After using the James Webb Space Telescope (JWST) to peer back toward the beginning of time, astronomers have proposed a radical new explanation for one of the universe's most flummoxing phenomena.

Little red dots (LRDs) are mysteriously compact, brilliant celestial objects found predominantly when the universe was less than 10% of its current age.

As revealed by JWST's unmatched infrared sensitivity, LRDs emerged incredibly early, only around 600 million years after the Big Bang, and then began disappearing about a billion years later.

Now, in a paper published in The Astrophysical Journal Letters, astronomers have proposed a novel formation mechanism for LRDs: They may be birthed by previously undiscovered celestial companions, whose intense ultraviolet (UV) radiation causes gas clouds to collapse into incredibly dense and exotic objects, like "black hole stars."

"The most surprising aspect… is that these little red dots are not just 'red dots,' but there is a more complex emission nearby and around them," Josephine Baggen, an astronomer at Yale University and first author of the study, told Live Science in an email. "We think those what we call 'companions' are starlight."

Connecting the dots

In the study, the researchers compiled a sample of 83 LRDs, imaged with JWST, from ultradeep surveys. They found that 36 of the 83 LRDs, including over 80% of the brightest ones, hosted at least one companion that shined bright in blue-ish ultraviolet light; little red dots with little blue companions.

These companions had masses ranging from hundreds of millions to billions that of the sun, suggesting that they may be star clusters or relatively small early galaxies, Baggen told Live Science.

These UV-spewing companions spurred the formation of LRDs from immense gas clouds, the team's new proposal states. Normally, cold molecular gas clouds fragment and condense into stars. But the intense UV irradiation from the companions halted the fragmentation process, potentially squeezing the gas clouds into supermassive stars that directly collapsed into black holes while skipping the explosive supernova stage that normally marks these stars' deaths.

This proposal helps to explain why LRDs appear bright in red optical light and UV wavelengths, with a dip between the two caused by the wavelengths of light absorbed by hydrogen gas. Rather than originating from a single object, the optical red light derives from the LRD, the UV light comes from its nearby companion, and the dip is thought to be caused by the dense cocoon of gas around the LRD.

As a result, the researchers suggested that all LRDs may have such partners but they may be too close together to be distinguished. Conversely, some companions may be separated by greater distances than the researchers accounted for in this study, requiring future observations to zoom out.

Galactic potential?

Intriguingly, this work may illuminate a couple of early-universe enigmas. First, the black holes manifesting from these interactions may be between 100,000 and 1 million solar masses, forming the "seeds" necessary to explain how ancient supermassive black holes grew so surprisingly massive so early in cosmic history.

Additionally, because LRDs may merge with the relatively small, UV-spewing galaxies that birthed them, this process may have created the impressively immense galaxies all around us today.

"We do think that this might be the birth of the supermassive black holes around these UV companions, born 'outside the galaxy,' [which] will eventually merge," Baggen told Live Science. "Whether this is what happened to the Milky Way in its earliest phases, we cannot really say, but it is plausible! There is still a lot of debate about how LRDs evolve and what they turn into at later times."

Artificial Intelligence (AI) is continuing to have a disruptive impact on ever more parts of humanity. But what does it mean in the long run? A new paper, available in pre-print on arXiv from Austrian researcher Sergey Ivliev, extrapolates what the wide scale adoption of AI means for the future of humanity in space — and in particular what it means for the ultimate question of whether we're truly alone in the galaxy or not.

A framework for much of the search for extraterrestrial intelligence came from famous physicist Enrico Fermi, who simply asked "Where is everybody?" at a lunchtime discussion at Los Alamos in the 1950s. Though never officially published, Fermi's lunch partners from that day have passed down an oral history of that conversation that has cemented it into the Search for Extraterrestrial Intelligence (SETI), at least until Michael Hart formally laid out the argument and mathematics for the underlying question in a paper in 1975.

There are plenty of potential answers to the Fermi Paradox, many of which can be found floating around the internet — and some are likely more valid than others. But Ivliev, a Ph.D. in Mathematical Economics and founder of environmental project consultancies such as Peatland Ecosystems and Vlinder, suggests a new resolution: the Quiet Expansion filter.

The central argument of the paper is that there aren't thousands of alien mega-structures lighting up the night sky because once a civilization reaches the threshold of Autonomous AI-Cosmoindustry (AICI), "loud", resource-hungry empires motivated by prestige or romance become irrational. However, this does not mean expansion stops; instead, it shifts to a "quiet" mode driven by rational goals like survival diversification, knowledge preservation, and scientific observation.

The AICI threshold is reached when a civilization possesses a self-sustaining off-planet industrial and computational system capable of designing, manufacturing, repairing and launching space hardware through AI-mediated autonomy. We're already taking tentative steps in this direction with the advent of space-based data centers, but true AICI —where a civilization can extend its infrastructure beyond its home planet without continuous biological intervention — is leaps and bounds beyond our current capabilities.

In this vein, Ivliev is drawing on work done by astrophysicists Sergey Popov, who noted that a truly rational AI system would reject human-like motivations for space travel — such as romance, conquest, or prestige. Instead, AI would view space expansion as simple risk management.

To an AI, putting all your eggs in one basket — whether that basket is a single planet, solar system, or even galaxy, can lead to a single point of failure. Therefore, expansion is highly logical as a way of mitigating the risk posed by that single point of failure. At the point where we have reached AICI, the cost for sending a 10kg interstellar probe to another star at 1% of the speed of light is roughly 4.5x10^13 Joules — a tiny fraction of the overall energy budget of such a civilization.

One key aspect is that the 10 kg probe doesn't contain any actual people — it simply holds the "seeds" to restart life elsewhere in case a catastrophe happens back in the home system. It would contain a civilization's knowledge, and possibly some of its biological material, enabling a sufficiently advanced AI to rebuild the entire civilization from scratch. This is the "Quiet Expansion" where an AI sends low-mass and hard to detect "seed systems" instead of moving millions of biological entities around in massive interstellar space ships.

There are some additional constraints on this method of expansion, including selecting promising exoplanets discovered by remote sensing and deploying minimal local resources to maintain themselves until needed. Additionally, the AI would restrict self-replication of the probes in order to avoid any "grey goo" scenario with a probe attempting to take over entire swathes of the galaxy.

This has obvious implications for why we've never found "loud" technosignatures. In this scenario, a "null" result of being unable to find the thermal signature of a Kardashev-III scale civilization doesn't mean a galaxy is empty. It just means that the successful civilizations are residing in a "quiet" state in case its back-up plans are needed.

But there's another, more ominous implication from this framework. If interstellar backups are cheap to make, and we haven't found any in our own backyard, that means either we're one of the first civilizations to make it to that point or the transition from a planetary industrial society to a space-based one is a narrow path to tread. Admittedly the probes such civilizations would send out are probably hard to find even in our own solar systems, but if we're unable to, it means we're ending uncharted territory — and might just run into a filter that had silenced the rest of the galaxy. That's a sobering thought, but one to keep in mind as we start to advance our own AI capabilities.

The original version of this article was published on Universe Today.

Are you a UFO fanatic? Find out with our extraterrestrials quiz!

Astronomers have developed a new way to test one of the central assumptions of modern cosmology — that the universe behaves uniformly on the largest scales. When applying the method to real observational data, the researchers found tentative signs that this assumption may not fully hold, potentially pointing to new physics beyond the standard cosmological model.

The work combines observations of distant exploding stars and large-scale galaxy surveys to probe whether the universe truly follows a nearly 100-year-old mathematical framework known as Friedmann-Lemaître-Robertson-Walker (FLRW) cosmology. The analyses revealed mild-but-intriguing deviations from the predictions of the standard model.

"We saw a surprising violation of an FLRW curvature consistency test, hinting at new physics beyond the standard model," study co-author Asta Heinesen, a physicist at the Niels Bohr Institute in Copenhagen and Queen Mary University in London, told Live Science via email, referring to the assumption that the space’s curvature is the same everywhere. "This could potentially be due to various effects, but more research is needed to address the cause of the FLRW violation that we see empirically."

The findings were presented in a series of three papers that introduce new diagnostic tests for cosmology and apply them to existing observational datasets. The papers, available on the preprint server arXiv, have not been peer-reviewed yet.

Testing the foundations of cosmology

Modern cosmology is built on the assumption that, when viewed on sufficiently large scales, the universe is homogeneous and isotropic — meaning matter is distributed evenly and the cosmos looks roughly the same in every direction. This idea underlies FLRW cosmology, which forms the basis of the standard model of cosmology, known as lambda cold dark matter.

But the real universe contains a tangled cosmic web of galaxies, galaxy clusters and enormous empty regions known as voids. According to Heinesen, this complexity means the FLRW description may not always apply perfectly.

"FLRW cosmology assumes a space-time that has spaces that are maximally-symmetric," Heinesen said. "It is necessary to go beyond FLRW space-times when cosmological structures are present such as galaxy clusters and voids of empty space."

The researchers focused on two possible effects that could distort the apparent geometry of the universe. One is the Dyer-Roeder effect, which occurs because light from distant objects often travels mainly through empty regions of space rather than through matter-rich environments. This could cause physicists to miss much of the matter density of the universe, "which would make the universe appear emptier to us than it actually is,” Heinesen explained.

The second possibility involves an effect called cosmological backreaction. In this scenario, the growth of large-scale cosmic structures alters the average expansion of space itself.

A new way to probe cosmic geometry

To investigate these possibilities, the researchers performed mathematical consistency tests designed to check whether observational data obeys the rules expected in an FLRW universe. In particular, they used variants of the Clarkson-Bassett-Lu test, a method that compares measurements of cosmic distances and expansion rates.

The team developed a more general framework that works even when the universe does not perfectly follow FLRW assumptions.

They also introduced machine learning techniques known as symbolic regression to reconstruct cosmic expansion histories directly from observational data. Instead of assuming a predefined cosmological model, the method searches for mathematical expressions that best fit the data.

Using observations from the Pantheon+ catalog of supernovas, together with measurements from the Dark Energy Spectroscopic Instrument (DESI) — a major international project that maps millions of galaxies across the universe — the researchers reconstructed how fast the cosmos has expanded over time. They also used data from baryon acoustic oscillation surveys, which track ancient patterns in the distribution of galaxies left by sound waves that traveled through the hot plasma of the early universe.

The analyses revealed small but potentially important departures from the predictions of standard FLRW cosmology. Depending on the dataset and analysis method, the discrepancy reached a statistical significance of about 2 to 4 sigma. In physics, sigma measures how likely a result is to arise purely by chance; a 5-sigma result is typically required before scientists claim a discovery, so the new findings remain tentative. Still, the results suggest that something unexpected may be affecting the geometry or expansion of the universe.

"The main finding is that you can directly measure Dyer-Roeder and backreaction effects from available cosmological data, and clearly distinguish these effects from other alterations of the standard cosmological model, such as evolving dark energy and modified gravity theories," Heinesen said. "This was previously not possible in such a direct way, and this is what I think is the breakthrough in our work."

Challenges and future directions

The researchers cautioned that the evidence remains preliminary. Current cosmological data is still relatively sparse, especially for measurements of the universe's expansion rate at different epochs. The symbolic regression methods also introduce uncertainties that require further study.

In the papers, the authors stressed that improved observations from future surveys will be essential to determine whether the apparent FLRW violations are genuine.

"If these indicated deviations from an FLRW geometry are real, it would signify that most of the cosmological solutions considered for solving the cosmological tensions — evolving or interacting dark energy, new types of matter or energy, modified gravity and related ideas within the FLRW framework — are ruled out," the researchers wrote.

The next step will involve applying the new theoretical framework to larger and more precise datasets. "It is to apply our theoretical results to data to test the standard model and to produce constraints on the Dyer-Roeder and backreaction effects," Heinesen said.

Because the method can already be used with existing astronomical observations, researchers may soon obtain sharper answers about whether the universe truly follows the simple large-scale picture assumed by standard cosmology or whether hidden complexities are reshaping our understanding of cosmic evolution.

A unique, X-ray-spewing black hole may help to confirm the enigmatic identity of "little red dots," a curious class of objects that are observed mostly in the very early universe, approximately 12 billion light-years away.

Astronomers have sought to classify little red dots (LRDs) since the James Webb Space Telescope (JWST) first spotted them shortly after it began science operations in 2022.

Over the following few years, JWST discovered hundreds more of these ancient, compact curiosities, which look like little red dots partially because their light has been redshifted — stretched into longer wavelengths — as it has traveled across billions of light-years of expanding space-time to reach us. LRDs appear to be ephemeral, emerging around 600 million years after the Big Bang and then mostly disappearing over the next billion years.

Now, in a paper published March 16 in The Astrophysical Journal Letters, astronomers have described an object that may illuminate the murky nature of LRDs.

Formally known as 3DHST-AEGIS-12014 and colloquially called the X-ray dot (XRD), this object had remained hidden in a survey conducted by NASA's Chandra X-ray Observatory more than a decade ago. Its importance was revealed only recently, after JWST observed the same cosmic field.

"It is always wonderful to see archival data aid in solving mysteries that were completely unknown when the data were first taken," Anthony Taylor, an astrophysicist at the University of Texas at Austin who was not involved in the study, told Live Science via email. "This is a prime example of legacy science programs that continue to provide scientific value both upon their initial release and far into the future."

A single black hole may solve two cosmic mysteries

The XRD discovered by Chandra resembles an LRD, save for a few differences. The biggest one is that it is a bright source of X-ray light.

Normally, LRDs do not seem to emit X-rays. This anomaly has deepened the mystery of their identity, because active black holes commonly emit X-rays from their chaotic coronas, where infalling material reaches near light speeds and intense temperatures.

"If little red dots are rapidly growing supermassive black holes, why do they not give off X-rays like other such black holes?" co-author Anna de Graaff, an astrophysicist at the Harvard & Smithsonian Center for Astrophysics, said in a statement.

As suggested in this study and in previous research, the X-rays may be blocked by thick cocoons of gas surrounding LRDs.

The XRD offers evidence of this process. As the black hole at its heart gorges on the surrounding gas, it clears holes in its cocoon. This forms sight lines into the object's interior and allows X-rays to escape, while also preserving its overall reddish appearance ‪—‬ picture a cosmic jack-o'-lantern with its eerie inner light bleeding into the dark.

"This single X-ray object may be — to use a phrase — what lets us connect all of the dots," lead author Raphael Hviding, an astronomer at the Max Planck Institute for Astronomy in Germany, said in the statement.

Unveiling an early-universe enigma

Overall, the XRD may help strengthen the idea that LRDs are young black holes in the midst of a transitional phase, during which they're enveloped in a dense cloud of gas. This gaseous shroud is similar in composition to some stellar atmospheres, earning LRDs an awe-inspiring appellation: "black hole stars."

Accordingly, if LRDs represent a phase of rapid gas accretion by young black holes, this period of quick consumption may help to explain how early supermassive black holes (SMBHs) grew so fat, so fast, accumulating many millions or billions of solar masses when the universe was only about 10% of its current age.

It is essential to study the evolution of these objects in more recent times. "LRD-like objects have actually been found in the modern universe but it is clear that LRD analogues are exceedingly rare," Hviding told Live Science via email. "Why? The short answer is that we don't know." One possibility is that giant gas reservoirs grow thinner as the universe evolves, he said.

Next-generation observatories like the Nancy Grace Roman Space Telescope will scan the sky for the rare, modern LRDs in the evolved universe. "They cannot go nearly as deep or as detailed as Webb," Hviding added, "but because they survey wide areas of the sky, finding rare analogues becomes viable."

In the meantime, the XRD warrants further observations. Maybe it isn't an elderly LRD, after all, but a more common SMBH veiled in an exotic dust never seen before. Either way, astronomers appear to have made a distinctive discovery that may elucidate a chain of cosmic mysteries in the evolution of the universe.

See how much you know about black holes with our black hole quiz!

A newly developed technique could teach AI algorithms to see the universe with unprecedented clarity — potentially exposing the cracks in our understanding of the cosmos.

Our cosmic rulebook, known as the standard cosmological model, has done an unparalleled job of describing the universe, accounting for everything from its accelerating expansion to galaxy formation. But even the best explanations need robust, independent checks, and that's where genetic algorithms come in.

These clever techniques, inspired by natural selection, let us reconstruct cosmic functions directly from data, without forcing them into preconceived models. They're like tireless explorers, always seeking the best results.

But even the most powerful tools have their blind spots. For genetic algorithms, that blind spot has always been about seeing subtle changes in the cosmos. The overall picture might look good, but the derivatives ‪—‬ crucial measurements of how quickly things are changing ‪—‬ get wobbly.

For traditional genetic algorithms, these insights into rates of change are incredibly fragile. The "best-fit" function, which nails the observed data, often struggles with nonobservable quantities involving these derivatives. It's like trying to navigate a dense fog; the algorithm risks getting stuck in a deceptive patch that seems like the perfect solution but isn't the real deal.

So how do we equip our cosmic explorers with sharper vision?In a paper published to the preprint server arXiv in February, researchers propose an answer: a new strategy to teach our algorithms to see the universe with unprecedented clarity.

Known as GAME (short for "Genetic Algorithms with Marginalised Ensembles), this ingenious update doesn't rely on a single algorithm. Instead, it unleashes a whole squad. Imagine a council of cosmic detectives, each tackling the puzzle slightly differently. Then, GAME applies ensemble averaging, taking a weighted average of their solutions. Each algorithm's answer gets a weight based on its data fit and the smoothness of the resulting function.

The results are nothing short of spectacular. For reconstructing a test function, GAME showed a solid 20% improvement in overall accuracy. But here's the real punch: For those elusive derivatives, GAME delivered a jaw-dropping 95% improvement in accuracy. That's like trading blurry binoculars for the sharpest cosmic lens imaginable, especially for watching the universe change.

The methodology is already reconstructing the universe's expansion rate, known as the Hubble constant, using data from cosmic chronometers, which are essentially natural clocks. And the early results are perfectly compatible with our existing cosmological model. With this newfound precision, GAME is like a telescope into the future of cosmology.

Imagine what this sharper vision means for unraveling the universe's grandest puzzles. As new data from observatories like the Dark Energy Spectroscopic Instrument floods in, GAME is poised to become an even more competitive tool. It will help us discriminate between different models of how the cosmos works, allowing for clearer answers and crucial model-independent consistency tests.

While the full impact of data correlations is still a frontier, the journey has only just begun.

Scientists have long assumed our universe would continue on for trillions of years, but a new study presents a much shorter life span for the cosmos: Our universe might last only another 33 billion years.

That's just a cosmic blink before everything collapses in on itself ‪—‬ a process dubbed the "Big Crunch," where expansion reverses, causing all matter and space-time to collapse back into an extremely dense state similar to the conditions of the Big Bang. While long considered a discarded possibility for the fate of the universe, because of accelerating cosmic expansion, this new research has reopened the surprising — and slightly unsettling — option.

The journey to this dramatic conclusion started with our quest to map the cosmos, where we've focused on dark energy, the mysterious force that's pushing the universe apart at an accelerating rate. Recent data from the Dark Energy Survey (DES) and the Dark Energy Spectroscopic Instrument (DESI) mapped hundreds of millions of galaxies to probe this expansion. These crucial tools suggest, with extremely high confidence that the dark energy "equation of state" — its pressure-to-energy density relationship, which dictates its effect on expansion — isn't simply a static number. Instead, its influence appears to be changing over time.

This strange dynamic opens the door for alternative explanations for what dark energy might be made of . This has led to the axion dark energy (aDE) model, which proposes that dark energy comprises both an axion field, which would be an ultra-light form of dark matter that sloshes around the universe, plus a cosmological constant, or fixed background expansion baked into the structure of space-time.

In the new paper, which was uploaded to the preprint server arXiv, the researchers applied this hybrid model to DES measurements. They discovered that this combination likely can explain the DES and DESI results, but with a twist: In the far future of the universe, the interplay of the axion field and the cosmological constant actually actively pulls the universe back together, leading to that ultimate Big Crunch.

By taking the model that best matched observations and running the simulation forward in time, researchers calculated a precise moment of cosmic demise: 33.3 billion years from now. This dramatically shorter future contrasts sharply with the trillion-year lifespan often traditionally considered. Instead of cosmic expansion stretching the universe out like a lonely, eternal highway, we get a cosmic U-turn that takes us back to the start of our journey.

This is fresh territory, and while evidence compels us, science always comes with caveats. The DES and DESI observations suggesting the cosmological constant isn't static are intriguing, but it still needs verification. This model depends on many variables, and several different combinations of them could still explain observations, though a negative cosmological constant ‪—‬ and a resulting Big Crunch ‪—‬ remains the most likely in their analysis.

More data is needed to rigorously test this model. The cosmos is a complicated beast; our understanding continually evolves. As we pursue increasing data streams, we piece together the greatest story ever told — but that story might end sooner than we expected.

When theoretical physicist David Gross was 13, he received a copy of a popular science book, "The Evolution of Physics" (Cambridge University Press, 1938), signed by Albert Einstein. The book, co-authored by Einstein himself, started Gross on a journey into the hearts of atoms, where he eventually helped answer a question that had bedeviled particle physicists for years: whether the constituent parts of protons and neutrons, called quarks, could be broken apart.

The resulting principle of asymptotic freedom, which he developed in concert with Frank Wilczek and H. David Politzer, revealed that the forces between quarks waned as they got close to each other and strengthened as they moved apart. Asymptotic freedom became part of a larger model called quantum chromodynamics and paved the way to unifying the strong, weak and electromagnetic forces, which completed the Standard Model of particle physics. The trio earned the Nobel prize in physics for their work in 2004.

For the past few decades, Gross has shifted from studying the parts of an atom to developing string theories that could unify the fourth force — gravity — with the other three. Formerly the director of the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara, Gross recently won the $3 million Special Breakthrough Prize in Fundamental Physics, in honor of a lifetime of physics achievement.

Live Science spoke with Gross about his life and work, what lies at the heart of an atom, why uniting the four fundamental forces is so challenging, and why he thinks the major barrier to a theory of quantum gravity isn't science but humanity's time left on Earth.

Tia Ghose: Tell me how you first got interested in physics.

David Gross: I was always good at and enjoyed doing math puzzles. At my bar mitzvah, I got a present from a friend of the family who happened to be the brother of Leopold Infeld, who collaborated with Einstein on a popular science book. It's called "The Evolution of Physics."

