The Latest

Cryostasis Revival, by Robert A. Freitas Jr. If you've got a friend who's been thinking about cryonics but "isn't sure about the science" give them this book. It presents the first comprehensive conceptual protocol for revival from human cryopreservation, using medical nanorobots. This 700-page book is available now as a FREE PDF 

Tim Urban wrote a remarkably good article on cryonics, "Why Cryonics Makes Sense". In it, he says "At the beginning of my research, my question was, “Is cryonics an okay thing to do?” By the end, the question was, “Is it okay to not sign up a dying child for cryonics, or will future people view that the way we see a parent refusing to allow life-saving medical treatment to their child for religious reasons?”"


Cryonics in the news

Links to further information


  1. The purpose of cryonics is to preserve human life and restore health.
  2. Today's medical technology can't always keep us alive, let alone healthy.
  3. A future medical technology based on a mature nanotechnology should be able to preserve life and restore health in all but the most extreme circumstances.
  4. Tissue preserved at the temperature of liquid nitrogen does not deteriorate, even after centuries of storage.
  5. Therefore, if current medical technology can't keep us alive we can instead choose to be preserved in liquid nitrogen, with the expectation that future medical technology should be able to both reverse any cryopreservation injury and restore good health.

A common misconception is that cryonics freezes the dead. As the definition of "death" is "a permanent cessation of all vital functions" the future ability to revive a patient preserved with today's technology implies the patient wasn't dead. Cryonics is actually based on the more plausible idea that present medical practice has erred in declaring a patient "dead." A second opinion from a future physician – one with access to a fundamentally better medical technology based on a mature nanotechnology – lets us avoid the unpleasant risk that we might bury someone alive.

The Debate

Each patient is a free agent entitled to full explanation and full decision-making authority with regard to his medical care. John Stuart Mill expressed it as: "Over himself, his own body and mind, the individual is sovereign." The legal counterpart of patient autonomy is self-determination. Both principles deny legitimacy to paternalism by stating unequivocally that, in the last analysis, the patient determines what is right for him.

If the [terminally ill] patient is a mentally competent adult, he has the legal right to accept or refuse any form of treatment, and his wishes must be recognized and honored by his physician.

American College of Physicians Ethics Manual. Part II: Research, Other Ethical Issues. Recommended Reading
The Ad Hoc Committee on Medical Ethics, American College of Physicians; Annals of Internal Medicine, July 1984; Vol. 101 No. 2, pages 263-267.

I, along with all of humanity, am terminally ill. I plan to treat this condition by cryopreservation when the symptoms of my progressive and otherwise untreatable illness become more severe. No hospital or physician will provide this service in the usual manner. I do not have the option of cryopreservation within the regular medical setting.

Alcor provides cryopreservation services, but has been forced, against my wishes, to perform this service only after I have been declared "legally dead".

The medical profession's proposed “treatment” is to either bury me alive or burn me alive. The medical profession attempts to force this upon me by declaring me "dead" at a point in time when my ability to respond to their claim is limited. However, their unilateral declaration that I am "dead" will be against my wishes, against a body of my written publications extending over decades, and against my publicly declared and publicly stated better judgment. Their declaration will be made despite there being good evidence that I could be revived in the future, and a striking lack of evidence that such revival is impossible.

Those who wish to deprive the terminally ill of the right to be cryopreserved in the manner they desire must, at the very least, prove, beyond a reasonable doubt, that cryonics does not work. The terminally ill deserve at least the rights of accused murderers. Given the abundant evidence supporting cryonics, finding such proof will be very difficult.

Those who argue against the rights of the terminally ill and the cryopreserved should be called cryonics deniers. They say it won't work, but offer no evidence in support of their claim, let alone proof.

Evaluating cryonics

The main reason that cryonics isn't viewed more favorably by the medical community is easy to explain. Medicine relies on clinical trials. Put more simply, if someone proposes a method for saving lives, the response is "Try it and see if it works." Methods that haven't been verified by clinical trials are called "experimental," while methods that have been tried and failed are rejected.

