'We don't yet have the know-how to properly maintain a corpse brain': Why cryonics is a non-starter in our quest for immortality

illustraion of a brain inside an icecube on a dark background
(Image credit: FlashMovie/Getty Images)

It's a scene plucked from science fiction: On their deathbed, a person is completely frozen and then stashed away, so that they might be revived in the future. But could it be possible?  In this excerpt from "Why We Die: The New Science of Aging and the Quest for Immortality," (Harper Collins, 2024) Nobel Prize-winning biologist Venki Ramakrishnan examines the decades-long quest for cryonic preservation — in which people would be frozen at the point of death and defrosted in the future — and the pitfalls of an industry borne out of the idea.

Egyptians mummified their pharaohs so that they could arise corporeally at some point in the future for their journey in the afterworld. Surely now, a few millennia after the pharaohs and with more than a century of modern biology behind us, we would not do anything even remotely so superstitious. But in fact, there is a modern equivalent. 

Biologists have long wanted to be able to freeze specimens so that they can store and use them later. This is not so straightforward because all living things are composed mostly of water. When this water freezes into ice and expands, it has the nasty habit of bursting open cells and tissues. This is partly why if you freeze fresh strawberries and thaw them, you wind up with goopy, unappetizing mush.

An entire field of biology, cryopreservation, studies how to freeze samples so that they are still viable when thawed later. It has developed useful techniques, such as how to store stem cells and other important samples in liquid nitrogen. It has figured out how to safely freeze semen from sperm donors and human embryos for in vitro fertilization treatment down the road. 

Animal embryos are routinely frozen to preserve specific strains, and biologists' favorite worms can be frozen as larvae and revived. For many types of cells and tissues, cryopreservation works. It is often done by using additives such as glycerol, which allow cooling to very low temperatures without letting the water turn into ice — effectively like adding an antifreeze to the sample. In this case, the water forms a glass-like state rather than ice, and the process should be called vitrification rather than freezing (the word vitreous derives from the Latin root for glass), but even scientists casually refer to it as freezing and the specimens as frozen. 

Enter cryonics, in which entire people are frozen immediately after death with the idea of defrosting them later when a cure for whatever ailed them has been found. The idea has been around a long time, but it gained traction through the work of Robert Ettinger, a college physics and math teacher from Michigan who also wrote science fiction. Ettinger had a vision of future scientists reviving these frozen bodies and not only curing whatever had ailed them but also making them young again. 

In 1976 he founded the Cryonics Institute near Detroit and persuaded more than 100 people to pay $28,000 each to have their bodies preserved in liquid nitrogen in large containers. One of the first people to be frozen was his own mother, Rhea, who died in 1977. His two wives are also stored there — it is not clear exactly how happy they were to be stored next to each other or their mother-in-law for years or decades to come. 

The Alcor Life Extension Foundation in Arizona has over 200 bodies and heads preserved in the hope of reviving them in the future.  (Image credit: Jeff Topping/Getty Images)

Continuing this tradition of family closeness, when Ettinger died in 2011 at age 92, he joined them. Today there are several such cryonics facilities. Another popular one, Alcor Life Extension Foundation, headquartered in Scottsdale, Arizona, charges about $200,000 for whole-body storage. How do these facilities work? Essentially, as soon as a person dies, the blood is drained and replaced with an antifreeze, and the body is then stored in liquid nitrogen. Theoretically, indefinitely. 

Then there are the transhumanists who want to transcend our bodies entirely. But they don't want humanity as we know it to end before we have figured out a way to preserve our minds and consciousnesses indefinitely in some other form. In their view, intelligence and reason may be unique to human beings in the universe (or at least they see no evidence for extraterrestrial intelligence). 

Related: Can minds persist when they are cut off from the world?

To them, it is of cosmic importance to preserve our consciousnesses and minds and spread them throughout the universe. After all, what is the point of the universe if there is no intelligence to appreciate it? These transhumanists are content to have only their brains frozen. This takes up less space and costs less. Moreover, it could be faster to infuse the magic antifreeze directly into the brain after death, increasing the odds of successful preservation. 

The brain is the seat of memories, consciousness, and reasoning, and that is their sole concern. At some point in the future, when the technology is ripe, the information in the brain will simply be downloaded to a computer or some similar entity. That entity will possess the person's consciousness and memories and will resume "life." It won't be limited by human concerns such as the needs for food, water, oxygen, and a narrow range of temperature. We will have transcended our bodies, with the possibility of traveling anywhere in the universe. 

Elon Musk is known for his transhumanist efforts, with current Neuralink projects aiming to merge the human brain with computers. (Image credit: Win McNamee/Getty Images)

Not surprisingly, transhumanists are generally ardent about space travel, viewing it as our only chance to escape destruction on Earth. One such proponent is business mogul and investor Elon Musk, said to be the wealthiest person in the world, depending on the year, who is well known for his desire to "die on Mars, just not on impact." Presumably one of his first goals upon reaching the red planet will be to construct a cryonics facility. 