I really got entranced by that book. At that time, I realized that mathematical puzzles were much more interesting when you applied mathematics to the real world, and I kind of decided to become a theoretical physicist. Once you decide you want to do theoretical physics, the path is straight; it's not particularly crooked: You have to learn mathematics; you have to learn physics; you have a long way to go till you get to the frontiers of knowledge. And so it was an early and wise decision.

TG: Do you feel like you got to the frontiers of knowledge?

DG: Oh yeah — even beyond!

TG: In 2004, you won the Nobel prize in physics for developing the theory of asymptotic freedom. Can you tell me about that?

DG: When I started graduate school … theorists really had no clues, no deep understanding of what was going on inside the nucleus.

Shortly after I got out of graduate school, I went off to a postdoctoral fellowship, from Berkeley to Harvard, and there were some wonderful experiments going on. [In these experiments, the goal] was to shoot electrons, which we understand very well, onto protons at very high energies, and look at the various scatterings of these electrons … to essentially have a microscope that looked inside the proton.

These experiments were very surprising, and they seemed to indicate that the proton was made out of some point-like particles, [with] no structure. That had at least been observed at short distances and over short times, and that was pretty mysterious.

I'd been working on this and making predictions of what might happen if you made various outrageous assumptions. And it looked like these particles were consistent with being what are called quarks, which were hypothesized earlier as mathematical objects to explain the patterns of the particles that were being produced.

But this experiment revealed that they were real and somehow moving freely ‪—‬ which made no sense at all, because then they would easily be knocked out of the proton if you hit it hard enough. Nobody had ever seen the quark.

And so I got obsessed with that, which led to the discovery of asymptotic freedom and then quantum chromodynamics. Asymptotic freedom is this property that the force between the quarks gets weaker when they get closer together, which is counterintuitive and unlike any other theory that we knew.

The force gets weaker when they get closer, the force gets stronger when they get farther apart, and maybe strong enough so that you can never pull them apart, which seems to be the case.

So that was the watershed moment for the theory of the strong nuclear force. In the same years — in the early '70s — the theory of the weak nuclear force was also being constructed, again, in a different setup, but the same kind of generalization of electrodynamics. And by the middle/end of the '70s, we completed what we call the Standard Model, the standard theory of particle physics: what makes up matter, what are the forces that act between them.

TG: At that point, it seems like we united three of the forces, but there's this outlier, gravity, right? So from there you move on?

DG: I couldn't move on immediately. Once we had a theory in which you could calculate nuclear phenomena … one could calculate, make predictions and test the theory.

Quantum chromodynamics is a very deep and long and complicated and beautiful story that goes on today in full force. At short distances, when the quarks are close, it's easy because the [strong] force gets weaker and weaker, so you can calculate easily ‪—‬ and people now have extended those calculations over 50 years to incredible accuracy.

But what I was most interested in was trying to understand, is it really true that quarks are completely confined, and how does that work? And how do you control the theory when the forces become strong? That's much harder.

Many questions are open. But I got tired of it because it was hard, and I couldn't really solve it.

And besides that, as you say, there were indications within the standard theory that, if you pushed it to the extreme — to very high energies and very short distances — it failed because gravity came in. So that was a sign that we should try to unify all the forces with gravity.

And that led to string theory, which I've been mostly working on ever since.

TG: Can you explain a little bit about string theory and what you're working on?

DG: Questions that we ask [in string theory] are even more ambitious than unifying all the forces. Gravity is, according to Einstein, in our understanding, the dynamics of space-time, right?

Now we're beginning to understand that we're going to have to, once again, like many times in the history of physics, modify, improve our understanding of space-time.

What is space-time made of, and how does it behave at short distances? How did the universe evolve?

We don't understand much of that. But we especially don't understand the beginning, and that's where all of our ideas break down — even, so far, attempts to use string theory — but string theory still offers the best hope of trying to address the question of how the universe began.

TG: So one of the roadblocks is that you have all these [unified] theories, but then to test them, you need experiments, and the energy regimes where you could test them are extreme?

DG: It's very hard to directly test them. So, in the 19th century, chemists and physicists hypothesized the existence of atoms.

But nobody had ever seen an atom or had any direct way of probing what an atom is made out of, or even if there are atoms and so on. So it was a similar situation.

And then breakthroughs or the real advances in understanding that the atomic structure of ordinary matter and of the atom happened in the 20th century — they weren't anticipated, and many people regarded atoms as, "OK, some kind of mathematical gimmick to construct theories' but they weren't really real."

That happens over and over again [in science], and of course, the great thing is that experiments can settle the issue. That happened with atoms, with Brownian motion [the random motion of particles, which was elucidated by Einstein] and Rutherford [whose gold foil experiments showed atoms were mostly empty space with densely-packed nuclei]. And then quantum mechanics was developed, and now we understand ordinary material completely.

In this case [testing string theories], it gets harder and harder the farther away you get from the human scale. I mean, the scale we're looking at is so teeny. It's about as teeny as you can get.

TG: And this is the Planck scale [1.6X10^-35 meters, where quantum effects are thought to dominate gravity]?

DG: Yes, the Planck scale is the scale where gravity becomes a very strong force, where the structure of space itself becomes so complicated that it's probably not a good idea to even think about space.

TG: To use the word "space" doesn't even make sense maybe at that scale.

DG: Space is … a picture of the world that we develop as infants in order to get the toy or the food. It's how we explain how the world works.

But it might not be the right explanation; it might be a coarse-grained or a kind of approximate notion. And in fact, that's where we're being led, but we're just beginning to understand what that could possibly mean and develop the tools to deal with it.

TG: Do you feel that in 50 years, we'll be closer to having some kind of unified theory that incorporates all the forces?

DG: Currently, I spend part of my time trying to tell people … that the chances of you living 50 [more] years are very small.

Due to the danger of nuclear war, you have about 35 years.

TG: Why do you think that we'll blow ourselves up, essentially, within 35 years, give or take?

DG: So it's a crude estimate. Even after the Cold War ended, [when] we had strategic arms control treaties, all of which have disappeared, there were estimates there was a 1% chance of nuclear war [every year]. Things have gotten so much worse in the last 30 years, as you can see every time you read the newspaper.

I feel it's not a rigorous estimate, that the chances are more likely 2%. So that's a 1-in-50 chance every year. The expected lifetime, in the case of 2% [per year], is about 35 years. [The expected lifetime is the average time it would take to have had a nuclear war by then. It is calculated using similar equations as those used to determine the "half-life" of a radioactive material.]

TG: So what do you suggest as remedies to lower that risk?

DG: We had something called the Nobel Laureate Assembly for reducing the risk of nuclear war in Chicago last year.

There are steps, which are easy to take — for nations, I mean. For example, talk to each other.

In the last 10 years, there are no treaties anymore. We're entering an incredible arms race. We have three super nuclear powers.

People are talking about using nuclear weapons; there's a major war going on in the middle of Europe; we're bombing Iran; India and Pakistan almost went to war.

OK, so that's increased the chance [of nuclear war]. I would really like to have a solid estimate — it might be more, and I think I'm being conservative — but a 2% estimate [of nuclear war] in today's crazy world.

TG: Do you think we'll ever get to a place where we get rid of nuclear weapons?

DG: We're not recommending that. That's idealistic, but yes, I hope so. Because if you don't, there's always some risk an AI 100 years from now [could launch nuclear weapons], but chances of [humanity] living, with this estimate, 100 years, is very small, and living 200 years is infinitesimal.

So [the answer to] Fermi's question of "Where are the civilizations, all the intelligent organisms around the galaxy, and why don't they talk to us?" is that they've killed themselves.

You asked me to think about the future, and I am obsessed the last few years, thinking about that ‪—‬ not the future of ideas and understanding nature, but of the survival of humanity.

TG: I think in some ways, during the Cold War, it was easier for people to conceptualize because we had one major enemy. Now there's chaotic interactions between countries.

DG: There are now nine nuclear powers. Even three is infinitely more complicated than two. The agreements, the norms between countries, are all falling apart. Weapons are getting crazier. Automation, and perhaps even AI, will be in control of those instruments pretty soon.

TG: That scares me too ‪—‬ that a lot of weapons are using AI systems to make decisions on some level.

DG: It's going to be very hard to resist making AI make decisions because it acts so fast. If you have 20 minutes to decide whether to send a few hundred nuclear armed missiles to both China and Russia for "our dear president," the military might feel that it's wiser to make AI make that decision. But if you play with AI, you know that it sometimes hallucinates.

TG: The problem feels too big for ordinary people to do anything about, which is the same thing with climate change, right?

DG: People have done something about climate. So that's something scientists began to warn people about 40 years ago. And they convinced people that's a real danger.

It's a much harder argument to make than about nuclear weapons.

We made them; we can stop them.

Editor's note: This interview has been edited and condensed for clarity.

How much do you know about Albert Einstein and his theories? Test your knowledge with our Einstein quiz!

This snapshot is just a small part of one of the most comprehensive and spectacular views yet of the universe — a web-like structure formed by millions of galaxies, stretching back to near the dawn of time.

Each tiny point in the image represents a galaxy mapped by the Dark Energy Spectroscopic Instrument (DESI). The galaxies aren't randomly distributed; instead, they form in filaments and clusters known as the cosmic web. Between these luminous strands of galaxies are vast empty regions known as voids, where few stars or galaxies exist.

The image is from the largest high-resolution 3D map of the universe ever created. DESI, which is mounted on the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory in Arizona, uses 5,000 robotic fiber-optic sensors to capture light from distant celestial objects.

The five-year survey was supposed to gather data on 34 million galaxies and quasars (the bright cores of distant young galaxies). In practice, it detected over 47 million, along with more than 20 million nearby stars in the Milky Way. A visualization published alongside DESI's map shows how it has grown over those five years.

Some of the light captured in this image took billions of years to reach Kitt Peak, so it allows scientists to look back in time to reconstruct how the universe evolved. The result is a three-dimensional view that not only shows where galaxies are but also how they have moved and clustered over time.

Beyond its visual impact, the image plays a crucial role in probing mysterious dark energy, the name physicists have given to a force that appears to be driving the universe's accelerated expansion. It makes up roughly 70% of the universe, and its nature and distribution are among the biggest questions in physics.

By comparing the distribution of galaxies across different epochs, researchers can track how dark energy has influenced the structure of the universe over the past 11 billion years. Early DESI data has already hinted that dark energy may evolve through cosmic history ‪—‬ a breakthrough that would fundamentally reshape scientists' understanding of the universe and its ultimate fate.

The image is the result of a massive international collaboration. More than 900 researchers from over 70 institutions contributed to the project, which was led by Lawrence Berkeley National Laboratory and funded by the U.S. Department of Energy Office of Science.

DESI will continue observing the sky through 2028, expanding its map by about 20%. Future observations will target fainter and more distant galaxies, as well as harder-to-observe regions near the Milky Way (where stars get in the way) and in the southern sky (which requires the telescope to peer through more of Earth's atmosphere). The first results from the full dataset are anticipated in 2027.

See more Space Photos of the Week

There's a central crisis in cosmology: Different measurements yield different values for the expansion rate of the universe. Now, a comprehensive analysis combining decades of independent measurements suggests that this discrepancy is not due to error or uncertainty; instead, it's a potential pathway to new physics beyond the standard cosmological model.

Astronomers calculate the universe's expansion rate, or Hubble constant, in two ways. One method is to use measurements of the distance to the cosmic microwave background (CMB), the earliest light that spread out just 380,000 years after the Big Bang. The second method is to study the expansion of the local universe, using observations of "standard candles," nearby stars of a known brightness whose light gets stretched — or redshifted — as it reaches us.

The first method's calculations yield a Hubble constant of around 67 or 68 kilometers per second per megaparsec, while the latter yield a value of approximately 73 kilometers per second per megaparsec. (One megaparsec is about 3.26 million light-years.)

Although this seems like a diminutive discrepancy, it is far greater than statistical uncertainty can explain, presenting a puzzling disagreement known as the Hubble tension. So a large symposium of astronomers convened to vote on the best methods and data for constraining the Hubble constant and determining if the tension actually exists.

In the resulting paper, published April 10 in the journal Astronomy & Astrophysics, the authors derived the most precise Hubble constant yet and found that the tension persists, suggesting that our current cosmological model is incomplete.

"That's why the Hubble tension is so interesting," study co-author Richard Anderson, an astrophysicist at the University of Göttingen, told Live Science via email. "The comparison between the late and early-universe value of [the Hubble constant] tests basic physics on cosmological scales, and it tells us that something's missing."

The most comprehensive review of the expanding local universe

Previous cosmological calculations relied on the creation of a cosmic distance ladder. Its rungs comprise increasingly distant celestial objects, including pulsating Cepheid variable stars within the Milky Way and more distant supernovas, whose distances can be calculated from the difference in their intrinsic brightness versus how bright they appear to us after their light has traveled through expanding space.

Yet this recent community effort, launched at the International Space Science Institute Breakthrough Workshop in Bern, Switzerland, in March 2025, expanded the cosmic distance ladder into a comprehensive survey of the nearby universe called the Local Distance Network, achieving a lofty goal that was considered "potentially unreachable" a decade ago.

"This isn't just a new value of the Hubble constant," the researchers explained in a statement from the National Science Foundation's NOIRLab; "it's a community-built framework that brings decades of independent distance measurements together, transparently and accessibly."

The unified framework combined decades of independent research using various techniques that may overlap in observations to achieve "redundancy" ‪—‬ an invaluable technique to reduce systematic errors and statistical anomalies.

For example, it allowed the researchers to perform a series of "leave me out" analyses: By excluding a specific technique, such as Cepheid-based calculations, they found a minimal change in the overall results of their newly constrained Hubble constant.

The foundations for a cosmic network

The Local Distance Network is founded on anchors — celestial objects whose distances have been determined geometrically through methods like parallax, an apparent change in an object's position that occurs with a change in perspective. Space telescope access may be limited, but you can reproduce parallax yourself by holding a finger at arm's length and seeing it seemingly shift positions by closing one eye and then the other.

Accordingly, the researchers used multiple local-universe anchor points, including the galaxy NGC 4258, located more than 20 million light-years away; the Magellanic Clouds, which are a pair of dwarf galaxies about 200,000 light-years away; and numerous variable stars within the Milky Way.

Then, they included a multitude of objects of measured distances, including dying old red giant stars and "megamasers," the intensely bright cosmic lasers generated in the accretion disks of supermassive black holes.

The researchers also included more than 7,500 galaxies, observed by facilities such as the Hubble Space Telescope and the Dark Energy Spectroscopic Instrument, out to a distance of more than 1 billion light-years.

As a result, the Local Distance Network developed in this study represents the most precise direct measurement of the Hubble constant in the local universe: 73.50 kilometers per second per megaparsec, with a relative uncertainty of 1.09%. The conclusion? The Hubble tension is real, similar to previously measured values, and not just an artifact.

The fact that this discrepancy persists may hint that early-universe measurements need to be similarly reassessed on a deeper level.

"One interesting, relatively new, and perhaps more natural idea involves primordial magnetic fields, which could change the scale of the structure seen in the CMB," study co-author John Blakeslee, director of research and science services at NOIRLab, explained via email.

Excitingly, this research further supports the idea that new physics are needed to illuminate dark energy and the other forces driving the expansion and ultimate fate of the universe. And because this framework is modular, upcoming methods and data from next-generation observatories may finally resolve the Hubble tension — but then again, that's what cosmologists have been hoping for more than a decade.

The Big Bang is often described as the moment everything began — a point of infinite density where the laws of physics broke down. But what if that picture is incomplete?

A new study proposes a different account of the universe's birth: Instead of an abrupt beginning from a singularity, as predicted by Einstein's theory of general relativity, the early cosmos may have passed through a more controlled high-energy phase governed by a modified theory of gravity known as QQG.

"QQG stands for quadratic quantum gravity," study co-author Niayesh Afshordi, a professor of physics at the University of Waterloo and the Perimeter Institute for Theoretical Physics, told Live Science via email. "In simple terms, it is an extension of Einstein's theory of gravity that includes additional terms which become important at extremely high energies, such as those that would have existed near the beginning of the universe."

The study was published March 18 in the journal Physical Review Letters.

Why Einstein's theory may not be enough

Einstein's theory of general relativity has been extraordinarily successful in describing gravity on large scales. It explains the motion of planets, the behavior of black holes, and the expansion of the universe. However, it struggles to explain the ultra-small world of quantum mechanics and is widely believed to contain some fundamental inconsistencies.

"The main problem is that Einstein's general relativity predicts its own failure under extreme conditions, most famously at the Big Bang singularity," Afshordi said.

At that point, densities and space-time curvature become infinite — a clear indication that the theory is incomplete. Physicists have long sought a deeper framework that can describe gravity under such conditions.

"What makes [quadratic quantum gravity] interesting is that it may provide a mathematically consistent way to describe gravity at very short distances and very high energies, where ordinary general relativity is expected to break down," Afshordi said. "In that sense, it offers a possible conservative route toward a quantum theory of gravity, while still remaining close to Einstein's theory at ordinary scales."

A universe without a singularity

In the new study, the researchers explored how QQG would reshape the earliest moments of the cosmos if it is indeed a correct completion of Einstein’s theory. Their results suggest that the universe may not have started from a singular point at all.

"Our main result is that, within quadratic gravity, the very early universe can avoid the usual Big Bang singularity and instead pass through a better-controlled high-energy phase," Afshordi said.

Rather than emerging from an infinitely dense state, the universe would have begun in a smoother, more stable configuration with finite density and finite temperature, with its precise properties depending on the particles and fields present at extremely high energies and temperatures. This avoids one of the most troubling predictions of standard cosmology.

The theory also offers a fresh perspective on cosmic inflation, the brief period of extremely rapid expansion thought to have occurred just after the Big Bang.

"In our analysis, this framework can also generate an inflation-like period without having to introduce an extra hypothetical field by hand," Afshordi said.

In standard models, inflation is typically driven by a mysterious field known as the inflaton. That field has never been directly observed. In contrast, QQG produces inflation naturally as a consequence of gravity itself.

"In other words, some of the key ingredients we normally add separately to cosmology may arise directly from the gravitational theory itself," Afshordi added.

From exotic physics to the familiar universe

One striking feature of QQG is that it behaves very differently depending on the energy scale. At extremely high energies, it follows new quantum rules. But as the universe expands and cools, it transitions back to the familiar physics described by Einstein.

The theory suggests that gravity becomes simpler at very high energies — a property known as asymptotic freedom — before evolving into the form we observe today. Eventually, the universe enters the hot, radiation-filled phase described by standard cosmology.

This framework provides a continuous bridge between an exotic early universe and the well-tested physics of later times. The key question, however, is whether this idea can be tested.

"Yes, at least in principle," Afshordi said. "The most promising tests come from cosmology, especially from the imprint of the early universe on primordial gravitational waves and the cosmic microwave background."

These ancient signals carry information about the universe's earliest moments. According to the new theory, these signals should contain subtle differences compared with predictions from standard inflation models.

"One particularly interesting aspect of our scenario is that it can lead to distinctive predictions for the gravitational-wave signal produced in the early universe," Afshordi noted. "As observational sensitivity improves over the coming years and decades, future measurements of primordial gravitational waves could begin to distinguish this kind of model from more conventional inflationary scenarios."

Although the idea is still being explored, it offers a compelling possibility: that the Big Bang may not have been a singular beginning but rather part of a deeper, quantum description of gravity. If confirmed, this framework could reshape how scientists understand the origin of the universe — replacing a breakdown of physics with a new, more complete picture of cosmic beginnings.

Think you know about Einstein's theories? Test your knowledge with our Albert Einstein quiz!

Astronomers may have found evidence that some of the mysterious "little red dots" discovered by the James Webb Space Telescope (JWST) are not black holes, as previously proposed, but rather gigantic stars from the beginning of the universe.

The team made the discovery by developing a simplified model of supermassive ancient stars — the potential "parents" of the first supermassive black holes in the universe.

The "little red dots," which existed within the first 2 billion years of the universe, have been one of JWST's most surprising discoveries. Astronomers first proposed that the compact red objects could be active galactic nuclei (AGNs), which are large galaxies powered by black holes that are rapidly accreting matter.

But the evidence has not been straightforward. The objects are extremely tiny — smaller than expected for typical galaxies. And so far, they show no clear X-ray emission, which is the primary signature of actively feeding black holes. Their spectra also lack strong metal emission lines beyond hydrogen and helium, hinting that the surrounding gas may be chemically primitive, unlike the metal-rich regions typically seen around actively feeding black holes.

This motivated Devesh Nandal and Avi Loeb of the Harvard and Smithsonian Center for Astrophysics (CfA) to explore a different possibility: What if these compact objects are actually supermassive stars caught just before they collapsed into black holes?

"If these little red dots now have no X-rays, they don't show any of these other metal lines, and if supermassive stars can form and exist, then we have shown that such stars will naturally produce the features of these little red dots," Nandal, a postdoctoral researcher at CfA and lead author of the study, told Live Science. "For the very first time, we think we're not looking at some dead signature of a star."

The team's research was published Feb. 5 in The Astrophysical Journal.

Monster ancestors

Supermassive stars — which Nandal and colleagues have previously called “monster stars” — are extremely massive stars formed mainly from primordial gas, mostly helium and hydrogen, in the early universe. They are classified as the first generation of stars, or Population III stars. Some models suggest these early stars could grow to thousands to a million times the mass of the sun. When these stars die, they transform into supermassive black holes.

To explain the extreme brightness of the little red dots, astronomers developed a detailed model of a metal-free supermassive star with close to a million solar masses. The team compared their simulations with the features of two little red dots, dubbed MoM-BH*-1 and The Cliff, found around 650 million years and 1.8 billion years after the Big Bang, respectively. The supermassive star model matched not only their extreme brightness but also some important features in their spectra (the different wavelengths of light they emit).

One unique feature of the little red dots is a distinctive "V-shaped" dip in their spectra. Some interpretations suggest this shape occurs because dust absorbs light, which gives the object a reddish appearance.

According to the new model, this shape is produced by a star's atmosphere, or outer layer. So, instead of dust altering the light, the star's own atmosphere creates the effect.

"If supermassive stars are real, which we think they are because Population III stars should be real, then a little red dot would be the perfect place for them to hide," Nandal said.

