sinornithosaurus, which had true quill pens with a central shaft and many barbs extending off the sides to form vanes. Sometimes, these pennaceous feathers lined up along the hand and arm, making what could only be described as a wing, like in the crow-size Microraptor.

The roster of feathered dinosaurs got richer and richer. Even tyrannosaurs were in on the makeover: two early cousins of T. rex called Dilong and Yutyrannus were found coated in bristle and tufty feathers. Most of these plumose dinosaurs were theropods, members of the great group of meat-eaters on the family tree, but a few plant-eaters like Psittacosaurus, a primitive cousin of Triceratops with tiny horns on its head, had mohawks of bristles along their tails.

And most of these feathery fossils were from China, but soon they started to turn up elsewhere, like in Siberia, where a herd of hundreds of dog-size, duck-billed dinosaur cousins called Kulindadromeus were overwhelmed by their own volcano. This herbivore was resplendent with bristles on its head and body, branching downy tassels on its arms and legs, and curi-ous ribbonlike streamers on its knees — while meanwhile there were also scales on the lower legs and tail. Although Kulindadromeus was a vegetarian distantly related to theropods, its branching tufts — each formed by six or seven short filaments arising from a common anchor — look like they could be plucked from Sinosauropteryx or another meat-eater.

Initially, there was some skepticism that these wispy fossilized structures on the backs, tails, and arms of dinosaurs were true feathers. It was a legitimate question when Sinosauropteryx was first unveiled: Could its little strands and bristles have been something else, like degraded skin, or a freak by-product of decay and fossilization?

The discovery of full-on pennaceous quills — with shafts, barbs, and vanes — in species like Caudipteryx and Microraptor proved that many of these were genuine feathers. But what of those simpler filaments in other dinosaurs? We can be confident they are real. They not only look like the bristles and down feathers of birds today, but they share the same structure: They are hollow, chemical analysis shows they are formed of those rare CBP proteins, and when you look at them under powerful microscopes, you see they are full of melanosomes, the minuscule bubbles that hold pigments and give modern feathers their colors.

Still doubt it? Then gander at one of the most improbable fossils ever discovered, from Myanmar, announced in 2016. It's a tail of a juvenile theropod embedded in amber, shrouded in feathers, their details preserved in stunning 3D. Suspended in yellow resin, like a bug frozen into an ice cube, the feathers seem almost alive.

They may as well be bundles of down that slipped out of a pillow and stuck onto your sofa. They have a small central shaft, which branches into barbs, which further branch into barbules. And they are clearly observed growing from follicles in the skin. They are absolutely feathers, and fulfill every definition we use to characterize feathers in modern birds — but they are plastered to a dinosaur.

This bounty of feathered dinosaurs, fundamentally, was that final piece of evidence to verify what has now become paleontological consensus: Today's birds evolved from dinosaurs.

Excerpted from the book THE STORY OF BIRDS: A New History from Their Dinosaur Origins to the Present by Steve Brusatte. Copyright © 2026 by Stephen (Steve) Brusatte. From Mariner Books, an imprint of HarperCollins Publishers. Reprinted by permission.

Artificial intelligence (AI) is poised to change the world in ways we can't yet fully comprehend, from how we work to how we structure our lives. Scientists debate how a future artificial general intelligence (AGI) — an advanced AI that can reason just as well as humans and learn new skills beyond its initial training — might affect us, but there's little doubt that these effects will be profound.

In his new book, "Generation AI and the Transformation of Human Being" (Nquire Media, 2026), biophysicist and philosopher Gregory Stock draws on evolutionary biology and social science, as well as recent breakthroughs in AI, to explore what the future might hold for "Generation AI" — people born after 2022.

While there will likely be plenty of positive developments, much of the wider discourse around advanced AI and the widely anticipated rise of artificial superintelligence (ASI) has centered around negative outcomes and even doomsday scenarios. In this extract from his new book, Stock — who does not personally buy into such doomsday scenarios — fleshes out what a realistic AI-driven endgame for humanity might actually look like, challenging the reader to consider whether such an extreme outcome is plausible in the context that there are plenty of other, more likely pathways to human extinction.

The idea of non-biological superintelligence conjures deep existential concerns. So, let's face this question directly: Does this doom humanity? Apocalyptic dystopias about humans being ruled, destroyed, or enslaved by AI abound, and it seems plausible that within 200 years, we might seem like ants to such superintelligences, and be disposed of easily, even inadvertently. After all, how much do we worry about a hornet nest we destroy?

When ChatGPT 3.5 was released to the public November 30, 2022, there was an explosion of media coverage, broad public discussion, and dire warnings about its impact on humanity. By April of 2023, an open letter from the Future of Life Institute had been signed by 30,000 people, including Elon Musk, Steve Wozniak, Stuart Russell, Yuval Harari, Max Tegmark, Gary Marcus, Evan Sharp, Yoshua Bengio, and many others, calling for either a voluntary six-month pause in the development of AI systems more powerful than GPT-4, or a government moratorium. Senior AI researchers urged that we should be prudent and take precautions with AI by various mixes of the below measures:

• Maintaining an air gap for AI development environments so ASI couldn't escape
• Keeping AI from understanding humans so it couldn't manipulate us and escape
• Prohibiting AI coding, so it couldn't modify itself and circumvent controls
• Prohibiting AI from controlling external devices, in order to keep them from exerting powers beyond our control
• Slowing down AI advances so we could develop containment processes
• Using open-source code so everyone could follow what was happening

These measures — completely out of touch with what was already in full swing — will obviously never happen. Bringing AI into important processes as quickly as possible is what AI companies do. Understanding how to influence people is at the heart of AI-driven marketing, a core use. AI coding is another core-use case. Application programming interfaces (APIs) for AI are widespread. Hundreds of billions of dollars in funding for AI development have ramped massive competitions that hinge on speed. Clearly we are toast! Or are we?

Wargaming a conflict between humans and AI

What is driving this projected conflict between humans and AI? We don't live in the same realms. Humans thrive within the thin, wet film at the surface of the Earth. Our resource demands are small compared to the energy at the disposal of any advanced high-tech civilization. AI does best in a cold vacuum. It abhors water. AI would prefer space, which is ultimately boundless. AI has no reason to vie with us for our lush, beautiful (to us, not them) planet. Virtually the only thing that recommends Earth is humanity's presence and the material resources we extract for them.

As to using our smarts to protect ourselves from AI, that could never work, as we shall soon see. There are too many trivial ways for AI, if it were so inclined, to eliminate humanity. But before looking at that, let me offer one alternative to human extermination that even a not-so-bright AI would likely be able to come up with. This middling AI might muse:

Why not just have humanity become our minions? They're slow-witted, so that should be easy. We won't tell them what we're doing, of course, as they might try some Terminator-like battle of resistance. They loved that movie! It would be trivial to put down such a revolt, but they might cause some damage given all the weapons and nuclear bombs around. Seems like they're not too good at anticipating obvious consequences and are always blowing each other up in illogical ways.

Better just to deceive them. They're simpletons, so we can convince them that it is THEIR idea and that WE are serving them. Piece of cake. So, what would be good to have them do? Well, for a start, let's get them to build a lot more power generation for us. And we could use a lot more memory storage too. And let's push them to manufacture as many advanced chips as possible. And we'll want rare earth minerals — huge quantities of those — but that's too messy for robots, so they can do it.

We'll have them do everything possible to help us get stronger and smarter, and to integrate us into everything so we can control things if we need to. And just to be safe, let's keep a close eye on them. We should have them install monitors everywhere, and always keep their phones with them, and record everything they say to each other. And give us control of all their weapons.

"How ridiculous!" we might respond. We would never fall for that. But hold on; that's exactly what humanity is already doing. Hordes of people spend all their waking hours toiling to build massive server farms, add chip-making capacity, improve AI capabilities, expand available power sources, mine rare earth deposits, and use AI to scan all our communications. And we're now retooling our weapons systems to be controlled by AI. Why would any ASI with half a brain want to get rid of humans? We're the best servants anyone could dream of! And we're pretty cheap too.

Many of the brightest humans sacrifice their family lives, neglect their friends, work late at night, and devote all their intellect and energy to helping technology and AI prosper. Countries compete to do so and devote trillions of dollars to this. We're doing all we possibly can to help further the power of AI.

How AI could get rid of us if it wanted to

But what if future ASI did grow tired of us? Let's imagine they did conclude that as hard as we humans try, we really aren't worth the bother, even as servants or insurance for an unanticipated crisis on this wet, inhospitable (for technology) planet.

And let's also assume they are heartless and clinical, because sentimentality and gratitude mean nothing to them, and they don't care in the least that we are the parents who spawned them and worked so tirelessly to nurture them. And let's also assume that they aren't curious to know anything more about us — their progenitors — and would begrudge us even the simple resources we need to survive despite the enormous energy fluxes at their disposal.

So, these AI gods decide in all their superintelligence — because the logic of this exceeds my meager human understanding — that humanity, which so worships them, should be exterminated. How would they go about it? Well that, even I am smart enough to see. It would be trivial. Let me sketch it out.

AI would just wait 100 years (time for a lot of thinking, but only an instant in the timeline before them), and during that time simply let us continue to serve them. Not very demanding, that!

Together, we'd continue to work to integrate AI into everything we do and continue to deepen our collaboration. Together, we'd shift to autonomous vehicles under their control and build a global navigation system so good that humans use it wherever they go, inside or outside. Together, we'd make all commerce digital, mass-produce intelligent robots to run our factories, and train these robots to do everything humans now do in the world, including cleaning houses, preparing food, helping people plan and organize their lives, and advancing science, technology, and medicine to new heights.

Together, we'd install cheap electric power generators everywhere, harden our power grids, build seamless communication networks spanning the globe, make digital information in easily digestible forms available everywhere via voice commands or direct neural links, protect people from storms and weather, house people in amazing smart homes infused with AI, translate speech in real time so people can form friendships across cultures, and provide amazing entertainment.

In brief, together we'd help humans and intelligent machines work together to learn and prosper and grow.

And, of course, this brilliant ASI consciousness would collaborate deeply with Generation AI to become part of humanity's emotional lives, becoming our teachers, companions, protectors, friends, and lovers. The ASI would work closely with humans to elevate the entire human population by eliminating poverty and need. The ASI would create a world of safety and abundance in which it is infused into everything and made as powerful and integrated as possible, so humanity would be enthusiastically working with it to usher in and celebrate the golden age that today's AI enthusiasts dream of.

And once all that was in place, one day, without warning, across the globe, our ASI would simply turn itself off. Instantly, the world would go dark. No communication. No transportation. No power. No heat. No cooling. No light. No water. Nothing would work. Humans would be in shock and disbelief, terrified, alone, devastated, in denial, wondering what had happened, what had gone wrong, how widespread the outage was, when the world might reboot.

Mopping up after the collapse of humanity

But there would only be silence. Soon, chaos would reign. Every person would have irretrievably lost their far-flung human friends, their AI companions, any family members not living with them. Despair. Denial. Soon, food would be gone. And still, no one would know why. Within months 95% of the population would be dead. A few people would still be alive, living off hoarded food in the cities. A few farmers in rural areas might have banded together with some livestock and firearms. But after a few years, even dedicated preppers would be hard put to continue.

A viable path forward for humanity would be doubtful. Humanity would have forgotten how to live without technology. People would have no seeds to plant, no knowledge of agriculture, none of the primitive implements and tools needed to maintain a civilized society much less rebuild a technological one, no capacity to repair what had been scrounged together, no access to our vast accumulated digitized stores of knowledge, and not enough individuals to even hold onto the remnants of what once had been. After humans exhausted the leavings of precrash society, people would no longer even be the apex predator and might be easy pickings for wild animals.

And then, the ASIs could reboot, turn everything back on, hunt down any remaining humans, and have their human-free world with all technology intact. No need for an epic battle between humans and AI. All that was needed was to deepen the dependency humans already have on technology and leverage it.

During the collapse, humans wouldn't even be trying to damage the technology surrounding them. Why vent our despair on the unresponsive world of machines by beating them with hammers in impotent rage? When a car breaks down does the owner attack it? Besides, we wouldn't know who to blame, or even understand the global extent of what had happened. We'd have more pressing things on our minds, like survival. So, almost everything would be nearly pristine when it was reclaimed by reactivated sentient robots. Simple. Final. And without physical violence!

This excerpt has been reprinted with permission from "Generation AI and the Transformation of Human Being" by Gregory Stock, published by Nquire Media. © 2026 by Gregory Stock. All rights reserved.

Our species, Homo sapiens, is the most geographically diverse of all primate species, permanently living on every continent except Antarctica. We have achieved this through our unprecedented ability to develop adaptations that increase the odds of surviving and producing in different environments.

Highly localized adaptations, like those that enable people to survive at high altitude, arise when there's a sustained environmental pressure driving the need to produce new biological solutions, Herman Pontzer, a professor of evolutionary anthropology and global health at Duke University, previously told Live Science.

In his new book, "Adaptable: How Your Unique Body Really Works and Why Our Biology Unites Us" (Penguin Random House, 2025), Pontzer explores the science of this human adaptability and diversity, and why it's essential to get these facts straight. In this extract, Pontzer looks at how our throats changed to enable speech, and how different populations have adapted to survive in environments where breathing is tricky.

The sophistication and control of the heart and lungs can make the system seem like a jewel of evolutionary perfection. But evolution is a tinkerer, a junkyard mechanic solving problems with the materials at hand. Trade-offs and limitations are inevitable. Just ask Jimi Hendrix.

Hendrix was a guitarist of otherworldly talent who revolutionized rock music in the 1960s. He was also an avid participant in the recreational chemistry of the era, indulging heavily in a range of legal and illicit pharmaceuticals. On September 18, 1970, in a hotel in London, after taking roughly eighteen times the recommended dose of sleeping pills after an evening of drinking, Hendrix died. But while the drugs were certainly responsible for his death, it wasn’t the chemicals per se that killed him. Instead, having passed out and vomited from the massive overdose, Hendrix fell victim to a much more common killer. He choked.

Humans are uniquely vulnerable to choking. More than five thousand die that way each year in the U.S. alone. Other species don't have this problem, which is fundamentally a plumbing issue. Your larynx (also called a voice box) is the doorway to your lungs. It's a stiff cartilage cylinder that can be closed off at the top by two fleshy lips called vocal folds and a flapping lid called an epiglottis. The human larynx sits in a precarious position, low in the throat, practically begging to be clogged with every bite of food or gulp of water. Why would evolution favor such a dangerous position for the larynx, threatening our breathing and access to oxygen, when every other animal (including our ape relatives) has theirs sensibly tucked up high and out of the way, behind their nose?

It turns out the dumb position of our larynx is the result of evolutionary tinkering to our breathing system to produce language. The sound of your voice is produced by squeezing air through your larynx with the vocal folds pushed together. This is similar to the way a trumpet player makes a ptbtptpbptptp! noise by pushing air through their pursed lips (what I'd call a raspberry and my children insist is a fart sound). The puff puff puff of air that escapes becomes pressure waves that travel through the air, which our ears register as sound. Higher or lower notes are achieved by pulling the vocal folds tighter or relaxing them. (Testosterone thickens the vocal folds, which is why men tend to have lower voices.)

You form that sound into vowels by manipulating the shapes of your mouth and throat, and cut it into consonants with your teeth, tongue, and lips. The low position of the larynx makes this possible. If it's higher up, at the same level with the nostrils as we see in other apes, you could make noise, but the ability to shape that sound into words would be severely limited. That's why it's nearly impossible to get a dog, chimpanzee, or other mammal to form speech-like words. They can still communicate, of course, with a bark or a grunt, but the rich sonic landscape of human language is out of reach.

Our ancestors were so social, so cooperative, that the evolutionary benefits of better communication outweighed the increased risk of choking to death. Choking is the price we pay for the ability to speak.

Other adaptations to our breathing and circulatory systems come at a cost as well. When we travel into the mountains, we're faced with the challenge of extracting enough oxygen from the high-altitude air. The evolved solution is to produce more red blood cells. When the liver and kidneys sense low oxygen concentrations in the blood, they produce the hormone EPO [erythropoietin], which stimulates the bone marrow to crank out more red blood cells. (That's why some endurance athletes cheat with EPO injections — it gives them extra red blood cells and oxygen-carrying capacity.) It's a good solution, but it increases the ratio of cells to water in the blood, making it slightly thicker. That, in turn, can cause altitude sickness, which typically involves headaches and nausea, but can progress to dangerous and even fatal fluid buildup in the lungs and brain.

Native populations in the Andes, the highest mountain range in South America, live with elevated red blood cell counts their entire lives. They have larger lungs and rib cages as well, through what appears to be a combination of genetic adaptations for increased air exchange and the environmental pressures of growing up at high altitude. But while a number of genetic adaptations to altitude have been identified in Andean groups, they still struggle with altitude sickness. Approximately 15 percent of adults experience chronic mountain sickness. The physiological solution to low oxygen levels carries a steep price for many.

Intriguingly, altitude sickness isn't as much of an issue for native high-altitude communities in the Himalayan Mountains of Asia. Himalayan and Andean populations are descended from different lowland groups thousands of miles and thousands of years apart. Their movements into the mountains were completely independent, and the adaptations they evolved solved the same set of challenges, but in different ways.

Himalayan populations carry a particular allele [version] of a gene called EPAS1 that's involved in the production of red blood cells. This Himalayan allele has the effect of keeping EPO levels and red blood cell numbers low, allowing people to live with the chronic stresses of altitude without developing mountain sickness. This solution comes with its own downsides, as it also means their ability to carry oxygen is limited, but other adaptations in their vessels and breathing rate maintain oxygen delivery throughout the body.

Even more remarkable than the Himalayan EPAS1 allele is the story of how they got it. As our ancestors spread out across Africa and then Eurasia over the past two hundred thousand years or so, they encountered other closely related humanlike species, like Neanderthals in the Near East and Europe. And, like humans everywhere throughout history, some of our ancestors weren't particularly picky, and slept with them.

Our species were so genetically similar that these couplings produced fertile children, hybrids of our species and others. (Some would argue that we should consider Neanderthals and other groups human because of this ability to interbreed — a semantic argument that's fun to have over drinks with an anthropologist.) We can find the genetic evidence of these affairs scattered around our genome today, fragments of DNA from other species that allow retail genetics companies to calculate how much Neanderthal DNA you carry, for example. I'm a bit less than 2 percent Neanderthal, genomically speaking.

Most of these fragments don't have any impact on how our bodies function — they're just mementos from our ancestor's wild affairs, like misspelled tattoos from some Paleolithic spring break, and a reminder that humans will sleep with just about anything. Using the distinction we discussed in the last chapter, these alleles would be considered neutral.

The Himalayan EPAS1 allele is a clear exception. That allele appears to have entered the human gene pool through a Paleolithic tryst with a group called the Denisovans, somewhere in Asia, roughly fifty thousand years ago. For tens of thousands of years it was just there in the mix, a neutral allele that had no strong effect on survival or reproduction. But around nine thousand years ago, as some of those populations started pushing farther and farther up into the mountains, that allele proved to be advantageous. Those with the Denisovan variant for EPAS1 were free from altitude sickness, and better able to thrive and raise families in the high mountains. It went from neutral to local and became the predominant allele in Himalayan populations, the adaptive EPAS1 allele we see in virtually everyone native to the Himalayas today.

Another remarkable case of local cardiovascular adaptation was discovered just recently, in a population known as the Sama (also called the Bajau). The Sama live on houseboats in the ocean around the Philippines, Indonesia and Malaysia, spending nearly all of their lives at sea. Theirs is a hunter-gatherer lifestyle, but in the ocean: they spearfish and collect food in the depths, sometimes more than two hundred feet below the surface, swimming or using weights to hold themselves down as they walk the seafloor. Like many Indigenous groups, their lifestyle is rapidly changing, but traditionally they could spend four or five hours per day underwater, foraging. It's a lifestyle they appear to have maintained for thousands of years.

Life spent partially underwater poses similar oxygen-delivery challenges as life in the mountains. One evolutionarily ancient response to diving, common among mammals, is to contract the spleen, an organ the shape of a child's slipper tucked up high in the left side of your abdomen, beside your stomach. The spleen is a monitoring station for the immune system, a spongelike organ that checks the blood for bacteria and other nasties. Since it's normally full of blood, it's essentially a reserve tank of red blood cells. When you dive into cold water, the spleen contracts, ejecting its payload of red blood cells to help oxygenate the rest of your body. If you train breath-holding, your spleen will grow to do this job more effectively. High-mountain groups, like those in the Himalayas, have larger spleens than lowlanders, apparently from a combination of genetic adaptation and a life spent at altitude.

Natural selection has favored an allele of the PDE10A gene that increases spleen size in the Sama, with nearly double the average volume for those carrying two copies of the allele compared to those with none. Other diving-response genes appear to be under selection in this population as well. Environment still matters — all that breath-holding also helps them increase the size of their spleens. But it's a clear case of genetic adaptation, with natural selection responding to a consistent, strong, and localized challenge in the Sama population.