The bad news is that there is not a shred of credible evidence that human cryogenics will ever work. The potential problems are myriad. By the time a technician can infuse the body, minutes or even hours may have elapsed since the moment of death — even if the "client" moved right next to a facility in preparation. 

During that time, each cell in the deceased person's body is undergoing dramatic biochemical changes due to the lack of oxygen and nutrients, so that the state of a cryogenically frozen body is not the state of a live human being. No matter, say cryo advocates: we simply must preserve the physical structure of the brain. As long as it is preserved enough that we can see the connections between all the billions of brain cells, we will be able to reconstruct the person's entire brain. 

Mapping all the neurons in a brain is an emerging science called connectomics. Although it has made tremendous advances, researchers are still ironing out the kinks on flies and other tiny organisms. And we don't yet have the know-how to properly maintain a corpse brain while we wait for connectomics to catch up. 

"Why We Die: The New Science of Aging and the Quest for Immortality" by Venki Ramakrishnan.  (Image credit: HarperCollins Publishers)

Only recently, after many years, has it been possible to preserve a mouse brain, and that requires infusing it with the embalming fluid while the mouse's heart is still beating — a process that kills the mouse. Not one of these cryonics companies has produced any evidence that its procedures preserve the human brain in a way that would allow future scientists to obtain a complete map of its neuronal connections. 

Even if we could develop such a map, it would not be nearly enough to simulate a brain. The idea of each neuron as a mere transistor in a computer circuit is hopelessly naive. Much of this book has emphasized the complexity of cells. 

Each cell in the brain has a constantly changing program being executed inside it, one that involves thousands of genes and proteins, and its relationship with other cells is ever shifting. Mapping the connections in the brain would be a major step forward in our understanding, but even that would be a static snapshot. It would not allow us to reconstruct the actual state of the frozen brain, let alone predict how it would "think" from that point on. It would be like trying to deduce all of the various aspects of a country and its people, and predict its future development, from a detailed road map. 

I spoke to Albert Cardona, a colleague of mine at the MRC (Medical Research Council) Laboratory of Molecular Biology who is a leading expert on the connectomics of the fly brain. Albert stresses that, in addition to the practical difficulties, the brain's architecture and its very nature are shaped by its relationship to the rest of the body. 

Related: Extreme longevity: The secret to living longer may be hiding with nuns... and jellyfish

Our brain evolved along with the rest of our body, and is constantly receiving and acting upon sensory inputs from the body. It is also not stable: new connections are added every day and pruned at night when we sleep. There are both daily and seasonal rhythms involving growth and death of neurons and this constant remodeling of the brain is poorly understood. 

Venki Ramakrishnan is one of the winners of the 2009 Nobel Prize in Chemistry and former President of the Royal Society.  (Image credit: Kate Joyce and Sante Fe Institute)

Moreover, a brain without a body would be a very different thing altogether. The brain is not driven solely by electrical impulses that travel through connections between neurons. It responds also to chemicals both within the brain and emanating from the rest of the body. Its motivation is driven very much by hormones, which originate in the organs, and include basic needs such as hunger but also intrinsic desires. The pleasures our brains derive are mostly of the flesh. A good meal. Climbing a mountain. Exercise. Sex. Moreover, if we wait until we age and die, we would be pickling an old, decrepit brain, not the finely tuned machine of a 25-year-old. What would be the point of preserving that brain?

Transhumanists argue that these problems can be solved with knowledge that mankind will acquire in the future. But they are basing their beliefs on the assumption that the brain is purely a computer, just different and more complex than our silicon-based machines. Of course, the brain is a computational organ, but the biological state of its neurons are as important as the connections between them in order to reconstruct its state at any given time. 

In any case, there is no evidence that freezing either the body or the brain and restoring it to a living state is remotely close to viable. Even if I were one of the customers who was sold on cryonics, I would worry about the longevity of these facilities, and even the societies and countries in which they exist. America, after all, is only about 250 years old. 

Excerpted from the book WHY WE DIE: The New Science of Aging and the Quest for Immortality by Venki Ramakrishnan. Copyright © 2024 by Venki Ramakrishnan. From William Morrow, an imprint of HarperCollins Publishers. Reprinted by permission.

Why We Die: The New Science of Aging and the Quest for Immortality - $24.76 at Amazon

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Venki Ramakrishnan, recipient of the Nobel Prize in Chemistry and former president of the Royal Society, takes us on a riveting journey to the frontiers of biology, asking whether we must be mortal. Covering the recent breakthroughs in scientific research, he examines the cutting edge of efforts to extend lifespan by altering our physiology. But might death serve a necessary biological purpose? What are the social and ethical costs of attempting to live forever?

Venki Ramakrishnan
Live Science Contributor

Venki Ramakrishnan shared the 2009 Nobel Prize in Chemistry for uncovering the structure of the ribosome. A member of the National Academy of Sciences, Venki runs his research group at the MRC Laboratory of Molecular Biology in Cambridge, England. From 2015 to 2020, he served as president of the Royal Society, one of the world's oldest scientific organizations. He is the author of the frank scientific memoir "Gene Machine."