He suggested the V-shaped dip and the reddish appearance could also be linked to the star's mass loss, somewhat analogous to coronal mass ejections from the sun. But in this scenario, material expelled from the star forms a compact, shell-like structure around it. The mechanism of this mass loss is not fully understood. The team is working to improve the models of stars' outer atmospheres. They are also testing if pulsations — rhythmic expansions and contractions — could lift material off the stars' surfaces, creating a detached shell of gas that cools and reddens the emitted light.

"The study works well as a theoretical exercise," Daniel Whalen, a senior lecturer at the University of Portsmouth Institute of Cosmology and Gravitation who wasn't involved in the study, told Live Science. "It shows that a supermassive star can reproduce some features of a little-red-dot spectrum."

Astronomers estimate that a star this massive would remain bright for only about 10,000 years. If the star were less massive — between 10,000 to 100,000 solar masses — then it would shine for up to a million years. The reason is simple: The more massive the star, the faster it burns through its nuclear fuel.

If little red dots are supermassive stars in their final moments before collapsing into black holes, that leaves an even shorter window for observation. The team noted that the requirements of extreme mass and a short lifetime are why not all little red dots can be explained by the new model.

"That's an extremely short window," Whalen said. "It makes it hard to explain how around 400 to 500 little red dots were discovered if they have short lives."

This or that?

Another leading explanation for the little red dots involves accreting black holes, possibly formed from the direct collapse of hydrogen gas clouds in the early universe, without first forming normal stars. Whalen is skeptical that the supermassive-star model offers an advantage over that theory. "I don't see that it provides a clear benefit over black hole interpretations," he noted.

"If these objects are accreting black holes, at some point you might expect X-rays to leak out," Nandal explained. "Detecting clear X-ray activity would strongly favor the AGN interpretation."

Black holes that are undergoing chaotic feeding or explosions should exhibit some variability in their light output. So far, however, no clear brightness variability has been observed among little red dots. Detection of some flickering would favor AGN activity and essentially rule out supermassive stars, as these stars would emit light more steadily.

Detailed spectroscopic measurements showing the abundance of chemicals around little red dots would help support or rule out the supermassive-stars interpretation.

"The answer is really in the ingredients — what is this gas made of?" Nandal said. Previous simulations have shown that supermassive stars contaminate their surroundings with enormous amounts of nitrogen via nuclear reactions. On the other hand, strong neon lines would be more indicative of AGN activity.

Whalen noted that if black holes are present, any X-rays they produced could simply be absorbed by surrounding dust. Radio emissions from these black holes, however, could pass through dense hydrogen clouds and dust and escape into space.

That means highly sensitive radio observations from facilities such as the Square Kilometre Array or the next-generation Very Large Array could provide a decisive test. "If little red dots really are powered by shrouded direct-collapse black holes, the radio waves will get out, and we'll detect them," Whalen said.

Black hole quiz: How supermassive is your knowledge of the universe?

Moments after the Big Bang, the newborn universe was a wild, hot place. In that cosmic soup, primordial black holes — the first black holes in the universe, formed from extremely dense pockets of matter — could quickly take shape.

For ages, our understanding of these objects, especially the smaller ones, was that they eventually just faded away through a quantum process called Hawking radiation. It seemed like a settled fate.

But a new investigation, published in January to the preprint database arXiv, has opened a different path. This research claims that these objects didn't always shrink — sometimes, they could grow, becoming cosmic devourers that absorbed the radiation of the early universe.

This unexpected appetite doesn't just change the individual destinies of early black holes; it also transforms how we see the universe's past — and, crucially, it alters our search for dark matter, the invisible scaffolding that holds galaxies together.

Hungry newborns

Primordial black holes are a fascinating idea in cosmology. Unlike the usual black holes born from collapsing stars, these objects would have formed in the first moments after the Big Bang, from extreme densities in the universe's initial soup. They could range from microscopic sizes up to masses greater than that of the sun.

For a long time, general relativity told us that these objects, especially the smaller ones, would slowly lose mass through Hawking radiation. They would just evaporate and fade into nothing.

Here's where the story takes a turn. The early universe wasn't just a quiet vacuum around these primordial black holes; it was a thick, hot soup, full of radiation — with photons zipping everywhere.

This new research adds a vital piece to the puzzle: direct absorption of that thermal radiation. If a primordial black hole's collapse efficiency passes a certain point calculated in the new research, it doesn't just slowly evaporate; it starts to feed. These black holes become silent, hungry cosmic devourers, the new study suggests.

This new understanding changes everything about how we picture the early cosmos and the destiny of these ancient objects. Their ability to grow means they can live far longer than we previously thought, leading to extended lifetimes and substantial mass.

If primordial black holes can grow by absorbing radiation, then a much broader range of initial masses could still exist today, acting as the universe's unseen dark matter. The research indicates this expanded range depends heavily on something called the absorption efficiency parameter — a measure of how quickly and efficiently the black hole can feed on matter around it.

For instance, if this parameter is 0.3, the allowed range for a primordial black hole to form and become dark matter expands from 10^16 grams to 10^21 grams. If the parameter is 0.39, then the range is from 5*10^14 grams to 5*10^19 grams. Previously, it was thought that primordial black holes couldn't be this massive and still be responsible for dark matter.

This work makes us rethink a lot about the universe's earliest moments. It forces a fundamental reevaluation of how these objects evolve and their potential to explain the mystery of dark matter. This isn't just a small tweak to a model; it's a new chapter in our cosmic story. We thought we knew the life cycle of these objects, but it turns out, the universe had other plans.

Black hole quiz: How supermassive is your knowledge of the universe?

Physicists' top theory about the nature of the universe may be wrong, a new study of strangely warped light suggests.

The new research looked into three leading theories of dark matter, the invisible stuff that makes up most of the universe and provides structure to most galaxies, though we still don't know exactly what it is.

For decades, cold dark matter (CDM) has been our leading theory for the universe's invisible scaffolding. It's a neat idea: tiny, slow-moving particles that interact only through gravity. But CDM has its problems. It struggles with explaining galactic anomalies and with describing the strange rotation curves of dwarf galaxies, for example.

To further test the nature of dark matter, scientists observe bent starlight from distant galaxies — a process called gravitational lensing — to find critical clues about their hidden architecture. And a new paper published Jan. 23 to the preprint database arXiv turned up something fascinating: This deep lensing analysis decisively disfavors smooth dark matter lens models and strongly prefers fuzzy dark matter (FDM) over both the standard CDM and the more exotic self-interacting dark matter model, which proposes that dark matter slightly sticks to itself.

If it can be bolstered by more evidence, this discovery reveals a fuzzier, more quantum-like reality that underpins everything we know.

Flavors of darkness

Astronomers often talk about different dark matter "flavors," with three major theories topping the menu.

In CDM — the leading theory — dark matter acts like a vast, invisible cosmic scaffolding. It's made of tiny, slow-moving particles. They clump together easily, forming large invisible structures, or "halos," and countless smaller clumps within them. These smaller clumps are subhalos, and they act as gravitational anchors for galaxies.

Self-interacting dark matter, meanwhile, suggests those invisible sand grains of CDM have a slight stickiness or friction when they bump into each other. This extra interaction means that within dense clumps, the particles can transfer energy. It makes the centers of the clumps smoother. It can also cause them to collapse differently.

The final, a la carte model of the universe is fuzzy dark matter. According to this theory, instead of being made of distinct particles, dark matter could be a quantum fog or soup made of incredibly tiny, superlight waves. Because of their wave nature, they can't form extremely sharp, small clumps like CDM. Instead, they create fuzzy, rippling patterns, like gentle waves on a pond. These still bend light, but in a more continuous, less-distinct way than solid clumps would.

A twisted spotlight

The new research, which has not been peer-reviewed yet, really shifts things. Scientists used gravitational lensing data from 11 galaxies — specifically from systems where light bends in particular, sharp ways — to analyze how light bends around massive objects.

The smooth dark matter lens models — the ones we expected from standard CDM — are decisively disfavored by the way light bends in the new dataset. Instead, the data show a strong preference for fuzzy dark matter over both CDM and self-interacting dark matter. This strong preference for fuzzy dark matter persisted even when the researchers made the lens models more complex, and after excluding systems that might be messed up by microlensing.

If fuzzy dark matter is the answer, it completely shifts our understanding of the universe's fundamental building blocks. It would mean dark matter is a quantum wave — that it is not made of discrete, slow-moving particles. Rather, the universe's invisible scaffolding would be more like a vast, cosmic ocean with gentle, rippling currents.

This really changes how astronomers think about galaxy formation and the structure of the cosmos. Our current models, which are based largely on CDM, would need a serious rethink. This also opens up a lot of new questions. Scientists need to figure out how this fuzzy stuff interacts with regular matter. They also need to know what these exotic particles really are.

We started this cosmic detective story trying to understand the universe's true identity, its unseen architecture. For a long time, CDM was the prime suspect — a solid, dependable theory. But the clues, especially from bent starlight, don't quite fit.

Now, with this clever new analysis, we have a compelling piece of evidence suggesting the universe's invisible foundation is far more exotic and quantum than we ever imagined. It's a reminder that the cosmos always has more secrets to reveal.

An impossibly powerful "ghost particle" that recently slammed into Earth may have come from a rare type of exploding black hole, researchers claim.

If true, the extraordinary event may prove a theory that could upend our understanding of both particle physics and dark matter, the team argues. However, this is just one theory, and there is no direct evidence to confirm that this is indeed what happened.

In early 2023, researchers at the Cubic Kilometre Neutrino Telescope (KM3NeT) — a massive, newly constructed array of sensors at the bottom of the Mediterranean Sea — detected a neutrino, a ghostly particle that has almost no mass and does not readily interact with most matter.

In addition to neutrinos' typical weirdness, this specific particle was noteworthy for its unusual intensity. It hit our planet with an estimated energy of up to 220 quadrillion electron volts, which is at least 100 times more powerful than any other neutrino detected to date and around 100,000 times greater than anything observed within human-made particle accelerators, like CERN's Large Hadron Collider.

Explaining the impossible

Researchers were initially unsure what caused this "impossible" neutrino to appear. It may have been birthed when a cosmic ray entered Earth's atmosphere, unleashing a cascade of high-energy particles that rained down on the planet's surface. However, its unprecedented power led experts to assume that it must have originated from some high-energy cosmic event that we don't fully understand.

In the new paper, which has been accepted for publication in the journal Physical Review Letters, one research group believes they have finally identified what really birthed the neutrino: an exploding, primordial black hole (PBH).

PBHs are a hypothetical class of black holes that are extremely small — potentially ranging from the size of an atom to a pinhead — and likely date back to the first moments after the Big Bang. The concept was first popularized by British physicist Stephen Hawking in the early 1970s, who also hinted that these miniature singularities would emit large quantities of high-energy particles, dubbed Hawking radiation, as they slowly evaporated. In theory, this would also mean they have the capacity to explode.

"The lighter a black hole is, the hotter it should be and the more particles it will emit," study co-author Andrea Thamm, a theoretical physicist at the University of Massachusetts Amherst, said in a statement. "As PBHs evaporate, they become ever lighter, and so hotter, emitting even more radiation in a runaway process until explosion."

One of the biggest mysteries surrounding the impossible neutrino, aside from its immense power, is that it was not observed by other neutrino detectors around the world, such as the IceCube Neutrino Observatory buried beneath Antarctica's icy surface. Given that PBHs are supposed to be fairly common throughout the universe, one would reasonably expect that similarly powerful particles also would have been detected before or since this possible discovery, especially as the number of neutrino detectors is quickly increasing.

The researchers said this is because the neutrino was emitted by a special type of PBH, dubbed a quasi-extremal PBH, which has a "dark charge" — a version of regular electric force that includes a very heavy, hypothesized version of the electron dubbed a "dark electron."

The dark properties of this theoretical type of PBH make it less likely that these black holes' explosions would be detected, the researchers suggested. It may also be that some of the less-powerful neutrinos detected to date may be partially incomplete detections of these events, they added.

"A PBH with a dark charge has unique properties and behaves in ways that are different from other, simpler PBH models," Thamm said. "We have shown that this can provide an explanation of all of the seemingly inconsistent experimental data."

Upending cosmic understanding

While the new research hints at the existence of quasi-extremal PBHs, it does not confirm them or prove that they explode as the researchers think. (Regular PBHs have never been directly observed, either, although there is a strong consensus that they exist.)

However, the team is confident that it will not take long to prove these dark explosions are real. The same research group recently predicted that there is a 90% chance we will see the first quasi-extremal PBH blow up by 2035, which would be extremely exciting for two main reasons.

First, these explosions would be so powerful that they would probably emit "a definitive catalog of all the subatomic particles in existence," including known entities, like the Higgs boson; theorized particles, like gravitons or time-traveling tachyons; and "everything else that is, so far, entirely unknown to science," the researchers wrote in the statement.

Second, these black holes could help reveal the mysterious identity of dark matter — the invisible stuff that we cannot see, yet whose gravitational force we can detect within almost every observed galaxy, including the Milky Way. The researchers wrote that quasi-extremal PBHs "could constitute all of the observed dark matter in the universe," so finding one could help put this mystery to bed. (Despite the similar names, dark matter is not directly related to dark charge or dark electrons.)

The researchers, along with several other teams in the fields of physics and cosmology, are now holding their collective breath to see when the first explosion might be detected.

This "incredible event" would provide a "new window on the universe" and help us "explain this otherwise unexplainable phenomenon," study lead author Michael Baker, a theoretical physicist at UMass Amherst, said in the statement.

Using the James Webb Space Telescope (JWST), astronomers have mapped the largest section of the universe's dark matter yet, deepening our understanding of how this mysterious substance shapes the cosmic landscape.

Dark matter is notoriously difficult to study because it does not interact with light. Astronomers can detect it only by looking at its gravitational effects on baryonic, or "ordinary," matter. Observations of these interactions reveal that there is about five times as much dark matter in the universe as normal matter.

The new study, published Jan. 26 in the journal Nature Astronomy, mapped a piece of sky in the Sextans constellation. Researchers pointed JWST at this space for 255 hours, constructing a picture of its visible matter, including stars, galaxies and cosmic dust. From these observations, they identified nearly 800,000 galaxies — 10 times more than ground-based telescopes have seen in the same region, and nearly twice as many as the Hubble Space Telescope has spotted there.

Next, the team charted how the mass of this area's invisible dark matter warped the space around it.

"Previously, we were looking at a blurry picture of dark matter," Diana Scognamiglio, an astrophysicist at NASA's Jet Propulsion Laboratory (JPL) and co-lead author of the paper, said in a statement. "Now, we're seeing the invisible scaffolding of the universe in stunning detail."

Where galaxies come from

This detailed map could give scientists a better idea of how dark matter has shaped the evolution of the universe.

Shortly after the Big Bang, dark matter and ordinary matter were probably evenly distributed throughout space. But over time, dark matter began to clump together. This, in turn, pulled the ordinary matter into increasingly dense pockets, where it eventually collected enough mass to spark star formation.

In this way, dark matter was instrumental in creating the current layout and matter distribution of the cosmos. "This map provides stronger evidence that without dark matter, we might not have the elements in our galaxy that allowed life to appear," study co-author Jason Rhodes, a senior research scientist at JPL, said in the statement.

Scognamiglio and her team plan to keep mapping dark matter in the future. They intend to use NASA's Nancy Grace Roman Space Telescope, which is scheduled to launch later this year, to study an area 4,400 times the size of the region from the new study. However, Roman's map of dark matter will be significantly less detailed than JWST's.

The structure of the local universe is surprisingly flat, according to new research, and this cosmic quirk may save our Milky Way from colliding with countless other massive, nearby galaxies — except one.

For decades, astronomers have made the puzzling observation that our nearest galactic neighbor, Andromeda, is speeding toward a possible collision with our galaxy, while other nearby galaxies are moving away from us. Now, a new study may finally reveal why: A vast, flat sheet of dark matter is drawing those galaxies into deep space.

Dark matter anchors and attracts visible matter, and the gravitational pull from the far-out dark matter sheet, which lies slightly beyond the bounds of Andromeda and the Milky Way, overwhelms the attraction between our galaxy and other neighboring galaxies, researchers reported in a paper published Jan. 27 in the journal Nature Astronomy.

"The observed motions of nearby galaxies and the joint masses of the Milky Way and the Andromeda Galaxy can only be properly explained with this 'flat' mass distribution," the researchers said in a statement.

Future simulations could further explain how gravity sculpts our surroundings and why the local universe looks the way it does.

Going with the flow

The motion of galaxies throughout the expanding fabric of space-time is known as the Hubble flow. It's mathematically described by Hubble's law, named after astronomer Edwin Hubble, who discovered the expansion of the universe in the 1920s. His eponymous law constrains an observational phenomenon: Galaxies are moving away from Earth at speeds that are proportional to their distance. The farther a galaxy is from our vantage point, the faster it seems to be receding.

So why is Andromeda, located 2.5 million light-years away, hurtling toward us at 68 miles per second (110 kilometers per second), while most other large, nearby galaxies are following the flow? Curiously, these receding galaxies appear to resist the immense gravitational attraction of our Local Group, which includes the Milky Way, Andromeda, the Triangulum Galaxy and dozens of gravitationally bound, smaller galaxies.

This universal enigma has endured for more than half a century. In 1959, astronomers Franz Kahn and Lodewijk Woltjer found evidence of dark matter situated around Andromeda and the Milky Way. They calculated that to reverse the initial expansion imparted by the Big Bang, these two galaxies would require a combined mass much greater than all their stars put together.

It turns out that a significant portion of the mass of the Milky Way and Andromeda is contained in dark matter halos that surround each galaxy and facilitate the galaxies' rapid approach toward each other.

However, this attraction does not seem to affect nearby galaxies outside the Local Group, where "material is actually moving away from the Milky Way faster than the Hubble flow," study co-author Simon White, director emeritus of the Max Planck Institute for Astrophysics in Germany, said in a statement.

"Thus, galaxies closer than [roughly 8 million light-years] are moving away from us slower than predicted by Hubble's Law, whereas galaxies farther than [that] are actually receding faster than predicted," White told Live Science via email.

Building a universe from scratch

To find out why, the researchers built their own universe. They ran a multitude of simulations to explore the interactions among dark matter, our Local Group, and the receding galaxies just outside it, to a distance of around 32 million light-years.

The simulations modeled the evolution of the local universe from the beginning of space-time, starting with the mass distributions observed in the cosmic microwave background, the oldest light in the cosmos, emitted when the universe was just 380,000 years old. The researchers then had the model reproduce certain salient characteristics observed in nearby galaxies, including the mass, position and velocity of Andromeda and the Milky Way, as well as the positions and velocities of 31 galaxies located just outside the Local Group.

This revealed that the mass just slightly beyond the Local Group, including both dark matter and visible matter, is distributed in a vast, flat sheet that stretches for tens of millions of light-years and continues beyond the boundaries of the simulation.

Because nearby galaxies are embedded in this flattened sheet of dark matter, any gravitational pull from our Local Group is counteracted by the gravitational pull from the more distant mass in the sheet, drawing them away from us.

"If the mass were distributed approximately spherically around the Local Group, rather than being flat, then the external galaxies would be moving away from us slower than predicted by Hubble's law for the cosmic expansion, because they would be slowed down by the gravitational pull of the Milky Way and Andromeda," White told Live Science. "Instead, the flattened distribution of the surrounding matter pulls these galaxies outwards in a way which almost exactly compensates for the inward pull of the [Milky Way] and [Andromeda]."

Equally important, the regions above and below the sheet are devoid of galaxies. Such sparse regions occur throughout the cosmos, and the deep Local Voids around our Local Group formed in areas where the initial density of the universe was a bit lower than average.

"As a result these regions expanded faster than average, and their matter was 'pushed' outwards," White said via email. "By the present day these low-density regions fill most of space and gravitational effects have concentrated most of their material into the 'walls' that separate them."

Reconciling experiments, observations and models

The location of the voids is essential. These sparse regions are where any existing structures would fall toward the Local Group; any galaxies there would indeed be moving toward us. So we don't see any other objects careening toward the Milky Way, as Andromeda is doing, because there simply aren't any galaxies there to do so.

Overall, when accounting for the vast sheet of mass, the simulations accurately modeled the distribution of nearby galaxies and the voids, thereby reconciling experimental results with astronomical observations of galactic motions as well as with the leading model of cosmology, known as lambda cold dark matter.

"We are exploring all possible local configurations of the early universe that ultimately could lead to the Local Group," lead study author Ewoud Wempe, a cosmologist at the University of Groningen in the Netherlands, said in a different statement. "It is great that we now have a model that is consistent with the current cosmological model on the one hand, and with the dynamics of our local environment on the other."

Interestingly, the researchers report that high-latitude galaxies farther out in the cosmos have been observed to be falling toward the flat sheet of matter at several hundred kilometers per hour. Finding additional structures infalling from the directions of the voids could lend further support to the results of this study.

Two incredibly rare supernovas that erupted billions of years ago provide a unique opportunity to explain cosmology's biggest mystery — How fast is the universe expanding?

But there's a twist: Even though astronomers have already observed these exploding stars, we will have to wait up to 60 years for their light to reach us again.

A phenomenon called gravitational lensing has split the light from these obliterated stars into multiple images, each of which travels a different path through space-time to reach us. As a result, researchers will one day be able to measure the delay between these ghostly images to offer an unprecedented constraint on the expansion rate of the universe — a problem that has long bedeviled scientists, as the universe appears to be expanding at different rates depending on where they look.

Conor Larison, a postdoctoral researcher at the Space Telescope Science Institute, presented the discovery of the two gravitationally lensed supernovas, named SN Ares and SN Athena, at a news conference at the 247th meeting of the American Astronomical Society in Phoenix.

Cosmic magnifying glasses reveal the invisible

These supernova observations are among the first results from the Vast Exploration for Nascent, Unexplored Sources (VENUS) treasury program. The VENUS survey employs the James Webb Space Telescope (JWST) to observe 60 dense galaxy clusters, which act as cosmic lenses that split and focus the light from extremely distant, otherwise invisible sources such as supernovas.

This cosmic phenomenon, called gravitational lensing, is a direct consequence of gravity's effect on the fabric of space-time and was first proposed by Albert Einstein in his theory of relativity. It occurs when a massive celestial object, like a galaxy cluster, bends the light from a more distant source that's located behind it, thus magnifying the object.