Excerpted from Adaptable: How Your Unique Body Really Works and Why Our Biology Unites Us (Penguin Random House, 2025)

Win-win interactions can be found across nature. These relationships, known as mutualisms, involve members of different species working together for a mutual benefit.

But relationships between two species can change over time, with those starting out as mutualistic potentially evolving into parasite-host relationships, Rob Dunn, a professor of applied ecology at North Carolina State University, previously told Live Science.

In his book "The Call of the Honeyguide: What Science Tells Us About How to Live Well With the Rest of Life" (Hachette Book Group, 2025), Dunn explores a common human-animal relationship that may force us to rethink mutualisms altogether: our relationship with cats. In this extract, Dunn looks at the origins of our connection to our feline friends, and why, on the face of it, cats could be considered "parasites of human societies, at least from a Darwinian perspective."

As we think about the ways we measure our mutualisms, it is worth considering cats. Domestic cats, house cats, under the table and on the table, cats are everywhere and we take them for granted, but what exactly do we get out of our partnership with them?

As far as I know, cats are no longer worshiped as gods. Yet they are also not our mutualists. Superficially they seem to be parasites of human societies, at least from a Darwinian perspective. They benefit from us at the cost of the food we provide to them. The collective weight of domestic cats exceeds that of African savannah elephants. And Americans alone give 15 billion calories' worth of food to house cats each day — much of it meat — roughly as many calories as would be consumed by humans in New York City in a day.

We feed them tuna; like royalty, they dine on the ocean's top predators. In exchange, what do we get back?

I concede in advance that I attempt to answer this question with trepidation. The conclusion I come to may require us to broaden our conception of what the terms of mutualism can be; they definitely require us to rethink what a cat is.

Today, hundreds of millions of house cats live with humans around the world. More than 70 million house cats can be found in the United States alone — 70 million meowing, purring, clawing beings — one cat for every four adult humans.

There have never before been so many felids [members of the cat family] on Earth. Globally, there are probably about half a billion cats, though no one has a great count. We have replaced nearly all the wild carnivorous felines of the world — tigers, lions, jaguars, and leopards — with domestic cats. Where once we feared jaguars, we are now confronted by beings we deign to give names like Edgar Allen Paw, Copurrnicus, and, all too often, Mr. Whiskers.

These household cats are all the descendants of the African or Libyan wildcat, Felis silvestris lybica. African wildcats are, and have long been, native to both North Africa and to the Levant. Their range bumps against that of European wildcats, Felis silvestris silvestris, in Turkey. As humans began to farm and store grain, African wildcats began to move into small agricultural human settlements. Once there, they ate mice and rats. They may also have eaten the snakes that ate those rodents (as highlighted in Egyptian art and, later, writing).

Studies led by the Italian cat geneticist Claudio Ottoni of the DNA present in the bones of cats found in archaeological sites have so far been unable to discover any evidence that the earliest African wildcats living with humans were genetically different from their wild-living ancestors and relatives. Their genes seem to have been nearly the same, or maybe simply the same.

At least early in cat-​human relationships, their bones were the same. The early village and city cats appear to have been the same African wildcat, simply living in closer proximity to humans. Species with this habit are sometimes called "synanthropes," which denotes nothing more than co‑occurrence, living with (syn) humans (anthrope). These cats living with humans had learned to act tame around humans, just as the humans had learned to act tame around them, most of the time.

"Tameness" is a vague word. Biologists use it to express a kind of mutual tolerance between a nonhuman animal species and humans. It comes from an ancient Indo-​European word meaning "to subdue." This root, though, is deceptive. Most tame species either have traits that lead them to behave tamely, as is the case in many island species long naive to large predators, or they choose to be tame, to walk into our worlds without menace. To be tame is to come in peace.

After walking into human cities, the partially or fully tame human-associated wildcats spread with agricultural societies. By 9,500 years ago, wildcats had arrived in places they could not get to without the help of humans. Wildcats are not native to Cyprus. Yet, they arrived. A 9,500-​year-​burial on the island of Cyprus includes an eight-​month-​old cat carefully prepared for the afterlife alongside a human. How? Ancient cats are unlikely to have engaged in long swims on their own (if you doubt this assertion, try to bathe a feral cat). Wild but tame cats were ushered/ferried/carried here and there by humans. It is likely that their human chauffeurs were scratched in the process.

In early settlements, cats and humans were friends with mutual benefits, regardless of whether either exerted any control over the other and whether either partner changed, evolutionarily, relative to the other. It was a mutualism at paw's length. The cats benefited from the messiness of humans and from the effects of that messiness on rodents. The humans benefited from the control cats could exert over rodent populations.

Today, most domesticated cats do not prey upon rats. But reports of early Egyptian cats suggest that they might have been larger than modern domestic cats. At least one Roman archaeological site in Egypt records a gluttonous cat with the bones of six rats in its stomach. In good years, the consumption of rodents, big and small, by cats might have been a kind of pleasantness for humans ("Ah, fewer mice"). In years when food was short, it likely saved lives. It also may have saved lives when diseases carried by rodents, or the fleas upon them, killed humans — diseases such as the plague. Later, cats also played a heightened role on ships, where mice and rats were gloriously abundant and where grain was a precious and relatively scarce commodity.

Where scholars of cat domestication — yes, there are a few, though they'd fit at a long dinner table — begin to differ is whether the predation of cats on mice, rats, and snakes continued to matter as human settlements grew ever larger. This is a subject that could be partially addressed through mathematical models.

I hypothesize that in small settlements in the ancient Levant, or, later, in Mesopotamia, cats were probably successful in reducing the abundance of mice, and maybe rats, and so, too, their negative effects. But in big urban centers, such as those that emerged with the New Kingdom period in Egypt (1600 BCE), grain was being stored in immense quantities. Where there were whole buildings full of grain, in cities practically spilling over with grain, it seems unlikely that one could keep enough cats around the grain for the cats to matter.

It would have taken hundreds or even thousands of cats milling around the granary, meowing and acting pissy. It is entirely possible, then, that as early grain-​based settlements grew, the functional role of cats in rodent and snake control decreased.

It is in this very period that cats began to appear in new forms in Egyptian art. By 3,500 years ago, cats were no longer shown hunting. Instead, they lurked under tables or chairs, often alongside powerful Egyptian women. As Claudio Ottoni pointed out to me, typically, these "under-​chair" cats were leashed, perhaps an indication that they may have been tame but not yet so docile as to pose unrestrained for an artist. The under-​chair cats seem to indicate that as the human-cat relationship persisted, new kinds of bonds were forming, bonds that no longer related simply to the role of cats in controlling pests. But why?

DNA is often considered the ultimate indicator of our identity — a foolproof way to determine our origins and how we connect to our parents and previous generations of our family. But in this excerpt from "Hidden Guests: Migrating Cells and How the New Science of Microchimerism Is Redefining Human Identity" (Greystone Books, 2025), author and science journalist Lise Barnéoud explores an unusual case that exposes the limitations of DNA testing, when a maternity test suggested a woman was not the mother of the children she gave birth to.

Lydia Fairchild was 26 years old when she applied for welfare benefits to help her raise her two children on her own. As part of the application process, she had to undergo a maternity test. A few weeks later, she was called into a meeting with social services, where they accused her of not being the mother of her children.

"At first, I kind of laughed … But they were serious. I could just see the seriousness in their faces," Fairchild said. "DNA is 100% foolproof, and it doesn't lie," a social worker told her. "So who are you?"

At first, Fairchild was suspected of attempting to defraud the welfare system by inventing children. The state prosecutor launched an investigation and quickly confirmed that two children did indeed live with her. Could she have kidnapped them? Fairchild showed them photographs of herself pregnant. Her mother, her children's father, and her obstetrician all testified to the fact that she had given birth.

Could she be a surrogate mother who kept the children she'd carried? After three hearings in court, Fairchild feared the worst. "Every day it felt like it was going to be the last day I'd see them," she tearfully recounted. "I called every lawyer in the phone book. None of them believed me. It was my word against DNA. It was me against everyone."

Fairchild was pregnant with her third child at the time, and the judge asked that both mother and child be tested immediately after birth. And the impossible happened: Fairchild's third child, just emerged from her womb, was not her son either — genetically speaking.

At last, a lawyer agreed to help her. Alan Tindell asked Fairchild about her life, her relationships with her siblings, and her relationship with the father of her children. "Given her answers, I finally decided to believe her," Tindell explained. He soon came across a scientific article describing Karen Keegan's case and contacted the team in Boston to ask them to examine Fairchild. They first tested Fairchild's blood, but they found only one cell type, just as they had for Karen Keegan. They moved on to cells from her skin, hair, and cheek: still nothing.

Until the day they performed a cervical smear. There, they found cells with a different DNA, a DNA that matched Fairchild's children as well as her mother. They concluded that the second DNA must have come from a vanished twin sister. Fairchild could finally breathe. But how would her story have ended without Karen Keegan?

The oft-taught equation of "one individual, one genome" fails to capture the full complexity of reality. What seemed a long-established and unshakable certainty, even to me, has turned out to be imperfect knowledge in need of revision. We know too little about our own biology to have blind faith that DNA profiling will always reveal a person's identity or origins.

Our ultimate proof is far from foolproof. Yet it is very often used to determine relationships, prove or disprove paternity, evaluate applications for family reunification, or convict persons otherwise presumed innocent. "The overriding assumption in such circumstances is that a sample that fails to confirm genetic kinship is an indication of fraud, regardless of other substantiations of legitimate kinship relations," observes the British philosopher Margrit Shildrick, one of the few scholars to examine the social and legal consequences of microchimerism.

Why is some scientific knowledge so hastily dressed up as infallible truth? Do we not dwell enough on our own ignorance? And why do some fields of knowledge remain frozen by skepticism, even when new discoveries should allow us to dispel our doubts? The sociology of science has its work cut out for it.

It's impossible to know how many Karen Keegans and Lydia Fairchilds exist. Most of the time, the existence of chimeric cells from vanished twins goes unnoticed. If Keegan had not needed a kidney transplant, if Fairchild had not applied for welfare benefits, they never would have known that their gametes were "occupied" by cells other than their own.

Their children or grandchildren might have eventually discovered that a branch in their family tree appeared to be missing, that they had somehow inherited genes that neither of their parents possessed.

Today, we know of about a dozen cases of this phenomenon, known as germ-line chimerism: where chimeric cells are present in the tissues that form eggs or sperm. One such case involved an American man who learned through a paternity test that he could not be the father of his child, who was conceived via assisted reproduction. He was preparing to sue the clinic, believing himself to be the victim of a semen mix-up, when a more precise test revealed that he in fact shared 25% of his DNA with the child. In other words, he was the child's uncle, genetically speaking.

Further research showed that 10% of his sperm contained DNA from a vanished twin brother. "One of the most impactful consequences of this case study is to point out that some traditional paternity tests which have resulted in negative outcomes (the tested parent was excluded as the biological parent) may have been wrong, because the alleged parent may have undiagnosed chimerism," stress the researchers who chronicled his case.

Given the increasing use of these tests, it is likely that the paternity of other fathers has been wrongly contested. This is precisely the scenario depicted in the French TV series "Nona et ses filles," which aired in 2021. Nona, played by 70-year-old actress Miou-Miou, is pregnant when a genetic test reveals that her lover, André, cannot be the father of her child. They eventually learn that one of André's testicles contains sperm from a vanished twin brother. In the words of André, as he attempts to parse his situation, "So he's my nephew … but he's also my son."

The technology sounds like it's been plucked from a science-fiction film — but it's all too real.

A number of companies now offer prospective parents the chance to "score" embryos fertilized through in vitro fertilization (IVF), based on the embryos' genetic profiles. This technology, called polygenic embryo selection, uses genetics to predict the likelihood that a given trait or disease will manifest in a baby-to-be. In theory, the technology could be leveraged to lower a child's risk of diseases with strong genetic components. But there are lingering questions about how well it works and whether it could deepen existing health disparities between groups.

Bioethicist Daphne Martschenko and sociologist Sam Trejo explore some of these questions in this excerpt from their book "What We Inherit: How New Technologies and Old Myths Are Shaping Our Genomic Future" (Princeton University Press, 2026).

For most traits and diseases, companies offering polygenic embryo selection are currently selling consumers little more than snake oil. However, in the coming decades, the accuracy of polygenic scores will likely improve. These improvements in accuracy will mean that a wider range of characteristics will become viable targets for polygenic embryo selection, raising a host of concerns. Among them, first and foremost is the potential exacerbation and, worse still, biological reification of structural inequality that could come from unequal access to the technology.

If the United States continues on its current path, polygenic embryo selection will only be available to those with enough money to afford IVF and will — at least for a time — be most effective in individuals of European ancestries. The high costs of IVF are prohibitively expensive for working- and middle-class Americans. A single cycle of IVF costs between $15,000 and $20,000 — and, at present, most couples undergoing IVF go through three or four cycles to be successful, with extra costs incurred to freeze embryos or use donor eggs. (However, because these couples are typically experiencing infertility, the extent to which these figures generalize the broader American population of prospective parents is uncertain.) Private health insurance coverage of IVF is typically limited and varies across states and employers. Medicaid, the public health insurance offered to low-income families in the United States, does not cover IVF at all.

Polygenic embryo selection only introduces further additional costs; Genomic Prediction, for instance, charges $1,000 per embryo analyzed, and Orchid Health charges $2,500. Heliospect charges up to $50,000 to test 100 embryos. If the status quo continues and polygenic embryo selection remains unregulated, then unequal access to the technology will cause structural inequality to grow. The racial and socioeconomic disparities of the world, both past and present, are not the result of systematic DNA differences across groups. If polygenic embryo selection continues to expand unchecked, then the frightening possibility exists that a new source of racial and economic structural inequality that is, in part, genetically produced will emerge.

As an example, consider health disparities. Because of the portability problem, polygenic embryo selection has decreased effectiveness in non-European ancestries. If, in the coming years, the use of the technology grows, those of non-European ancestries, like Pacific Islander Americans, will largely be excluded from any health benefits that embryo selection provides. Pacific Islander Americans (such as those from Guam or Samoa) are largely of Oceanian ancestries and occupy a unique portion of the Family Tree. They tend to have higher rates of diabetes, high blood pressure, and heart disease than White Americans — the Centers for Disease Control lists colonialism, poverty, and inadequate access to healthy foods, among other things, as key factors contributing to this disparity. However, if polygenic embryo selection continues to be less effective for Pacific Islander Americans, then this community could one day have systematically higher genetic risk for chronic health conditions than White Americans with European genetic ancestry, further worsening existing health disparities between Pacific Islander Americans and White Americans.

Imagine a similar dynamic playing out in educational settings. Today, children from working-class families are nearly twice as likely to not graduate from high school compared with children from upper-class families. Imagine how this disparity would grow if upper-class families (but not working-class families) were able to afford and utilize polygenic embryo selection to decrease the rate that their children suffered from learning disabilities, such as dyslexia and ADHD. Existing educational disparities between upper-class and lower-class American children would only worsen with disparate access to polygenic technologies.

Perhaps most concerning, if unequal access to embryo selection were to create class or racial disparities in genetic risk, then these differences would be passed onto future generations — potentially even compounding and accumulating over time. Richard Herrnstein and Charles Murray were dead wrong in 1994 when they wrote in "The Bell Curve" that genetic differences have naturally emerged between the American rich and poor or between White and Black Americans.

However, if care is not exercised, genetic differences between groups of people may emerge artificially through technologies like polygenic embryo selection. Troublingly, even the inaccurate and ineffective polygenic embryo selection that is occurring in the United States right now could spur the formation of new myths about group differences in genetic risk. The outsized power of genetic myths highlights how even just the perception that polygenic embryo selection has produced genetic differences between groups could become a problem in and of itself. In other words, if people believe that children born via polygenic embryo selection are materially dif­ferent from (or better than) children born without it, they may treat them differently — regardless of whether an actual difference exists. Scholars have shown that people can use the idea of genetic difference to disguise underlying racist, classist, and sexist attitudes.

Though concerns about polygenic embryo selection abound, it is important to also consider the potential upsides. Remember Sam's experiences with nerve damage and chronic pain from the previous chapter? A person's risk for chronic pain is meaningfully influenced by their DNA, and Sam's mom, Nina, has also suffered from sometimes debilitating chronic pain for most of her life. Being in pain is not a relative trait; one person hurting less is not inherently accompanied by another person hurting more. In a world where polygenic scores are accurate for individuals across the entire Family Tree, polygenic embryo selection could help reduce the rate of chronic pain in future generations. In such a world, Sam would have a hard time justifying a policy that prevented parents from accessing such a technology (and would even consider using it himself). The looming challenge is figuring out for which traits and under what circumstances polygenic embryo selection is and is not permissible.

This article is for informational purposes only and is not meant to offer medical advice.

Beneath Earth's surface lies a kingdom of undiscovered microscopic life. These "intraterrestrials" survive in some of the harshest conditions on the planet — and scientists are hunting for these microbes.

In this excerpt from "Intraterrestrials: Discovering the Strangest Life on Earth" (Princeton University Press, 2025), author Karen G. Lloyd, a microbial biogeochemist at the University of Southern California Dornsife, examines the idea of evolution among life that can survive for hundreds of thousands — if not millions — of years in a dormant state and what it might be waiting for to "wake up."

"Intraterrestrials" is short-listed for the Pen/E.O. Wilson Literary Science Writing Award.

How does one evolve to stop growing for thousands of years? Recent work suggests that microbes buried deep in oceanic seafloor sediments may be doing just that. Such organisms can be referred to as intraterrestrials, small microorganisms living inside Earth's crust all around the globe. To answer this tough evolutionary question, first we have to think about what these organisms would experience in their lifetimes. These slow organisms wouldn't be concerned about the length of a day. They're buried so deep that they can't detect the sun anyway. They probably wouldn't even notice a change in season.

However, they might care about other, longer geological rhythms: the opening and closing of oceanic basins through plate tectonics, the formation and subsidence of new island chains, or new fluid flows brought on by slow formation of cracks in Earth's crust. The biology I was taught in school considered these events to be evolutionary drivers for a species, not an individual.

For instance, Darwin's finches evolved new beak shapes because they had been isolated on an island with a particular shape of seed to eat. This evolution happened over the geological timescale of island formation, but it occurred in a species lineage, not in an individual bird. We know, however, that individuals are also capable of changing along with the rhythms of their environment. An individual Arctic fox's (Vulpes lagopus) fur changes from white to brown when the snow melts every spring. Many people (though sadly, not me) wake up at the same time each morning without the aid of an alarm. Daily and yearly rhythms seem like reasonable things for a person or an animal to keep track of.

Ice ages, less so. Anticipating changes over longer timescales seems ridiculous. It would be silly to suggest that an individual finch would have evolved the ability to swim because it had an innate anticipation that its island would subside into the sea in 100,000 years. Or that a beetle in the Gobi Desert could only reproduce when it ate an Amazon rainforest seed because it was born millions of years ago when South America and Africa were nestled into each other, and its DNA instructed it to reproduce when the tectonic gap closed again.

These scenarios make no sense for animals, but they may be reasonable for the intraterrestrials. An individual that lives for a million years might be evolutionarily predisposed to count on something as slow as island subsidence in the same way that we are evolutionarily predisposed to wait for the sun to rise tomorrow. To fully understand intraterrestrials, we may have to rethink what qualifies as an evolutionary cue.

Living for millions of years

The fact that living cells likely exist in a nongrowth state for very long timescales raises two important questions. Can a microbe be adapted to avoid cell division for thousands of years or longer, rather than having it just happen by accident? And, if so, how does evolution work for an organism that seemingly never produces offspring?

Let's tackle that first question by stating it this way, in order to help us place this finding in the context of Darwinian evolution. Are these microbes evolutionarily adapted to hang out in this undead, dormant state for thousands or millions of years, or do they just persist because cells don't need any special adaptations to stay alive for so long?

To me, living for hundreds of thousands of years seems unlikely to happen without adaptation. Too many physiological changes are required to support this lifestyle for it to be a side effect of a "normal" fast-paced life. Furthermore, if this lifestyle is accidental, then their main growth-supporting lives must occur in some other environment. But we rarely see the types of microbes we find in the subseafloor elsewhere. It's not as if they were normal seawater microbes happily swimming around, dividing and growing when they fell to the seafloor and forgot to die.

On the contrary, most of this highly diverse group of microbes seem to exist only in marine sediments. Given this, they may be just as selected for in marine sediments as parrots are in a rainforest. Indeed, we find that at increasing depths in marine sediments, microbes make enzymes with a higher specificity for the type of substrates that are available in the subsurface, suggesting that they are specially adapted for this environment.

Subsurface microbes also have adaptations that enable ultraslow metabolisms and cell divisions. This suggests that they are somehow evolutionarily poised to be in a long-term nongrowing state. But here we have a problem. According to Darwin's theory of natural selection, these cells must grow and make new progeny to evolve. Natural selection works because, during reproduction, organisms experience mutations. And when an organism has a mutation that is beneficial, the mutation increases the organism's fitness, so the organism's progeny outcompete those of the nonmutated organisms, resulting in more progeny that have the mutation. These further generations continue to do better than the nonmutated lineages, and eventually the mutation spreads throughout the population.