  • Dr Nuero
    The story really misses the point of cryonics and a very basic tenant of the scientific method. The author claims that cryonics revival is not possible and therefore it is invalid. The whole point of cryonics is that revival is not possible and we will not know the outcome for a long time or until the experiment is completed. It is as if he is dismissing a cancer research trial because cancer has not been cured yet. Very poor science on his part and sloppy research which is evident by many other verifiable falsehoods in the story.
  • zbark
    To truly preserve everything that was "you" at any particular moment, you would need to preserve all of the synapses in your brain. This is not undoable but it is not particularly palatable and would not be reversible biologically without reconstructing you in silico or a clone...the later also unlikely and possibly needlessly intensive for the purpose. Researchers have been able to do this for decades in animal, but it requires vascular perfusion with paraformaldehyde and glutaradehyde while the heart is still beating to ensure all the microscopic nooks and crannies are pickled within seconds. Essentially you would have to kill your biological form to accomplish this. I personally don't have any issue that any faithful reconstruction of such wouldn't still be "you", at least not any less you than those natural forces which effectively make an imperfect clone of you from day to day with the passage of time do right now. The real question is for what purpose? I think we need to honestly ask ourselves what really is identity, and I think it's a lot less meaningful or more meaningful depending how you think. We probably share so much in common with other human beings that parts of our identity...and probably the most important parts...are already transcribed into the future through our children, language, ideas, etc, and that even in one lifetime our identity changes so radically that there are probably people out there who are a more faithful representation of the person you were 20 years ago than the one you are today...Ship of Theseus and all that. There may be some niche uses for such technologies, but I think in general they will be superseded by alternate ways of viewing our identity and even better ways to cement a positive influence into the future. Probably our best shot at immortality may simply to be a good person.
  • saintpetejackboy
    This is a good article and you did a lot of amorphous connections to other data - top tier.

    What I propose is that, you don't need to freeze yourself or live in the modern day. All life and existence can be recalculated from similar input parameters. Not to say this is a simulation - we had ideas like Boltzmann Brain for a very long time now - even before computers, our own organism + infinite math could resolve our immortality in some tangible way that you can't exactly write a proof against such a hypothesis - (that I know of).

    There are so many ways we achieve immortality that none of them even matter. What you do here in this lifetime echoes through eternity - like it or not. So live accordingly. You don't need money or status to be resurrected - no data is ever lost and all can be recalculated from the same starting variables.

    Being a robot body who lives until the end of the universe only gets you so far - there are many levels beyond that for our consciousness to expand. A whole universe is but the blink of an eye for some creatures - and nothing prevents us from also being those same beings.

    You can augment. You can assimilate. You can transcend. These are all options open to you. Even if you never do anything, we will bring you back one day, exactly as you were. What you did echoes through all of eternity and can be recalculated from the data emitted by our very existence.

    Do not strive for immortality for - it is inevitable.
  • sven
    Dr Nuero said:
    The story really misses the point of cryonics and a very basic tenant of the scientific method. The author claims that cryonics revival is not possible and therefore it is invalid. The whole point of cryonics is that revival is not possible and we will not know the outcome for a long time or until the experiment is completed. It is as if he is dismissing a cancer research trial because cancer has not been cured yet. Very poor science on his part and sloppy research which is evident by many other verifiable falsehoods in the story.
    The point being that it is an industry selling people a lie. It is nothing like a cancer research trial because there is no trial. It's just freezing people with the absurd hope that the power doesn't go out and future super technology will revive them.
  • Neal@ChurchofPerpetualLif
    I reflect on the statement by that amazing futurist, Sir Arthur C. Clarke, who made so many astounding futuristic predictions which have come true, and others which once where the subjects of his insights on the future of human conditions which are now simply a fact of life, such as the technology which allows us to have global communications via cell phones.

    “When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong."
    Arthur C. Clarke

    I agree with Arthur C. Clarke, as he addressed cryonics specifically. We are most certainly going to discover ways to cryonically suspend and revive people someday in the future, the sooner the better.

    For anyone with an open mind, more information is at www.Perpetual.Life
  • TheBox
    admin said:
    In a new book, renowned biologist Venki Ramakrishnan explores the reasons why we die, and discusses unproven ways people hope to cheat death, such as cryogenics.

    We don't yet have the know-how to properly maintain a corpse brain': Why cryonics is a non-starter in our quest for immortality : Read more
    Immortality already exists as long as words exist because every human being is formed from letters .
    When the Feral body dies that the letters occupy , the electrical energy of the body is grounded by the earth etc but the light travels across space to be conserved at the edge of space-time , becoming a part of space-time .
    Inside the mind , letters are wave-functions and made of light , so in essence the letters join space-time .
    I am Stephen only by label , I have a personality that is irreplaceable but Stephen will be formed many many times .

    The point I am making is that people hope for mortality of the soul (personality) which is a product of letters . It is selfish for personalities to want to exist forever knowing that the earth can't keep sustaining population growth . Personalities just have to accept that they exist in letters even when the personality is gone .