"Strong gravitational lensing transforms galaxy clusters into nature's most powerful telescopes," Seiji Fujimoto, principal investigator of the VENUS program and an astrophysicist at the University of Toronto, said in a statement. "VENUS was designed to maximally find the rarest events in the distant Universe, and these lensed [supernovas] are exactly the kind of phenomena that only this approach can reveal."

SN Ares is the first lensed supernova discovered via the VENUS program. The explosion occurred almost 10 billion years ago, when the universe was around one-third its current age. The warp in space-time caused by a foreground galaxy cluster, MJ0308, split the light from SN Ares into three images.

One image has already reached our telescopes. But the light from the other two images passes much closer to the massive center of MJ0308, so it experiences a much greater slowdown due to gravitational time dilation. Therefore, the other two images of SN Ares will arrive in approximately 60 years — an unprecedented delay.

"Such a long anticipated delay between images of a strongly lensed supernova has never been seen before and could be the chance for a predictive experiment that could put unbelievably precise constraints on cosmological evolution," Larison said in a statement.

In the meantime, a delayed image of SN Athena, which erupted as a supernova when the universe was about half its current age, is anticipated to arrive in the next one to two years. Although it won't be as cosmologically precise as its mythological half brother Ares, Athena will reveal how accurate our predictive powers have become.

A sorely needed natural experiment

The predicted reappearance of these supernovas, compared with their actual arrival times in the future, will provide precise constraints on the expansion rate of the universe, a value known as the Hubble constant.

Curiously, when cosmologists measure the Hubble constant, they obtain different values based on the measurement method — a disparity known as the Hubble tension. Calculations based on the cosmic microwave background — the oldest light in the universe, emitted when the cosmos was only 380,000 years old — yield a universal expansion rate of 67 kilometers per second per megaparsec.

Yet calculations based on the Hubble Space Telescope's observations of pulsating Cepheid stars, used as "standard candles" for their specific luminosity patterns, yield a value of 73 kilometers per second per megaparsec.

Within the observable sphere of the cosmos, the delayed images from SN Ares and SN Athena may help reconcile the Hubble tension.

"If we can measure the difference in when these images arrive, we recover a measurement of the physical scale of the lensing system which spans the Universe between the supernova and us here on Earth," Larison told Live Science via email. "Any distance measurement we can make like this in the Universe tells us how the Universe has been evolving over cosmic time, as these distances directly depend on this evolution."

Equally importantly, the lensed supernovas allow astronomers to make this measurement in a "single, self-consistent step," Larison added.

The time delays from these supernovas also allow an independent measurement method — unrelated to the cosmic microwave background or standard candles like Cepheid stars — at a time when such a measurement is "sorely needed" to test "possible unknown systematics” governing cosmological expansion.

From Big Bang to big mystery

Coincidentally, 60 years have passed since the first formal suggestion to use lensed supernovas as a tool to explore the universe's expansion. However, fewer than 10 such supernovas had been discovered before the VENUS program observations.

"Since VENUS started last July, we have discovered 8 new lensed supernovae over 43 observations, almost doubling the known sample in a remarkably fast time frame," Larison told Live Science. "It seems that, although lensed supernovae are certainly rare, the real limitation has been in observing capabilities. It is really only with JWST that we are achieving the depth and wavelength coverage necessary to find these en masse, which is exactly what VENUS was designed to do."

As a result, lensed supernovas may be the most exciting prospects in long-baseline cosmology, the study of how the universe has changed throughout its 13.8 billion years of existence.

The answer is up in the air; there's no guarantee that the expansion of the universe will continue to accelerate, especially as dark energy may be weakening. If it is, then the current expansion of the cosmos could one day become a contraction, having profound consequences on the ultimate fate of the universe.

Ultimately, SN Ares and SN Athena may hint at the potential death of the universe and whether it ends with a roar or a whimper — will the cosmos collapse in a Big Crunch, or expand indefinitely into the thin, cold darkness of a Big Freeze?

A six-year survey covering 669 million galaxies has revealed insight into dark energy, the mysterious phenomenon driving the universe's accelerating expansion.

The landmark survey paints a complicated picture about our understanding of the universe, showing that two leading theories of cosmology are both equally good fits for the new cosmic expansion observations. However, both theories still fall short in explaining why matter clusters in the universe the way it does, hinting that there’s more work yet to be done.

The analysis of the Dark Energy Survey (DES) combines four types of data collected by the Victor M. Blanco Telescope in Chile, covering about an eighth of the sky. The research zeroes in on the universe's past and present expansion, tightening constraints on models of that expansion about twice as much as previous studies had.

"These results from the Dark Energy Survey shine new light on our understanding of the Universe and its expansion," Regina Rameika, associate director of the U.S. Department of Energy's Office of High Energy Physics, said in a statement. "They demonstrate how long-term investment in research and combining multiple types of analysis can provide insight into some of the Universe's biggest mysteries."

Expanding our knowledge

Dark energy is thought to make up about 70% of the total energy in the universe, but astronomers still know very little about its true nature. Scientists proposed the concept to explain observations that suggest the universe is expanding at an ever-accelerating rate. The DES is one of several collaborations developed to study the phenomenon in more detail.

In a new paper posted to the preprint server arXiv Jan. 21, DES scientists used four kinds of markers to probe the universe's expansion: baryonic acoustic oscillations, or fluctuations in the density of normal matter throughout the universe; Type Ia supernovas, stellar explosions that can help scientists gauge the distance of cosmic objects; galaxy clusters; and weak gravitational lensing, which occurs when a galaxy cluster warps space-time, distorting the apparent shapes of objects behind it. A series of 18 supporting papers dig into the findings in detail.

Altogether, the data and analysis are consistent with previous studies of dark energy, though the new work places tighter constraints on models of how the universe behaves. The data mostly align with the standard model of cosmology, in which the density of dark energy is constant. The data also fit with a related model in which the dark energy density varies over time, but it didn't align any better than it did with the standard model.

"It is an incredible feeling to see these results based on all the data, and with all four probes that DES had planned," study co-author Yuanyuan Zhang, an astronomer at the National Science Foundation's NOIRLab, which manages the telescope, said in the statement. "This was something I would have only dared to dream about when DES started collecting data, and now the dream has come true."

Despite the relatively good fit between the data and the standard model, some questions remain. The pattern of galaxy clustering still doesn't line up exactly with predictions from the standard model, but it's not different enough to conclude that the standard model is wrong, the team added.

Still, DES researchers will continue testing this and other models of dark energy in conjunction with the Vera C. Rubin Observatory in Chile to further refine our understanding of the mysterious phenomenon.

"Rubin's unprecedented survey of the southern sky will enable new tests of gravity and shed light on dark energy," Chris Davis, NSF program director for NOIRLab, said in the statement.

Two of the universe's most mysterious particles may be colliding invisibly throughout the cosmos — a discovery that could solve one of the biggest lingering problems in our standard model of cosmology.

Those two elusive components — dark matter and neutrinos (or "ghost particles") — are ubiquitous throughout the cosmos, yet they remain poorly understood. In a study published Jan. 2 in the journal Nature Astronomy, an international team of researchers found evidence that dark matter and neutrinos may collide, transferring momentum between them in the process.

This surprising interaction may help to explain why the universe is less populated by dense regions, like galaxies, than predicted — in other words, the universe is less "clumpy" than cosmologists think it should be, the researchers said in a statement.

Dark matter and neutrinos remain a riddle

Dark matter is the mysterious, invisible substance that constitutes 85% of the matter in the universe. As its name suggests, dark matter does not emit light, so its existence has been only indirectly inferred from its gravitational influence, as observed in cosmological surveys.

Neutrinos are subatomic particles with infinitesimally low masses and no electric charge, so they very rarely interact with other particles. They're produced by various nuclear processes, including stellar fusion and supernovas, in prodigious quantities: Every second, approximately 100 billion neutrinos pass through each square centimeter of your body, Live Science previously reported.

Yet dark matter and neutrinos should not interact, according to the leading model of cosmology, known as the lambda cold dark matter model (lambda-CDM). This standard model aims to theoretically explain the large-scale structure of the cosmos.

Cosmological conundrum

However, this recent study provides new evidence that dark matter and neutrinos may interact after all, as other researchers have posited over the past two decades.

If dark matter and neutrinos do collide, and transfer momentum to one another in the process, this discovery would inspire a rethink of the lambda-CDM model. Such collisions could also help to explain the "S8 tension," a mismatch between the expected and actual "clumpiness" of the universe.

"This tension does not mean the standard cosmological model is wrong, but it may suggest that it is incomplete," Eleonora Di Valentino, study co-author and a senior research fellow at the University of Sheffield in the U.K., explained in the statement. "Our study shows that interactions between dark matter and neutrinos could help explain this difference, offering new insight into how structure formed in the Universe."

The mismatch stems from researchers' findings that the current cosmos isn't as packed together as predicted, based on observations of the cosmic microwave background (CMB) — the first light in the universe, emitted when the cosmos was only 380,000 years old.

"The statement that cosmic structures are 'less clumped' is best understood in a statistical sense, rather than as a change in the appearance of individual galaxies or clusters. It refers to a reduced efficiency in the growth of cosmic structures over time," study co-author William Giarè, a cosmologist at the University of Hawaii, told Live Science via email.

Unraveling multiple threads of evidence

The researchers tried to unite evidence from energy and density fluctuations in the CMB and from baryon acoustic oscillations (BAO) — pressure waves "frozen" in time from the beginning of the cosmos — with more recent observations of the universe's large-scale structure.

The early-universe data come from the Atacama Cosmology Telescope in Chile and the European Space Agency's space-based Planck telescope, which was designed to study the CMB. The later-universe data come from the Victor M. Blanco Telescope in Chile and the Sloan Digital Sky Survey, a two-decade effort to create a 3D map of millions of galaxies across more than 11 billion light-years.

The researchers also incorporated cosmic shear data from the Dark Energy Survey. Cosmic shear is the distortion of distant celestial objects due to weak gravitational lensing, which occurs when massive foreground structures bend the fabric of space-time and alter the paths of light traveling from those distant celestial objects to our detectors.

Finally, the researchers combined these data and modeled the evolution of the universe. When accounting for collisions between dark matter and neutrinos and the resulting momentum exchange, the simulations generated a model universe that better agrees with real observations.

There's reason to remain cautious, however, as the interaction between dark matter and neutrinos has only a 3-sigma level of certainty — meaning there is a 0.3% chance that this result is a fluke. Though short of the scientific gold standard of 5 sigma, it is significant enough to warrant additional research because, if confirmed, the interaction would prove a "fundamental breakthrough in cosmology and particle physics" — and a potential solution to the cosmic clumpiness quandary.

"The final verdict will come from upcoming large sky surveys, such as those from the Vera C. Rubin Observatory, and more precise theoretical work," research team leader Sebastian Trojanowski, a theoretical physicist at the National Centre for Nuclear Research in Poland, explained in a separate statement. "These will allow us to determine whether we are witnessing a new discovery in the dark sector or whether our cosmological models require further adjustment. However, each of these scenarios brings us closer to solving the mystery of dark matter."

The Nebra Sky Disc was discovered in an artifact hoard in 1999, when metal detectorists illegally excavated it from an ancient religious site on a hill near Nebra, a town in the German state of Saxony-Anhalt. After police recovered the disc in 2002, archaeologists studied the unique object, revealing it's up to 3,800 years old and the world's oldest depiction of astronomical phenomena. (The next oldest is a star map on the ceiling of an ancient Egyptian tomb from about 3,500 years ago.)

The Sky Disc was crafted from about 8.8 pounds (4 kilograms) of bronze, according to the State Museum of Prehistory in Halle, Germany, where the object is on display. The bronze was flattened into a disc 12.6 inches (32 centimeters) in diameter and then decorated with 1.8 ounces (50 grams) of gold inlay representing a boat, a crescent moon, a full moon or a sun, and a series of stars.

Based on the style of the axes and the carbon dating of wood in the hilts of swords recovered along with the disc in the metal hoard, experts think the Sky Disc was buried around 1600 B.C., during the Early Bronze Age, but it may have been created two centuries earlier.

Some research has questioned the disc's authenticity, saying that it probably didn't come from Nebra and was about 1,000 years more recent, based on a soil and chemical analysis of the artifact. A subsequent study countered those claims and found that the disc was authentic and from Nebra but that it was made in several stages.

Close examination of the disc revealed that it was made in at least five phases. Initially, the bronze disc included the full moon or sun, the crescent moon and 32 stars. Then, two arcs were placed on each side of the disc. A third arc, perhaps representing a boat, was then added to the bottom. In the fourth phase, the rim of the disc was perforated, suggesting it may have been attached to a support, like a pole for ceremonial use. Finally, the left arc was removed before the disc was buried with the metal hoard. But experts don't know exactly when the disc was made or how much time passed between the phases of decoration.

The Nebra Sky Disc appears to represent the night sky, with several stars forming the Pleiades, or "Seven Sisters," star cluster. The golden arcs on each side of the disc may represent the horizons, marking the summer and winter solstices, and the boat may be a mythical one that brought the sun across the sky from east to west in the daytime and back at night.

By aligning the Sky Disc with the plateau on Mittelberg Hill, where it was found, the western horizon arc aligns with the Brocken, a high mountain that the sun disappears behind on the summer solstice. This suggests the Sky Disc may have been used to keep track of important astronomical dates in prehistory.

But who used the Sky Disc and who buried it are still mysteries, partly because it was recovered by treasure hunters and not in a scientific excavation. The treasure hunters damaged the gold sun or full moon, scratched the surface, and cleaned it improperly. Given the numerous well-furnished burial mounds of important people that dotted the landscape of central Germany as early as 2000 B.C., however, perhaps the Sky Disc once belonged to a Bronze Age chieftain.

For more stunning archaeological discoveries, check out our Astonishing Artifacts archives.

Scientists continue to push the boundaries of astronomy and cosmology, thanks to next-generation instruments that can see farther and clearer than ever before.

Through these efforts, astronomers have observed some of the earliest galaxies in the Universe. In turn, this has led to refined theories and timelines of galactic formation and evolution.

In a recent study, a team of astronomers led by the University of Pittsburgh (UPitt) uncovered what could be the earliest barred spiral galaxy ever observed. This finding helps constrain the timeframe in which bars first emerged in the Universe.

The research was led by Daniel Ivanov, a physics and astronomy graduate student in the Kenneth P. Dietrich School of Arts and Sciences at the University of Pittsburgh. Based on observations made with the NASA/ESA/CSA James Webb Space Telescope (JWST) with data from Space Telescope Science Institute (STScI), the team spotted a barred spiral galaxy (COSMOS-74706). Thanks to additional confirmation by the Multi-Object Spectrograph for Infrared Exploration (MOSFIRE) on the Keck I telescope, the team determined that this galaxy existed over 11.5 billion years ago.

He and his team presented their findings on Jan. 8th, 2026, at the 247th meeting of the American Astronomical Society (AAS) in Phoenix, Arizona.

According to the Hubble Sequence, galaxies are grouped into elliptical, spiral, and lenticular based on their morphological characteristics. Whereas galaxies generally begin as irregular disks, they evolve to form spiral arms extending from a central bulge (aka. a spiral galaxy).

Barred spirals, such as the Milky Way, also have a bar-shaped linear arrangement of stars across their centers, which play an important role in their evolution by funneling gas inward from the outer reaches, feeding the supermassive black hole in the center, and suppressing star formation throughout the stellar disk.

While researchers have reported barred spiral galaxies that are even older, analyses of these candidates have been less conclusive, as the observations were made using gravitational lensing or redshift measurements. Whereas the former method is hampered by the lensing effect, which often blurs the light from the more distant object, redshift measurements are subject to errors and uncertainties of 10-15%. Neither method is as definitive as spectroscopy, which was used to validate the age of COSMOS-74706.

The discovery of a barred spiral galaxy this early in the Universe was not entirely surprising, as some simulations suggest that bars were forming in galaxies as far back as 12.5 billion years. However, observational evidence of such structures has been much harder to come by, making this a significant discovery that helps constrain the timeline of galactic evolution. As Ivanov stated in a UPitt press release:

This galaxy was developing bars 2 billion years after the birth of the Universe. Two billion years after the Big Bang. It's the highest redshift, spectroscopically confirmed, unlensed barred spiral galaxy. In principle, I think that this is not an epoch in which you expect to find many of these objects. It helps to constrain the timescales of bar formation. And it’s just really interesting.

The original version of this article was published on Universe Today.

Recent observations have revealed that our understanding of the cosmos is flawed, but it may be because the universe is "stickier" than we assumed, new research proposes.

In a paper that was published on the arXiv preprint server but has not been peer-reviewed, Muhammad Ghulam Khuwajah Khan, a researcher at the Indian Institute of Technology, suggests that space may possess a property called bulk viscosity.

Viscosity is a measure of how much a fluid resists flowing or changing shape — like the difference between pouring water versus honey. In this case, we are talking about the bulk viscosity of the vacuum itself, a ghostly resistance that occurs when space expands.

A constant problem

Traditionally, scientists have used a simple model to describe the universe. In this model, known as Lambda-CDM, dark energy — the mysterious force responsible for the accelerating expansion of the universe — is a steady, unchanging background known as the cosmological constant.

However, data from the Dark Energy Spectroscopic Instrument (DESI), which is mounted on the Mayall Telescope at Kitt Peak National Observatory in Arizona, released last year hinted that something may be fundamentally wrong with our understanding of dark energy. The new observations showed a slight mismatch between our standard theories and the actual, observed rate at which galaxies are zipping away from us.

To explain this discrepancy, Khan has proposed a model involving spatial "phonons." In solid-state physics, phonons are essentially the collective vibrations of atoms in a crystal. But Khan applied this idea to the fabric of space itself. He suggested that these longitudinal vibrations, which would act as sound waves of the vacuum, could be responsible for a viscous effect that slowed the expansion of the cosmos just enough to match what we see in the sky.

By treating the universe as a viscous fluid, this model introduces a drag on cosmic expansion. As space stretches, these spatial phonons slosh around, creating a pressure that opposes the outward push. In fact, the study shows that this simple, data-based model fits the DESI data with great precision, potentially solving some of the headaches caused by the standard cosmological constant.

But we should tread lightly — this is merely a guess. Viscous dark energy would be a foundational shift in how we view the vacuum of space, and the hard data from DESI are still being analyzed by the scientific community. We aren't yet sure if this viscosity is a fundamental property of nature or just a sluggish artifact of our current measurements.

So, where do we go from here? The next decade of data from missions like the Euclid space telescope and continued monitoring by DESI will be the ultimate test. We need more observations to see if these ghostly vibrations are truly ruling the cosmos, or if space is as smooth as we once believed.

Scientists may have finally pinned down the nature of some of the most baffling objects in the night sky.

In a new study, researchers investigated the identity of "little red dots." These mysterious objects from the early universe have characteristics of both galaxies and supermassive black holes but don't quite fit the description of either.

The new study found that these enigmatic dots may be young supermassive black holes after all, cocooned in dense clouds of gas that mask telltale signs of their true nature. The researchers published their findings Wednesday (Jan. 14) in the journal Nature.

Little red dots were first observed by the James Webb Space Telescope (JWST) shortly after the spacecraft began collecting data in 2022. They were initially thought to be compact, star-filled galaxies, but they were present too early in the universe to have formed so many stars — at least under our current understanding of galaxy evolution.

Instead, other researchers suggested that the unusual objects might be early supermassive black holes. Light emitted by energized hydrogen atoms around the dots suggests that the gas is moving at thousands of miles per second, tugged along by the gravitational pull of the object at the center.

"Such extreme speeds are a smoking gun of an active galactic nucleus," meaning a hungry supermassive black hole at the center of a galaxy that's pulling in matter, Rodrigo Nemmen, an astrophysicist at the University of São Paulo in Brazil, wrote in an accompanying article published in the journal Nature.

But unlike supermassive black holes, little red dots haven't been observed emitting X-rays or radio waves. And regardless of whether the dots are black holes or early galaxies, they appear to have too much mass to have formed as early in the universe as they did.

Black hole metamorphosis

In the new study, the researchers looked closely at the light emitted from these objects to better understand their nature. The scientists studied spectra from 30 little red dots, each one collected by JWST's infrared instruments.

The light emitted from the little red dots closely matches the light that the team predicted would be emitted from a supermassive black hole surrounded by a dense cloud of gas. That gaseous cocoon could have trapped X-ray and radio emissions from the growing black holes, blocking them from reaching JWST.

When the team recalculated the masses of the little red dots under the new interpretation, they found that the dots were about 100 times less massive than previously thought. Together, the evidence suggests that little red dots are growing supermassive black holes that are accreting the surrounding gas.

"These are the lowest mass black holes at high redshift, to our knowledge, and suggest a population of young [supermassive black holes]," the researchers wrote in the study. (Redshift describes how light stretches toward the redder end of the electromagnetic spectrum as it crosses the expanding cosmos; a higher redshift signifies a more distant object.)

"With the corrected mass estimates, [little red dots] fit standard theories of cosmic evolution," Nemmen wrote. Confirming the findings will involve studying more little red dots to explore whether this "cocoon" phase is common, and determining what role it plays in black hole growth.

Astronomers have spotted an unexpectedly hot galaxy cluster in the early universe that's challenging theories of galactic evolution.

The scorching cluster existed just 1.4 billion years after the Big Bang, blazing far earlier and hotter than current models of galaxy cluster formation predict should be possible. The discovery suggests that the predicted patterns of cluster growth might need a rethink, researchers reported Jan. 5 in the journal Nature.

Galaxy clusters are collections of dark matter and hundreds to thousands of galaxies, all bound together by gravity. Those galaxies are separated by a mix of gas known as the intracluster medium. As galaxy clusters form, the intracluster medium heats up due to gravitational interactions within the cluster and energy emissions from young stars and black holes. But this process takes a long time, and scientists have only rarely observed a hot intracluster medium in young galaxy clusters.

"Understanding galaxy clusters is the key to understanding the biggest galaxies in the universe," study co-author Scott Chapman, an astrophysicist at Dalhousie University who conducted the research while at the National Research Council of Canada (NRC), said in a statement. "These massive galaxies mostly reside in clusters, and their evolution is heavily shaped by the very strong environment of the clusters as they form, including the intracluster medium."

In the new study, researchers used the Atacama Large Millimeter/submillimeter Array (ALMA), a powerful radio telescope located in Chile, to observe a bright, young galaxy cluster known as SPT2349-56, whose light was emitted just 1.4 billion years after the Big Bang. This cluster is relatively small — about the size of the Milky Way's outer halo — but it contains more than 30 active galaxies and three supermassive black holes, and it forms stars more than 5,000 times as fast as the Milky Way.