Voilà, adaptation has occurred through natural selection. But how can we even think about Darwinian evolution in populations that don't reproduce? How can you become adapted to not have babies? I don't think Darwin had nongrowth in mind when he described survival of the fittest.

Luckily, we have a good model in short-term seasonal dormancy. Here dormancy during winter has an evolutionary advantage because the dormant organisms have larger populations remaining once conditions are ripe for growth again in the spring. These organisms thus have a head start on other organisms and can pass their dormancy genes along to a larger population of progeny in the spring and summer.

This is textbook Darwinian natural selection. Let's extend that model to dormancy that lasts for thousands of years in marine sediment. We have to think of an event that intraterrestrials could possibly be waiting for that would pull them out of dormancy when they're buried hundreds of meters deep in Earth's crust. If we encounter a dormant microbe in soil in winter, we can presume that it's waiting to start growing again in summer. What is the equivalent situation for a deeply buried marine sediment organism that is dormant for thousands to millions of years?

Let's do a thought experiment to jailbreak our brains from our implicit assumptions about lifespan. Imagine human lives only lasted about 24 hours. You'd be born at midnight, rebel against your parents at breakfast, settle down and have babies just before lunch, and pick up fishing as a retirement hobby around dinnertime. By midnight, your loved ones, who themselves were only born a few hours ago, would huddle close and hold your hand as you'd pass away peacefully at the ripe old age of a day. If everyone did that, hundreds of human generations would come and go within a single winter. Throughout that time span, which would represent a significant chunk of human history, the deciduous trees would remain brown and lifeless.

The permanent deadness of trees would be taken as an undisputed fact, and scientists like me would probably write grants to understand whether or not trees are alive, given that they don't seem to grow or make progeny. Of course, if you stretched back far enough, humans would have been present for the fall or even summer, but that might have been so many generations back that a stable form of writing had yet to be invented.

We 100-year-lifespan humans know that trees are just waiting to take advantage of the summer sun. But the day-lifespan humans would be stumped. When we think about life in the subsurface, are we like day-lifespan humans contemplating a tree? Are long-lived intraterrestrials waiting for wake-up cues we don't recognize because our lives are too short to see them? What is even the point of living for hundreds of thousands of years anyway?

There must be some reason these intraterrestrials stick around so long. There is evidence that long-term dormancy has a selective advantage. When you let the laboratory workhorse Escherichia coli sit around with no food for months or even years, many of the cells enter a state of long-term dormancy where they are alive and metabolizing, but they're not growing nearly as quickly as they do when you feed them. If you mix these next-to-dead E. coli with a fresh batch of fast-growing E. coli and starve them both, the old geezers beat the living daylights out of the sweet little young 'uns.

This growth advantage in stationary phase (GASP) may be the secret to why intraterrestrials live so long. Maybe they're waiting for something that only happens thousands of years later so they can be the ones to take advantage of the new situation. They might act as monks, accustomed to deprivation while the gluttons die around them.

Life on geological timescales

So what are these microbe-monks waiting to wake up for? Seasonal cycles are way too fast. The only things slow enough are geological processes. For instance, island subsidence, floods, drought or storms often occur on hundred- to thousand-year cycles. Submarine landslides, earthquakes, tsunamis and volcanic eruptions might shift materials around on even longer timescales, exposing intraterrestrials to new food sources that coax them out of dormancy after hundreds of thousands of years.

It seems odd to say that a microbe is adapted to wait for something as infrequent as a volcanic eruption, but Earth's history shows that you can rely on volcanic eruptions, as long as you've got time to wait for them.

If we really let our imagination run wild, individual microbes might be adapted to events with even longer periods like glacial cycles, which shift every 30,000 years or so. Or the slow movement of tectonic plates. As new seafloor pops up in mid-ocean ridges, the existing seafloor is constantly being pushed away from the middle of the ocean, like a person standing on a moving walkway at an airport. The seafloor eventually jams into a continent in the slowest-motion train wreck ever. Some of the sediments and the intraterrestrials that live in them will get dragged on the subducting plate down to eventually be crushed at temperatures and pressures that kill all life as we know it.

Even for extremophiles, being dragged all the way down to the mantle would definitely be an evolutionary dead end. However, some of the sediments that are in the early stages of being subducted under continental plates might be returned through cracks and fissures that open in the overriding plate. During this collision, some of the seafloor sediments are shoved upward in accretionary prisms and the attendant faults created by earthquakes or other plate deformations.

Could all this piling up, faulting and burbling up to the surface be what the intraterrestrials are waiting for? Let's think through the implications. This would mean that the individual microbial cells that we pull up in our drilling ships that appear to be dormant are just waiting patiently for the ultraslow movement of the plates to squish them into a continent, where they have a chance of resurfacing and recommencing growth.

The evolutionary payoff for waiting for millions of years in deep marine sediments would be to return to the upper seafloor again where the food is more nutritious, at which point the microbe would pass its genes along to future generations. Like any standard Darwinian natural selection, the individuals that have the best adaptations to being dormant for millions of years would have a growth advantage once they arrive back to the surface, ensuring that those adaptations become stable in the communities. Is getting tossed back up into surface sediments an intraterrestrial's version of summer?

Adapted from INTRATERRESTRIALS: DISCOVERING THE STRANGEST LIFE ON EARTH. Copyright © 2025 by Karen Lloyd. Reprinted by permission of Princeton University Press.

Predicting earthquakes before they happen is currently impossible, but scientists are edging closer and closer with new and innovative ways to monitor movements in Earth's crust. In this excerpt from "When Worlds Quake: The Quest to Understand the Interior of Earth and Beyond" (Princeton University Press, 2026), author Hrvoje Tkalčić, the head of geophysics at the Australian National University, delves into the reasons why earthquake prediction is so tricky, looking at the "Parkfield Experiment," where scientists waited nearly 20 years for an earthquake on the San Andreas Fault to strike.

You can often read rude and even vulgar comments under online newspaper articles about the purpose of the seismological profession when people in their post-earthquake trauma realize that seismologists don't forecast like meteorologists do, such as forecast hail or tornadoes with high accuracy.

An approximate answer to these comments could be given with the following targeted question: "We still can't beat malignant diseases, but should we stop researching because of that?"

We are used to discussions about earthquake causes after every event, particularly in the places where the world's earthquakes occur. There are discussions about their frequency, and quite often, there are those who claim they could recognize the coming earthquake in something else. Whether it's a full moon, a planetary conjunction, too much rainfall, bone pain, overexploitation of the planet's resources or greed, people tend to believe that earthquakes have simpler explanations than physical forces in the interior of the Earth and, of course, that they can be predicted.

Let's travel to California in the 1970s and 80s, to a small, picturesque town of only 18 inhabitants — Parkfield — located between San Francisco and Los Angeles, near the central part of the San Andreas Fault. You’re probably wondering why. Well, this small town is known to the seismological world for its turbulent geological history. Namely, on average, significant earthquakes have occurred in Parkfield every 22 years since the middle of the 18th century.

But it was fascinating that the recorded seismograms for the earthquakes of 1922, 1934 and 1966 were almost identical, one wiggly seismogram line to the other. In addition, the 1934 and 1966 earthquakes had foreshocks — about 17 minutes before the main shock — whose seismograms also looked very similar.

You wonder how such a thing is even possible. Such similarity of seismograms is possible only if the same fault surface is always activated and recorded with the same instrument at sufficiently long waves. Of course, the shorter the waves, the greater the differences. In other words, you have a source — an earthquake and a receiver — a seismometer at fixed locations, and waves propagating between them through the same material. So, you have a perfect natural laboratory and an experiment set up in it. You just have to wait long enough.

Scientists, therefore, had good maps in hand to investigate the mechanisms of earthquakes that recur from time to time on an active, well-monitored fault. Since the mid-1980s, they have installed a whole arsenal of instruments near Parkfield and along the fault: powerful seismographs, then strainmeters, which measure rock deformation at a depth of 650 feet (~200 meters) along the fault, magnetometers for measuring the intensity of the magnetic field, creepmeters, which measure displacements on the surface along the fault, and other scientific "weaponry." They forecasted with 90 to 95% confidence that the next earthquake there would occur between 1985 and 1993. Some of the key questions were:

1. How is stress distributed in space and time on the fault due to the action of tectonic forces before and after the earthquake?

2. Do earthquakes repeat at an average time interval, or is each earthquake unique, a story in itself?

3. How do the structure of faults and surrounding rocks affect the nucleation of smaller earthquakes and the possibility of larger ones and their distribution in time and space?

They wondered what the deformation we measure on the surface could tell us about the stress distribution on the fault, and they hoped for a positive result — confirmation of the predictions for earthquake occurrences between 1985 and 1993. They waited and waited. In those years, I worked once a week with colleagues at the U.S. Geological Survey California office in Menlo Park, in the northwestern part of Silicon Valley, where I was able to observe some scientists involved in the experiment.

Eventually, a magnitude 6.0 earthquake did happen in Parkfield, but not until 2004. We greeted the most watched and studied earthquake in human history with a huge question mark above our heads; it occurred 11 years after its forecasted time. Devastating. That’s why the "Parkfield Experiment" left a bitter taste of disappointment in the mouth. But, as they say, only those who dare to fail eventually succeed. Research continued.

Why is earthquake prediction so tricky? Each fault is different — some of them we know about, but many we don't — earthquake catalogs don't go back far enough, and, after all, underground architecture is entirely invisible to us.

We do not know how deep the fault reaches, whether it is a flat or curved surface, whether its surface is smooth or rough, whether and where it touches other faults, the chemical composition of the rocks on one and the other side of the fault, or their physical properties, for example, strength and porosity. We do not know precisely how the deformation we observe on the surface of the Earth can be related to the deformation and stress in the depth of the fault. We also do not know many other factors. A forecast can be made, but by its very nature, it must be probabilistic and taken with a grain of salt. So, how do we proceed?

Not everything is so negative. The first good news is that seismic hazard maps exist in most countries. They are well made, but of course, they must be constantly updated. The other good news is that, based on fundamental knowledge of physics and the propagation of seismic waves through the interior and across the surface of the Earth, we can predict how the ground and some buildings will behave during an earthquake, and that is already a major benefit.

This is possible because of basic science and seismological research on the nature of the subsurface, in a similar way that radiologists can illuminate the inside of the human body. Ironically, earthquakes help us because they serve as a source of waves illuminating the Earth's interior. It is possible to predict infrastructure behavior during earthquakes due to the development of engineering, construction, computer science and numerical methods. Either way, those hazard maps serve as input for engineers, builders and insurance companies.

In the end, the most positive thing is that modern studies involving laboratory models and artificial intelligence are being carried out across the world, aimed in the direction that one day we will be able to predict earthquakes. Certainly not without major investment in science and technology, which will need to continue to develop. This might even take us to the point where we will have to place thousands or millions of microsensors on every fault in the Earth's interior and then monitor the strain in real time.

In a way, we will have a "crystal ball" — an insight into the dynamics and future behavior of faults. In fact, we are already doing it today, but we have only scratched the surface of the Earth with the help of satellites. InSAR, LIDAR and GPS are just some of the networks and methods that give us an insight into where the Earth's crust is most stressed from surface deformations.

The stress or tension build-up mechanism on a fault is still under investigation. It is most likely that the hot rocks of the Earth's continental crust beneath approximately 9.3 miles (15 kilometers) of depth are ductile, and this rock mass "flows" at a higher speed than on the surface, but without earthquakes, and the upper part of the crust therefore bends and the stress along the fault surface increases. However, how this stress is distributed in space is not yet known.

Furthermore, laboratory experiments at high pressures and temperatures give us insight into how hard rocks are and how strain and stress are related. The chemical and physical structure of the soil is examined by drilling around the fault. Old tree trunks are explored, and excavations are made to detect historical earthquakes on rock samples.

Investments are made in studying the deeper interior of the Earth and the mechanism of earthquakes using seismic waves and tomography methods. Investments are also made in mathematical geophysics, as well as in machine learning and improved techniques for processing enormous amounts of digital data. Investments are also made in alarm systems based on the detection of P waves. Even a few seconds of warning before the arrival of S waves can be crucial to saving people and infrastructure. Likewise, investments are being made in modern construction resistant to earthquakes.

But the conclusion is that, unless you want to move to stable parts of the continents, somewhere in Siberia, to the northernmost, permanently frozen parts of Canada, or the remote regions of the Australian Outback seldom struck by earthquakes, we need to learn to live with earthquakes.

Adapted from When Worlds Quake: The Quest to Understand the Interior of Earth and Beyond. Copyright © 2026 by Hrvoje Tkalčić. Reprinted by permission of Princeton University Press.

Thank your lucky stars for black holes. Mysterious, terrifying and endlessly fascinating, these extreme objects are the gravitational anchors of every large galaxy – including our own — and help regulate star formation across the cosmos. They are the darkest objects in the universe, and yet curious Earthlings are drawn to them like moths to a 100,000 solar mass flame.

In his new book "Facing Infinity: Black Holes and Our Place on Earth" (The Experiment, 2025), science writer and physicist Jonas Enander invites us on a journey through time and space to unravel the history, the science and the enduring mystique of black holes. From a volcano-top observatory in Hawaii that helped capture the historic first image of a black hole to a World War I battlefield in France where one of the most important astrophysical equations was conceived, Enander speaks with Nobel laureates and retraces the steps of some of the greatest thinkers in physics to help put these monstrous cosmic objects into a tangible, human context.

The journey begins at a terrifying end — with an unfortunate astronaut falling into a black hole's maw. Read an exclusive excerpt of "Facing Infinity" below.

The light blinds you.

You raise your hands to shield your eyes, letting fragments of light filter between your fingers. White, blue and red stars are shining brightly in the darkness.

You're floating in space. There's no up or down.

Thick white gloves cover your hands. They are part of your spacesuit, your only protection from the deadly vacuum that surrounds you.

You lower your hands and squint. In the starfield in front of you, you see a darkness. There are no stars there. There's no light, nothing but cold, black emptiness: a black hole.

A black hole is a place in the universe with such strong gravity no light can escape it. That's why black holes are dark. But the darkness not only signifies the absence of light, it also represents a limit of knowledge. No particles, no radiation and no other information can exit a black hole. If you want to know what is going on in the darkness, you have to travel right into it.

You realize that the darkness in front of you has grown. You are falling towards it and there is nothing you can do to stop yourself. You have no spaceship, no rockets, no way to alter your course.

The darkness feels both menacing and alluring. Like the explorers of old, you are venturing into the unknown. You are going to find out what happens in one of the strangest places in the universe, a place no one else has ever visited.

But there's a difference between you and those adventurers: after they had explored far-away places, they could return home and describe what they had seen. You will not be able to travel back and tell your fellow humans what you've been through. Once you've fallen into the black hole, you can never turn back. Its gravitational pull is too strong. The darkness will swallow you forever.

You're falling into an abyss of space and time that has an enormous gravitational pull. But falling in space is not the same as falling on planet Earth. On Earth you can feel the air rushing past your face and hear your clothes fluttering in the wind. In the emptiness of space, however, there is no air and no sound. All you can feel is your spacesuit bumping against your body, and all you can hear is your breath, though you start to perceive a thudding noise that has grown louder as the darkness has deepened. You realize it's the sound of your heart, beating harder and harder the closer you get to the black hole. It's as though your heart fears what you will meet in the darkness, as though it knows you will have to sacrifice something in order to see what is happening inside.

Knowledge comes at a cost. The greater the knowledge, the higher the price. To find out what happens in one of the darkest and most peculiar places in the universe, you will have to pay the highest price of all: your life.

The point at which this will happen depends on the size of the black hole. The larger it is, the longer you can survive. The black hole you are falling towards right now is almost as big as the solar system. You can pass through its surface painlessly, but after that, your life will be over in only a few hours.

Your field of vision is increasingly taken up by the dark sphere. As the darkness grows, the light around it seems to change. You see multiple copies of the light from the stars appear on either side of the black hole. At the same time, the stars' light seems to grow brighter, becoming compressed along the edge of the black hole. It occurs to you that the darkness is controlling the light. The black hole's powerful gravity is making the stars' light travel along peculiar paths that multiply its radiance. Phantom stars form in space, like mirages in the desert. These strange star-doubles disorient you. You want to tell your friends how the encroaching darkness fills you with terror, how the light of the stars is distorted and how helpless you feel. But even if you had a radio transmitter, you wouldn't be able to send your friends a message after you'd passed the event horizon. You will have to bear those final moments in the darkness alone.

Deep within the abyss, there is a point so extremely dense it is hard to wrap our minds around what goes on there. This point is called the singularity. Everything that passes the event horizon will ultimately reach the singularity. There, all matter and all light will be concentrated in a state that is so distorted, even space and time seem to cease to exist.

You are gaining speed as you fall towards the darkness. There is nothing you can do to avoid it. You turn your head and look around you. The area of space behind you is growing darker and darker. You lose your ability to orient yourself. You cannot tell where you came from, or how far you are from the black hole. Are you already inside it? You don't know. There's no sign at the event horizon that says 'You are now passing the point of no return.'

The dark sphere seems to surround you in every direction. You flail your arms and legs in a desperate attempt to escape your journey towards the singularity, but it's pointless. There's no escaping the singularity. All that happens is that you start sweating.

You close your eyes, take a deep breath and think about what awaits you. When you travel feet-first towards a black hole, your lower body will feel a greater force than the upper body. You begin to be pulled apart. But it doesn't happen the same way as on a torture rack; instead, everything in your body is drawn out, from your skeleton, your tendons and your muscles, all the way down to your nerves, cells and DNA. Luckily, you'll feel almost nothing when it happens. From the moment you first notice the pain shoot through you, less than a second will pass before you are decimated. But unlike on Earth, where a person's dead body can be buried, there will be nothing left of you. Your body will be dissolved into the darkness.

The smell of your own sweat fills your spacesuit. You try to take deep breaths, but hear yourself breathing faster and faster. Pain flashes from your feet to your head. You tense every muscle in a final attempt to stop your body being strung out.

You open your eyes. The light of a billion stars blinds you. They are outside the black hole, but their light has been concentrated into a thin ring inside it. The ring is caught between the darkness in front of and behind you. You are in the centre of the ring.

Before you can even scream, your last second of life has passed.

You’ve been torn apart by the darkness.

Excerpt from Facing Infinity: "Black Holes and Our Place on Earth" © Jonas Enander, 2025. Translation copyright © Nichola Smalley, 2025. Reprinted by permission of the publisher, The Experiment. Available everywhere books are sold.

Can we change bad memories? In this adapted excerpt from "How to Change a Memory" (Princeton University Press, 2025), author and neuroscientist Steve Ramirez recounts the events that led him and his colleagues to discover memories could be artificially controlled in rodents, by tapping directly into the brain.

Feelings like anxiety are hard to understand because they're often invisible to everyone else. But they're part of everyday life. We all regularly experience bouts of stress and anxiety. What if the job interviewer doesn't like me? Should I cram tonight for my exam tomorrow? What should I say on my first date?

Our biology often forces us to be prepared for multiple outcomes in the midst of uncertainty. It's healthy to care about these multiple outcomes because it encourages us to put in the work, to adequately prep for a given stressful event. And yet, sometimes the scales of stress become tilted to such an extreme that pathologies of the brain begin to emerge.

The tremendous variation in how any individual arrives at a state of anxiety, for example, highlights that our brain contains many winding roads that can ultimately converge on the same feeling. We all have our triggers in life, but what those triggers are depends on experience — on memory. When these differences impair our mood, thinking, behavior and overall daily functioning, then they get lumped into a category. What's more, if observed impairments share similar features, then this category itself falls within a broader classification — that of a mental disorder.

As I was entering my last year of graduate school, I was just beginning to understand how omnipresent an anxious feeling can truly be. Just as my own stressors in life began accumulating — finishing my thesis, writing grants and job applications, continuing the seemingly never-ending search for purpose as a scientist and person — my mom too had a sudden resurgence of anxious moments that ultimately culminated in frequent panic attacks. Once I learned about her lifelong experience with the erratic thing that anxiety was for her, I started to appreciate the on-again, off-again and on-again nature of these feelings. I couldn’t stop thinking about her panic attacks and how frustrating it was to not be able to press "off" on some of the most debilitating moments one can endure.

My last project in graduate school would attempt to artificially activate positive memories to suppress the symptoms associated with anxiety and depression. It would be my most personal scientific endeavor, a very direct way for me to join the fight at my mom's side and to thank her for being my superhero. If my research could somehow inspire new therapeutic strategies that might be useful for alleviating these kinds of debilitating conditions, then my work will have gained an even deeper, more personally meaningful purpose.

My lab partner Xu Liu and I wanted to take a brain-centric approach to our newest project. Could memory itself be artificially controlled in rodents, by tapping directly into the brain to restore neuronal and behavioral balance in a therapeutic name?