In keeping with this tradition, we'd like to conduct clinical trials of the effectiveness of cryopreservation to determine whether it does (or does not) work. The appropriate trials can be easily described. Cryonics proposes to cryopreserve people with today's technology in the expectation that medical technology of (say) the year will be able to cure them. Thus, the appropriate clinical trials would be to:

  1. Select N subjects.
  2. Cryopreserve them.
  3. Wait 100 years.
  4. See if the technology of can indeed revive them.
The reader might notice a problem: what do we tell the terminally ill patient prior to completion of the trials?

While this problem is not entirely unique to cryonics (the plight of a dying patient who wishes to know whether or not to take a new experimental treatment is well known), cryonics poses it in a qualitatively more severe fashion: we must wait longer to determine the outcome and we have no preliminary results to provide a clue about what that outcome might be. If a new treatment is being tested we normally have the results of animal trials and perhaps some preliminary results from human patients. Further, we expect to get reliable results in not too long. In the case of cryonics, we are quite literally awaiting the development of an entirely new medical technology. Preliminary results, even on experimental animals, are simply not available; and the final results might not be available for many decades.

Thus, while we can begin the clinical trials required to evaluate cryonics today, clinical trials cannot provide a timely answer about the effectiveness of cryonics. It is not possible (utilizing the paradigm of clinical trials) to draw conclusions today about whether physicians tomorrow will (or will not) be able to revive someone who was cryopreserved using today's technology.

Does cryonics work?

The correct scientific answer to the question "Does cryonics work?" is: "The clinical trials are in progress. Come back in a century and we'll give you an answer based on the outcome." The relevant question for those of us who don't expect to live that long is: "Would I rather be in the control group, or the experimental group?" We are forced by circumstances to answer that question without the benefit of knowing the results of the clinical trials.

When we think about this question, it is important to understand that future medical technology will be no mere incremental or evolutionary advance over today's medicine. Think of Hippocrates, the prehistoric Greek physician, watching a modern heart transplant. Advances in medical technology in future decades and centuries will be even more remarkable than the advances we have already seen in centuries past. At some point in the future almost any infirmity that could in principle be treated is likely to be treatable in practice as well. In principle, the coming ability to arrange and rearrange molecular and cellular structure in almost any way consistent with physical law will let us repair or replace almost any tissue in the human body. Whether it's a new liver, a more vital heart, a restored circulatory system, removing some cancerous cells, or some other treatment -- at some point, nanomedicine should let us revitalize the entire human body and even revive someone who was cryopreserved today. We can describe today, with remarkable certainty, the ultimate capabilities of medical technology. While the technological route and development time might be uncertain, we will eventually be able to evaluate the molecular structure of your cryopreserved tissues, and restore every molecule to where it belongs in your healthy body. The expected eventual feasibility of such future capabilities makes the credibility of claims that cryonics won't work hard to take seriously.

Is the treatment worse than the disease?

Finally, there is the risk that a proposed treatment might be worse than the disease (which creates a strong prejudice against the use of experimental treatments on human beings). Current laws require that cryopreservation begin after "legal death" (which should be distinguished both from death by current medical criteria and death by the more fundamental information theoretic criterion). This presumably implies a rather small risk. It should be clearly understood that a declaration of "legal death" is based on purely ad hoc criteria without any underlying theoretical framework which might lend credibility to the oft repeated but never coherently defended claim that future medical technology will have some difficulty in restoring the cryopreserved patient to good health. In fact, "legal death" can be pronounced at a point in time when the patient can be revived, this being the point of DNR or "Do Not Resuscitate" orders. Even with complete patient autonomy and the ability to start cryopreservation prior to legal death (as could happen in the future) cryonics will only be used when the patient is terminal and has little remaining life, either in quantity or quality. There is little need, in the case of cryonics, to fear that the cure will be worse than the disease.

What to do

Cryonics Payoff Matrix
It works It doesn't work
Sign up Live Die, lose life insurance
Do nothing Die Die

How might we evaluate cryonics? Broadly speaking, there are two available courses of action: (1) sign up or (2) do nothing. And there are two possible outcomes: (1) it works or (2) it doesn't. This leads to the payoff matrix to the right. In using such a payoff matrix to evaluate the possible outcomes, we must decide what value the different outcomes have. What value do we place on a long and healthy life?