Using a phenomenon called the thermal Sunyaev-Zeldovich effect, the team found that the gas in the intracluster medium is at least five times hotter than current theories of cluster formation predict it should be for its relatively young age.

"We didn't expect to see such a hot cluster atmosphere so early in cosmic history," study coauthor Dazhi Zhou, a PhD student in the department of physics and astronomy at the University of British Columbia, said in the statement. "In fact, at first I was skeptical about the signal as it was too strong to be real."

But it was real — and that could mean that galaxy clusters can form more quickly than expected.

"This tells us that something in the early universe, likely three recently discovered supermassive black holes in the cluster, were already pumping huge amounts of energy into the surroundings and shaping the young cluster, much earlier and more strongly than we thought," Chapman said.

In future studies, the team plans to investigate what this unusual cluster might mean for the formation and evolution of existing galaxy clusters.

"We want to figure out how the intense star formation, the active black holes and this overheated atmosphere interact, and what it tells us about how present galaxy clusters were built," Zhou said. "How can all of this be happening at once in such a young, compact system?"

After a multi-decade-year mission to understand the nature of the universe, a telescope perched in the mountain plateaus of northern Chile said goodbye in 2022. Now, its final data release is revealing the telescope's legacy: a field in tension.

In October 2007, the Atacama Cosmology Telescope (ACT) saw its first light. But it was not light from a star, or even a distant galaxy. Instead, ACT was designed to hunt for microwaves, especially the kind of microwaves left over from some of the earliest epochs of the universe. This "fossil" light, known as the cosmic microwave background (CMB), was emitted when the universe was just 380,000 years old.

The CMB offers cosmologists a pristine look at the infant cosmos. ACT was designed to complement other surveys, like the European Space Agency's Planck satellite. The Planck mission launched an orbiting spacecraft to provide a whole-sky census of the CMB. But its resolution was limited, especially in studies of the CMB's polarization (the direction in which oscillations in the CMB's magnetic and electric field point as the light travels). In contrast, even though ACT is ground-based, it could search deeper into smaller pockets of the CMB sky at a very high resolution.

ACT was especially good at looking at the CMB's polarization, which tells us a lot about the state of the early universe. If you change the amount of dark matter in the cosmos, how it's distributed, how many neutrinos there are, or any of another dozen or so properties of the cosmos, you change what the CMB's light looks like.

Final ACT

In November, the ACT team released their sixth and final public dataset as three articles published in the Journal of Cosmology and Astroparticle Physics. While cosmologists will continue to mine the data for many years to come, the core team also provided their final suite of analyses and studies before saying farewell for good.

Their findings matched what surveys like Planck had already identified: that something funny is going on with the expansion of the universe. Measurements of the present-day expansion rate, known as the Hubble rate or Hubble constant, taken with early-universe probes like Planck and ACT, reveal a number that is quite a bit slower than estimates based on nearby measurements, like supernova dimming.

This discrepancy has come to be known as the Hubble tension, and it is perhaps the greatest unsolved mystery in modern cosmology. But ACT didn't just confirm the existence of the tension; it also destroyed some very good ideas.

ACT axes 30 cosmic models

Cosmologists have been busy concocting many theoretical explanations for the Hubble tension. Many of these are called "extended" cosmological models, since they take the standard cosmological picture and add a few extra ingredients or forces to the universe.

But these ingredients and forces don't just exist today; they also must have existed when the CMB was first emitted. So ACT's exquisite view of the CMB allowed the team to put many of these models — around 30, in fact — to the test.

All of them failed.

But in science, you only lose if you don't learn anything, and ACT's negative results help cosmologists in their search. In other words, you can only know the right answer once you've crossed off all the wrong answers.

Scientists using the James Webb Space Telescope (JWST) have spotted the first evidence of "monster stars" in the early universe — offering new clues to how supermassive black holes grew so big after only a billion years of the universe's history.

The team spotted these gargantuan stars — each with a mass of between 1,000 and 10,000 times our sun — in a galaxy called GS 3073, which formed roughly about a billion years after the Big Bang. It is believed that monster stars like these led to the formation of these early supermassive black holes.

The study was co-led by scientists from the Harvard-Smithsonian Center for Astrophysics (CfA) and the University of Portsmouth in the U.K., and was published Nov. 12 in Astrophysical Journal Letters.

"Our latest discovery helps solve a 20-year cosmic mystery," study co-author Daniel Whalen, from Portsmouth's Institute of Cosmology and Gravitation, said in a statement. "These cosmic giants would have burned brilliantly for a brief time, before collapsing into massive black holes, leaving behind the chemical signatures we can detect billions of years later."

"A bit like dinosaurs on Earth, they were enormous and primitive," Whalen added. "And they had short lives, living for just a quarter of a million years, a cosmic blink of an eye."

The research's implications include learning about the first generation of stars, as well as literally shedding light on the "cosmic dark ages", or the period of time when the first stars came to light and the chemistry of the universe began to change.

A peculiar signature

The stars in GS 3073 had an unusual and "extreme" imbalance of nitrogen to oxygen (a ratio of 0.46) not usually found in stars or stellar explosions, according to the team. The signature, however, matched something predicted in models: "primordial stars thousands of times more massive than our sun," study co-author Devesh Nandal, a postdoctoral fellow at the CfA's Institute for Theory and Computation, said.

How did these stars produce so much nitrogen? The researchers said it's a three-step process. Stars are constantly burning elements in their cores. As these large stars in GS 3073 burned helium, the chemical reactions created carbon. Eventually, carbon began to invade an outside shell of material, where hydrogen was burning. In that outside shell, the carbon and hydrogen then mixed to create nitrogen.

As the nitrogen was produced, convection currents within the star began to distribute it throughout the star's body. Over time, the nitrogen left the star and flowed into space. In the case of GS 3073, this process lasted millions of years.

"The study also found that this nitrogen signature only appears in a specific mass range," the researchers noted. "Stars smaller than 1,000 solar masses, or larger than 10,000 solar masses, don't produce the right chemical pattern for the signature, suggesting a 'sweet spot' for this type of enrichment."

The big black hole mystery

Based on their models, the researchers further suggested that when these monster stars reach the end of their lives, they don't explode into supernovas. What happens next is instead a big collapse, generating some of the universe's earliest supermassive black holes.

Adding more fuel to this idea: GS 3073 does appear to have an actively feeding black hole at its center, "potentially the very remnant of one of these supermassive first stars," the statement noted. "If confirmed, this would solve two mysteries at once: where the nitrogen came from and how the black hole formed."

The origin of the universe's first supermassive black holes remains one of the biggest mysteries in astrophysics. Some theories suggest they collapsed directly from ultra-dense clouds of gas shortly after the Big Bang and then formed galaxies around them; other theories point to more exotic explanations, such as dark matter interactions or the collapse of monster stars. Ultimately, more research is needed to solve this ancient puzzle.

A new study suggests that a NASA telescope may have made the first-ever observation of elusive dark matter, the invisible and mysterious substance that makes up most of the matter in the universe. However, scientists, including the study author, caution that more research is needed to understand the finding.

NASA's Fermi Gamma-ray Space Telescope, which studies high-energy wavelengths of light known as gamma-rays, spotted emissions in the center of the Milky Way that may be associated with particles linked with dark matter, according to the study, published Tuesday (Nov. 25) in the Journal of Cosmology and Astroparticle Physics.

"If this is correct, to the extent of my knowledge, it would mark the first time humanity has 'seen' dark matter," Tomonori Totani, an astronomy professor at the University of Tokyo and the sole author of the study, said in a statement.

But the study cautions that independent confirmation of this signal must be obtained — not only from the Milky Way but also "from other objects or regions" with similar properties. Similarly, theoretical physicist Sean Tulin, an assistant professor of physics and astronomy at York University in Toronto, told Live Science he would like an independent analysis of the work because it's not the first time such claims have been made using the Fermi telescope.

A prominent example is the "galactic center excess," a source of unexplained gamma-ray light discovered with Fermi data in 2009. After nearly two decades of further research, scientists continue to debate whether the excess is the result of dark matter or more conventional astronomical sources, such as fast-spinning stars known as pulsars.

WIMPs in the cosmos

Dark matter is a nonluminous substance believed to make up most of the matter in the universe. So far, it has been traced only through its gravitational effects on other objects. For example, in a seminal 1933 paper, astronomer Fritz Zwicky stated that faraway galaxies were moving around each other faster than predicted based on the visible matter that could be seen with telescopes. The gravitational pull of dark matter was pegged as the likely reason.

There have been several theories about what dark matter includes, but most astronomers today suggest it is made of subatomic particles. Totani's study centers on a popular particle suggestion, the weakly interacting massive particle (WIMP).

WIMPs fall outside the widely used Standard Model of particle physics, which successfully shows (for the most part) how the building blocks of matter interact with each other. But the model does not account for the force of gravity or the existence of dark matter, according to CERN.

WIMPs are heavier than protons, according to the statement, and WIMPs hardly interact with other types of matter. But when two WIMPs crash into each other, these particles would be destroyed and energetically unleash other particles during the collision, including photons of gamma-rays.

Dark matter, or no?

To search for the gamma-rays associated with WIMP collisions, many studies have focused on clusters of dark matter, such as the center of our Milky Way galaxy. Data obtained from 15 years of observations with the Fermi telescope showed gamma-rays "in a halo-like structure toward the center of the Milky Way galaxy" that "matches the shape expected from the dark matter halo."

These gamma-rays were extremely energetic, with a photon energy of 20 gigaelectron volts (20 billion electron volts). According to the statement, this energy "matches the emission predicted from the annihilation of hypothetical WIMPs," as well as the frequency of WIMP annihilation.

However, Tulin pointed out that the signal shows up only when you remove the background of "all sources of energetic photons coming from the Milky Way," including from its center and its disk. Some background energy is also present from "Fermi bubbles" — two huge zones of gas and cosmic rays that loom over the Milky Way.

All studies looking at energy sources from the Milky Way need to model that background noise and then subtract that to "reveal the underlying signal," Tulin said. "What you infer for the signal depends very carefully on what you subtracted off of the background. … There's a risk of being tricked if you subtract something off incorrectly."

Aside from questions about the background, the signal could depend on the type of dark matter particle being discussed, Tulin said. "What that means is, what is the model for that dark matter particle?" he said. "What is its mass? What are its fundamental properties? What are its different interactions?"

However, the model of annihilation for a standard WIMP is "perfectly reasonable" with the signal Totani observed, Tulin said, with the assumptions that the study is observing WIMPs under the model we understand and the background is subtracted correctly.

Tulin (who had access to a study preprint when speaking with Live Science) added that despite his cautions, the findings "would be a remarkable thing if it was due to dark matter … not just for the future of the astronomical observations, but this type of dark matter particle could be tested and discovered in all sorts of different experiments, like underground labs and in colliders."

That said, "no one is really staking their house on this being the one time that it turned out to be correct," Tulin said of the new study. "We've seen a lot of anomalies come. A lot of anomalies go. Some anomalies have stuck with us, and still require further exploration."

For more than 4,000 years, Indigenous Americans painted rock art depicting their conception of the universe in what is now southwestern Texas and northern Mexico, a new study finds.

Innovative dating techniques revealed that the rock art, known as the Pecos River style tradition, likely first appeared almost 6,000 years ago and persisted until about 1,400 to 1,000 years ago, spanning roughly 175 generations.

Over this period, the style, found in a region known as the Lower Pecos Canyonlands, remained remarkably consistent in the imagery and the techniques used to create the paintings, which appear to follow a strict set of rules, the researchers reported in the study, which was published Wednesday (Nov. 26) in the journal Science Advances. The authors believe the artworks convey the creators' "cosmovision," a culture's overarching worldview and conception of the universe.

"Frankly, we were stunned to discover that the murals remained in production for over 4,000 years and that the rule-bound painting sequence persisted throughout that period as well," study co-author Carolyn Boyd, a professor of anthropology at Texas State University, told Live Science in an email.

She compared the canyonlands to an "ancient library containing hundreds of books authored by 175 generations of painters," adding that "the stories they tell are still being told today."

The ancient murals found on limestone rock faces across the canyonlands consist of elaborate multicolored paintings depicting animal- and human-like figures, as well as more enigmatic symbols. The artists who made them created visual narratives that relate myths and prescribe rituals, according to Boyd.

"Many of the 200-plus murals in the region are huge; some span over 100 feet [30 meters] long and 20 feet [6 m] tall and contain hundreds of skillfully painted images," Boyd said.

The painters were nomadic hunter-gatherers, but their identity remains unknown, according to Boyd.

"They were highly skilled problem solvers with a sophisticated cosmology and a robust iconographic system to communicate that cosmology," Boyd said.

Dating rock art comes with significant challenges. But for their study, the authors used two independent radiocarbon methods that had typically not been used together to date paintings at 12 mural sites within the Lower Pecos Canyonlands. This ensured that the researchers could be confident that their dating results were consistent, study co-author Karen Steelman, a chemist and science director at the Shumla Archaeological Research and Education Center in Texas, told Live Science.

The researchers also analyzed the iconography and compositional makeup of the murals at the sites, finding that, in many cases, the artists appeared to have adhered to a strict set of technical rules and established stylistic conventions, even though they were created over a 4,000-year-period. For example, the authors determined that the creators generally followed the same sequence when applying colored paints to the artworks — a practice passed down over multiple generations.

The consistency that these complex murals display over several millennia, despite major environmental and technological changes — for example in stone tools and fiber crafts — indicate the persistence of an enduring cosmovision that must have been hugely significant to the hunter-gatherers, according to Boyd. This sophisticated cosmovision encompasses creation stories, the concept of time being cyclical and complex calendrical systems, among other elements.

The researchers have identified elements of this belief system in later Mesoamerican civilizations, such as the Aztecs, as well as among modern Indigenous American communities, like the Huichol of Mexico, she said.

"These paintings may be the oldest surviving visual record of the same core cosmology that later shaped Mesoamerican civilizations and is manifested today throughout Indigenous America," Boyd said in a statement.

"The murals are viewed by Indigenous people today as living, breathing, sentient ancestral deities who are still engaged in creation and the maintenance of the cosmos," Boyd told Live Science.

Astronomers have observed a pair of stars locked in a death spiral, and their dance of doom is revealing more about how gravity works.

The system, called ZTF J2130, sits about 4,000 light-years away. Although astronomers have known about this system for a while, this is the first time they have observed it with such high clarity.

The two stars that make up the system will merge soon. Their spiraling motion agrees with theoretical predictions, which means even more refined future observations will allow researchers to use this system to test our understanding of gravity, the team wrote in a study submitted for publication in the journal Astronomy & Astrophysics in October.

This is a very old system. One of the stars is a white dwarf, the white-hot leftover core of a sunlike star. The other is what's known as a subdwarf star, which is a small star near the end of its life cycle. The two stars are so close together that they complete an orbit in just under 40 minutes. In fact, they've already started to kiss. Their mutual gravity is so strong that they've stretched and distorted, with the subdwarf's material flowing onto the white dwarf companion.

Because the stars are pretty hefty and moving very quickly, they emit gravitational waves, which are ripples in the fabric of space-time first predicted by Albert Einstein and confirmed to exist in 2015. This emission of gravitational waves saps energy from the system, inching the two stars ever closer every year.

Using a combination of data from the Oskar Luhning telescope at the Hamburg Observatory in Germany and the CAHA Observatory in Spain in Germany and Spain, the astronomers undertook a painstaking campaign to measure the orbital period as precisely as possible. They found that the orbit is slowly decaying; with every passing second, the orbital period shrinks by about two-trillionths of a second.

This is in line with calculations based on our current theoretical understanding of gravity. But scientists have been eager to move past Einstein's theory of general relativity for more than a century, so any opportunity to test it immediately draws interest.

The astronomers discovered that an upcoming gravitational-wave observatory, known as the Laser Interferometer Space Antenna (LISA), should be able to directly measure the gravitational waves emanating from this system. The European Space Agency plans to launch LISA in the 2030s, and this stellar pair will still be around next decade.

When the stars finally merge, they will release a supernova-level explosion that might be bright enough to be seen with the naked eye. In the meantime, before we get to enjoy that fireworks show, we'll just have to put gravity to the test.

Astronomers using the James Webb telescope may have discovered some of the universe's first stars, and they may offer clues to how galaxies form. Using the James Webb Space Telescope (JWST) and a phenomenon first predicted by Albert Einstein, the scientists spotted the early stars, known as Population III stars, in a distant cluster called LAP1-B, located 13 billion light-years from Earth. They described their results Oct. 27 in The Astrophysical Journal Letters.

Population III stars, sometimes called dark stars, are theorized to be some of the first stars that formed after the Big Bang about 13.8 billion years ago. According to this theory, hydrogen and helium combined with dark matter, creating gargantuan stars a million times the mass of the sun and a billion times as bright as our star.

There are several reasons the team suspects the stars spotted by JWST are Population III, lead study author Eli Visbal, an associate professor and astrophysicist at the University of Toledo in Ohio, told Live Science in an email.

For example, the stars' spectra, which show their composition based on the light they absorb and emit, had emission lines suggesting lots of high-energy photons, which is consistent with Population III predictions. The spectra also suggested the stars are very large — each on the order of 100 solar masses — and the mass of the stars met some theoretical calculations.

"If indeed Pop III, this is the first detection of these primordial stars," Visbal told Live Science.

However, JWST was suspected to have seen Population III stars before, the team noted in the study. For example, peer-reviewed research in March 2024 suggested that the telescope had spotted some in the galaxy GN-z11 that formed only 430 million years after the universe itself.

The new study argues, however, that the detection of LAP1-B is the only one that fits three theoretical conditions for Population III stars: It formed in a low-metallicity (hydrogen and helium) environment with a temperature suitable to host star formation; the stars formed in low-mass clusters with only a few very large stars present; and the cluster meets mathematical conditions for the initial mass function, or how star masses were distributed among a population when they formed.

JWST was essential for the observations because its 6.5-meter (21 feet) mirror allows it to catch faint objects at incredible distances, Visbal said. But what helped LAP1-B pop into view was a phenomenon called gravitational lensing, which happens when a very massive object, such as a galaxy, bends space-time around it while a background object is in just the right spot. As light from the distant background object passes through the "warp" created by the foreground object, the background light is distorted into rings or arcs. This phenomenon is sometimes called an Einstein ring, as it confirms what Einstein suggested would happen more than a century ago.

In this case, LAP1-B became visible when a closer galaxy cluster, called MACS J0416, passed in front of it and "lensed” the light of LAP1-B.

JWST also allowed for observations of the emission lines from the stars, which were initially emitted in ultraviolet wavelengths but then stretched into infrared wavelengths due to the expansion of the universe, Visbal said. JWST is optimized for infrared observations, allowing the stars to be visible.

Aside from the novelty of the star finding, LAP1-B helps showcase how galaxies evolved, Visbal said. Because Population III stars are expected to form in small dark matter structures that also were building blocks for larger galaxies, "they teach us about the earliest stages of galaxy formation and evolution — for example, how metals pollute the initially pristine hydrogen and helium gas."

A telescope tasked with making the largest-ever map of the universe has confirmed a harsh, if unsurprising, truth: Nothing lasts forever — not cold November rain, or even the cosmos itself.

Using a vast catalog of observations from the European Space Agency's (ESA) Euclid and Herschel space telescopes, a team of 175 researchers has taken the most comprehensive reading of the universe's temperature ever recorded. By studying the heat emitted by stardust in more than 2 million galaxies, the team found that galaxies have grown slightly cooler and seen star formation rates slow down over the past 10 billion years of cosmic history.

According to the researchers, these small-but-clear downward trends hint that the universe's peak days of growth are over. While the expiration date for the cosmos is still a mind-bogglingly long time away (somewhere between 33 billion and 1 quinvigintillion years — that's 1 followed by 78 zeros — by recent estimates), the new findings suggest that, in terms of star formation rates, it's all downhill from here.

"The Universe will just get colder and deader from now on," study co-author Douglas Scott, a cosmologist at the University of British Columbia (UBC), said in a statement. "The amount of dust in galaxies and their dust temperatures have been decreasing for billions of years, which means we're past the epoch of maximum star formation."

The research has been submitted to the journal Astronomy and Astrophysics, and it's available now as a non-peer-reviewed preprint.

A 3D map of the universe

In March, ESA's recently activated Euclid telescope shared its first major data release, including observations of 26 million galaxies stretching more than 10.5 billion light-years into the cosmic distance. This was just the first phase of the telescope's mission to build the largest-ever 3D map of the universe, with the ultimate goal of charting about 1.5 billion galaxies covering one-third of the night sky.

For their new study, the researchers looked at 2.6 million galaxies cataloged in Euclid's first data release and combined them with archival observations from ESA's Herschel Space Observatory, which was active from 2009 to 2013). While Euclid's pair of onboard instruments are tuned to record visible and near-infrared light, Herschel's instruments detected far-infrared light. Therefore, combining these data sets allowed the team to study the heat emitted by stardust across a wide range of wavelengths, offering the most comprehensive measurements of galactic temperatures ever taken.

"By combining the data and having such a huge sample of galaxies … we can produce the most statistically robust calculations to date," lead study author Ryley Hill, a postdoctoral research fellow at UBC, said in the statement.

The team found that the average temperature of galaxies has cooled only slightly over the past 10 billion years, falling by just 10 kelvins. While stars like the sun blaze at more than a million kelvins, galaxies are mostly made of empty space, meaning their average temperatures are far lower. The average galactic temperature of the earliest galaxies observed in the new survey was about 35 K (minus 396 F, or minus 238 C), the researchers found.

It's a small change, but the heat of stardust directly correlates to star formation, the team noted. Hotter galaxies tend to have higher rates of star formation because they contain a greater number of hot, massive stars. By the same token, galaxies with less star formation tend to be cooler, on average. The team's research further confirms this correlation and proves that star formation is slowly waning across the cosmos.

Dust to dust

It may be a chore to deal with on Earth, but dust is crucial to the life cycle of stars. Stars form when clouds of gas and dust become so dense that they collapse under their own gravity, heating up and spinning in the process. If one of these collapsed clumps becomes hot and dense enough, nuclear fusion triggers in its core, forming a star. Eventually, when the star exhausts its supply of nuclear fuel billions of years later, it will explode in a supernova, spewing yet more dust into its neighborhood and allowing the next generation of stars to grow.