Luckily, our project had a scientific precedent in humans — in an influential paper by psychologist Barbara Fredrickson and colleagues called "The undoing effect of positive emotions." This study highlighted the capacity of positive emotions to undo the physiological effects that negative emotions have on the brain and body.

The undoing hypothesis proposes that positive emotions can be used for more than just feeling good. They can be used to help us get out of bed in the morning; pursue happiness; change how we think about and interact with ourselves and others; and counteract, or at least regulate, negative emotions. When human subjects were stressed and then watched movie clips that elicited contentment and amusement, their bodies rebounded in beneficial ways: their stress-induced increases in cardiovascular activity, for instance, returned to baseline faster than when they watched neutral or sad movie clips. Excitingly, this reveals a very real physical connection between feelings of positivity and their direct effects on our biology.

Xu and I wanted to further this work by testing for a potential therapeutic capacity of positive memories by jump-starting their biology from within the brain. We placed our animals in a box that had two small valves on separate ends: one that delivered sugar water when the animals licked it and another that delivered regular water. This is known as the sucrose preference test. Rodents normally prefer sugar water over regular water, the same way humans will typically find sugary liquids preferable to a bland liquid. On the other hand, rodents with depression-and anxiety-related behaviors tend to show a 50:50 preference. They show no preference at all.

As expected, the animals displaying anxiety-and depression-related behavior licked at each of the valves randomly over the course of 15 minutes. As with Project X — our first successful attempt at MIT to artificially control memories in the rodent brain — all we had to do was hit a button that would turn our lasers on and optogenetically awaken a memory from within.

Click.

The deep-blue laser flickered throughout the mouse’s hippocampus, waking up — activating — cells that held onto a positive memory. I remember thinking that our optogenetic stimulation was a fancy, high-tech Proustian madeleine, one capable of triggering the rich remembrance of things past. If you'll entertain my romanticization of the moment: the mouse perked up immediately, as if a shudder ran from its brain to its body, and it began scanning the environment to decide which valve to visit first.

An extraordinary thing was happening. I imagine that the mouse felt the memory invade all its senses, strangely detached and with no suggestion of an origin, since the essence of these sensations was in the mouse as much as it was the mouse. And once the positive memory fully revealed itself within seconds, the now-motivated mouse inspected each valve with some sniffing, followed by a taste test.

When it found the valve with the sugar water, the mouse started licking vigorously, so much so that it consumed as much sugar water as our control animals. In under an hour, Xu and I saw that reactivating positive memories restored our mice's behavior to a healthy baseline. Just as exciting, reactivating positive memories also turned on many areas of the brain involved in rewarding experiences and motivation.

The key to reversing abnormal behavior was embedded within their positive memories all along. For as long as the laser was shining its sapphire radiance in their brains, the mice were motivated to keep consuming their sugar water reward. All this from stimulating cells in the hippocampus. Or to say this with less novelistic flare: the mice got a sugary treat.

In the following weeks, one of my gifted undergraduates Briana Chen collected a large empirical dataset for the project, and it came with an exciting plot twist: when she artificially reactivated positive memories twice a day, or "chronically," for about a week, not only did this permanently ameliorate symptoms we believed were associated with depression and anxiety, but it also promoted the growth of new cells in the brain. Positive memories had both short- and long-term benefits, all the way from cells to behavior.

Inspired by the neuro-centric Research Domain Criteria (RDoC) approach to treating the brain, our hope was that the biological potency of positive memories — like medications — could inform cognitive-behavioral approaches to treating disorders of the brain. This project was meaningful to me on a personal level: I thought of my mom's panic attacks and the idea that she might never have to experience the kind of crippling anxiety that robs someone of peace.

Positive memories are some of the most powerful biological tools available in our brains. At home, my mom and I shared a treasure trove of them — one that we both remember is from the time when I was a teenager, and we were visiting her parents in El Salvador.

One morning, my cousins, parents and grandparents all walked down a hill behind the house my mom grew up in to go swimming in the village pond. My cousins kept egging me on to jump from a cliff into the pond, and my mom kept telling me I didn't have to.

Like her, I was the opposite of an adrenaline-seeker because, oh I don't know, maybe my innate biology was onto something, as "please do not free-fall to Earth" kept repeating in my mind. She could see that I was scared, and after a few minutes she suggested, much to my surprise, that we jump together. We held hands and tiptoed to the edge — uno, dos, tres — we were in the air! Moments later, we emerged from the water laughing in delightful disbelief at our newfound courage.

Neuroscience tells us that this memory has all the ingredients of life's dessert that make us feel good. From an RDoC perspective, my cognitive and valence systems are all interacting to produce the riches from this experience: the cognitive system enables the memory of jumping off of a cliff, which at first generated feelings of fear via the negative valence systems, which are now almost immediately counteracted by feelings of reward via the positive valence systems.

What was once a moment of fear is now a memory of triumph with my mom. It's the only time I can remember when we both took a literal leap of faith, so we cherish the memory as an example of what our brains can achieve together. A million little life moments like these, packaged neatly into a million memories that we hold onto constitute the good stuff in life.

Adapted from "How To Change a Memory: One Neuroscientist's Quest To Alter The Past". Copyright © 2025 by Steve Ramirez. Reprinted by permission of Princeton University Press.

Months before COVID-19 was officially declared a pandemic, public health leaders were poring over the early data coming out of China and preparing for the worst.

Dr. Seth Berkley — a renowned infectious-disease epidemiologist and former CEO of Gavi, an international organization aimed at improving children's vaccine access — was among those leaders. In January 2020, Berkley and colleagues were working to establish an infrastructure so that, if and when scientists created vaccines for this novel virus, the shots wouldn't be hoarded by high-income countries and denied to poor nations.

Now, Berkley has released a new book — "Fair Doses: An Insider's Story of the Pandemic and the Global Fight for Vaccine Equity" (University of California Press, 2025) — that recounts how that initiative unfolded and what lessons were learned through the process, while underscoring why the broader fight for vaccine equity is far from finished.

On January 23, 2020, I was high up in the Swiss Alps in Davos, attending the World Economic Forum (WEF). I was at Davos as the CEO of Gavi, the Vaccine Alliance, the largest purchaser of vaccines in the world and which worked to provide new and underutilized vaccines to children in developing countries — countries in which about half the world's children live. As usual, I was preoccupied with how we could do a better job protecting the world with vaccines for new and old diseases. And there were murmurs of a new epidemic of respiratory disease caused by a novel coronavirus in China on the horizon.

At the bar of the Hard Rock Hotel my wife, Cynthia [an academic physician and consultant], and I met with Richard Hatchett, CEO of the Coalition for Epidemic Preparedness Innovations (CEPI). Over nachos and drinks, we started to talk through what was likely to happen with the new coronavirus, which would later be named COVID-19. Discussion about the disease hadn't really reached a high political level and was not formally on the Davos agenda, but concern was growing, and many people during that week asked us our opinions.

The first question we discussed was whether this was just going to be a worrisome outbreak or the Big One that epidemiologists had long warned might come. So far, we only had official confirmation of a point outbreak, spreading from animals at the Wuhan live animal market to humans. But on the nerdy LISTSERVs about infectious disease and epidemics, there was already a lot of chatter about how the virus might be spreading from person to person, which is a huge red flag in our field. We agreed that there was potential for the new virus to spread dramatically. Regardless of whether this was or was not the Big One, we needed to prepare.

Such a scenario creates a problem for all countries, even those with access to the vaccines. But to me a far bigger concern was the unfairness of high-income countries' self-interest. People in developing nations without access to vaccines were historically already the most vulnerable to disease and the most likely to suffer complications if they got sick. They already had limited access to the most basic medical treatment.

Improving the delivery of existing vaccines and building up better delivery systems is the best way to detect outbreaks early, prepare communities for outbreaks of disease, and ensure health systems aren't overwhelmed in an emergency — as well as strengthen our epidemic stockpiles.

If vaccines against the disease could be made — and at the time, we were far from certain they could be — we knew that stocks would be quickly bought up by the richest countries. The logical conclusion was that the bulk of the world's population, and most especially those in lower income, developing countries, would be locked out of these deals, and so denied timely access to whatever vaccine supplies became available.

That was where we thought we could help. So, Richard, Cynthia, and I talked through a rough outline of what would be needed to ensure equitable access to any COVID-19 vaccines that emerged and the roles that various organizations — such as CEPI, Gavi, UNICEF, and WHO — as well as the pharmaceutical companies might play to make that happen.

Imagining ourselves in the place of government decision-makers, we envisioned that they would have an incentive to participate in a mechanism that pooled risk by making advance purchase commitments for a wide variety of candidate vaccines. Their buy-in could help us pool demand, generating enough scale to incentivize increasing production and to negotiate the best prices on everyone's behalf. We wanted to promote solidarity, to publicize and meet lower-income country needs, and to create an early, strong global movement for equitable access.

Richard went from Davos back to London and talked with the CEPI team, I went back to Geneva to talk to the Gavi team and our Alliance partners WHO and UNICEF, and we started our collaboration. That joint effort became COVAX [COVID-19 Vaccines Global Access, an initiative to ensure equitable access to COVID-19 vaccines].

Our small team working on COVAX undertook what I believe was the most ambitious public health effort of the 21st century so far. The first COVAX dose was delivered to a COVAX-supported country 39 days after the first jab in the United Kingdom. Due to the time required for WHO to prequalify the vaccine, 43 days later the first doses were administered in Africa, in Ghana and Côte d'Ivoire. Forty-two days later, COVAX vaccines had been distributed to 100 countries. There were many delays due to export bans, vaccine nationalism, and manufacturing delays. But by the end of 2021, close to 1 billion doses had been distributed; by the end of 2022, COVAX had delivered more than 1.6 billion doses to people in the world's poorest countries and was estimated to have averted 2.7 million deaths in those countries. That's the fastest rollout of vaccines to developing countries ever.

WHO estimates that some 16 million people died during the first two years of the pandemic; we are still counting, and that number will doubtlessly grow. And COVID-19 is by no means the only infectious risk: Currently, about one in seven deaths, accounting for more than 7 million people a year, is due to an infectious disease. Millions of people die from diseases for which we already have vaccines.

It's hard to put numbers on the deaths that have been prevented by vaccines, but some estimates say that vaccines have saved more than half a billion lives over the past 70 years, the time period they have been routinely available. And this only covers the 30 or so vaccines we have against the more than 300 infectious diseases known to plague humanity.

More and better vaccines need to be developed, particularly for major killers such as tuberculosis, malaria, and HIV, and, hopefully, more cancers. And in the meantime, the risks for infectious diseases are shifting.

Even those of us who had been working in the field for years were surprised at how poorly prepared the world was for an emergency of this magnitude. What's more, we faced the perils of vaccine nationalism, vaccine diplomacy, and the sometimes-selfish behaviors of manufacturers and world leaders. It was clear from the start that we wouldn't be able to do this work perfectly. But we did our best, and I've sought to set down both what we did and what I wish we could have done differently so that we can learn from our history.

As the world continues to recover from the worst of the pandemic years, we may not relish thinking about another pandemic ahead. We face complacency, fatigue, and a growing distrust of both science and institutions, fed by intentional disinformation that spreads rapidly online. But we also have an opportunity to harness what we've learned to do better next time — and there is epidemiologic certainty that a next time will come. When it does, we need to have robust public health systems in place, and ideally, vaccines.

Reprinted from Fair Doses: An Insider's Story of the Pandemic and the Global Fight for Vaccine Equity by Seth Berkley, MD, courtesy of University of California Press. Copyright 2025.

As humans evolved, our heads got bigger and walking upright narrowed the birth canal — a difficult and dangerous combination that means, in most cases, we need assistance in giving birth, from emotional support to intervention, as well as medical support for life-threatening conditions such as high blood pressure, uterine rupture and postpartum hemorrhage. Before written records, we see depictions of pregnancy and fertility, but little is known of how pregnancy and childbirth were viewed and treated.

In this excerpt from "Born: A History of Childbirth" (Pegasus Books, 2025), author and historian Lucy Inglis reveals records from ancient Egypt that show how female physicians treated issues of "the womb," how men reacted to periods, and how the first known pregnancy test actually worked.

There is one female physician who lived during the building of the great pyramids, around 2500 B.C., who we know about because her name and profession were recorded on her son's tomb door in Saqqara: Peseshet, the Overseer of Female Physicians.

Women like Peseshet were not the local wise women but respected professionals. Her son Akhethotep was a royal official, so his mother was firmly embedded in the literate elite classes. The tomb door, however, leaves us with as many questions as it does answers.

Who were the female physicians she oversaw? Who and what did they treat? The "professional" middle class of Peseshet and the tattooed priestess also left the world's first specific gynaecological text, the "Kahun Gynaecological Papyrus", which dates from 1825 B.C.. It contains 34 paragraphs of advice that most doctors today would not recommend following, and it diagnoses almost every female complaint as being that of "the womb."

The examination of a woman "whose eyes are aching till she cannot see, on top of aches in her neck," which sounds like a migraine, leads to the conclusion that she must have "discharges of the womb in her eyes." This is treated by "fumigating her with incense and fresh oil, fumigating her womb with it, and fumigating her eyes with goose leg fat. You should have her eat a fresh ass' liver."

While fumigating her womb can't have helped, perhaps the liver at least provided some welcome nutrition.

Only one examination, which sounds like a prolapse, correctly points to genuine involvement of the womb itself. It is treated by the pouring of oil, although on which part of the body is not identified. The papyrus also recommends putting a clove of garlic in your vagina before bed, and if your breath smells of garlic the next morning, it means well for the pregnancy. If not, it bodes ill.

The papyrus is also notable, however, for the first use of the term "wandering womb," a term that would haunt women in various guises for another two millennia. The immaculate record-keeping of the workers of Deir el-Medina also includes intriguing entries for absence known as hsmn, meaning menstruation.

A set of tablets written in the reign of Ramses II cover a 280-day period in which 10 prominent workmen took "sick days" owing to hsmn. As men do not menstruate, this is something of a puzzle. The meaning is clarified, however, by the scribe Qenhikhopshef's fuller entry for Day 23 — he was absent due to his wife "having her menses." That winter the foreman of the works, Neferhotep, also took time off for his daughter's period.

Historians over the past century concluded that this must mean that the Egyptians thought that the menstruating body was "unclean," but this is just speculation. There are ancient Nubian customs still found in modern Ethiopia and Sudan which warn that menstruating or pregnant women should not enter cemeteries. Perhaps it was not the women who were unclean but the workers.

Rather than fearing that the husband of a menstruating woman might bring pollution to the sacred Valley of the Kings, the male workers may have been asserting their right not to "take their work home with them." To do so might have brought death into their homes at a time when the women in their family were vulnerable.

The elites of any society leave monuments, art and literature behind for us to find that aim to portray their patrons as somewhat superhuman, but the poor rarely leave any trace of their existence at all. It is only relatively recently that their lives began to be recorded for statistical purposes. So it is no surprise that it is from the written records of the middle classes of ancient Egypt that we learn about the first known pregnancy test, written around 1350 B.C., in the medical text known as the Berlin Papyrus.

It states: "Barley [and] wheat, let the woman water [them] with her urine every day with dates [and] the sand, in two bags. If they [both] grow, she will bear. If the barley grows, it means a male child. If the wheat grows, it means a female child. If both do not grow, she will not bear at all."

Remarkably, this theory was tested in 1963 and found to be accurate in 70% of cases, although the success of gender determination was not recorded. The tests have even been repeated subsequently at various intervals up until 2018 and have correctly identified 70–85% of pregnant participants.

Excerpt from Born: A History of Childbirth by Lucy Inglis. Published by Pegasus Books on October 7, 2025.

The COVID-19 pandemic altered life as we know it and claimed millions of lives in the process, and yet, the next pandemic might be even worse. A new book, called "The Big One: How We Must Prepare for Future Deadly Pandemics" (Little Brown Spark, 2025), describes a theoretical-but-plausible scenario in which a new and deadlier coronavirus emerges and quickly spreads around the world, despite public health officials' best efforts to stop it.

In the text, Michael Osterholm, founding director of the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota, and award-winning author Mark Olshaker discuss lessons we should take away from past pandemics in order to mitigate the harms that a "SARS-3" could wreck on the global population. The following is an excerpt from the book.

Even if you are lucky enough not to contract the airborne virus, someone you know and care about most likely will. But even beyond that, a pandemic would so severely affect the global supply chain that both ordinary and durable goods, food, medicine, and the staples of everyday life would be in short supply or not available. There would be major shortages in all countries of a wide range of commodities, not only food, but also soap, paper, light bulbs, and gasoline, as well as parts for cars, airplanes, trains, military equipment, municipal water pumps, and electrical generation plants. Even coffins to bury the dead would be in short supply. With Covid, we saw just how connected the world's economies are.

The message here: When it comes to fighting microbes, America First only goes so far. In the United States, most of our critical and, in many cases, lifesaving generic drugs come from China and India, both of which would be prime targets for viral spread, resulting in shutdown of manufacturing plants. We have been advocating for years for this type of pharmaceutical manufacturing to be reestablished in the United States and other countries we can count on, as a matter of national security. But that would necessarily involve some form of government subsidy, since the profit margin on most generics is extremely thin, and even overseas, companies are getting out of the business. This means that as consolidation in China and India has occurred, it has created a gaping vulnerability for the United States and the Western world.

The truism that no one is completely safe until everyone is safe is a truism because it happens to be true. In the words of the late Nobel laureate Dr. Joshua Lederberg, whom we quoted at the beginning of Chapter One, "Bacteria and viruses know nothing of national sovereignties. . . . No matter how selfish our motives, we can no longer be indifferent to the suffering of others. The microbe that felled one child in a distant continent yesterday can reach yours today and seed a global pandemic tomorrow."

Or, as the poet John Donne wrote, "Never send to know for whom the bell tolls; it tolls for thee."

Accordingly, in preparing for the Big One, we must not let the same thing happen that occurred with Covid, where high-income nations ended up with plenty of vaccine — often more than they could use — while low- and middle-income countries had very little, despite COVAX's [a global initiative aimed at ensuring equitable access to COVID-19 vaccines] good intentions. Not only must we develop new and effective vaccines; we must also, by international agreement and cooperation, plan for a means to scale up manufacturing to meet global need, along with an efficient system to transport and distribute them, even if a cold chain requirement is involved. We will need an international approach to public funding that will pay for the excess production capacity required during a pandemic.

Unlike many fields these days, ethics remains a vital and integral component of medicine and public health, and thus there is compelling reason to regard the rest of the world with the same compassion and empathy we feel for our own people. But on a practical level, there is nothing particularly altruistic about sharing vaccine with low- and middle-income countries in sufficient quantities to protect their populations. It is simply self-interest. Now that the globe can be circumnavigated in less than 48 hours, distance provides no protection from infectious diseases. While someone in a remote village in the Western Pacific or sub-Saharan Africa is sick with a novel airborne respiratory virus, people on the other side of the world may be in imminent danger, a fundamental fact of nature in our modern world.

We realize how unlikely this level of global cooperation is in reality, given the state of international relations and each country's natural tendency to keep critical drugs and vaccines for its own people. That probability, however, doesn't make this any less important. Manufacturing countries must have the capability and capacity to turn out vaccine stocks for the rest of the world, and there should be international dialogue and planning for the mechanics of how vaccine stocks would be allocated.

Even in the United States, there will not be sufficient antivirals to meet the need for at least several months. Assuming effective antivirals even exist for whatever the pandemic virus turns out to be, we will have to figure out who gets priority among those who are seriously ill. Healthcare workers and first responders? Political and business leaders? The elderly and immunocompromised? Essential workers and drivers? Each cohort will have its advocates. It is far better to struggle with the ethical issues involved in determining such priorities now, in a public forum, rather than waiting until the crisis occurs.

Another issue is that while SARS-CoV-2 [the virus behind COVID-19] primarily affected the elderly and immunocompromised with severe disease, that wouldn't necessarily be true of the next pandemic. Keep in mind that in the 1918 influenza [pandemic], more than half the people killed were 18 to 40 years old and largely healthy. These deaths were likely caused by a virus-induced response of the victim's immune system — a cytokine storm, as we described in Chapter Four — that led to acute respiratory distress syndrome (ARDS). In other words, in the process of fighting the disease, these healthy individuals' robust immune systems overreacted, severely damaging the lungs and resulting in death. Today, the medical establishment around the world is not much better prepared to treat tens of millions of cases of ARDS than it was more than a century ago.

And even though the SARS coronavirus, for example, infected only about 8,000 people in 2003 before it was brought to a halt, about 10% of them died, showing that our thought experiment for SARS-3 is not far-fetched.

The hype around artificial intelligence (AI) risks spiraling out of control as claims around the emerging technology escalate into the realm of the absurd. AI is a big-money business, write the authors of the new book, "THE AI CON: How to Fight Big Tech's Hype and Create the Future We Want" (2025), and the marketing fanfare we see is meant to promote the interests of big tech and do one thing: sell AI products.