What does cryonics cost and what (presumably negative) value do we place on being dead? And finally, in the absence of direct experimental results in one direction or the other, what estimate do we make of the chances that it will work? Athough this analysis has been compared with Pascal's Wager, it avoids the logical problems that beset the latter.

When evaluating the possible outcomes, it's important to understand that if you sign up and it works, that "Live" does not mean a long, wretched and miserable life. Many people fear they will wake up, but still suffer from the infirmities and morbidities that the elderly suffer from today. This is implausible for two very good reasons. First, the kinds of medical technologies that are required to restore today's cryonics patients will be able to restore and maintain good health for an indefinite period. The infirmities of old age will go the way of smallpox, black death, consumption, and the other scourges that once plagued humanity. Second, as long as we are unable to restore cryopreserved patients to satisfactory good physical and mental health, we'll keep them cryopreserved until we develop better medical technologies. To put these two points another way, when that future day arrives when we have a medical technology that can revive a patient who was dying of cancer today, and was cryopreserved with today's technology, that same medical technology should be able to cure their senile dementia and restore their musculature; they'll walk out into a future world healthy in mind and body. If we can't restore full health to both mind and body, we'll keep our patients in liquid nitrogen until we develop a medical technology that can.

It's also important to understand that technology is moving rapidly, and accelerating. When you wake up, your children and your younger friends and acquaintances are likely to be alive and well, along with most of your awakened friends from the cryonics community. While several decades might have passed, your social network within the cryonics community will still be there and likely many of the younger members of the rest of your social network.

Present successes

It is worth pointing out that a fairly wide range of simple tissue types have been successfully cryopreserved and then rewarmed, including very early human embryos, sperm, skin, bone, red and white blood cells, bone marrow, and others. Glycerol (anti-freeze, see molecular structure at left) has historically been used to greatly reduce freezing damage. New cryoprotectants in combination with ice blockers are now able to eliminate ice formation in a process called vitrification. The most sophisticated vitrification solution, M22 (adopted by Alcor because of its demonstrated success) was used to vitrify a rabbit kidney, which survived subsequent transplanation and served as the sole renal support for a rabbit, conclusively demonstrating full functional recovery of that complex mammalian organ. Vitrification successfully preserves memory in a simple organism, making the case for cryonics even stronger. The fact that cryopreservation protocols only need to be good enough to prevent information theoretic death for cryonics to be successful; and that modern vitrification protocols are already fully reversible today in many cases (in one case even that of a whole mammalian organ); provides good reason to believe that today's cryopreservation protocols, when carried out under favorable conditions, are in fact preventing information theoretic death.


Cryonics proposes to use an experimental treatment on human patients with no expectation that clinical trials will be completed anytime in the near future. This has created some controversy. Despite this, cryopreservation is the medically conservative course of action (in the best sense of the word "conservative.") Conventional medical criteria pronounce the cryopreserved patient "dead." These criteria are disputed by those who support cryonics, who argue that future medical capabilities should be able to decisively contradict this diagnosis by restoring patients cryopreserved under favorable conditions (and many cryopreserved under less than favorable conditions) to full physical and mental health. If there is a debate about whether or not a patient is dead it would seem inappropriate to resolve the dispute by burying or burning them, particularly if this course of action is against the wishes of the patient. Unfortunately, current legal and social forces produce this outcome all too often.

At some point in the future we will have direct experimental proof that today's cryopreserved patients either can or cannot be revived by future medical technology. Unfortunately, most of us must decide today if we wish to pursue this option. If we wish to gain some insight today about the chance that cryonics will or will not work we must consider several factors, including most prominently (a) the kinds of damage that are likely to occur during cryopreservation and (b) the kinds of damage that future medical technologies might reasonably be able to repair. Those interested in pursuing this subject should read this web page which discusses the chances of success, The Molecular Repair of the Brain, and Cryostasis Revival.