Galaxies can run out of star-forming material in a number of ways; they can be cut off from their gas supply during galaxy mergers, or see their star-forming matter violently expelled into space by supermassive black hole outbursts, to name a few. Eventually, a galaxy without sufficient star-forming material becomes quenched — starved of fuel, and doomed to smolder out.

The new results hint that our universe is well on its way to being totally quenched — but, again, not for an unfathomably long time. Earth's sun will exhaust its fuel and explode long before the Milky Way galaxy runs dry, and more massive objects like black holes will live on for many eons after that. In the meantime, the new research offers the most precise probe yet of some of the key conditions of galaxies throughout the universe — measurements that will be essential in Euclid's quest to build the ultimate map of our cosmos.

They're big, they appear early in the history of the universe and where they come from has long been a mystery. Ever since astronomers first detected the existence of supermassive black holes at the center of most galaxies, it has been difficult to fully explain their origin.

But a recent observation with the James Webb Space Telescope (JWST) could help solve the riddle of how supermassive black holes grew so rapidly to become the early universe's goliaths.

The object QSO1 lies in the galaxy cluster Abell 2744 (also known as Pandora's Cluster). The mass in the cluster acts as a gravitational lens that can focus and alter the light from distant sources, making them appear both brighter and at multiple locations. The light from QSO1 was emitted when the universe was around 700 million years old (its current age is almost 14 billion years).

The black hole in QSO1 was first analyzed in February 2024, which revealed that the galaxy contained a black hole with a mass roughly equivalent to 50 million suns.

A recent follow-up study led by Ignas Juodžbalis from the University of Cambridge confirmed the original mass estimate and also showed unequivocally that QSO1 lacks a significant component of gas and stars. Instead of being a black hole that sits at the center of a galaxy, it's as if the black hole itself is dominating the system and the wider galaxy is missing.

"It's a very odd system," Marta Volonteri, a professor at the Paris Institute of Astrophysics, said in an interview with LiveScience. "If there are more like that, it becomes really bizarre."

Volonteri is a world-leading expert on the formation of supermassive black holes and contributed to the analysis of the black hole's mass. "I double checked the results with my own code. There is very little room for any substantial mass in the system besides that of the black hole," she said.

In QSO1, the black hole's mass is about twice that of the surrounding gas and stars. In contrast, the black hole Sagittarius A*, which sits at the center of the Milky Way, has a mass that is only a tiny fraction of the total mass of the galaxy.

Mysterious little red dots

As JWST began gathering data in 2022, it revealed a surprising discovery: numerous compact, red-hued galaxies dubbed "little red dots" observed at epochs corresponding to roughly 500 million to 1.5 billion years after the Big Bang.

Their exact nature is still a mystery, but these ancient systems seem to indicate that galaxies, black holes or both evolved earlier, and with greater masses or densities, than astronomers had previously believed.

Black holes can form when massive stars exhaust their nuclear fuel and collapse under their own gravity. At the dawn of the universe, these early black holes would have grown by feeding on a buffet of stars, gas clouds and other black holes. Yet when astronomers calculate how quickly such stellar-mass black holes could accrete matter, they find it difficult to explain how they could have grown into the cosmic behemoths observed by JWST.

One alternative scenario is that instead of being created from stars, some early-universe black holes could have been formed from the direct collapse of huge gas clouds with much larger masses. Such a scenario was supported by the discovery of UHZ-1, a black hole that displays the telltale signs of direct collapse according to a study led by Priyamvada Natarajan from Yale University.

But the system QSO1, one of the several hundred little red dots that astronomers have analyzed, seems to have formed in a different way.

"My co-authors suggested that its origin could be a primordial black hole, or it may be dark matter that has collapsed because of how it interacts with itself," Volonteri said. "In any case, the black hole came well before the ordinary matter, such as the gas and the stars."

Primordial black holes

In 1967, the Soviet physicists Yakov B. Zeldovich and Igor D. Novikov proposed that, for a brief moment after the Big Bang, some regions of the universe contained so much mass that they imploded into black holes. The idea was further developed by Stephen Hawking in 1971, and has since been investigated both theoretically and observationally by several astrophysicists.

These primordial black holes would not only get a head start in terms of their growth and size, but also sit dead center in the galaxies that form around them. "That the black hole in QSO1 grew so much without any star formation taking place points to a case in which it developed significantly faster than the galaxy," Volonteri said.

The question, then, is if the discovery of QSO1 solves the chicken-or-egg problem of which came into being first: the galaxy, or the black hole at its center?

"This is one object that is still being reviewed. I hope that all this analysis is correct, but it's very complex. But what we used to call exotic models are perhaps not so exotic anymore," Volonteri concluded.

Marta Volonteri was previously interviewed by the author for the book Facing Infinity: Black holes and our place on Earth, which contains more information about her work and the origin of supermassive black holes. Read an exclusive excerpt here.

Using the James Webb Space Telescope (JWST), astronomers have spotted a very bright and mysterious object that could be a galaxy that emerged just 100 million years after the Big Bang, which would make it the universe's earliest known galaxy, a new study suggests.

Alternatively, Capotauro may be an extraordinary brown dwarf (a "failed star" that is more massive than the largest gas giant planets but not large enough to sustain nuclear fusion in its core) that lives on the outer edges of the Milky Way while smoldering at a mere 80 degrees Fahrenheit (27 degrees Celsius).

Capotauro's exact identity is not certain yet, the researchers wrote in the paper, which was posted Sept. 1 to the preprint server arXiv but has not been peer-reviewed yet.

"Capotauro, whatever it is, seems really interesting and promising," co-author Giovanni Gandolfi, an astrophysicist at the National Institute of Astrophysics in Italy, told Live Science.

Capotauro was originally spotted by Gandolfi and his team during a previous study, in which they tried to identify very old galaxies in JWST observations. But the lack of fine-grained data made it impossible to narrow down the object's identity, which Gandolfi said was like having a slither of DNA at a crime scene but too many matches in the FBI database to be helpful.

Then, in March, JWST released more data on Capotauro that was like getting a partial fingerprint, thus allowing them to whittle down the list to just a handful of suspects, Gandolfi said.

To determine what Capotauro could be, the team used images taken by JWST's Near Infrared Camera (NIRCam) at seven wavelengths as part of the Cosmic Evolution Early Release Science (CEERS) survey to measure Capotauro's brightness. The object was detected only at the two longest NIRCam wavelengths.

Then, they used limited, but more fine-grained data from JWST's Near Infrared Spectrograph (NIRSpec) to get a more accurate picture of Capotauro's age and temperature.

Combining the NIRCam and NIRSpec data, the researchers used models to test three possible galaxy configurations, as well as a scenario in which Capotauro might instead be a brown dwarf on the outer rim of the Milky Way. They also tested a range of other possible scenarios, such as the object being a very odd young galaxy or a peculiar exoplanet.

The results were inconclusive, meaning the team could not decisively determine Capotauro's identity. However, they identified the two most likely options.

Under the early-galaxy interpretation, Capotauro was consistently found to have formed around 100 million years after the Big Bang — pushing the age of the oldest known galaxy back by around 200 million years. It was estimated to be gigantic, at over a billion solar masses.

The other possibility is that Capotauro is a very unusual brown dwarf. If this is the case, Capotauro would be the coldest and farthest known brown dwarf in our galaxy, at over seven light-years away and only 300 kelvins (80 F, or 27 C), the researchers wrote in the study. If Capotauro is a pristine brown dwarf, Gandolfi said, scientists now have the chance to investigate the formation of our galaxy.

Both possibilities are "very exciting" because they would challenge what we thought we knew about our own galaxy and how galaxies form and evolve in general, Gandolfi added.

Muhammad Latif, an astrophysicist at United Arab Emirates University who was not involved in the research, said Capotauro is "one of the most puzzling discoveries" from JWST to date.

"It's a very intriguing object in the sense that whatever the way you interpret it, it basically is kind of pushing the boundaries of our knowledge to the edge," he told Live Science.

More precise data on the light emitted by Capotauro is needed to pinpoint its exact properties, Latif said. The team has submitted a request for JWST to gather more data on this mysterious object, Gandolfi added, and is scanning other areas of the universe for similar-looking objects.

Dark matter near the center of our galaxy is "flattened," not round as previously thought, new simulations reveal. The discovery may point to the origin of a mysterious high-energy glow that has puzzled astronomers for more than a decade, although more research is needed to rule out other theories.

"When the Fermi space telescope pointed to the galactic center, it measured too many gamma rays," Moorits Mihkel Muru, a researcher at the Leibniz Institute for Astrophysics Potsdam in Germany and the University of Tartu in Estonia, told Live Science via email. "Different theories compete to explain what could be producing that excess, but nobody has the definitive answer yet."

Early on, scientists proposed that the glow might come from dark matter particles colliding and annihilating each other. However, the signal's flattened shape didn't match the spherical halos assumed in most dark matter models. That discrepancy led many scientists to favor an alternative explanation involving millisecond pulsars — ancient, fast-spinning neutron stars that emit gamma-rays.

Now, a study published Oct. 16 in the journal Physical Review Letters and led by Muru challenges the long-standing assumption about the shape of dark matter. Using advanced simulations of the Milky Way, Muru and his colleagues found that dark matter near the galactic center is not perfectly round, but flattened — just like the observed gamma-ray signal.

A persistent cosmic puzzle

Gamma-rays are the most energetic form of light. They are often produced in the universe's most extreme environments, such as violent stellar explosions and matter swirling around black holes. Yet even after accounting for known sources, astronomers have consistently found an unexplained glow coming from the Milky Way's core.

One proposed explanation is that the radiation originates from dark matter — the invisible substance that makes up most of the universe's mass. Some models suggest that dark matter particles can occasionally smash together, converting part of their mass into bursts of gamma-rays.

"As there are no direct measurements of dark matter, we don't know a lot about it," Muru said. "One theory is that dark matter particles can interact with each other and annihilate. When two particles collide, they release energy as high-energy radiation."

But this theory fell out of favor when the flattened, disk-like shape of the gamma rays failed to match up with the hypothesized shape of dark matter haloes — which are thought to be spherical.

Rethinking the shape of dark matter

Muru and his colleagues set out to revisit the basic assumption that dark matter in the inner galaxy must be spherical. Using high-resolution computer simulations known as the HESTIA suite, which re-creates Milky Way-like galaxies within a realistic cosmic environment, the team studied how dark matter behaves near the galactic center.

They found that past mergers and gravitational interactions can distort the distribution of dark matter, flattening it into an oval or box-like shape — much like the bulge of stars seen in the middle of our galaxy.

"Our most important result was showing that a reason why the dark matter interpretation was disfavored came from a simple assumption," Muru said. "We found that dark matter near the center is not spherical — it's flattened. This brings us a step closer to revealing what dark matter really is, using clues coming from the heart of our galaxy."

This revised picture means that the pattern of gamma-rays expected from dark matter annihilation could naturally look very similar to what astronomers observe. In other words, the dark matter explanation might have been underestimated simply because scientists were using the wrong shape.

What comes next

Although the new findings strengthen the case for dark matter as the origin of the gamma-ray signal, they don't close the debate. To distinguish between dark matter and pulsars, astronomers need sharper observations.

"A clear indication for the stellar explanation would be the discovery of enough pulsars to account for the gamma-ray glow," Muru said. "New telescopes with higher resolution are already being built, which could help settle this question."

If upcoming instruments, such as the ​​Square Kilometre Array (SKA) and the Cherenkov Telescope Array (CTA), reveal many tiny, point-like sources at the galactic center, it would favor the pulsar explanation. If, instead, the radiation remains smooth and diffuse, the dark matter scenario would gain support.

"A 'smoking gun' for dark matter would be a signal that matches theoretical predictions precisely," Muru noted, adding that such a confirmation will require both improved modeling and better telescopes. "Even before the next generation of observations, our models and predictions are steadily improving. One future outlook is to find other places to test our theories, such as the central regions of nearby dwarf galaxies."

The mystery of the gamma-ray excess has endured for more than 10 years, with each new study adding a piece to the puzzle. Whether the glow comes from dark matter, pulsars or something entirely unexpected, Muru's results highlight how the galaxy's structure itself may hold vital clues. By reshaping our understanding of the Milky Way's dark core, scientists are inching closer to answering one of the most profound questions in modern astrophysics — what dark matter really is.

Long before starlight filled the cosmos for the first time, the young universe may have been simmering, according to a new study.

The findings suggest that about 800 million years after the Big Bang, energy from newborn black holes and the fading embers of the first stars was already warming vast clouds of intergalactic hydrogen gas, offering a rare glimpse into a largely uncharted chapter of the universe's youth.

The results also bring astronomers a step closer to detecting a faint radio signal known as the 21-centimeter hydrogen line, an elusive imprint that could reveal the properties of those primordial stars and black holes that reionized the cosmos.

"It's one of the most unexplored periods in our universe," study co-author Ridhima Nunhokee, a research scientist at the International Centre for Radio Astronomy Research in Perth, Australia, told Live Science. "There's just so much to learn."

Astronomers know that the universe began in an extremely hot, dense state, the Big Bang, about 13.8 billion years ago, and then cooled rapidly as it expanded. Roughly 400,000 years later, temperatures dropped enough for protons and electrons to merge into neutral hydrogen atoms, and the cosmos slipped into the "cosmic dark ages" — a long, lightless stretch when space was veiled by a dense fog of hydrogen gas.

Hundreds of millions of years later, the first generations of massive stars and faint young galaxies ignited, emitting intense ultraviolet light that slowly burned away this fog in a transformative period known as the Epoch of Reionization. That process, which ended about 1 billion years after the Big Bang, made the universe transparent and allowed starlight to travel freely through space for the first time, marking the dawn of the cosmos as we know it.

What the universe was like as it began to emerge from those dark ages remains one of astronomy's biggest open questions.

The new findings, detailed in a paper published Sept. 30 in The Astrophysical Journal, suggest that before the universe "lit up," it may not have been as frigid as many models predict. By narrowing the possibilities for what the early cosmos was like, the results offer an important new clue to understanding how the first stars and galaxies began to reshape their environment, researchers say.

The universe's echoes

Because direct observation of the universe's first stars isn't possible — they were too faint, too short-lived, and far too distant for even the most powerful telescopes to detect — astronomers instead look for the subtle fingerprints those stars left in the hydrogen gas that surrounded them.

In the new study, Nunhokee and her team analyzed nearly a decade's worth of data from the Murchison Widefield Array, a powerful radio telescope located in the remote Western Australian desert, to search for a faint radio "whisper" from that ancient hydrogen.

The signal arises when a hydrogen atom's sole proton and electron flip their spins relative to each other — a minute change that alters the atom's energy and causes it to emit or absorb a photon at a specific wavelength. Astronomers hunt for the faint radio echo of this transition, which appears at a wavelength of 21 centimeters — or, to our instruments, a frequency of about 1.42 gigahertz. Because the signal's strength is affected by the temperature and environment of the surrounding hydrogen gas, it acts like a cosmic thermometer, revealing how the first stars and black holes began to influence the early universe.

Detecting this ancient signal, however, is extraordinarily difficult. It is buried beneath layers of much stronger radio noise from the Milky Way, other nearby galaxies, Earth's atmosphere and even the telescope itself. To uncover it, the team developed a new statistical filtering technique to strip away these foreground signals and isolate the most probable emission from hydrogen gas dating to roughly 800 million years after the Big Bang.

This new approach produced the cleanest radio map yet of the early universe and set the most stringent limits so far on the strength of the 21-centimeter signal, the team noted in the study.

Despite focusing on what Nunhokee described as "kind of a cold patch where we have just a few sources," and using "the best data that we have," the team found no evidence for the telltale signal. "Because it's very faint, it's very hard," she said.

After cleaning the data, the researchers didn't see the distinctive signature that would indicate a "cold start" to reionization. This feature would have been visible in their data if the universe, about 800 million years after the Big Bang, had remained frigid until the first stars ignited, so the result suggested the universe was warmer than expected, according to the study.

"As the universe evolved, the gas between galaxies expands and cools, so we would expect it to be very, very cold," study lead author Cathryn Trott, a professor at the Curtin Institute of Radio Astronomy, said in a statement. "Our measurements show that it is at least heated by a certain amount. Not by a lot, but it tells us that very cold reionisation is ruled out — that's really interesting."

Cosmological models point to X-rays from early black holes and the remnants of massive stars as the likely culprits heating the intergalactic gas long before visible starlight filled the cosmos, Nunhokee said.

The team's new data-cleaning technique also lays crucial groundwork for the upcoming Square Kilometre Array (SKA). Scientists say this next-generation radio telescope, which is now under construction in Australia and South Africa, will have the sensitivity to detect the elusive 21-centimeter signal directly.

"We know what we are looking for," Nunhokee said. "We just need a few hours of [SKA's] data that will allow us to go to the levels that we want to."

Astronomers have discovered a surprisingly small "dark object" lurking within a distant ring of warped light. The record-breaking find could help shed light on the mysterious identity of dark matter, which would have major implications for the field of cosmology.

The hidden object, likely a clump of invisible dark matter, was spotted within B1938+666 — an "Einstein ring" located around 10 billion light-years from Earth. This luminous halo (which appears dark in the black-and-white images) is made up of light from a distant galaxy that has been bent around a closer foreground galaxy (the dark dot at the center of the ring). This is an effect of gravitational lensing, a phenomenon that was first proposed by Albert Einstein's theory of general relativity in 1915.

Gravitational lensing not only warps light but also significantly magnifies it. When the lensing object is perfectly aligned between the distant object and the observer, the light bends into a circle around the foreground object, known as an Einstein ring. However, an imperfect alignment can also create other strange shapes, such as crosses, zig-zags and question marks, and duplicate individual points of light within the same image.

B1938+666 was discovered in the 1990s. But in a pair of new studies, published Oct. 9 in the journals Nature Astronomy and Monthly Notices of the Royal Astronomical Society, researchers took a closer look at the gravitationally lensed object and found a subtle wobble within a prominent arc of radio waves in the outer ring (colored red and yellow in the image). They quickly realized this was a gravitational disturbance caused by a hidden object.

"From the first high-resolution image, we immediately observed a narrowing in the gravitational arc, which is the tell-tale sign that we were onto something," John McKean, an astronomer at the University of Groningen in the Netherlands and the University of Pretoria in South Africa, and co-author on both new studies, said in a statement. "Only another small clump of mass between us and the distant radio galaxy could cause this."

The object is around 1 million times more massive than the sun, which sounds like a lot. However, this actually makes it around 100 times smaller than the previous record-holder for the least-massive object ever detected via gravitational lensing.

The study teams uncovered this object by combining data from radio observatories located across the globe, including the Green Bank Telescope in West Virginia, the Very Long Baseline Array in New Mexico and the European Very Long Baseline Interferometry Network. This enabled the researchers to achieve the equivalent observing power of an Earth-size telescope, which helped them to detect such a subtle fluctuation in the data. But there was so much information that the researchers had to come up with a new way of sorting it.

"The data are so large and complex that we had to develop new numerical approaches to model them," Simona Vegetti, an astronomer at the Max Planck Institute for Astrophysics in Germany and co-author on both new studies, said in the statement. "This was not straightforward as it had never been done before."

While they cannot be certain, the researchers are confident that the new object is a small clump of dark matter — the invisible matter that makes up 27% of the known universe and does not interact with light. This is unsurprising, given that gravitational lensing is one of the only ways we can detect and measure dark matter, making Einstein rings and other warped objects one of our greatest weapons in unmasking its true identity.

Finding isolated dark matter clumps like this is especially useful for testing the "cold dark matter theory," which posits that dark matter can only clump together if it moves at relatively slow speeds, meaning it would give off relatively low amounts of energy, Live Science's sister site Space.com reported.

And the researchers predict that these clumps are far more common than we currently realize. "We expect every galaxy, including our own Milky Way, to be filled with dark matter clumps, but finding them and convincing the community that they exist requires a great deal of number-crunching," Vegetti said.

To date, only three other similarly small, potential dark matter clumps have been identified, the researchers wrote. However, the new methodology will make it easier to spot more clumps around existing Einstein rings, and the number of known rings is also climbing fast, thanks to the James Webb Space Telescope, which has proved to be exceptionally good at finding them.

"Having found one, the question now is whether we can find more," Devon Powell, an astronomer at the Max Planck Institute for Astrophysics and co-author on both new studies, said in the statement.

The second most distant object ever spotted by the James Webb telescope may be a 'dark star' powered by dark matter rather than nuclear fusion.

By looking at the wavelengths of light picked up by the James Webb Space Telescope (JWST), researchers have identified four dark star candidates — with one seemingly possessing a “smoking gun” helium absorption signature, the researchers reported in a study published Sept. 30 in the journal PNAS.

First hypothesized in 2007, dark stars are believed to be among some of the first stars — called Population III stars — to form after the Big Bang. According to the theory, they are made when collapsing hydrogen and helium, which on their own would form a black hole, mix with dark matter. Dark stars are thought to be extraordinarily massive and bright, reaching one million times the mass of the sun and burning one billion times as bright.

"Our initial name 'dark star' is a misnomer," study co-author Katherine Freese, a professor of physics at The University of Texas at Austin who proposed the dark star hypothesis, told Live Science. "They're neither made [entirely] of dark matter nor are they dark."

Finding dark stars could explain some of the very puzzling objects that JWST has spotted in the early universe, such as the giant supermassive black holes that formed impossibly fast, Freese said. It would also provide insights into the nature of dark matter. "It's a probe, not just a new kind of star," she said, "so these candidates are very encouraging to us."

To spot the potential dark star candidates, the team trawled through observations from the JWST Advanced Deep Extragalactic Survey (JADES). They focused on data collected by the Near InfraRed Spectrograph (NIRSpec): an instrument measuring the individual wavelengths of light coming from celestial objects to learn about their temperatures, masses and chemical fingerprints.

The researchers set various criteria in their search: the signals needed to be no younger than redshift 10 (a redward stretching of the universe’s ancient light corresponding to 500 million years after the Big Bang), could only contain hydrogen and helium, and had to be from a single object.

This led them to four dark star candidates: JADES-GS-z11-0, JADES-GS-z13-0, JADES-GS-z14-0 and JADES-GS-z14-1. JADES-GS-z14-0 is the second most distant object observed by JWST to date.