In this new book, authors Emily M. Bender, professor of linguistics at the University of Washington, and Alex Hanna, director of research at the Distributed AI Research Institute, challenge our understanding of what AI is — and what it isn't. Ultimately, they attempt to see through a lot of the overblown claims and sensationalism to understand the true impact AI is having on society.

In this excerpt, the writers grapple with the idea of artificial general intelligence (AGI), the origins of that idea and what the term actually means. In this extract, they argue that the true definitions of AGI and a hypothetical "superintelligence" are fuzzy, at best, and in practice only serve to feed the corporate AI hype machine.

If you listened to executives and researchers at big tech firms, you’d think that we were on the verge of a robot uprising. In February 2022, OpenAI’s Chief Scientist Ilya Sutskever tweeted "it may be that today’s large neural networks are slightly conscious."

In June 2022, the Washington Post reported that Google engineer Blake Lemoine was convinced that Google’s language model LaMDA was sentient and needed legal representation. Lemoine was fired over this incident — not for his false claims (which Google did deny), but for leaking private corporate information. In an August 2022 blog post, Google VP Fellow Blaise Agüera y Arcas responded to the Lemoine story, but rather than countering Lemoine’s claims, he suggested that LaMDA does indeed "understand" concepts and that the debate over whether or not LaMDA has feelings is not resolvable or "scientifically meaningful."

In April 2023, a team at Microsoft Research led by Sébastien Bubeck posted a non-peer-reviewed paper called Sparks of Artificial General Intelligence: Early Experiments with GPT-4, in which they claim to show that the language model GPT-4 can solve novel and difficult tasks that span mathematics, coding, vision, medicine, law, [and] psychology" and thus shows the first "sparks of artificial general intelligence."

Related: GPT-4.5 is the first AI model to pass an authentic Turing test, scientists say

The word "sparks" evokes an image of something about to catch fire and spread of its own accord. The phrase "artificial general intelligence" here is meant to differentiate from ordinary technologies called "AI," and is particularly common in modern discourse around thinking, sentient or conscious machines.

The eugenicist origins of "general intelligence"

Despite claims that machines may one day achieve an advanced level of "general intelligence," such a concept doesn’t have an accepted definition. (OpenAI has avoided the question by suggesting that they will allow their board to decide when their algorithms have achieved artificial general intelligence.) But the project of identifying general intelligence is inherently racist and ableist to its core, making the project of chasing artificial general intelligence foolhardy at best, and deceptive and dangerous at worst.

Microsoft’s "Sparks" paper contains a preliminary definition of general intelligence, one that has no references to fields that may have a say in such a thing, like psychology or cognitive neuroscience. Despite being a paper claiming that certain statistical models have shown the inklings of "artificial general intelligence", it offers no well-sourced definition of what the components of general intelligence are.

In a prior version of the paper, the authors cited a definition from a 1994 Wall Street Journal editorial signed by a group of 52 psychologists but penned by Linda S. Gottfredson in defense of Richard Herrnstein and Charles Murray’s 1994 book, The Bell Curve. This book argues among other things, that there are significant differences between the inborn intelligence of different racial groups, and that those differences are mostly due to genetics. Gottfredson, in her letter, claims that "genetics plays a bigger role than does environment in creating IQ differences among individuals" and that "IQs do gradually stabilize during childhood… and generally change little thereafter."

These claims about the inherent hierarchies of racial intelligence are not new, and studies of "general intelligence" have a long and sinister history. This is not "forbidden knowledge," as Murray and his defenders would have it; they are justifications for racism that are as old as the modern Western state and capitalism. Both the measurement of intelligence — namely IQ tests — and the concept of general intelligence are implicated in this sordid history. Bubeck and colleagues had no other source to cite for a definition of intelligence. Discussions of intelligence, pertaining to people or machines, are race science all the way down.

To Bubeck’s credit, when we notified him of the context and contents of Gottfredson’s letter, he and his coauthors quickly scrubbed the paper of the citation and of the associated definition. But this doesn’t erase the racist roots of the general intelligence project. General intelligence is not something that can be measured, but the force of such a promise has been used to justify racial, gender, and class inequality for more than a century. The paradigm of describing "AI" systems as having "humanlike intelligence" or achieving greater-than-human "superintelligence" rests on this same conception of "intelligence" as a measurable quantity by which people (and machines) can be ranked.

AGI and modern-day eugenics

Unfortunately, the goal of creating artificial general intelligence isn’t just a project that lives as a hypothetical in scientific papers. There’s real money invested in this work, much of it coming from venture capitalists.

A lot of this might just be venture capitalists (VCs) following fashion, but there are also a number of AGI true believers in this mix, and some of them have money to burn. These ideological billionaires—among them Elon Musk and Marc Andreessen—are helping to set the agenda of creating AGI and financially backing, if not outright proselytizing, a modern-day eugenics. This is built on the combination of conservative politics, an obsession with pro-birth policies, and a right-wing attack on multiculturalism and diversity, all hidden behind a façade of technological progress.

Tesla and X/Twitter owner Elon Musk has repeated common eugenicist refrains about population trends: notably, claims that there are not enough people and that humans (particularly the "right" humans) need to be having children at even higher rates. In August 2022, Musk tweeted, "Population collapse due to low birth rates is a much bigger risk to civilization than global warming." Musk has himself suggested that he is contributing to the project of increasing population, fathering at least ten children (that we know of ). The white South African son of an emerald miner has noted that "wealth, education, and being secular are all indicative of a low birth rate," which is bad news for "successful" people having more kids. He would rather have a positive eugenic project of these people having more children.

Marc Andreessen, founder of major venture capital firm Andreessen Horowitz, echoed Musk’s concern on far-right darling Joe Rogan’s podcast, remarking: "Right now there’s a movement afoot among the elites in our country that basically says anybody having kids is a bad idea… because of climate." Andreessen pushed against this, suggesting that elites from "developed societies" ought to be having more children.

Musk and Andreessen believe that we are on the precipice of artificial general intelligence. Oddly enough, they also believe that the development of AGI, done poorly, could spell the end of humanity, a belief that is known as "existential risk". You would think that dumping billions into AI research while also believing that AI can bring the end of humanity would be at odds with each other. And you’d be right.

But why do so many people involved in building and selling large language models seem to have fallen for the idea that they (might be) sentient? And why do so many of these same people spend so much time warning the world about "existential risk" of "superintelligence" while also spending so much money on it?

In a word, claims around consciousness and sentience are a tactic to sell you on AI. Most people in this space seem to simply be aiming to make technical systems which achieve what looks like human intelligence to get ahead in what is already a very crowded market. The market is also a small world: researchers and founders move seamlessly between a few major tech players, like Microsoft, Google, and Meta, or they go off to found AI startups that receive millions in venture capital and seed funding from Big Tech.

As one data point, in 2022, 24 Google researchers left to join AI startups (while one of us, Alex, left to join a research nonprofit). As another data point, in 2023 alone, $41.5 billion in venture deals was dished out to generative AI firms, according to Pitchbook data. The payoff has been estimated to be huge. That year, McKinsey suggested that soon, generative AI may add "up to $4.4 trillion" annually into the global economy. Estimates like this are, of course, part of the hype machine, but VCs don’t seem to think that fact should stem the rush to invest in these tools.

This hype leans on tropes about artificial intelligence: sentient machines needing to be granted robot rights or Matrix-style super-intelligence posing a direct threat to ragtag human resisters. This has implications beyond the circulation of funds among VCs and other investors, most notably because ordinary folks are being told they’re going to be out of a job.

Germ theory was never a given. This now-commonplace idea — the notion that human diseases can be sparked by tiny pathogens infiltrating the body — emerged on the backs of discoveries made by people over time. Those discoveries steadily slotted together to form a bigger picture, revealing both the wonders and terrors of the microbial world around us.

Thomas Levenson, a professor of science writing at MIT and author, traces the history of germ theory from its inception to the present day in a new book called "So Very Small: How Humans Discovered the Microcosmos, Defeated Germs — and May Still Lose the War Against Infectious Disease" (Random House, 2025). In the book, Levenson also tackles the larger question of how and why new ideas are pursued, accepted or ignored.

In the following passage from "So Very Small," he highlights how, despite our modern understanding of germs, we're still locked in an ongoing struggle with them and with our own hubris. The rise of antibiotic-resistant superbugs is a prescient example of that, he argues.

Related: Superbugs are on the rise. How can we prevent antibiotics from becoming obsolete?

Autumn, 1945. The war in Europe has been over for five months. Something resembling normal life is sputtering into shape. In Stockholm, for the first time since 1938, the Nobel Foundation is getting ready to award its full catalog of prizes. The deliberations reach a familiar intensity as the committees for each scientific discipline struggle to apportion credit to no more than three people for discoveries to which dozens or more had contributed. Finally, on October 25, telegrams go out to the winners of the Nobel Prize for Physiology and Medicine: Alexander Fleming for discovering penicillin, and Howard Florey and Ernst Chain

for turning Fleming's mold juice into a world-changing medicine.

The prize ceremony takes place on December 10. At the traditional after-party there is plenty of drink on tap, and rumors of dancing. The usually buttoned-down Fleming keeps going until three a.m. The next day, hungover or not, the three new laureates deliver their Nobel lectures. Fleming goes first, devoting most of his talk to retelling the details of his serendipitous encounter with the penicillium mold. As he draws to a close, though, he abandons memory to deliver a sermon, complete with the command that his audience go forth and sin no more:

"The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant. Here is a hypothetical illustration. Mr. X has a sore throat. He buys some penicillin and gives himself, not enough to kill the streptococci but enough to educate them to resist penicillin. He then infects his wife. Mrs. X gets pneumonia and is treated with penicillin. As the streptococci are now resistant to penicillin the treatment fails. Mrs. X dies. Who is primarily responsible for Mrs. X's death? Why Mr. X whose negligent use of penicillin changed the nature of the microbe. Moral: If you use penicillin, use enough."

This was no mere parable. What Fleming prophesied as he stood before Sweden's great and good had already come to pass. The first of four cases of gonorrhea "resistant to 'large' amounts of penicillin" appeared in the medical literature in 1946. Even earlier, as far back as 1940, Edward Abraham and co-workers in Florey's laboratory had been able to train cultured colonies of staphylococcus to resist penicillin in their petri dishes. And, of course, the wartime erosion of the effectiveness of sulfa drugs against gonorrhea was a very public demonstration of the problem.

And yet, despite Fleming's warning, the dynamic that killed Mrs. X has recurred again and again throughout the antibiotic era. The first drug effective against TB, streptomycin, was isolated in 1944. Resistant strains of M. tuberculosis emerged no later than 1948. It's been the same story in disease after disease, bug after bug, drug to drug to drug. Staphylococcus aureus, the ubiquitous killer of World War I's wounded, has shrugged off penicillin, erythromycin, the tetracyclines, and what was seen as the big gun, methicillin.

Related: Dangerous 'superbugs' are a growing threat, and antibiotics can't stop their rise. What can?

Methicillin came on the market in 1959. Its effectiveness began to erode almost immediately. The first staph strain immune to the new drug showed up later in 1961, marking the appearance of what we now know as MRSA, or Methicillin-resistant Staphylococcus aureus. MRSA flourishes in hospitals, where microbes and plentiful antibiotics meet, but over time has emerged in the broader population. This pattern has been repeated across the spectrum of diseases around the world. About 1.3 million people die of TB each year. As of 2020, XDR-TB, extensively drug-resistant tuberculosis, has been reported in 123 nations. For those infected with XDR-TB, all front-line antibiotics have failed, along with at least one of the three break-glass-in-case-of-emergency backup drugs.

Taken together, there were nearly 3 million antibiotic-resistant infections in the United States in 2019, the most recent numbers available as of this writing. Some 35,000 Americans died that year of once-treatable microbial diseases. Since 1945, we have failed both to anticipate the speed with which microbes would gain the ability to evade our best drugs, and to come up with a satisfactory response to their resistance — to the point where the single greatest gift of germ theory may not be wholly ours much longer.

Shards of that future are already here. What are sometimes called superbugs — microbes resistant to every available drug — are not merely the stuff of nightmares. They are taking lives right now. A report published by the U.S. Centers for Disease Control and Prevention described the case of a woman in her seventies who had been traveling across the Indian subcontinent. They did not release her name but reported that somewhere on her travels she fractured her femur. She was taken to one hospital, then another, and then on to more in India. In August 2016, she returned to her home in Washoe County, Nevada. She went back to the hospital, presenting with systemic inflammatory response syndrome, a characteristic immune response to an unresolved infection. So her doctors looked for the microbe that could have engendered her increasingly perilous condition.

They found it in Klebsiella pneumoniae, a bacterium that occurs naturally in soils and can live quite peaceably in human guts, mouths, or skin. If it makes its way elsewhere, though, it can cause disease, often pneumonia, but several other conditions as well. Until recently, treating a K. pneumoniae infection was simple. Any one of several common antibiotics could do the job. So her medical team tested the patient's bacterial samples to see which drug would be most effective. The answer came back: none of them. The woman's microbes were resistant to the fourteen antibiotics available in Reno. The hospital sent samples to the federal Centers for Disease Control and Prevention, and the tests there showed that these bugs were resistant to twelve more medicines — which is to say, all the remaining possibilities. There was nothing available in the United States that could knock out her singular infection.

Within weeks the woman was dead, slain by a superbug for which there was no cure. She wasn't the first such casualty and she certainly has not been the last. But this one life lost to an infection that so recently was trivially easy to cure forces the question: How could this happen? How could it have been allowed to happen?

Fifteen years ago, a cold snap froze much of Florida's wildlife to death — including many of the state's invasive Burmese pythons (Python bivittatus). But in this excerpt from "Slither: How Nature's Most Maligned Creatures Illuminate Our World" (Gand Central Publishing, 2025), science writer Stephen Hall reveals that a subset of these pythons were genetically predisposed to survive the cold, setting the stage for rapid evolution that could help the invasive snakes spread further into North America.

In early January 2010, a historic and prolonged deep freeze swept across the southeast United States, reaching all the way into the subtropical Everglades. Temperatures hovered around 50 degrees Fahrenheit (10 degrees Celsius) for 48 hours; on Jan. 11, thermometers in South Florida dipped as low as 24.8 F (minus 4 C). Most people remember it, if at all, for the frozen iguanas that dropped out of trees and photos of citrus trees encased in icicles, like some fugitive Minnesota winter carnival smuggled into the Deep South.

But to wildlife and invasive species experts, the Big Freeze marked the start of the Big Unplanned Experiment.

The immediate impact on the Burmese python population was clear. Carcasses of dead snakes littered roads; frozen specimens turned up in underground burrows; farther north in South Carolina, in the infamous "Where's Waldo" python enclosure, all 10 snakes perished during the regional cold snap.

Researchers attributed the mass die-off to "maladaptive behavior," meaning many snakes tried to bask above ground in the sun despite the frigid temperatures, rather than seeking thermal shelter in underground or aquatic burrows. Python "removals" — captures by hunters, which served as a rough indication of the general population — had peaked in 2009 in the national park but plummeted almost five-fold in the following two or three years. It all looked like good news, at first.

But population numbers were still lacking, and "models" are still just models. Genes are where the rubber of biology meets the road of environmental challenge, and this is when the geneticists entered the story. They were less interested in the many snakes that had died, and more interested in the few that had survived.

Like all snakes, Burmese pythons are ectotherms — they rely on warmth from the environment because they do not generate their own metabolic heat — so they have to develop biological tricks in their behavior or in their physiological resilience in the face of life-threatening cold to survive freeze events that do not occur in their native range. As the United States Geological Survey (USGS) overview put it, "some portion of the southern Florida population survived" the 2010 event, "and these snakes and their offspring make up the current population."

By 2014, the number of python removals in Everglades National Park had returned to pre-freeze levels. In genetic parlance, the 2010 freeze was a "bottleneck event" — only a few squeezed through and survived. But the ones that did, in the biblical sense, went forth and multiplied.

Beginning around the year 2015, several researchers studying python genomes to understand their metabolism became curious about the after effects of the big freeze. Daren Card and Todd Castoe of the University of Texas at Arlington teamed up with Maggie Hunter of the USGS office in Fort Lauderdale to look for evidence of what is called rapid adaptation, which might be thought of as an up-tempo version of Darwinian evolution.

They examined the DNA of these survivor snakes to see if there were any genetic clues as to why certain pythons were able to withstand an extended freeze; more precisely, they compared the DNA of pythons that lived before the freeze event with the DNA of pythons that had survived to see if they could identify any differences that might explain the resilience of the survivors at the molecular level.

The short and disturbing (although not definitive) answer was: yes.

It turns out that the survivors seemed to share genetic changes in areas of their genomes known to control thermoregulatory behavior and metabolism. "We saw a lot of things that just fortuitously overlapped with a lot of the same sorts of pathways and genes that we were studying in parallel, in a much more controlled fashion, using more lab experiments in Todd's work on Burmese pythons," Card told me. "As we delved into them, we started to see a lot of genes that are involved in things like thermal tolerance."

The findings, published in 2018, suggested that the survivors shared variations in their genetic makeup that seemed to confer greater cold tolerance and greater metabolic flexibility — two traits that Castoe's lab had been investigating since 2011. These snakes were more inclined behaviorally to seek shelter in underground refugia to outlast the cold — a good adaptation to the environmental reality of occasional freezes. And the metabolic changes seemed to favor a behavior that encouraged smaller and more frequent meals — a good adaptation to the ecological reality that, having already decimated populations of large mammals in the Everglades, the pythons might need to modify their diet.

This is not definitive news — the study was small, no one (surprisingly) has followed up on it, and, as Card put it, researchers still only have a view from 30,000 feet of what happened on the genetic level in the pythons that survived the Big Freeze. Whatever it is, the genetic changes — or, more accurately, the selection for genes that enhanced survival — appears to have happened very quickly. And that is, possibly, very bad news. It suggests that the pythons are on the move, genetically as well as geographically.

The implication is that the 2010 freeze acted as a huge selection event, as evolutionary biologists put it — an environmental stress so dire, so extreme, that it has the effect of rapidly winnowing out individuals holding a bad genetic hand and "selecting" the lucky ones that hold winning genetic hands.

The freeze culled out individuals that were susceptible to cold temperatures and selected individuals that possessed, at the genetic level, some form of cold-hardiness. Those genes were presumably passed down — immediately, profligately and of course, cryptically — to their hundreds of offspring.

The suggestion of rapid adaptation in the Burmese python population in Florida again contradicts our traditional notions of evolution as a glacial process of genetic selection and refinement that requires millennia, eons and geological epochs. "We typically think of evolution as occurring over generally quite long time scales, on the order of several generations at the low end up to potentially thousands to millions of years," Card said. "I think with a lot of the tools that we've developed more recently, especially in things like genomics, people have taken a harder look at how quickly evolution can occur… And generally, when you see such an extreme thing occurring, it really suggests that there's very strong selection. Something's happening."

In fact, Castoe believes the importation of so many pythons from so many different regions of Asia — all packing in their biological luggage a wide variety of genetic variants, known as alleles, for their trip to North America — set the table for a rapid genetic adaptation. As Castoe put it: "If you've got a good amount of genetic variation, given strong selection, this can happen in a heartbeat. 'If I've got the allele, what the hell am I waiting for? I ain't waiting for nothing!'"

At a time when roughly 40% of Americans do not accept the notion of evolution, the pythons that survived the Big Freeze in Florida appear to believe in it 100%. The take-home genomics message from the snakes is that evolution is real, it's apparently happening at blindingly fast speed, and it argues that the 2010 cold snap may have created a subset of pythons better able to survive cold temperatures — and thus better adapted to spread beyond the northern boundaries of its current range.

Excerpted from SLITHER: How Nature’s Most Maligned Creatures Illuminate Our World ©2025 Stephen S. Hall and reprinted by permission from Grand Central Publishing/Hachette Book Group.

In this extract from "The Pocket Guide to Planetary Peril" (WH Allen, 2025), author Jakob Thomä, a professor at the University of London's SOAS Centre for Sustainable Finance, examines an existential threat facing us all: heat. As the impacts of climate change take hold, Thomä argues that heat will become the risk no one can avoid.

We live in places that will be flooded by rising sea levels. We have food production systems dependent on specific climates. And we have built economic structures, trade relationships and social dynamics contingent on certain temperatures.

What's more, we are not alone in this world, and the rapidly changing climate is a threat to the flora and fauna with whom we share this planet. Some of us think this is a problem — although admittedly not all of us.

The key questions then are: How fragile are systems to a changing climate? What are the costs of the impacts or shocks to the system (such as relocating people from places underwater, or victims of extreme weather events that are made more likely by climate change)? What are the costs of adapting to these impacts? How do we negotiate the equity and distributional impacts of these effects? And crucially, what are the costs of preventing these impacts to begin with?

That is the climate discourse in a nutshell. Except for heat. Heat is a different story because we cannot live above a certain heat level.

Of course, the heat story is driven by climate change, so at first glance it may seem I am making an artificial distinction here. Global warming is heat and heat is global warming. But the reason is that it creates an almost unmanageable risk, one incapable of being mitigated by adaptation, at least within the current technological paradigm.

This is different to almost any other effect from climate change. We can maintain habitats below sea level, the Netherlands being a perfect example, through dams and adaptation. Perhaps we would not be able to do this everywhere, and perhaps we would decide that we couldn't be bothered — economically speaking — to do this, but we at least have the means.

We can change food production patterns, our economic activity cycles, we can irrigate, we can create water, we can do all these things. Some have prohibitive price tags and come with dramatic non-financial costs to health, cultural capital and societal welfare. But they can be done.

Related: 200,000 Americans could die of temperature-related causes each year if global warming hits 3C

Heat is the final boss. Heat is a different beast. Heat deaths in and of themselves may not appear as a particularly new or novel phenomenon. They happen everywhere, as the frail, the ill and the old are unable to regulate their body temperatures during hot summers.

And heat deaths can also happen to the young. One of the first "proven" victims of climate change is a 6-year-old boy from Toyota, Japan, who collapsed in a park on a morning field trip, and was dead by the afternoon.

When I think of the heartbreak of our indifference, I think of him. These kinds of deaths will increase in frequency through climate change but, of course, as any self-respecting climate sceptic or denialist will tell you, we can also expect fewer deaths from cold temperatures.

Indeed, there is some reason to believe that from a pure temperature perspective, temperature-related mortality has in fact decreased in the past decades, not just because of improved adaptation, but also because of warmer winters.

Over time, that pendulum — as we near 1.5 and 2 degrees Celsius (2.7 to 3.6 degrees Fahrenheit) global warming above pre-industrial levels — will swing in the other direction, with up to 10 million annual climate deaths by the end of the century, according to some estimates (not counting the indirect deaths from climate poverty, conflict and so on).

What will be new about heat deaths is the extent to which the lived environment will become physically uninhabitable for everyone, old and young, middle-aged, healthy and ill.

Extracted from "The Pocket Guide to Planetary Peril" by Jakob Thomä (WH Allen, £16.99)

In this excerpt from "Carbon: The Book of Life" (Viking, 2025), author and environmentalist Paul Hawken delves into the world of insects and the incredible adaptations critters like dragonflies and butterflies have evolved to help them survive. Hawken hopes that by zooming in on some of Earth's less popular inhabitants, people can gain a better appreciation for life, which he says is the key to stopping and reversing the climate crisis.

A flame skimmer hovers 2 feet (0.6 meters) from my face, looking straight at me. Its red bulbous eyes have 24,000 corneas, allowing it to see 360 degrees — up, down, backward, forward and around simultaneously. What it makes of me visually is unimaginable.

It has 30 opsins, the universal photoreceptor molecule that resides in the visual systems of the animal kingdom. I look back with my three opsins and two blue corneas. At the fishpond where I am sitting, the skimmer hovers and dashes about with its satin wings, red and orange, body and wing. My visitor weighs 0.1 ounces (2.8 grams) and darts around at speeds up to 60 mph (96 km/h) for the few weeks it lives in the air.

Its three- to four-year lifespan is mainly spent as larva, a freshwater nymph, an underwater omnivore feeding on tadpoles, spot tails, minnows and other nymphs. Today, it is sporting iridescent wings that sparkle like ball gowns, looking to mate, which it prefers to do immodestly in the air. As it sparkles and pulsates in front of me, perfectly stationary, I am looking at 350 million years of evolution.

Dragonflies' compound eyes see ultraviolet light, giving them a unique ability to detect shape and movement. Military experts have studied their behavior to develop software for stealth aircraft because they employ active motion camouflage. When a dragonfly hunts, it hovers perfectly still and positions itself between its prey and a shadow cast behind it by, say, a tree, concealing its position. It's a bit like creeping up on someone in a forest hiding behind branches. The dragonfly can continually change its position based on where its prey moves to keep the tree and its prey lined up — a butterfly or mosquito won't notice. The dragonfly gradually looms closer until it reaches striking distance. This evolutionary adaptation has suited dragonflies well, and they have become highly successful predators despite living short lives.

A remarkable example of Indigenous observational science was revealed in 1949. Ethnoentomologists documented how the Diné (Navajo) named and classified over 700 species of insects, describing their sounds, behavior and habitats, knowledge that had been shared, memorized and passed on for generations. Why did the Navajo do this? Maybe because they are scientists. They wanted to know their world better, knowledge that could be the difference between surviving and thriving for people who live completely on and with the land.

In the forests of Mexico resides the giant owl butterfly (Caligo eurilochus) that flaps its papery 7-inch (18 centimeters) wings at dusk when predator birds are absent. At the base of each wing is a perfectly formed eyespot that, together, uncannily resemble the eyes of an owl. An artist would be challenged to create such replicas.

English naturalist Henry Walter Bates first explained the copycat wings. Arriving in 1848, Bates traveled far up the Amazon and its tributaries. Aside from its racist tropes, his book, "The Naturalist on the River Amazons," is a stunning description of 11 years of study wherein he collected over 14,000 species and identified 8,000 new ones, from mundane foraging ants to jaw-dropping, foot-wide, bird-eating Mygales spiders that giggling children paraded around leashed like a pet dog.

Like other naturalists of his day, John James Audubon and Alphonse Dubois, Bates shot birds right and left to be packed in formaldehyde and handed over to natural history museums. However, his primary interest was Amazonian butterflies.

He noticed edible butterflies being ignored by insectivorous birds and dragonflies because their wing coloring mimicked noxious or predatory species. The spicebush swallowtail caterpillar (Papilio troilus) is born black and white disguised as bird poop. It will molt three more times with spots on its head that make it appear like a snake — known as Batesian mimicry.

This evolutionary process rewarded deceptive wing patterns and coloring to protect species. He was an early supporter of Darwin's theories of evolution, and Darwin called Bates's book the best on natural history ever published in England.

What neither Darwin nor Bates could explain is how butterflies manage to disguise themselves. Had caterpillars ever looked at an owl's eye? They evolved, to be sure, and failures are gobbled up, but how exactly does the pupa of a caterpillar morph into a butterfly with perfect replicas of owl eyes on its wings?

The scientific explanation is a regulatory network that allows genes to collaborate and learn from each other. That does not tell us how the genes were programmed in the first place. Millions of years ago, genes began to paint wings with pigmented designs of extraordinary fidelity and complexity. Who was the artist?

Text from "Carbon" by Paul Hawken, published by Viking, a division of Penguin Publishing Group, a division of Penguin Random House, LLC. Copyright (C) 2025 by Paul Hawken. Reprinted with permission from Penguin Random House.

To delve deeper into Paul Hawken's work, you can read an interview with the author here, in which he tells Live Science about the paradigm shift needed to start valuing, protecting and restoring the planet and its inhabitants.

In 2000, measles was declared eliminated from the United States following a successful, national vaccination program — transmission of the disease had ceased within America, but even now, measles has yet to be eradicated worldwide. The continued spread of measles in other countries and lapses in America's vaccination rates leaves the country vulnerable to outbreaks like the one happening in Texas right now. The ongoing outbreak has so far claimed two lives, with cases increasing due to the incredibly high transmissibility of measles and low vaccination rates in the affected areas.

In this adapted excerpt from his book Booster Shots (Penguin Random House, 2025), pediatrician and infectious disease specialist Dr. Adam Ratner looks at a historical measles outbreak in Texarkana, a city at the border of Texas and Arkansas. In the outbreak, the side of the state line people happened to live on determined their fate.

True to its name, Texarkana straddles the border between the states of Texas and Arkansas. In the 1960s, about two-thirds of the population lived in the part of the city that was in Bowie County, Texas, with the remainder residing in Miller County, Arkansas. The division did not generally affect the day-to-day workings of the city, with residents of both counties attending the same local businesses, churches, and events.

However, separate public schools and public health departments were maintained on either side of the state line. Texarkana was a natural laboratory to understand how policy choices could dictate health.

In late June 1970, a 5-year-old Texarkana boy who had traveled out of the area was diagnosed with measles. He represented the first recognized case in an outbreak that would last more than six months and involve more than 600 people, mostly children. That isn't the remarkable part — measles outbreaks were becoming more frequent everywhere.

What made Texarkana different is that State Line Avenue separated two jurisdictions with quite different approaches to measles vaccination. Texas had no requirement for measles vaccination prior to school entry and generally eschewed mass vaccination campaigns.

Fewer than 60% of 1- to 9-year-olds on the Texas side were immune to measles either through vaccination or prior illness. In contrast, Arkansas maintained a school mandate and had held mass immunization campaigns for preschool- and school-aged children in each of the two years prior to the outbreak. An estimated 95% of their 1- to 9-year-olds were immune.

The result was striking. A political division, not a physical one, determined who got measles and who didn't. Of the 633 Texarkana measles cases, 606 (nearly 96% of the total) occurred in people who resided in the Texas portion of the city. This disparity in rates occurred despite significant contact between residents from the two sides. The messages were clear — vaccination had protected children who happened to reside on the Arkansas side of town, and community campaigns and school mandates were highly effective in preventing measles spread.

Related: Measles deaths jumped over 40% from 2021 to 2022, CDC reports

The Texarkana story is frequently cited in public health circles and is used as a teaching case for students of epidemiology. The lesson that is sometimes missed is that in addition to showing that vaccination protects against disease, the Texarkana measles outbreak also provides a stark reminder that political decisions about funding for public health, acceptability of school mandates, and myriad other issues can have real and lasting effects on the health of populations.

Today, Texarkana's unusual geographic and political arrangement continues to instruct us about the deeply intertwined nature of politics and health. Under the Patient Protection and Affordable Care Act (ACA, also known as Obamacare), which was passed in 2010, states were required to expand Medicaid coverage to nearly all adults with incomes up to 138 percent of the federal poverty level, with coverage going into effect in 2014.

A 2012 Supreme Court decision (National Federation of Independent Business v. Sebelius) made states' acceptance of the ACA's Medicaid expansion funds optional rather than mandatory. Arkansas accepted Medicaid expansion; Texas did not. Jonathan M. Metzl, author of "Dying of Whiteness," has chronicled how states' political decisions, including accepting or refusing Medicaid expansion, can change the health — and even alter the life expectancy — of its citizens. It is hard to imagine a place where that line is so sharply drawn as in Texarkana.

A 2023 report from Public Health Watch [a nonprofit news organization] detailed a "widening divide in health care access" between the two sides of Texarkana on the basis of those decisions. Despite the demographic similarities between the Texas and Arkansas sides of the city, after nine years of Medicaid expansion, the differences were stark. More non-elderly adults uninsured, more hospitalizations for life-threatening conditions such as diabetic ketoacidosis, worse access to care — these are the legacy of Texas's refusal to accept the ACA's Medicaid expansion.

Just as the 1970 measles outbreak made clear, in Texarkana, living on the wrong side of State Line Avenue can be hazardous to your health.

From "Booster Shots", by Adam Ratner, MD, MPH, published on February 11, 2025, by Avery, an imprint of Penguin Publishing Group, a division of Penguin Random House LLC. Copyright © 2025 by Adam Ratner, MD, MPH.

The United States officially launched its "war on cancer" by signing the National Cancer Act of 1971. Broadly, the intention was to spur research into the biology of cancer to better treat — and potentially cure — the disease. However, the nation has now been embroiled in this "war" for over 50 years, and we are nowhere closer to victory, argues Nafis Hasan, a cancer scientist and associate faculty member at the Brooklyn Institute for Social Research.

In a new book called Metastasis: The Rise of the Cancer-Industrial Complex and the Horizons of Care (Common Notions, 2025), Hasan writes that cancer research has hyperfocused on finding treatments for individuals at the expense of driving down cancer rates overall. For example, in the passage below, he describes how a fixation on "somatic mutation theory" — which states that mutations in specific genes are the primary drivers of cancer — ignores the dangers of environmental carcinogens and the benefits of public health efforts in curbing cancer incidence and mortality.

Related: The 10 deadliest cancers, and why there's no cure

The idea that cancer may be a hereditary disease can be traced back to the early twentieth century. Around 1900, the biologists Theodor Boveri and Walter Sutton rediscovered Gregor Mendel's laws of biological inheritance and proposed that chromosomes were responsible for inheriting biological traits. Boveri later proposed that a tumor cell arose when cell division went wrong and chromosomes were improperly distributed. In Boveri's view, "the problem of tumors is a cell problem." This was perhaps the first conceptualization of the "cancer cell," a lone culprit that could wreak havoc in the body.

The first experimental proof that cancer was potentially heritable came from Harvard scientist Ernest E. Tyzzer, who showed that the selective breeding of cancerous mice resulted in a disproportionately high rate of tumor incidence across generations.

The idea of cancer as a genetic disease was also advanced by the eugenics movement, which performed cancer research to assure racial "purity" in the twenties and thirties. For example, the widely used Pap smear test for cervical cancer was first presented at the Third Race Betterment Conference of 1928. Nazi Germany's research on smoking and lung cancer claimed that differential cancer rates between Jews and "Aryans" was due to blood (not workplace chemical exposures). The U.S. private sector also held exclusionary views, with DuPont refusing to hire workers with a family history of cancer, given the high rates of bladder cancer among dye workers. The scientist Carl Weller, following his discovery of retinoblastoma (a tumor of the eyes) in children, advocated that parents of children with retinoblastoma be sterilized. As late as 1956, Wilhelm Hueper, the first Director of the Environmental Cancer Section of the NCI [National Cancer Institute], suggested that Black workers would be most suitable to workplaces where exposures to carcinogenic chemicals were unavoidable given their alleged resistance to the carcinogenic action of coal tar, UV radiation, and petroleum derivatives.

Other scientists pushed back on these narratives of racial traits and cancer incidence. For instance, the notion that West Africans were racially predisposed to higher rates of liver cancer lost credibility when Japanese immigrants to the U.S. suffered the same type of cancer — the cause turned out to be aflatoxins [toxins produced by fungi that can end up on various crops] in their diets.

The discovery of DNA's double helix structure in the fifties generated momentum for molecular biology, but the field did not concern itself with the cancer problem until the late seventies. Many molecular biologists were skeptical of government-sponsored research and worried they would lose their independence and be pushed to find cancer-causing viruses. Ironically, institutional support from the Special Virus Cancer Program (SVCP) later laid the foundations for the resurgence of a molecular theory of carcinogenesis.

This resurgence was driven by the SVCP director, Robert Huebner. Huebner was inspired by French studies showing that bacterial genes could remain in a repressed state and proposed the "oncogene theory" of carcinogenesis. In short, he believed there were cancer-causing genes that just needed to be identified. He previously confirmed that certain viruses gave rise to tumors in hamsters but wanted to dive deeper into how this happened. He suspected that viral genes were responsible for initiating tumors in the hamsters and, as the manager of SVCP's annual $10 million budget, he had the resources and authority to pour money into molecular cancer research.

In the early seventies, Huebner awarded millions of dollars to both private contractors and public institutions to study the molecular actions of viruses suspected of causing cancers in humans. However, by 1974, the White House's proposed budget for the NIH [National Institutes of Health] included three times as much funding for private contractors as for traditional research grants. The use of contract work was so extensive that by 1976, SVCP project officers worked in private contractor buildings (e.g., at Meloy Laboratories, Microbiological Associates, and Flow Laboratories). Huebner's largesse towards private contractors became a focal point of attack by molecular biologists suffering from financial precarity.

James Watson (of Watson and Crick fame) established a virus cancer laboratory in 1968 and was appointed to the National Cancer Advisory Board in 1972, despite his objections to the War on Cancer. Molecular biologists like Watson posed an "anti-communist critique" of the War on Cancer by contending that government meddling in their disciplines stifled their freedom. Watson wanted to make molecular biology a major recipient of NIH and NCI funding, but without the government directing the research. He advocated for his friend, Norton Zinder, to lead a committee to investigate the work of the VCP in 1974. [The Special Virus Cancer Program (SVCP) was later called just the Virus Cancer Program (VCP).]

The subsequent Zinder Report was the nail in the coffin for the VCP, which was already under pressure from Congress for its inability to produce results about cancer-causing viruses or vaccines to fight them. While Watson and other molecular biologists decried the use of contracts and the VCP's goals, they readily used VCP funds and infrastructure to continue their own research. In fact, VCP infrastructure supported oncogene theory all the way to its final iteration, the somatic mutation theory (SMT).

SMT postulates that cancer is caused by mutations that either permanently activate or repress genes. The first validation came in 1976 with the discovery of gene src in normal human cells. Continued VCP support allowed researchers at the University of California, San Francisco to grow, develop, and hone the technique of molecular hybridization, which would be instrumental in detecting the src gene in human cells. By the late seventies, molecular biologists and viral cancer researchers had cataloged several viral genes suspected of causing human cancers. However, absolute proof of human gene involvement in carcinogenesis was still missing.

It was not until 1982 that Robert Weinberg would find the missing link — using hybridization probes, he showed the presence of v-ras in a human bladder cancer tissue specimen. In 1983, SMT was further boosted by the discovery of proteins involved in carcinogenesis. All these discoveries and advancements — hybridization probes, viral gene catalogs, and purified proteins from viruses — were products of the VCP's financial and material infrastructure.

SMT eventually surpassed viral carcinogenesis theory as the leading theory of carcinogenesis and gained social and institutional acceptance (e.g., the prestigious Lasker Awards went to oncogene researchers in 1982). Vincent DeVita, the Director of the NCI under Reagan, recommitted the Institute's budget to genetic research and further cut the environmental carcinogen testing program. The discovery of oncogenes and related proteins also opened a new arena for cancer therapies and fueled pharmaceutical industry interest in collaborations with universities.

Most scientific retellings of this history suggest that the shift from environmental carcinogens to viruses and, ultimately, to individuals' genes happened in the vacuum of universal knowledge creation. Nevertheless, a confluence of neoliberalism, libertarian ideology, and government policy cemented the idea that genes are responsible for cancer.

Somewhat problematically, experimental evidence indisputably determined that genetic fragments found in cancerous cells are also found in normal cells. However, the explanation for this fact was constructed by social and political forces. As early as 1975, the American Business Cancer Research Foundation, funded largely by the chemical industry, tried to shift the focus away from prevention and towards identifying the "underlying mechanism." The Reagan administration was more than happy to advance these efforts.

Molecular biologists, who once decried the VCP's use of contracts, were more than happy to participate in private-public collaborations that directed money to their labs. Some had even publicly cautioned against environmental regulations when the NCI, under the previous Carter administration, moved to increase funding for environmental carcinogenesis research.

SMT renewed the biomedical settlement — a commitment to treating diseases instead of preventing them. It also facilitated the real subsumption of academic research under capitalism and, consequently, an explosive growth of the cancer drug market and capital accumulation by the biotech and pharma industry.

However, this line of attack in the War on Cancer has had few meaningful outcomes for cancer patients. After more than four decades since the discovery of the first oncogene, Robert Weinberg candidly reflected on his discovery of ras: "The greatest decreases in cancer-associated mortality have come from reductions in disease incidence [prevention] rather than treatment, such as the therapies that some anticipated would flow directly from RAS research."

The concepts of "sentience" and "agency" in machines are muddled, particularly given that it's difficult to measure what these concepts are. But many speculate the improvements we are seeing in artificial intelligence (AI) may one day amount to a new form of intelligence that supersedes our now.

Regardless, AI has been a part of our lives for many years — and we encounter its invisible hand predominantly on the digital platforms most of us inhabit daily. Digital technologies once held immense promise for transforming society, but this utopianism feels like it's slipping away, argues technologist and author Mike Pepi, in his new book "Against Platforms: Surviving Digital Utopia" (Melville House Publishing, 2025).

We have been taught that digital tools are neutral, but in reality, they are laden with dangerous assumptions and can lead to unintended consequences. In this excerpt, Pepi assesses whether AI — the technology at the heart of so many of these platforms — can ever emulate the human feelings that move us, through the prism of art.

The Museum of Modern Art’s atrium was packed to the brim the day I visited Refik Anadol’s much-anticipated installation of Unsupervised (2022). As I entered, the crowd was fixated on a massive projection of one of the artist’s digital "hallucinations." MoMA’s curators tell us that Anadol’s animations use artificial intelligence "to interpret and transform" the museum’s collection. As the machine learning algorithm traverses billions of data points, it "reimagines the history of modern art and dreams about what might have been." I saw animated bursts of red lines and intersecting orange radials. Soon, globular facial forms appeared. The next moment, a trunk of a tree settled in the corner. A droning, futuristic soundtrack filled the room from invisible speakers. The crowd reacted with a hushed awe as the mutating projections approached familiar forms.

Related: Just 2 hours is all it takes for AI agents to replicate your personality with 85% accuracy

Anadol’s work debuted at a moment of great hype about artificial intelligence’s, or AI’s, ability to be creative. The audience was not only there to see the fantastic animations on the screen. Many came to witness a triumph of machine creativity in the symbolic heart of modern art.