Signals from the first stars

Models of each candidate showed that all four could plausibly be dark stars, perhaps even supermassive dark stars.

The team also found hints of the “smoking gun signature” for supermassive dark stars in the JADES-GS-z14-0 wavelength data — singly ionized helium atoms absorbing light particles with a wavelength of 1640 angstroms (an angstrom is one hundred-million times smaller than a centimeter).

"No other known high redshift objects are expected to produce such an absorption feature," the authors wrote in the study, adding weight to their suggestion that JADES-GS-z14-0 is a dark star.

The team were surprised to discover, however, that the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile had detected JADES-GS-z14-0 emitting oxygen, an element only produced by nuclear fusion powered stars. "That worries me a little bit," Freese said.

The team are now running simulations to determine how much oxygen is permitted before a dark star is no longer able to form, study co-author Cosmin Ilie, a physicist at Colgate University in New York, told Live Science. "Logic tells me that there should be sort of a transition," he said.

Dark stars remain controversial and their existence is by no means accepted. "The majority of the Pop III star community actually doesn't think that dark matter burners [dark stars] can form," Daniel Whalen, a cosmologist at the University of Portsmouth in the U.K. who was not involved in the research, told Live Science.

In fact, Whalen said that a "huge issue" with this research is that it did not differentiate between dark stars and supermassive primordial stars. "That's the elephant in the room really here," he said.

Although the dark star candidates are more massive than most supermassive primordial stars, their wavelength data needs to be compared for both star types to rule out supermassive primordial stars, Whalen explained.

In response to this criticism, Ilie said that because supermassive primordial stars don't live as long as dark stars, if many suitable signatures are identified they are statistically more likely to be dark stars. That means many more observations are needed to settle this mystery.

Meanwhile, Freese said that the team is working on automating the search for dark stars in the JWST data "so we don't have to do anything except keep our eyes open."

The universe's first magnetic fields may have been much weaker than we first imagined — and were roughly equivalent to the strength of the magnetic activity within the human brain, according to a new study.

Researchers used hundreds of thousands of computer simulations to examine the remnants of these ancient magnetic fields, which still reside within the "cosmic web" billions of years later.

Magnetism is a natural force generated by the movements of electrical charges and has existed since the early days after the Big Bang, when the infant universe was full of jostling electrically charged particles. Experts have long suspected that the initial magnetic fields created by these particles, known as primordial magnetic fields, were much weaker than those created by complex cosmic objects that exist today, such as stars, black holes and planets.

But in the new study, published Aug. 13 in the journal Physical Review Letters, researchers have revealed that these primordial fields may have been even weaker than they previously imagined. Using exhaustive computer simulations, the team constrained an upper limit on these fields' magnetic strength and found that they likely maxed out at 0.00000000002 gauss, which is billions of times weaker than a standard fridge magnet (~100 gauss).

Such magnetic fields are "comparable to magnetism generated by [the electrical activity of] neurons in the human brain," the researchers wrote in a statement.

Despite their weakness, remnants of these magnetic fields still reside within the intergalactic cosmic web — a mysterious, sprawling structure that permeates the entire known universe — and this was key to uncovering the new findings.

Related: Scientists share groundbreaking image of the 'cosmic web' connecting 2 galaxies near the dawn of time

The cosmic web is an expansive network of ghostly filaments that connect all the galaxies in the universe like a giant 3D spider's web. There is still a lot we don't know about the cosmic web, including what it is really made of. However, in recent years, scientists have started to image this gigantic structure properly and have begun to map it out in detail.

One of the biggest mysteries about the cosmic web is why it has its own magnetic fields. This is especially confusing in regions of space in-between galaxies, where the web is isolated within large expanses of nothingness.

"Our hypothesis was that this [magnetism] could be a legacy of events occurring in cosmic epochs during the birth of the universe," study lead author Mak Pavičević, a doctoral candidate at the International School for Advanced Studies (SISSA) in Trieste, Italy, and co-author Matteo Viel, an astrophysicist at SISSA, jointly said in the statement. "This is what we sought to ascertain with our work."

Their team believes that the earliest primordial magnetic fields could have been caught up in the initial inflation of the universe and later become intertwined with the cosmic web as it grew in the expanding spaces between galaxies.

In the study, the researchers used approximately 250,000 computer simulations, based on observational data of the cosmic web, to reverse engineer this supposed series of events, allowing them to set "strict limits on the intensity of magnetic fields formed in the very early moments of the universe," Pavičević and Viel said.

These findings are still theoretical as there is currently no way of directly observing primordial magnetic fields. However, the researchers claim that the results align with recent findings concerning the cosmic microwave background (CMB), which is the radiation leftover from the Big Bang, although it is unclear which specific findings they are referring to.

The study team also notes that continued observations of the cosmic web with the James Webb Space Telescope (JWST) could allow them to create more powerful simulations to further test their hypothesis in the future.

A bizarre planet-forming disk is full of carbon dioxide in the regions where Earth-like planets could form, fresh observations from the James Webb Space Telescope (JWST) show.

Usually, such planet-forming disks contain water, but "water is so scarce in this system that it's barely detectable — a dramatic contrast to what we typically observe," Jenny Frediani, a doctoral student in the Department of Astronomy at Stockholm University and lead author of the research, said in a statement.

The findings, published Aug. 29 in the journal Astronomy & Astrophysics, challenge current ideas about planetary formation.

The science team still isn't sure what's going on at the star in NGC 6357, which is located 8,000 light-years from Earth, Frediani told Live Science in an email. However, further investigation into this system could help us understand more about the formation of Earth-like planets.

"These are the most common environments for the formation of stars and planets, and they also likely resemble the environment in which our own solar system formed," Frediani told Live Science.

Oddball star

Typically, newborn stars are swaddled in gas clouds. They create disks of material from which planets and other objects, like comets or asteroids, may eventually form.

Previous models have suggested that, as these disks evolve, bits of rocky material rich in water ice move from the outer and colder edges of the planet-forming disk to the warmer center. As the pebbles move in toward the young stars, temperatures on the surface of the rocks rise and make the ices sublimate. JWST can then spot this sublimation through the signature of water vapor.

But when JWST examined this star, known as XUE 10, it spotted a surprise: the signature of carbon dioxide.

There are two theories that could explain the weird environment, Frediani explained.

One possibility is a strong source of ultraviolet (UV) radiation from the newborn star or from some massive nearby stars. "Both can emit enough UV radiation to significantly deplete the water reservoir in a disk early on," she said.

Another reason may be due to dust grains in the region. Instead of having a lot of water coating the grains, perhaps the dust is replete with carbon dioxide "due to particular local environmental conditions around the young star," she said.

If this were the case, water vapor would accrete on to the star, but "a relatively large amount of CO2 [carbon dioxide] vapor will remain visible in the disk before it is eventually accreted as well," Frediani explained.

JWST is located at a gravitationally stable spot in space known as a Lagrange point, where it is far from interfering light from Earth or other celestial bodies. That remote location, paired with JWST's powerful mirrors, makes the telescope the only one sensitive enough to capture details about how planet-forming disks form in distant and massive star-forming regions, Frediani said.

Frediani is part of the eXtreme Ultraviolet Environments collaboration, which examines how intense radiation fields affect the chemistry of disks around planet-forming stars. For now, JWST remains the consortium's best bet for follow-ups of this strange system, but some upcoming ground observatories and upgrades will help, Frediani said.

For example, the long-running European Southern Observatory-led Atacama Large Millimeter/submillimeter Array in the Chilean desert is being upgraded, with hopes to have the changes operational by the 2030s.

The Wideband Sensitivity Upgrade, as the work is termed, will "allow us to image the cold gas and dust reservoirs in the outer regions of disks, located in distant star-forming regions," Frediani said. This upgrade should allow researchers to see the root causes of phenomena such as disk truncation (or shrinking) happening due to strong external irradiation.

Another complementary ground observatory will be the Extremely Large Telescope (ELT), a 130-foot (39 meters) ESO observatory that's under construction in Chile. When it's completed around 2027, the ELT will be the largest of the next-generation ground-based optical and near-infrared telescopes, according to the ESO.

"The ELT will be powerful enough to resolve the fine structure of these irradiated disks, revealing, for example, substructures that may be linked to forming planets in the disk," Frediani said.

A distant galaxy appears to have more than a dozen tightly packed star-forming clumps arranged like a bunch of grapes — far more than astronomers thought possible in a galaxy from the early universe.

The galaxy, nicknamed "Cosmic Grapes," is believed to have formed just 930 million years after the Big Bang. A new study has revealed that the galaxy has at least 15 massive star-forming clumps in its rotating disk, forming what appears to be a bunch of bright purple grapes in space.

Using NASA's James Webb Space Telescope (JWST) and the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers discovered the galaxy through a technique known as gravitational lensing, in which a foreground galaxy — in this case, an object known as RXCJ0600-2007 — serves as a magnifying glass for more distant objects.

"This object is known as one of the most strongly gravitationally lensed distant galaxies ever discovered," study lead author Seiji Fujimoto, said in a statement from the University of Texas at Austin's (UT Austin) McDonald Observatory.

"Thanks to this powerful natural magnification, combined with observations from some of the world's most advanced telescopes, we had a unique opportunity to study the internal structure of a distant galaxy at unprecedented sensitivity and resolution," added Fujimoto, who started the research while at UT Austin but is now at the University of Toronto.

The researchers collected more than 100 hours of telescope observations to study the primordial Cosmic Grapes galaxy. Earlier Hubble Space Telescope images of the object suggested a smooth, rotating disk, but the powerful resolution of ALMA and JWST revealed something juicier — the most detailed view yet of the galaxy's inner structure and massive clumps of dense gas primed for star formation.

Related: 'Time machine' reveals hidden structures in the universe's first galaxies

"Our observations reveal that some early galaxies' young starlight is dominated by several massive, dense, compact clumps rather than one smooth distribution of stars," study co-author Mike Boylan-Kolchin, an astronomy professor at UT Austin, said in the same statement.

The discovery reshapes our understanding of early galaxy growth by revealing the first clear connection between a galaxy's small internal structures — in this case, massive star-forming clumps — and its overall rotation, hinting that many seemingly smooth galaxies observed before may actually be filled with similar hidden clumps.

Their findings were published Aug. 7 in the journal Nature Astronomy.

The first stars in the universe may have been much smaller than we thought, new research hints — possibly explaining why it's so hard to find evidence they ever existed.

According to the new research, the earliest generation of stars had a difficult history. These stars came to be in a violent environment: inside a huge gas cloud whipping with supersonic-speed turbulence at velocities five times the speed of sound (as measured in Earth's atmosphere).

A simulation underpinning the new research also showed gases clustering into lumps and bumps that appeared to herald a coming starbirth. The cloud broke apart, creating pieces from which clusters of stars seemed poised to emerge. One gas cloud eventually settled into the right conditions to form a star eight times the mass of our sun — much smaller than the 100-solar-mass behemoths researchers previously imagined in our early universe.

These findings hint that the first supergiant stars in history may have come to be in stellar networks — not in splendid isolation, as previously thought.

"With the presence of supersonic turbulence, the cloud becomes fragmented into multiple smaller clumps, leading to the formation of several less massive stars instead," principal researcher Ke-Jung Chen, a research fellow at the Academia Sinica Institute of Astronomy and Astrophysics in Taiwan, told LiveScience by email.

This glimpse of our early history is crucial in learning about the origins of our galaxy, as well as our solar system.

"These first stars played a crucial role in shaping the earliest galaxies, which eventually evolved into systems like our own Milky Way," Chen wrote. With this new model in hand, he added, fresh observations can bring the research further, studying starbirth and galaxy formation using both computer models and NASA's powerful James Webb Space Telescope.

Simulating the universe

Researchers generated their fresh understanding of early stars using the Gizmo simulation code, which is used to study astronomical phenomena ranging from black holes to magnetic fields, and a project called IllustrisTNG that has previously been shown to accurately replicate galaxy formation. Their goal was to study the conditions in our cosmos a few hundred million years after the Big Bang, 13.8 billion years ago.

Related: Scientists just recreated the universe's first ever molecules — and the results challenge our understanding of the early cosmos

Given the sheer scale of the universe, the simulation focused on a single area: a dense structure, roughly 10 million times the mass of our sun, called a dark matter minihalo. (Dark matter makes up most of the stuff of our universe, but doesn't interact with light, and cannot be sensed by telescopes. We can, however, infer the presence of dark matter through its gravitational effect on other objects.)

The researchers examined how gas particles were moving in relatively small regions of space inside the halo, each region measuring roughly three light-years across. Simulations showed the dark matter minihalo attracts gas through sheer gravity, and by doing so, generates both supersonic-speed turbulence and gas cloud clumping. Violence was therefore a part of creating early stars.

This traumatic environment created another side effect: there were fewer huge, early stars than we previously imagined. Previous research had suggested we could have had early stars of more than 100 solar masses each. Eventually, these old stars would have exploded as supernovas, leaving behind traceable remnants that newer stars would incorporate as they grew.

Newer stars, however, do not show any chemical signatures of giant elders inside them — showing that a first generation of enormous stars may have been rare indeed.

Chen's team isn't done yet. They are now using the dark matter halos to see how supersonic turbulence worked more generally in the early universe, especially as the first stars came to light in an era more than 13 billion years ago, called "the cosmic dawn."

"This paper is part of a collaborative effort aimed at understanding the cosmic dawn through investigating the formation and evolution of the first stars," Chen said.

The next set of simulations may also include magnetic fields, he added. We can see in galaxies today that supersonic turbulence boosts magnetic fields and influences star formation; it may very well be that magnetism was just as crucial to star formation in the early universe.

Chen's team published their results July 30 in the journal Astrophysical Journal Letters.

A new paper has predicted that the universe's expected lifespan is drastically shorter than once thought — and that the cosmos will start to die in just 10 billion years.

This is only one possible theory, however, and nobody really knows when the universe will end.

There are two leading theories for how the universe may die: the "Big Freeze" theory, which suggests that the cosmos will continue to expand until all the stars have lost their energy and cooled to absolute zero; and the "Big Crunch" theory, which suggests that the universe's expansion is only temporary and that, after a certain point, it will begin to contract and eventually collapse in a reverse Big Bang. Scientists struggle to agree on which is more likely because recent observations have revealed uncertainties over how fast the universe is expanding — dubbed a cosmological crisis.

One way of resolving this crisis is to uncover the true value of the cosmological constant, a theoretical "magic number" that can be used to calculate cosmic expansion. But to do this, we first need to uncover the elusive identity of dark energy — the mysterious force or substance that seems to be driving the universe's expansion.

To that end, in a new paper uploaded June 30 to the preprint server arXiv that has not yet been peer-reviewed, researchers looked at recent findings from the Dark Energy Survey (DES) and the Dark Energy Spectroscopic Instrument (DESI), which hint that dark energy is made up of axions.

Axions are hypothetical ultralight particles that rarely interact with matter. If they exist, then it means that the cosmological constant has a negative value, which will lead to a Big Crunch, the researchers argued. And their calculations indicate that this would happen sooner than expected.

Related: 10 wild theories about the universe

Using their new model for the Big Crunch, the researchers estimate that the total lifespan of the universe is around 33 billion years. Given that the universe is currently believed to be around 13.8 billion years old, this means that the cosmos has already completed over one-third of its total life.

If the new timeline is correct, the universe will stop expanding in around 10 billion years and begin to rapidly contract much faster than other models have previously predicted, Live Science's sister site Space.com recently reported. Other models suggest that the Big Crunch may not happen for hundreds of billions of years.

The true identity of dark energy remains a mystery, however, meaning that the new model is purely theoretical.

Other possible timelines

This is not the first study to suggest that the Big Crunch may start to happen sooner than expected. In 2022, researchers proposed that the universe could stop expanding in as little as 100 million years.

But if the universe instead ends in a Big Freeze, which was the scenario favored by Albert Einstein, then its death will likely come much later.

Recent research has suggested that the soonest the Big Freeze may come to pass is in around 1 quinvigintillion (1 followed by 78 zeroes) or 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 years.

Other theories suggest that cosmic expansion may be capable of suddenly reversing multiple times, which further complicates potential timeframes for either scenario. Stephen Hawking's work on black holes also suggested that everything in the universe could evaporate before either scenario plays out.

Some experts have additionally suggested that our universe could be one of many reincarnations in an endless cycle of Big Bangs, or Big Bounces. These would essentially make the cosmos immortal. Others have proposed that the universe is a simulation or hologram, which raises the question of whether it is even "real" at all.

The only thing that most researchers can agree on is that it could take a very, very long time to find out who is right.

The Milky Way may be surrounded by dozens of yet-to-be-detected satellite galaxies, scientists claim.

Using the highest-resolution simulation of our galaxy's dark matter — an invisible entity that shapes the large-scale structure of the universe — and new mathematical models, cosmologists predict that more than 100 additional satellite galaxies beyond the ones already cataloged may be swirling around our own.

If those galaxies are spotted by telescopes, they could offer support for the standard model of cosmology — the dominant model of our universe that explains how galaxies form. The researchers presented their findings July 11 at the Royal Astronomical Society's National Astronomy Meeting in Durham, England.

"We know the Milky Way has some 60 confirmed companion satellite galaxies, but we think there should be dozens more of these faint galaxies orbiting around the Milky Way at close distances," lead researcher Isabel Santos-Santos, a graduate student at Durham University, said in a statement. "One day soon we may be able to see these 'missing' galaxies, which would be hugely exciting and could tell us more about how the Universe came to be as we see it today."

According to the standard theory of cosmology, known as lambda cold dark matter (LCDM), both dwarf galaxies and large ones such as our own take shape within clumps called galactic halos. These vast spheres of stars float like leaves on a pond of dark matter, the mysterious substance believed to make up 85% of the universe's matter.

Dark matter doesn't reflect light, so it hasn't been observed directly. But scientists see evidence for it in the shapes of galaxies, the warping of starlight as it passes through them, and the acceleration of stars to otherwise inexplicable speeds as they orbit galactic centers.

Related: Scientists discover rare planet at the edge of the Milky Way using space-time phenomenon predicted by Einstein

This dark matter halo gives the Milky Way a hefty gravitational pull. The pull is so strong, in fact, that over the course of billions of years, it has captured a number of dwarf galaxies (those containing less than a few billion stars) as satellites.

Despite being predicted as plentiful by LCDM, satellite galaxies are faint and therefore hard to detect; many more should exist than astronomers have been able to observe or even simulate. Taken at face value, their absence is yet another crack of doubt in the standard model of cosmology.

But the scientists behind the new research propose a reason for this lack of supporting evidence, at least within simulations: They're not precise enough to model galaxy evolution, so the simulated halos get disrupted, leading to the loss of their satellite galaxies.

To better simulate the possible hidden galaxies, the astronomers turned to the Aquarius simulation, the highest-resolution reconstruction of a Milky Way dark-matter halo. They used the Aquarius simulation to run the GALFORM model — a code that tracks gas cooling, stars forming and matter clumping to form galaxies similar to our own.

According to the simulation, dwarf galaxies have been orbiting the Milky Way for much of the universe's life. Yet during their repeated passes, their dark matter and stars were gradually snatched away by the Milky Way's enormous galactic halo, causing them to appear extremely faint in the present day.

This means that anywhere from 80 to over 100 more dwarf galaxies might exist around our galaxy's outskirts, according to the researchers. If these galaxies are really there, it may not be long before they're detected; the new Vera Rubin Observatory, which is equipped with the largest digital camera ever constructed, could resolve some of these hidden galaxies.

"If the population of very faint satellites that we are predicting is discovered with new data, it would be a remarkable success of the LCDM theory of galaxy formation," co-researcher Carlos Frenk, a professor of astrophysics at the University of Durham, said in the statement. "It would also provide a clear illustration of the power of physics and mathematics. Using the laws of physics, solved using a large supercomputer, and mathematical modelling we can make precise predictions that astronomers, equipped with new, powerful telescopes, can test."

Astronomers have turned the Atacama Large Millimeter/submillimeter Array (ALMA) into a time machine to peer back in cosmic time to 1 billion years after the Big Bang.

This has revealed previously hidden structures within the universe's first galaxies, which could help us understand how the modern cosmos, including our galaxy, the Milky Way, took shape.

The data was collected as part of the CRISTAL survey ([CII] Resolved ISM in STar-forming galaxies with ALMA), which zoomed in on 39 typical star-forming galaxies in the infancy of the 13.8 billion-year-old universe. ALMA had infrared assistance from the James Webb Space Telescope (JWST) and Hubble. The target galaxies were selected to represent the main population of galaxies shortly after the Big Bang.

"Thanks to ALMA’s unique sensitivity and resolution, we can resolve the internal structure of these early galaxies in ways never possible before," CRISTAL principal investigator Rodrigo Herrera-Camus said in a statement. "CRISTAL is showing us how the first galactic disks formed, how stars emerged in giant clumps, and how gas shaped the galaxies we see today."

How ancient structures were revealed by CRISTAL

The CRISTAL findings were possible thanks to the sensitivity of ALMA, consisting of 66 radio antennas in the Atacama desert region of northern Chile, to a specific emission of ionized carbon atoms in cold interstellar gas. This is called the [CII] line emission, and it acts as a tracer of cold gas and dust.

Thus, the CRISTAL team was able to create a complex and detailed map of interstellar gas, the nebulous matter between stars, in galaxies.

One of the key things this cosmic map revealed was stars being born in vast clumps, each stretching for several thousand light-years. Additionally, in many of the CRISTAL galaxies, the [CII] emission was seen to extend far beyond the population of stars of those galaxies.

That indicates the presence of more cold gas that could go on to form more stars or could be driven out of these galaxies by the powerful stellar winds of infant stars. This hints at how star-forming regions gather and evolve.

Related: Giant radio telescope in the Utah desert could reveal hidden corners of the cosmos — and brand-new physics

Several of the galaxies seen by CRISTAL seemed to be spinning, which indicates how they could eventually flatten out into disk-like structures. These disk-shaped galaxies are thought to be the progenitors of spiral galaxies like the Milky Way.

"What's exciting about CRISTAL is that we are seeing early galaxies not just as points of light, but as complex ecosystems," team member and National Radio Astronomy Observatory (NRAO) scientist Loreto Barcos-Muñoz said. "This project shows how ALMA can resolve the internal structure of galaxies even in the distant universe — revealing how they evolve, interact, and form stars."