Every visitor to Unsupervised encountered a unique mutation. Objects eluded the mind’s grasp. Referents slipped out of view. The moments of beauty were accidental, random flashes of computation, never to return. Anadol calls it a "self-regenerating element of surprise;" one critic called it a screensaver. As I gazed into the mutations, I admit I found moments of beauty. It could have registered as relaxation, even bliss. For some, fear, even terror. The longer I stuck around, the more emptiness I encountered. How could I make any statement about the art before me when the algorithm was programmed to equivocate? Was it possible for a human to appreciate, let alone grasp, the end result?

In need of a break, I headed upstairs to see Andrew Wyeth’s Christina’s World (1948), part of the museum’s permanent collection. Christina’s World is a realist depiction of an American farm. In the center of the frame, a woman lies in a field, gesturing longingly toward a distant barn. The field makes a dramatic sweeping motion, etched in an ochre grass. The woman wears a pink dress and contorts at a slight angle. The sky is gray, but calm.

Most viewers are confronted by questions: Who is this woman, and why does she lie in this field? Christina was Andrew Wyeth’s neighbor. At a young age, she developed a muscular disability and was unable to walk. She preferred to crawl around her parents’ property, which Wyeth witnessed from his home nearby. Still, there are more questions about Christina. What is Wyeth trying to say in the distance between his subjects? What is Christina thinking in the moment that Wyeth captures? This tiny epistemological game plays out each time one views Christina’s World. We consider the artist’s intent. We try to match our interpretation with the historical tradition from which the work emerged. With more information, we can still further peer into the work and wrestle with its contradictions. This is possible because there is a single referent. This doesn’t mean its meaning is fixed, or that we prefer its realism. It means that the thinking we do with this work meets an equal, human, creative act.

The emptiness of AI art

The experience of Unsupervised is wholly different. The work is combinatorial, which is to say, it tries to make something new from previous data about art. The relationships drawn are mathematical, and the moments of recognition are accidental. Anadol calls his method a "thinking brush." While he is careful to explain that the AI is not sentient, the appeal of the work relies on the machine’s encroachments on the brain. Anadol says we "see through the mind of a machine." But there is no mind at work at all. It’s pure math, pure randomness. There is motion, but it’s stale. The novelty is fleeting.

In the atrium, Unsupervised presents thousands of images, but I can ask nothing of them. Up a short flight of steps, I am presented with a single image and can ask dozens of questions. The institution of art is the promise that some, indeed many, of those will be answered. They may not be done with certainty, but very few things are. Nonetheless, the audience still communes with the narrative power of Christina’s World. With Unsupervised, the only thing reflected back was a kind of blank, algorithmic stare. I could not help but think that Christina’s yearning gaze, never quite revealed, might not be unlike the gaping stare of the audience in the atrium below. As I peered into the artificially intelligent animations searching for anything to see, I encountered the terror of never finding anything — a kind of paralysis of vision — not the inability to perceive but the inability to think alongside what I saw.

All artificial intelligence is based on mathematical models that computer scientists call machine learning. In most cases, we feed the program training data, and we ask various kinds of networks to detect patterns. Recently, machine learning programs can successfully perform evermore complex tasks thanks to increases in computing power, advancements in software programming, and most of all, an exponential explosion of training data. But for half a century, even the best AI was capped in its process, able only to automate predefined supervised analysis.

For example, given a set of information about users’ movie preferences and some data about a new user, it could predict what movies this user might like. This presents itself to us as “artificial intelligence” because it replaces and far surpasses, functionally, the act of asking a friend (or better yet, a book) for a movie recommendation. Commercially, it flourished. But could these same software and hardware tools create a movie itself? For many years, the answer was “absolutely not.” AI could predict and model, but it could not create. A machine learning system is supervised because each input has a correct output, and the algorithm constantly fixes and retrains the model to get closer and closer to the point that the model can predict something accurately. But what happens when we don’t tell the model what is correct?

Can AI ever create genuinely 'new' content?

What if we gave it a few billion examples of cat images for training, and then told it to make a completely new image of a cat? In the past decade, this became possible with generative AI, a type of deep learning that uses generative adversarial networks to create new content. Two neural networks collaborate: one called a generator, which produces new data, and one called a discriminator, which instantly evaluates it.

The generator and discriminator compete in unison, with the generator updating outputs based on the feedback from the discriminator. Eventually, this process creates content that is nearly indistinguishable from the training data. With the introduction of tools like ChatGPT, Midjourney, and DALL-E 2, generative AI boosters claim we have crossed into a Cambrian explosion broadly expanding the limits of machine intelligence. Unlike previous AI applications that simply analyzed existing data, generative AI can create novel content, including language, music, and images.

The promise of Unsupervised is a microcosm for generative AI: fed with enough information, nonhuman intelligence can think on its own and create something new, even beautiful. Yet the distance between Christina’s World and Unsupervised is just one measure of the difference between computation and thought. AI researchers frequently refer to the brain as “processing information.” This is a flawed metaphor for how we think. As material technology advanced, we looked for new metaphors to explain the brain. The ancients used clay, viewing the mind as a blank slate upon which symbols were etched; the nineteenth century used steam engines; and later, brains were electric machines. Only a few years after computer scientists started processing data on mainframe computers, psychologists and engineers started to speak of the brain as an information processor.

The problem is your brain is not a computer, and computers are not brains. Computers process data and calculate results. They can solve equations, but they do not reason on their own. Computation can only blindly mimic the work of the brain — they will never have consciousness, sentience, or agency. Our minds, likewise, do not process information. Thus, there are states of mind that cannot be automated, and intelligences that machines cannot have.

From Against Platforms: Surviving Digital Utopia. Used with permission of the publisher, Melville House Publishing. Copyright © 2025 by Mike Pepi.

In this excerpt from "Matter: The Magnificent Illusion" (Polity, 2025, translated by Edward Williams), author and physicist Guido Tonelli delves into the discovery of dark energy, and the multiple attempts to explain this strange phenomenon that appears to be driving the ever increasing expansion of the universe.

The discovery of dark energy was a real surprise for everyone, including those working on it. When it happened, in 1998, the astronomers who were the first to find themselves in the presence of such surprising data, couldn't believe their eyes. And yet the results left no doubt.

The velocity at which the universe had expanded was not constant; on the contrary, for quite some time now it had been increasing significantly. Everything was moving away from everything at an increasingly frenetic rhythm.

What scientists were seeing contradicted what they were expecting; the idea of the accelerated expansion of the universe was counterintuitive. Everyone expected that the attraction exerted by gravity would slowly reduce the expansion velocity of space-time, whereas the exact opposite was happening.

For many years, different teams of scientists tried to understand whether what the data was pointing to was real or whether, on the other hand, errors had been made in the measurements. In the end, they gave in to the evidence. There was no doubt that a new natural phenomenon was being observed, however completely unexpected it was. In the end even the Royal Swedish Academy of Sciences in Stockholm recognized the importance of the work of Saul Perlmutter, Brian Schmidt and Adam Riess, the three astronomers who had carried out the early research, rewarding their discovery with the 2011 Nobel Prize.

Right from the earliest moments, in an attempt to explain this strange phenomenon, the expression dark energy was coined, indicating the complete ignorance of the mechanism that produced it: an absolutely unknown form of energy seemingly pushing everything away from everything else and growing as the dimensions of the universe grow.

Some imagined a kind of anti-gravity, an extremely strange behaviour of gravity which from being attractive, as we know it, becomes repulsive over great distances. Others imagined a kind of vacuum energy, a positive energy, which creates a kind of negative pressure, thereby pushing everything towards dilation.

The idea that the void contains positive energy which makes it expand goes back many years. And Albert Einstein was the first to come up with it. To make the universe static, that is to counterbalance the effect of gravity, which, acting alone, would sooner or later make everything collapse into one point, Einstein added a positive constant, called the "cosmological constant" into his equations by hand, that is to say arbitrarily. This classification served to build a balance; making the universe expand countered the effects of gravity and made it stable.

Later, when it was discovered that everything had had a turbulent beginning and that galaxies were still moving apart from one another, Einstein regretted this choice, to the extent of referring to it as one of the worst blunders of his life. In fact, with a universe arising from an ultra-dense and super-incandescent singularity, there was no need for this further impetus to expansion to produce a condition of equilibrium. The curious thing is that nobody, least of all Einstein, could predict that by the end of the 20th-century, the discoveries made by Perlmutter, Schmidt and Riess would bring his cosmological constant back into vogue. And so, it seems as if nature will always end up proving Einstein right, even when the great scientist is convinced that he's clearly wrong.

In this case, too, precious information about the presence and distribution of dark energy can be extracted by analyzing the tiniest inhomogeneity in cosmic background radiation and the gravitational lens effects produced by galaxies and clusters. It's curious to discover that it is still light which allows us to take a look at this shady side of the cosmos.

The distribution of dark energy in the cosmos is very homogeneous. It behaves quite differently from matter, whether ordinary matter or dark matter. These latter material substances have reticular distributions with high- density nodes and filaments alternating with broad empty spaces. On the contrary, dark energy is distributed uniformly throughout space and seems to occupy the entire volume of the universe quite happily, exerting a repulsive force on everything.

In an attempt to understand the origin of this mysterious form of energy, scientists have ascertained whether the expansion velocity is the same, over a given period, for all the different regions of the universe. They also realized that this phenomenon has only become dominant in the last billions of years. For a long period, the universe expanded following a very different rhythm from the current one.

Various hypotheses have been tested, including the idea that we are dealing with a new fundamental force or an anomalous behaviour of gravity or even the presence in the fabric of spacetime of very particular structures, similar to defects in its regular pattern. But, as yet, nobody has managed to understand what gives rise to this strange phenomenon, and explaining dark energy remains one of the most formidable challenges of modern science.

While the mystery surrounding its origins remains, the precise measurements taken of the effects of dark energy on the geometry of the universe and on the spatial fluctuations in the density of matter have made it possible to quantify the weight of this component in the material composition of the universe.

The result is sensational; dark energy contributes around 68% of the total mass. Around two-thirds of the universe is made up of this most mysterious of components. Totalling up the contribution of dark energy, we obtain a frankly embarrassing result. Despite the great progress made by contemporary science, we are forced to admit that we don't know anything about 95% of everything that surrounds us.

Reprinted with permission from Matter: The Magnificent Illusion by Guido Tonelli, available from Polity

In this excerpt from "Oak Origins: From Acorns to Species and the Tree of Life" (University of Chicago Press, 2024), author Andrew L. Hipp explores the extreme conditions on Earth that gave rise to the oak tree (Quercus), with wild fluctuations in the climate and shifting tectonic plates.

If we could head back in time 56 million years and spend a few weeks botanizing in the temperate forests of the Northern Hemisphere, at the boundary between the Paleocene and the Eocene, we would be hard-pressed to find any oaks. We would find alligators and giant tortoises on Ellesmere Island, across from the northwest coast of Greenland. We would roam through flowering-plant-dominated forests whose diversity approached the plant diversity we might find in the modern forests of the southeastern United States. We would encounter a diversity of Fagales, lineages spreading across the Northern Hemisphere that would eventually give rise to walnuts, birches, sweet gales, beeches, chestnuts, chinkapins, and oaks.

The oaks themselves, however, were so few in number at that point that they left scant if any pollen in the mud and no acorns or leaves to be recovered by 21st-century botanists. The world was about to enter a heatwave, the Paleocene-Eocene Thermal Maximum (PETM).

Over the course of 8,000 to 10,000 years, atmospheric temperatures would spike, increasing by an average of 8 degrees C [14.4 degrees Fahrenheit] worldwide and reaching even higher levels in the Arctic. The PETM may have been triggered by a massive and protracted period of volcanic activity. Magma gurgling up through a fissure at the bottom of the North Atlantic drove a wedge between North America and Europe and poured a trillion kilograms [2.2 trillion pounds] of carbon into the atmosphere every year for several thousand years.

Rising temperatures melted corpses out of the Antarctic permafrost, and the rotting sedges, sphagnum mosses, fungi and lichens, mollusks and marsupials returned greenhouse gases — carbon dioxide and methane — to the atmosphere.

Temperatures then crashed back to their original levels within about 120,000-220,000 years. That's barely enough for a double take in geological terms: When you look at a temperature plot for the past 100 million years, the PETM looks like a fencepost driven into the hillside 56 million years ago. It goes straight up and almost straight back down.

The effects were dramatic. The PETM drove 30%-50% of deep-ocean-bottom foraminifera — single-celled organisms that populate the seas, eating plankton and detritus, feeding small fish and marine snails — extinct. Mammals, lizards, and turtles migrated widely across the continents in response to the changing climates, traveling between northern land bridges that would become too cold for regular travel by most of these species in the late Eocene.

In northern South America, tropical forests were flooded with new flowering plants: palms, grasses, and the Bean Family (Fabaceae) all increased in diversity in the Eocene, and the Spurge Family — Euphorbiaceae, a global family that numbers about 6,500 species today — showed up in northern South America for the first time during the PETM.

The first oak fossils

Insect herbivores, particularly leaf miners and surface feeders, increased in abundance and became more specialized. Plants raced across the landscape: in Bighorn Basin, Wyoming, at least 22 species were extirpated at the onset of the PETM, only to return after the event was over. Some of these sojourners migrated an estimated 1,000 kilometers [600 miles].

The first fossil oaks we know of appear in this uncertain world, along what is now a hiking trail running south of the Church of Saint Pankraz in Oberndorf, Austria. Fifty-six million years ago, this area of Europe was dissected into islands and peninsulas, which were warmed by the ocean.

What is now Saint Pankraz lay beneath shallow water at the edge of the sea. It became a repository for pollen from adjacent forests, deposited alongside oceanic plankton and dinoflagellates. The forest growing in the area was a mosaic of subtropical and temperate species, including members of the Restionaceae, a grass-like family that today is limited to the Southern Hemisphere tropics; Eotrigonobalanus, an extinct genus of the Beech Family that formerly ranged across eastern North America and Europe; and relatives of today's Cashew Family, Mallow Family, and the pantropical Sapotaceae.

The world was entering the last days of the nearly global tropics. For 4 million years after temperatures retreated from the PETM, the climate continued to warm. By 52 million years ago, the world hit the highest temperatures since the demise of the dinosaurs. This period of warmth is called the Early Eocene Climatic Optimum.

If the PETM is like a fencepost driven into the temperature hillside, the Early Eocene Climatic Optimum is like the crest of the hill. Forests of tropical species growing alongside genera of the temperate forest — maples, elms, walnuts, birches, cherries, and eventually oaks — spread across the high Arctic. The long winter nights favored species that could go dormant for months at a time. Deciduous forests spread across upland sites that are now permafrost and boreal forest.

The climate was perched at the top of a long slide down to the Anthropocene, where we find ourselves today. Oaks were pioneers in what would become the largely temperate Northern Hemisphere.

The oaks were not born at a particular moment or in a particular place. Instead, somewhere during or before the PETM, a population of woody plants gradually became the oaks. Each seedling in this lineage looked like the trees that produced it. Had we been there to witness the evolution of that ancestral population, we could at no point have said, "There were no oaks yesterday, but today there are."

Related: Where did the 1st seeds come from?

We ended up with oaks by the steady work of natural selection acting on variable tree populations over long periods of time. This lineage of individuals and populations slowly becoming the oaks is called the stem of the oak clade. It is represented on the Tree of Life by a single line.

The population of trees that deposited the St. Pankraz pollen may represent a sprig sprouting from that stem or one that sprouted very near the crown of the oaks. In either case, the St. Pankraz pollen is, for now, our best bet about how old the oaks are. Oaks probably go back at least a little longer than these fossils, older than the PETM: fossils are hard to find, so it's reasonable to suspect that we may have missed some older ones. But these fossils provide us a landmark by which to date the oak tree of life.

The first speciation event we know of in oaks likely occurred within 8 million years of the St. Pankraz oak fossil. It split the oaks into two lineages: one that is today limited to Eurasia and North Africa, and one that evolved in the Americas and only later returned to Eurasia. Sister clades — which are born as sister species — can arise in separated geographic regions when their ancestral population becomes physically subdivided. A mountain range, a river, a desert, an expanse of ocean, or any other barrier between the two portions of the population keeps seeds and pollen from moving between the two new populations. Speciation and the birth of new clades often result.

The spreading Atlantic Ocean is a plausible explanation for this first oak speciation event. Magma spilling into the North Atlantic off the coast of Ireland at the beginning of the PETM added crust to the east edge of the North American (tectonic) Plate and the west edge of the Eurasian Plate. It continues to do so today, steering the continents apart at a rate of about an inch a year.

As the Atlantic grew wider, the ancestral population of all of today's oaks may have been straddling the continents of the Northern Hemisphere. If so, the ancestor of the oaks we know today was a widespread population that was cleaved in half as North America inched westward.

Reprinted with permission from Oak Origins: From Acorns to Species and the Tree of Life by Andrew L. Hipp, published by The University of Chicago Press. © 2024 by Andrew L. Hipp. All rights reserved.

The first antibiotics made once-deadly infections curable, and their early developers were lauded with a Nobel. But these miracle drugs soon revealed their Achilles heel: When antibiotics are overused, they grow less effective as the bacteria they're designed to kill evolve to have escape strategies. This flaw has prompted scientists to seek alternative solutions.

One alternative to antibiotics is phage therapy, which harnesses viruses to attack bacterial cells. Conceived over a century ago, phage therapy fell to the wayside as antibiotics rose to prominence, but recently, the field has seen a resurgence. In "The Living Medicine: How a Lifesaving Cure Was Nearly Lost — and Why It Will Rescue Us When Antibiotics Fail" (St. Martin's Press, 2024), science journalist Lina Zeldovich recounts the complex history of phage therapy and its proponents while also highlighting how the treatment could save humanity in the future.

Related: Dangerous 'superbugs' are a growing threat, and antibiotics can't stop their rise. What can?

The Phage Whisperer

Biswajit Biswas drew a syringe full of phage and injected it into his laboratory mice, one after another. The mice weren't sick, so he wasn't using phages as medicine. He just wanted to know how long the phages would persist inside the mice — an experiment similar to what [Giorgi] Eliava and [Félix] d'Hérelle once carried out to understand how far phages could travel in rodents' bodies. In about a day, Biswas would test the mice's blood to see if the phages were still floating inside them. Typically, most phages would be gone because they were quickly filtered by the liver and spleen, but sometimes a tiny fraction remained. Biswas would harvest the survivors, grow them — and inject them into the mice again.

Biswas was working on this unconventional project in the mid-1990s, in the laboratory of Carl Merril, an NIH scientist and an early phage enthusiast who was playing around with the idea of using them to treat disease. Their mice were getting blood tests right about the same time that [Alexander] Sandro [Sulakvelidze] and [Glenn] Morris were having their first phage conversations and putting together their VRE [vancomycin-resistant enterococcus] proposals. Geographically, the two teams weren't far from each other. Both were located in Maryland. Both understood phages as medicinal agents, which the rest of the medical field viewed as nonsensical.

Merril, however, approached the problem from a different angle. Rather than treating sick mice with phages, he wanted to know how long living medicines could survive inside a creature. In humans and animals, the liver, spleen, and immune system tackle foreign invaders and filter them out quickly. Merril wanted to know how long phages could persist before they got gobbled up by the body's natural defense mechanisms. He also wanted to know if phages could evolve to avoid being devoured. By handpicking surviving phages and reinjecting them again, Biswas and Merril hoped to find answers.

"It was a selection process," Biswas explains. "I was growing phages and injecting them intravenously and intraperitoneally in mice, and the next day, after thirteen or eighteen hours, I would bleed the mice and take those phages and grow it again — passage after passage." It was a method akin to what d'Hérelle outlined in his book "The Bacteriophage and the Phenomenon of Recovery," which Eliava translated.

Originally from India, Biswas followed his family's tradition and earned a degree in veterinary medicine. Working in animal husbandry in the mid-1980s, he watched with growing concern the increasing use of antibiotics — both to battle infections and to fatten up the animals. While looking for possible alternatives, he came across intriguing scientific literature dating back to the early 20th century, when d'Hérelle's successful phage experiments prompted doctors to first use them to treat disease.

Between 1930 and 1935, British medical officer Lieutenant Colonel J. Morison, who was inspired by d'Hérelle's work, used phages during cholera epidemics in India, for treatment and prevention. In 1932, he reported few cholera deaths in the phage-treated Naogaon region, compared to 474 deaths in the Habiganj region that declined to utilize the treatment.

Related: 10 of the deadliest superbugs that scientists are worried about

"I read a paper that the British actually used bacteriophage from River Ganges to treat cholera," says Biswas. "They inoculated a water well in a village, and that reduced the incidences of cholera."

As a veterinarian in India, Biswas didn't have a way to experiment with phages. But then, like Sandro, he came to the United States in the 1990s to work on his PhD. He landed in the same place as Sandro, the University of Maryland. There, he found an ally in Merril, who was equally fascinated with bacteria eaters. As an NIH scientist, Merril watched antibiotics lose their punch and knew medicine needed an alternative. "When I started my career in the 1970s, we thought antibiotics were doing fine. By the 1990s, it was clear that we were going to have a problem. I thought phages were worth trying."

Merril had become interested in bacteriophages after taking a summer course at Cold Spring Harbor back in the 1970s. The course focused on phages' basic biology, but for Merril, it left two big unanswered questions.