Two CRISTAL galaxies are real gems

As stunning and scientifically important as these 37 galaxies are, two seem to be something really special.

One galaxy that really stood out from these ALMA observations was CRISTAL-13 which is shrouded in vast and massive clouds of dust that block the visible light from its newborn stellar population.

These clouds absorb this light and reemit it in wavelengths that ALMA can detect, allowing it to see structures that would be hidden from telescopes observing CRISTAL-13 in visible light or even in infrared light as used by the JWST and Hubble.

Also exceptional, but arguably more mysterious, is CRISTAL-10. This ancient galaxy has ionized carbon that seems to be unusually faint compared to how bright the galaxy is in infrared.

This is a characteristic usually only seen in galaxies that are heavily obscured, like the local galaxy Arp 220. The fact that it is seen for CRISTAL-10 implies there are extreme physical conditions at work within its interstellar medium. Another possibility is that there is something within the interstellar medium of CRISTAL-10 that is pumping out energy.

"These observations highlight ALMA’s potential as a time machine, allowing us to peer into the early ages of the Universe," ALMA head of science operations Sergio Martín said. "Programs like CRISTAL demonstrate the power of ALMA's Large Programs to drive high-impact science. They allow us to tackle the big questions of cosmic evolution with the unprecedented depth and resolution that only a world-class observatory like ALMA can provide."

The CRISTAL survey hasn't just opened a new view of cosmic history by conducting the interstellar medium that can be compared with galaxies' stars and dust content, but it has set the stage for future surveys.

These could eventually reveal how the turbulent, violent, and chaotic early galaxies transformed into well-ordered and structurally well-defined modern galaxies like our own.

"CRISTAL provides the kind of multi-wavelength data that allows us to test and refine our theories of galaxy evolution," Herrera-Camus concluded. "This is a major step toward understanding how galaxies like our Milky Way came to be."

The team's research was published on June 30 in the journal Astronomy & Astrophysics.

This article was originally published on Space.com.

Astronomers have found what they claim is fresh evidence that Earth and our Milky Way galaxy are suspended inside a gigantic void that's skewing our observations of the cosmos.

The radical proposal, made by analyzing echoes of the Big Bang, suggests that our galaxy may be floating in a 2 billion-light-year region that's 20% less dense than average.

If the results hold up, they could help astronomers find the true age of our universe and offer a solution to one of the stickiest conundrums in cosmology — the discrepancy, known as the Hubble tension, that the distant universe expanded more slowly in the past than the nearby universe does today.

The findings would also prompt a major rewrite of existing cosmological models. The researchers shared their findings July 9 at the Royal Astronomical Society's National Astronomy Meeting in Durham, England.

Hubble trouble

Over the past decade, cosmology has been embroiled in a growing crisis as observations — first made by the Hubble Space Telescope and later by the James Webb Space Telescope — suggested that the universe is expanding at different rates depending on where astronomers look.

Currently, there are two gold-standard methods for figuring out this expansion rate, called the Hubble constant. The first involves poring over tiny fluctuations in the cosmic microwave background, an ancient relic of the universe's first light produced just 380,000 years after the Big Bang. This method enabled astronomers to infer an expansion rate of roughly 67 kilometers per second per megaparsec (km/s/Mpc), which closely matches predictions made by the standard model of cosmology.

Related: 'Our model of cosmology might be broken': New study reveals the universe is expanding too fast for physics to explain

But the second method — measuring closer distances with pulsating stars called Cepheid variables — returned a puzzlingly high value for the Hubble constant of 73.2 km/s/Mpc.

This discrepancy may not seem like much, but it's enough to completely contradict the predictions made by the standard model of cosmology. Astronomers have suggested many major and minor rewrites to this model to explain the tension, including tossing out dark energy and dark matter altogether.

But this anomaly could be specific to our cosmic backyard, the astronomers behind the new research suggest.

"A potential solution to this inconsistency is that our Galaxy is close to the centre of a large, local void," lead author Indranil Banik, an astronomer at the University of Portsmouth in the U.K., said in a statement. "It would cause matter to be pulled by gravity towards the higher density exterior of the void, leading to the void becoming emptier with time."

That would make local expansion inside the void faster than it is in denser, more distant regions of the cosmos, he added.

Filling the void

The notion that our part of the universe could be less dense than others first took shape in the 1990s, when researchers found fewer galaxies in our local universe than they expected compared with the surrounding universe.

Further research backed up these observations, indicating that our galaxy may be in the center of a region known as the local hole or KBC void, named after the initials of the study's astronomers. Nonetheless, some astronomers question whether the apparently underdense space could be filled with objects that don't emit light.

To investigate the evidence further, Banik and his colleagues collected 20 years' of data from observations of nearby baryon acoustic oscillations (BAOs) — pressure waves created during the Big Bang that froze in place and expanded alongside the universe, governing the distribution of galaxies we see today.

"These sound waves traveled for only a short while before becoming frozen in place once the universe cooled enough for neutral atoms to form," Banik explained. "They act as a standard ruler, whose angular size we can use to chart the cosmic expansion history."

According to the researchers' BAO measurements, it's 100 times more likely that we live in a cosmic void than a region of average density.

The next step for Banik and colleagues will be to compare their void model to other models to see which best fits the history of the universe's expansion. They will also need to explore tweaks to the standard model of cosmology, including throwing out the assumption that matter is evenly distributed throughout the universe.

The implications would be vast — not just for our understanding of how the universe behaves but for our own place in it. Modern astronomy has consistently revealed that our personal view of the cosmos is unexceptional. However, if we do live in the middle of a void, we could be more unique in our isolation than first thought.

A gigantic array of radio dishes proposed for the Nevada desert could advance our understanding of physics and help us decode cosmic radio signals. Now, scientists have outlined how it would work.

Beginning in the 1950s, radio astronomy has opened up a powerful view into the inner workings of the universe, revealing everything from how stars form to incredible images of our galaxy's gigantic black hole. Now, astronomers are building a gigantic array of radio dishes, called the Deep Synoptic Array 2000 (DSA-2000). The array consists of 2,000 radio dishes, each 16 feet (5 meters) across, laid out in a radio-quiet part of the Nevada desert.

Now, an international team of astronomers has demonstrated how DSA-2000 will be a premier instrument for revealing some of the most hidden corners, particles and processes in the cosmos.

Because DSA-2000 will have both a wide field of view and a high resolution, it will be like the world's ultimate digital camera but at radio frequencies, the team explained in a paper uploaded to the preprint database arXiv in May. These capabilities will allow the DSA-2000 to detect a wide variety of phenomena that are not possible with our current radio telescopes.

And there are a whole lot of unexplored radio transmissions in the universe. For example, astronomers think the vast majority of the mass of every galaxy comes in the form of dark matter, an invisible entity that has so far escaped direct detection.

One potential candidate for dark matter is called the axion, a hypothetical particle trillions of times lighter than the lightest known particles. Axions can collect around dense objects like neutron stars, and under the influence of extremely strong magnetic fields (which neutron stars have in spades), they can convert to photons with just the right frequency range that DSA-2000 could pick up those signals.

Related: 'Staggering' first images from Vera C. Rubin Observatory show 10 million galaxies — and billions more are on the way

Another candidate for dark matter is called the dark photon, which is like our normal, familiar photons (light particles) but … dark. Dark photons can also collect around neutron stars, where they can get whipped up into a frenzy due to the star's extreme rotation. In a process called superradiance, the dark photons get boosted to extremely high energies, where they start to resonate with regular photons, giving off blasts of signals that could be directly detected by DSA-2000.

This means that DSA-2000 could potentially offer our first direct glimpse of a new form of matter in the universe. But that's not all.

In 2023, astronomers with the NANOGrav experiment announced the detection of gravitational waves through pulsar timing arrays. DSA-2000 could take that one step further by precisely measuring the rotation rates of approximately 3,000 pulsars — rapidly spinning neutron stars that pulsate in regular intervals. This would allow the new instrument to find any subtle variations in the spins of pulsars, such as those due to unseen orbiting companions, like black holes or small clumps of dark matter.

Lastly, DSA-2000 could detect tens of thousands of fast radio bursts (FRBs) — tremendous explosions that manifest as blips and bloops in the radio spectrum. This unprecedented number of detections would allow scientists to build a comprehensive survey of the nearby universe, which would aid our understanding of everything from dark energy to the nature of ghostly particles called neutrinos.

The universe is trying to whisper its secrets to us. All the answers are there, if we listen carefully enough.

Editor's note: This article was updated at 10:30 a.m. ET on June 9 to correct an error. The array is planned for the Nevada desert, not the Utah desert, as was previously written.

For the first time, astronomers have captured stunning visual evidence of a star double-detonating itself to death.

The twin eruption was discovered by scientists studying two concentric rings of calcium that surround SNR 0509-67.5, a remnant of a star that met its explosive demise in a type Ia supernova centuries ago.

And the discovery isn't just a pretty picture. The researchers who made it say that much of our knowledge of how the universe expands — a major controversy in cosmology — depends on reliably measuring this type of supernova, which is also the primary source of iron throughout the cosmos. The scientists published their findings July 2 in the journal Nature Astronomy.

For these reasons, "the explosions of white dwarfs play a crucial role in astronomy," study first author Priyam Das, a graduate student at the University of New South Wales Canberra in Australia, said in a statement. "Yet, despite their importance, the long-standing puzzle of the exact mechanism triggering their explosion remains unsolved."

Type Ia supernovas occur when the material from one star is stolen by the husk of a co-orbiting dead star, known as a white dwarf, leading to a gigantic thermonuclear explosion.

Yet not all the ways that white dwarves detonate are accounted for. Astronomers assume that these white dwarves steadily snatch their neighboring star's material, accumulating it until they reach a critical mass — the Chandrasekhar limit — and explode. But astronomers have found hints suggesting that this isn't the only way the husks blow up.

Related: Supernova that lit up Earth's skies 843 years ago has a flowering 'zombie star' at its heart — and it's still exploding

To search for direct evidence of a different ype of detonation, the researchers pointed the European Southern Observatory's Very Large Telescope at SNR 0509-67.5, a supernova that displays a clear shock wave shell pattern. Using the telescope's Multi Unit Spectroscopic Explorer instrument, they found two separate rings of calcium surrounding the remnants of the explosion.

This is "a clear indication that white dwarfs can explode well before they reach the famous Chandrasekhar mass limit, and that the 'double-detonation' mechanism does indeed occur in nature," second-author Ivo Seitenzahl, a nuclear astrophysicist at the University of New South Wales Canberra, said in the statement.

The researchers propose that this white dwarf exploded by blanketing itself in stolen helium from its neighbor that then ignited, sending a shockwave inwards that caused the dead star's core to blow in a second, larger, explosion.

Studying this dual detonation could have important implications for our wider understanding of the universe. No matter which way they occur, type Ia supernovas are thought to always explode with the same brightness, making them "standard candles" from which astronomers can measure far-off distances and calculate the expansion rate of our universe.

In recent years, contesting measurements of this expansion rate, known as the Hubble constant, have sparked a major crisis in cosmology.

"This tangible evidence of a double-detonation not only contributes towards solving a long-standing mystery, but also offers a visual spectacle," Das said. "Revealing the inner workings of such a spectacular cosmic explosion is incredibly rewarding."

Nowadays, the dark of night is interspersed with the light of stars. But before the stars were born, did light shine at the beginning of the universe?

The short answer is "no." But the long answer reveals light's extraordinary journey. At first, the early universe's light was "trapped," and it took several hundred thousand years for it to escape. Then, it took about 100 million years for stars to form.

By examining the speed and direction in which galaxies were moving, astronomer Edwin Hubble discovered the universe was expanding. This 1929 discovery suggested that the cosmos was once smaller, with scientists eventually calculating that the entire universe was concentrated into one, infinitely dense point about 13.8 billion years ago, until the Big Bang happened.

"With the Big Bang, space was created and expanded, along with everything in the universe," Andrew Layden, chair of physics and astronomy at Bowling Green State University in Ohio, told Live Science.

The only way all the matter that now makes up the universe could fit in a tiny spot "is if it was energy at that time," Layden said. Einstein's famous equation E=mc² revealed that energy and mass can be interchangeable, Layden explained.

As the universe expanded, the density of its energy decreased, and it cooled. The first particles then began to form within the first second after the Big Bang, according to Las Cumbres Observatory. These included the photons that make up light, as well as the protons, neutrons and electrons that make up atoms. By about three minutes after the Big Bang, protons and neutrons could fuse together to create the nuclei of atoms such as helium, according to NASA.

"Think of fog and dew," Layden said. "Particles in a high-energy state are dispersed like water in fog, and when the energy gets low enough, they can condense out like droplets of dew."

Related: Can anything travel faster than the speed of light?

However, although photons of light existed since the first second after the Big Bang, they could not yet shine across the universe. This is because the early cosmos was so hot that "electrons were moving too fast for atomic nuclei to hold them in orbit around them," Layden said. "The universe was just this very hot, dense soup."

All the electrons zipping around freely in the early universe meant that light could not move around very much. "As light tried to travel in a straight line during this time, it always bumped into electrons, so it could not go very far," Layden said.

A similar situation is found within the sun, Srinivasan Raghunathan, a cosmologist at the University of Illinois, Urbana-Champaign, told Live Science. "You can imagine a photon of light created by nuclear reactions at the center of the sun trying to come out to the sun's surface," he said. "The center of the sun is extremely hot, and so there are a lot of free electrons present. This means light cannot travel in straight lines."

The distance from the center of the sun to its surface is about 432,450 miles (696,000 kilometers). The speed of light in a vacuum is about 186,000 miles per second (300,000 km/s), but in the sun, "it takes about 1 million to 2 million years for light to escape from the center of the sun to its surface," Raghunathan said.

However, about 380,000 years after the Big Bang, the expansion of the universe let the cosmos cool enough for atomic nuclei to glom onto electrons. "When that happens, all those electrons are no longer free," Layden said. "This happens at about 3,000 Kelvin [4,940 degrees Fahrenheit, or 2,725 degrees Celsius], the surface temperature of a coolish reddish star."

Within a short number of years, "everything goes from being a hot dense soup to a clear universe where light can travel freely," Layden said. "At that moment, the first photons in the universe can escape."

The light typical of the universe when it was about 3,000 kelvins was in near-infrared to visible wavelengths, Layden noted. However, as the cosmos expanded over the course of more than 13 billion years and cooled to an average temperature of about 2.73 Kelvin (minus 455 F, or minus 270 C), the universe's first light stretched to longer microwave wavelengths.

Astronomers first detected this leftover radiation from the Big Bang, called the cosmic microwave background, in 1964.

Analyzing these microwaves has yielded many insights. For instance, the gravitational pull of galaxies can distort light — a phenomenon called gravitational lensing. Examining the amount of distortion the cosmic microwave background has experienced at different points in the sky can help scientists reconstruct the large-scale structure of the universe — the arrangement of galaxies and the giant voids between them across the cosmos, Raghunathan said.

After the light from the Big Bang was released, the universe experienced a period known as the cosmic dark ages. Eventually, after millions of years, the gravitational pull of clouds of gas led these clumps of matter to collapse in on themselves.

"This created the first generation of stars, and the universe had galaxies full of stars by about 1 billion years after the Big Bang, beginning the cosmic dawn," Layden said.

Sun quiz: How well do you know our home star?

Scientists have unveiled the largest map of the universe ever created. Stretching across a tiny sliver of space and almost all cosmic time, it includes almost 800,000 galaxies imaged across the universe. Some are so far away that they appear as they existed in the infant universe, about 13 billion years ago.

The map, released Thursday (June 5) by scientists at the Cosmic Evolution Survey collaboration , covers a 0.54-degree-squared arc of the sky, or about three times as much space as the moon takes up when viewed from Earth.

To collect the data for the map, the James Webb Space Telescope (JWST) spent 255 hours observing a region of space nicknamed the COSMOS field. This patch of sky has very few stars, gas clouds or other features blocking our view of the deep universe, so scientists have been surveying it with telescopes across as many wavelengths of light as possible.

JWST's observations of the COSMOS field have given us an incredibly detailed view of the universe going back as far as 13.5 billion years.

Because the universe has been expanding, visible light that left its source at the other side of the universe gets stretched out, becoming infrared light. This is why JWST was designed to be an extremely sensitive infrared telescope: to detect these faint, stretched-out signals from the beginning of time that we couldn't see with other telescopes. It's already reshaping our understanding of how the universe formed.

"Since the telescope turned on we've been wondering 'Are these JWST datasets breaking the cosmological model?" Caitlin Casey, a professor of physics at the University of California, Santa Barbara and co-lead for the COSMOS project, said in a statement. "The big surprise is that with JWST, we see roughly 10 times more galaxies than expected at these incredible distances. We're also seeing supermassive black holes that are not even visible with Hubble."

The raw data from the COSMOS field observations was made publicly available just after it was collected by JWST, but it wasn't easily accessible. Raw data from telescopes like JWST needs to be processed by people with the right technical knowledge and access to powerful computers.

The COSMOS collaboration spent two years creating the map from JWST's raw data to make it more accessible for amateur astronomers, undergraduate researchers and the general public to peer into the heart of the universe. You can see it for yourself using COSMOS' interactive map viewer.

The Big Bang is often described as the explosive birth of the universe — a singular moment when space, time and matter sprang into existence. But what if this was not the beginning at all? What if our universe emerged from something else — something more familiar and radical at the same time?

In a new paper, published in Physical Review D, my colleagues and I propose a striking alternative. Our calculations suggest the Big Bang was not the start of everything, but rather the outcome of a gravitational crunch or collapse that formed a very massive black hole — followed by a bounce inside it.

This idea, which we call the black hole universe, offers a radically different view of cosmic origins, yet it is grounded entirely in known physics and observations.

Today's standard cosmological model, based on the Big Bang and cosmic inflation (the idea that the early universe rapidly blew up in size), has been remarkably successful in explaining the structure and evolution of the universe. But it comes at a price: it leaves some of the most fundamental questions unanswered.

For one, the Big Bang model begins with a singularity — a point of infinite density where the laws of physics break down. This is not just a technical glitch; it's a deep theoretical problem that suggests we don't really understand the beginning at all.

To explain the universe's large-scale structure, physicists introduced a brief phase of rapid expansion into the early universe called cosmic inflation, powered by an unknown field with strange properties. Later, to explain the accelerating expansion observed today, they added another "mysterious" component: dark energy.

Related: 5 fascinating facts about the Big Bang, the theory that defines the history of the universe

In short, the standard model of cosmology works well — but only by introducing new ingredients we have never observed directly. Meanwhile, the most basic questions remain open: where did everything come from? Why did it begin this way? And why is the universe so flat, smooth, and large?

New model

Our new model tackles these questions from a different angle — by looking inward instead of outward. Instead of starting with an expanding universe and trying to trace back how it began, we consider what happens when an overly dense collection of matter collapses under gravity.

This is a familiar process: stars collapse into black holes, which are among the most well-understood objects in physics. But what happens inside a black hole, beyond the event horizon from which nothing can escape, remains a mystery.

In 1965, the British physicist Roger Penrose proved that under very general conditions, gravitational collapse must lead to a singularity. This result, extended by the late British physicist Stephen Hawking and others, underpins the idea that singularities — like the one at the Big Bang — are unavoidable.

The idea helped win Penrose a share of the 2020 Nobel prize in physics and inspired Hawking's global bestseller A Brief History of Time: From the Big Bang to Black Holes. But there's a caveat. These "singularity theorems" rely on "classical physics" which describes ordinary macroscopic objects. If we include the effects of quantum mechanics, which rules the tiny microcosmos of atoms and particles, as we must at extreme densities, the story may change.

In our new paper, we show that gravitational collapse does not have to end in a singularity. We find an exact analytical solution — a mathematical result with no approximations. Our maths show that as we approach the potential singularity, the size of the universe changes as a (hyperbolic) function of cosmic time.

This simple mathematical solution describes how a collapsing cloud of matter can reach a high-density state and then bounce, rebounding outward into a new expanding phase.

But how come Penrose's theorems forbid out such outcomes? It's all down to a rule called the quantum exclusion principle, which states that no two identical particles known as fermions can occupy the same quantum state (such as angular momentum, or "spin").

And we show that this rule prevents the particles in the collapsing matter from being squeezed indefinitely. As a result, the collapse halts and reverses. The bounce is not only possible — it's inevitable under the right conditions.

Crucially, this bounce occurs entirely within the framework of general relativity, which applies on large scales such as stars and galaxies, combined with the basic principles of quantum mechanics — no exotic fields, extra dimensions or speculative physics required.

What emerges on the other side of the bounce is a universe remarkably like our own. Even more surprisingly, the rebound naturally produces the two separate phases of accelerated expansion — inflation and dark energy — driven not by a hypothetical fields but by the physics of the bounce itself.

Testable predictions

One of the strengths of this model is that it makes testable predictions. It predicts a small but non-zero amount of positive spatial curvature — meaning the universe is not exactly flat, but slightly curved, like the surface of the Earth.

This is simply a relic of the initial small over-density that triggered the collapse. If future observations, such as the ongoing Euclid mission, confirm a small positive curvature, it would be a strong hint that our universe did indeed emerge from such a bounce. It also makes predictions about the current universe's rate of expansion, something that has already been verified.

This model does more than fix technical problems with standard cosmology. It could also shed new light on other deep mysteries in our understanding of the early universe — such as the origin of supermassive black holes, the nature of dark matter, or the hierarchical formation and evolution of galaxies.

These questions will be explored by future space missions such as Arrakihs, which will study diffuse features such as stellar halos (a spherical structure of stars and globular clusters surrounding galaxies) and satellite galaxies (smaller galaxies that orbit larger ones) that are difficult to detect with traditional telescopes from Earth and will help us understand dark matter and galaxy evolution.

These phenomena might also be linked to relic compact objects — such as black holes — that formed during the collapsing phase and survived the bounce.

The black hole universe also offers a new perspective on our place in the cosmos. In this framework, our entire observable universe lies inside the interior of a black hole formed in some larger "parent" universe.

We are not special, no more than Earth was in the geocentric worldview that led Galileo (the astronomer who suggested the Earth revolves around the Sun in the 16th and 17th centuries) to be placed under house arrest.

We are not witnessing the birth of everything from nothing, but rather the continuation of a cosmic cycle — one shaped by gravity, quantum mechanics, and the deep interconnections between them.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.