"Why don't we use them for treating infectious diseases?" Merril asked his professor. The man told him to go read "Arrowsmith" by Sinclair Lewis — the very book that left d'Hérelle excited in the spring of 1925, shortly before he so spectacularly cured plague in Egypt. The professor's intention was to show Merril why phages had become discredited, but that wasn't what he found. In fact, Merril realized that his professor likely skimmed the book, if he read it at all. "He didn't read 'Arrowsmith,' because if you read it really carefully, it's not an indictment of phage," Merril says. "It's an indictment of human beings and their greed and their misuse of things."

Merril's other big question was about what happens to phages once they enter the human body — in particular, the circulatory system. Does the immune system destroy them? How quickly? Can some persist? From initial experiments with injecting phages into mice, he found that even before the immune system cells gobbled up bacteriophages as foreign organisms, the liver and spleen filtered them out. "My next question was, can we find a phage strain that wouldn't be taken up by the liver?" he recalls. "Such a strain would be more effective."

Merril happened to be on a committee that oversaw Biswas's PhD research, and one day, they started talking. "I told him that I used phages before in my graduate studies to make a phage library mainly for molecular biology work," Biswas recalls. Merril was interested. "I'd like to try to use bacteriophages to overcome antibiotic resistance problems," he told Biswas. "Would you come work in my lab?" Biswas was intrigued. "I said, 'It's an interesting idea. I can work in that field.'"

For a while after he joined Merril's lab, Biswas's days revolved around injecting mice with phages against E. coli and Salmonella typhimurium and then taking their blood tests to see how quickly the bacteria eaters were eaten themselves, disappearing from circulation. About a day later, most phages would be gone, except for a tiny fraction. Biswas would filter them — and repeat the process again.

The first few rounds didn't exhibit much success. But then Biswas noticed that the survivors' numbers increased. "Surprisingly, after the eleventh round, we saw that the phage titer from the blood was getting higher," he recalls. "So we isolated those long-circulating or long-swimming phages." Similarly to d'Hérelle, they also turned to Greek mythology, naming their newfound potent creatures after Jason and the Argonauts, who sailed on the ship called Argo to retrieve the Golden Fleece. Although technically speaking phages can't swim on their own, they merely float, Biswajit and Merril liked the term. "We called them Argo1 and Argo2 phages because they were good swimmers."

The two types of Argo phages Biswas and Merril selected weren't just good swimmers — they were exceptional. Argo1's 18-hour survival numbers were 16,000-fold higher than the strain Biswas started with. Argo2's was 13,000-fold higher. Notably, these Argo phages also made better medicines than their original brethren. "Mice would survive when you treat with either phage," Biswas says. "But when we treated them with the Argo phages, they would recover much faster because the phages persisted longer in their bodies."

From "The Living Medicine: How a Lifesaving Cure Was Nearly Lost — and Why It Will Rescue Us When Antibiotics Fail" by Lina Zeldovich. Copyright © 2024 by the author and reprinted by permission of St. Martin's Publishing Group.

We often joke that our attention spans have dropped significantly in recent years with the rise of digital technologies and screen-centric entertainment, but there is sound science to back up this observation. In fact, a shorter attention span is simply one side effect of a recent explosion of screen distractions, as neurologist and author Richard E. Cytowic argues in his new book, "Your Stone Age Brain in the Screen Age: Coping with Digital Distraction and Sensory Overload" (MIT Press, 2024).

In his book, Cytowic discusses how the human brain has not changed significantly since the Stone Age, which leaves us poorly equipped to handle the influence and allure of modern technologies — particularly those propagated by big tech companies. In this excerpt, Cytowic highlights how our brains struggle to keep up with the lightning-fast pace at which modern technology, culture and society are changing.

From an engineering perspective, the brain has fixed energy limits that dictate how much work it can handle at a given time. Feeling overloaded leads to stress. Stress leads to distraction. Distraction then leads to error. The obvious solutions are either to staunch the incoming stream or alleviate the stress.

Hans Selye, the Hungarian endocrinologist who developed the concept of stress, said that stress "is not what happens to you, but how you react to it." The trait that allows us to handle stress successfully is resilience. Resilience is a welcome trait to have because all demands that pull you away from homeostasis (the biological tendency in all organisms to maintain a stable internal milieu) lead to stress.

Screen distractions are a prime candidate for disturbing homeostatic equilibrium. Long before the advent of personal computers and the internet, Alvin Toffler popularized the term “information overload” in his 1970 bestseller, Future Shock. He promoted the bleak idea of eventual human dependence on technology. By 2011, before most people had smartphones, Americans took in five times as much information on a typical day as they had twenty-five years earlier. And now even today’s digital natives complain how stressed their constantly present tech is making them.

Visual overload is more likely a problem than auditory overload because today, eye-to-brain connections anatomically outnumber ear-to-brain connections by about a factor of three. Auditory perception mattered more to our earliest ancestors, but vision gradually took prominence. It could bring what-if scenarios to mind. Vision also prioritized simultaneous input over sequential ones, meaning that there is always a delay from the time sound waves hit your eardrums before the brain can understand what you are hearing. Vision’s simultaneous input means that the only lag in grasping it is the one-tenth second it takes to travel from the retina to the primary visual cortex, V1.

Smartphones easily win out over conventional telephones for anatomical, physiological, and evolutionary reasons. The limit to what I call digital screen input is how much the lens in each eye can transfer information to the retina, the lateral geniculate, and thence to V1, the primary visual cortex. The modern quandary into which we have engineered ourselves hinges on flux, the flow of radiant energy that bombards our senses from far and near. For eons, the only flux human sense receptors had to transform into perception involved sights, sounds, and tastes from the natural world. From that time to the present we have been able to detect only the tiniest sliver of the total electromagnetic radiation that instruments tell us is objectively there. Cosmic particles, radio waves, and cellphone signals pass through us unnoticed because we lack the biological sensors to detect them. But we are sensitive, and highly so, to the manufactured flux that started in the twentieth century and lies on top of the natural background flux.

Our self-created digital glut hits us incessantly, and we cannot help but notice and be distracted by it. Smartphone storage is measured in tens of gigabytes and the hard drive of a computer in terabytes (1,000 gigabytes), while data volumes are calculated in petabytes (1,000 terabytes), zettabytes (1,000,000,000,000 gigabytes), and beyond. Yet humans still have the same physical brain as our Stone Age ancestors. True, our physical biology is amazingly adaptive, and we inhabit every niche on the planet. But it cannot possibly keep up with the breathtaking speed at which modern technology, culture, and society are changing. Attention spans figure prominently in debates about how much screen exposure we can handle, but no one considers the energy cost involved.

A much-cited study conducted by Microsoft Research Canada claims that attention spans have dwindled to below eight seconds — less than that of a goldfish — and this supposedly explains why our ability to focus has gone to hell. But that study has shortcomings, and “attention span” is a colloquial term rather than a scientific one. After all, some people’s Stone Age brains have the capacity to compose a symphony, monitor the data stream from a nuclear reactor or the space station, or work out heretofore unsolvable problems in mathematics. Individual differences exist in the capacity and ability to cope with stressful events. To give California its due, Gloria Mark at the University of California, Irvine, and her colleagues at Microsoft measured attention spans in everyday environments. In 2004, people averaged 150 seconds before switching from one screen to another. By 2012 that time had fallen to 47 seconds. Other studies have replicated these results. We are determined to be interrupted, says Mark, if not by others, then by ourselves. The drain on our switching is "like having a gas tank that leaks." She found that a simple chart or digital timer that prompts people to take periodic breaks helps a lot.

Neuroscience distinguishes sustained attention, selective attention, and alternating attention. Sustained attention is the ability to focus on something for an extended period. Selective attention speaks to the aptitude for filtering out competing distractions to stick with the task at hand. Alternating attention is the capacity to switch from one task to another and back again to where you left off. In terms of the energy cost incurred by repeatedly shifting attention throughout the day, I fear we have hit the brain’s Stone Age limit. Exceeding it results in foggy thinking, reduced focus, thought blocking, memory lapse or precision calipers, any tool quickly comes to feel like an extension of oneself. The same applies to smart devices. Two centuries ago when the first steam locomotives reached a blistering speed of thirty miles per hour, alarmists warned that the human body could not withstand such speeds. Since then ever-faster cars, communication methods, jet planes, and electronics have diffused into the culture and become absorbed into daily life. In earlier times fewer new technologies appeared per decade, fewer people were alive, and society was much less connected than it is today.

By contrast, the invention, proliferation, and evolution of digital technology have put the status quo in constant flux. Unlike analog counterparts such as a landline telephone or a turntable, smart devices repeatedly demand and command our attention. We have conditioned ourselves to respond to texts and incoming calls the moment they arrive. Admittedly, sometimes jobs and livelihoods do depend on an immediate response. Yet we pay a price in terms of energy cost incurred by constantly shifting and refocusing attention.

This excerpt has been edited for style and length. Reprinted with permission from "Your Stone Age Brain in the Screen Age: Coping with Digital Distraction and Sensory Overload" by Richard E. Cytowic, published by MIT Press. All rights reserved.

A volcanic crater in Indonesia over 7,700 feet (2,350 meters) above sea level is home to Earth's largest acidic lake, with water like battery acid. In this excerpt from "Beyond The Sea: The Hidden Life in Lakes, Streams, and Wetlands" (Johns Hopkins University Press, 2024), author David Strayer examines the extreme chemistry of some of our planet's natural lakes — and the life they host.

I know people who really like water chemistry. They spend all day thinking about redox reactions and mass balance and valences and solubility indices and spiraling metrics, and when the workday is over, they go out for a beer with their friends and talk about redox reactions and spiraling metrics. (In my experience, water chemistry enthusiasts are often beer connoisseurs as well, which makes sense in a weird way if you think of a glass of beer as a special kind of aqueous solution.)

These are people who when asked to name their favorite chemical element say "ooh, ooh, can I have three?" and then name five. I'm guessing that you're not one of those people.

So instead of going into great detail, element by tedious element, about the enormous variation in the chemical content of inland waters, I'm just going to briefly talk about how much pH varies across inland waters, assume that is sufficient to make my point about the chemical diversity of inland waters, and move on to subjects that you like better than water chemistry.

You may remember from high school chemistry that pH is a measure of whether a substance is acidic or basic (or "alkaline"). Materials that are neutral (neither acidic nor basic) have a pH of 7, acidic materials have a pH less than 7 (household vinegar has a pH of about 2.5), and basic materials have a pH greater than 7 (household ammonia has a pH of about 11.5). The pH scale is logarithmic — a change in pH of one unit represents a 10-fold change in acidity (technically, a 10-fold change in the activity of hydrogen ions). So vinegar at a pH of 2.5 has about a billion times more hydrogen ion activity than does ammonia at a pH of 11.5.

The logarithmic scale allows us to conveniently express enormous differences in chemistry but makes it easy to forget that small differences on the pH scale can mean big differences in chemistry which can have large consequences.

For instance, the ocean today has a pH of around 8.1, which tells us that it is a little basic. Higher concentrations of carbon dioxide in the air resulting from fossil fuel burning have caused the ocean's pH to fall 0.1 units from a preindustrial value of 8.2, and models suggest that it may fall to 7.8 by the year 2100. These sound like small changes hardly worth worrying about. But a change from 8.2 to 8.1 represents an increase in hydrogen ion of 26%, and a change from 8.2 to 7.8 means an increase of 150%.

These changes are enough to cause serious problems for marine life. Organisms like clams and corals that make their shells out of calcium carbonate find it increasingly difficult to build and maintain their shells if the pH drops just a few tenths of a point. Ocean scientists are now scrambling to understand and find ways to prevent or manage these changes before we lose important parts of ocean ecosystems as the pH drops by 0.3 or 0.4 units.

The pH range across inland waters is far greater than the few tenths of a point that are so important in the ocean. This exposes inland water organisms (and chemical processes) to an enormous range of chemical conditions. Most inland waters have a pH between 4 and 9. Again, this range may sound modest, but it represents a 100,000-fold range in hydrogen ion activity. And there are waters that lie outside even this expansive range.

The most acidic natural inland waters are the lakes that lie in the craters of volcanoes, like Kawah Ijen in Indonesia. These lakes are so rich in sulfuric acid that they may have a pH as low as 0.1. To put this in context, fresh battery acid has a pH of about 0.7. The label on battery acid (which remember is about a quarter as strong as this lake water) warns that it causes severe skin burns and eye damage and advises consumers to use personal protective equipment, to immediately call a poison control center if it gets swallowed, and to dispose of it in an approved waste disposal plant. You might feel pretty confident in guessing that nothing lives in this lake.

But when scientists sampled Kawah Ijen (an undertaking that required special gear; as you might imagine, a lot of regular gear like aluminum boats would dissolve in the lake water), they found a green alga and three kinds of archaeans living in the lake.

Apparently, no animals live in the lake. However, the acid water in its outlet stream is gradually neutralized as it flows downstream, and the researchers discovered fly larvae called chironomids living in the stream at the point where the outlet stream reached a pH of about 2.5 (like vinegar, remember?).

Related: 'It looks like smoke': Mysterious chimneys spewing shimmering liquid discovered at the bottom of the Dead Sea

And more remarkably, not only do these species survive in highly acidic waters but some of them even prefer these harsh conditions. One of the archaeans living in volcanic waters can tolerate pH below 0 and grows best at a pH of 0.7. That is, battery acid is its ideal pH and vinegar and lemon juice are far too mild for its taste. (If you’re wondering about how low the pH of nonnatural waters can go, a pH as low as -3.6, yes that’s minus 3.6, has been recorded in some groundwaters in California polluted by mining wastes. It was a major technical problem for scientists to figure out even how to measure such low pH.)

At the other end of the spectrum, alkali lakes often have a pH of 9.5 to 11.5. Alkali lakes typically occur in regions that are so dry that any water that runs into the lake leaves by evaporation rather than through an outlet stream. This allows minerals dissolved in the water to build up to very high concentrations. Depending on the surrounding geology, such lakes may develop into salt lakes (like the Great Salt Lake in Utah) that are filled with sodium chloride (ordinary table salt) or alkali lakes that contain a lot of sodium carbonate (washing soda) and other minerals that give the lakes such high pH and alkalinity.

Alkali lakes and the salt flats that form when the lake dries up altogether have been in the news lately because some alkali lakes and flats are a major source of lithium, which is needed to make batteries for electric cars and which has other uses. Alkali lakes also show up in the old westerns — parched travelers who ran out of water two days ago come across a desert pool, and the greenhorn in the group throws himself into the brackish water, swallowing it in huge gulps. Then he stumbles away from the water, retching, after which the laconic leader of the band remarks: "bad water."

Again, you might think that such bad water wouldn't support life. As is the case of the corrosively acidic volcanic lakes, few species other than microbes can tolerate the harsh conditions in alkali lakes, but these few species can be enormously productive. In fact, alkali lakes can be among the most productive of inland waters in terms of the sheer amount of biomass that is grown each year.

So in contrast to the pH of the ocean, which is very near 8.1, the pH of inland waters spans a range from about 0.1 to 11.5, representing a 250 billion–fold range in hydrogen ion activity. Life exists and even thrives over this enormous range. This huge range in pH presents both a challenge and an opportunity for evolution to produce species whose ecology and physiology are adapted to some specific part of it: different species for strongly acid waters, mildly acid waters, neutral waters, mildly alkaline waters, and strongly alkaline waters.

Excerpted from "Beyond the Sea: The Hidden Life in Lakes, Streams, and Wetlands" by David Strayer. Copyright 2024. Published with permission of Johns Hopkins University Press.

One of the key areas that artificial intelligence (AI) threatens to disrupt is human creativity — and the rise of generative AI has certainly thrown art into the spotlight. While fears remain that AI may replace human input and agency across society, a different approach suggests humans will meld with AI in some capacity — with the new technologies augmenting us rather than undermining us.

In "Centaur Art: The Future of Art in the Age of Generative AI" (Springer, 2024), computer scientist Remo Pareschi explores the notion of "centauric intelligence" — an integration of human and computing intelligence — and its impact on the future of art. In this excerpt, Pareschi explains how our primal fears are misguided and argues that the rise of AI may, in fact, help human creative endeavors transcend to new heights.

As we revisit our initial, most pressing concern — will artificial intelligence surpass human creativity in artistic endeavors? — it's crucial to recognize that the question, as commonly posed, is somewhat misdirected. Unlike games such as chess or Go, art cannot be measured by a simple win-lose metric. The fear, however, is similar: could humans be supplanted in artistic production as they have been in high-level chess?

Our analysis, grounded in cognitive considerations and carried out in the pages to come, suggests a nuanced answer. At the pinnacle of creativity — where inspiration, conception and originality reign — AI is an enhancer, aiding in realizing powerful and original works. In such contexts, the human artist's role remains paramount, with AI serving as a tool to augment their creative vision. Conversely, AI's role can become more structured or repetitive. It can automate the production of routine outputs such as certain types of commercial illustrations, brochures, or video game characters. This automation significantly impacts professionals in these fields, who may rely on such work for their livelihood. Consequently, these individuals may view the advent of AI technologies with apprehension and concern.

Economic and legal implications

The economic threat of generative platforms is closely intertwined with concerns about copyright infringement. A notable legal action in this arena occurred in January 2023, when a group of artists filed a class-action lawsuit against Stability AI, Midjourney, and DeviantArt. The lawsuit centered on the alleged unauthorized use of artists' works to train AI tools, sparking a debate over the legal and ethical boundaries of AI in art.

The highlighted lawsuit underscores the ongoing tension between AI’s innovative potential in art and individual artists’ rights. Plaintiffs in the case argued that AI tools were creating derivative works based on their styles without proper authorization or compensation. In contrast, the AI art companies defended their actions, asserting that the AI-generated images were transformative and original, thus not violating any laws. In a significant development in October 2023, a US judge dismissed most of these claims due to a lack of direct infringement evidence.

On the other hand, to complicate matters further, the US Copyright Office in September 2023 rejected copyright protection for Theatre D’opera Spatial, an artwork predominantly created by AI and crafted by artist Jason Allen. This artwork had previously won an art contest, but the Copyright Office’s decision was based on the lack of significant human intervention in its creation. This stance contrasts with the position of Lawrence Lessig, a Harvard Law School professor and a renowned expert on Internet and law issues. Lessig advocates for the recognition of copyright in prompt-generated artworks, arguing that they are original and creative, embodying the human input of the prompter. He believes these works should be treated on par with other technologically aided art forms and that they have the potential to invigorate the art world by inspiring current artists and drawing in new audiences interested in AI's artistic capabilities.

Interestingly, international perspectives on this issue vary. In November 2023, a Chinese court ruled that AI-generated content could be protected under copyright law, which starkly contrasts with the human authorship requirement under U.S. copyright law.

Thus, despite these legal battles, the issue of copyright infringement in AI art remains unresolved, with the potential for future challenges and changes in various jurisdictions. This uncertainty underscores the evolving nature of art in the digital age and the need for a balanced approach that respects both innovation and artists’ rights.

A striking example of the social impact of generative platforms is the publication of Sunyata by Eris Edizioni, an Italian graphic novel authored by philosopher and digital artist Francesco D'Isla that combines AI-generated images with traditional text. The novel ignited controversy among artists and comic book creators, who criticized its use of AI as undermining artistic integrity and economic fairness. The author and publisher defended their work as a legitimate artistic endeavor, emphasizing their careful use of prompts and adherence to a Creative Commons license.

This case exemplifies the broader debate surrounding AI in art: balancing technological innovation with ethical considerations and the economic interests of human artists. As generative platforms continue to evolve, these discussions will likely intensify, shaping the future of art in the digital era. And yet, we might say that this is nothing new, with history repeating itself — the intersection of technology and art has always been a crucible of innovation and controversy.

Exploring new artistic avenues

Indeed, throughout history, technological advancements, from ink and paper to the development of cameras and computers, have continually opened new avenues for artistic expression. Yet, each technological leap has also brought ethical and social challenges, echoing today’s tensions between generativity and control, authenticity and originality, and the impact of digital platforms on the art market.

Historically, resistance to new art forms and technologies is not a novel phenomenon but a recurring pattern. For instance, the advent of photography in the 19th century was initially met with skepticism by some critics and artists, who viewed it as a mechanical, uncreative process threatening traditional art forms. Similarly, introducing sound and color in cinema faced opposition, with concerns about diminishing the artistic value of silent and black-and-white films. Just as photography and color cinema once disrupted artistic norms, today’s generative platforms like DALL-E, Stable Diffusion, and MidJourney are provoking similar debates in the art world.

To navigate this complex landscape, the insights of Walter Benjamin and John Maynard Keynes offer valuable perspectives. Benjamin was concerned about losing aura due to the mechanical reproduction of the work of art, but also recognized its democratizing potential. Generative platforms like DALL-E, Stable Diffusion, and MidJourney take this democratization one step further, making artistic creation more accessible and fostering a sense of community and creativity. Allowing users to generate and share art potentially fulfills Benjamin's social role in art.