In the news:

LessWrong, July 2023, "Cryonics and Regret" – "Last year, my father died. ... I know that he would have been all in. A second chance to live, rejuvenation, a future with maybe endless possibilities. ... The funds were there, everything could have been arranged in time. ... I can easily accept most of the mistakes I made, I can live with my past shortcomings. But this I do regret, and I do not think that my regret will ever vanish, that I did not arrange for a second chance for my dad."

Euronews, January 2023, "Inside the US facility where 199 'legally dead' humans and almost 100 pets await being revived" – "That [cryonics] may seem like science fiction, but today there are many people among us who were conceived in a petri dish. Over 5 million people. In 1978, the first test tube baby was considered shocking, immoral, unethical and people wondered, 'is this a human'? And the same type of criticism is often reflected on cryonics. 'They won't be human when they're revived,' or 'Who will they be?', 'Will they remember themselves?' 'It will be a frightening world'. I don't think so."

The Business Standard, January 2023, "Want to avoid death? Maybe cryonics isn't crazy" – "But it's foolish to dismiss an option that looks at least potentially viable given the advances technology has made in the last few decades and the milestones science will likely continue to achieve amid the declining cost of cryonics. The field overall deserves to be taken more seriously."

Forbes, September 2022, "The Spring Of Cryobiology: One Enabling Technology That Will Help Build The New Industry Of The Future" – "Imagine a world, where freezing and thawing of biological organisms without damage is available. In that world, if I had a terminal disease, I could freeze (or cryopreserve) myself before my body collapses and “wait“ until humanity discovers a cure for it in the future..."

The Washington Post, August 2022, "Technology promises to change the meaning of death — at least for some" – "If we extrapolate on the potential of the Yale team’s OrganEx system, we may eventually be capable of reviving silent brains and restarting organs that once would have been considered irreversibly dead." "With advancements in cryonics and emerging technologies such as OrganEx, this is no longer just a science fiction hypothetical but a reality conceivable within our century."

Relatto, April 2022, "Cryonics, the icy hope of a longer life" – "I adhere to the position of Benjamin Franklin. Possibly the biggest determinant in my life has been curiosity. I would like to know and experience the changes that the next hundred or five hundred years will bring, and so if I can choose between worms, fire and freezing".

CBS News, November 2021, "Cryonics: Putting your future plans for life on ice" – "Neuroscientists say we are still hundreds of years away, but that didn't stop Leis from signing up for Alcor 18 years ago, using a life insurance policy. 'I hope that it's me, this person I am today,' he said. 'At the same time, if it's not, then I wish that person well, who is revived.'"

Abnormal Voyages, May 2021, "A New Tomorrow" – "Using cutting edge technology to preserve patients, Alcor aims to someday soon reverse the hands of time and revive humans decades after what would have been their final curtain."

South China Morning Post, September 2020, "Freezing bodies for ‘reanimation’ in China and why the country’s cryonics tech has the potential to leapfrog the West" – "The Shandong Yinfeng Life Science Research Institute has 10 bodies on ice already with dozens more who have committed to its service", "China could quickly catch up and lead in the cryonics area"

The Daily Beast, January 2020, "The Bizarre Fight Over a Wealthy Biochemist’s Frozen Head Keeps Getting Weirder" – "The 90-page filing by Alcor seeks to vacate the court’s previous release of the elder Pilgeram’s estate to his beneficiaries, including Kurt [Pilgeram], potentially leaving him with just $1. (Kurt’s brother and fellow beneficiary Karl is not named as a respondent in the suit.)"

“He not only signed up for his remains to be preserved by Alcor, but he also signed a codicil to his will that said that if family member challenged his wish to be cryo-preserved, they would be disinherited and only receive a dollar,” Diane Cafferata, who represents Alcor, told The Daily Beast on Friday.

“After Pilgeram died in 2015, his son hid this codicil and all his father’s testamentary documents from the probate court and falsely claimed his father died intestate,” landing Kurt and his brother about $16 million, alleged Cafferata.

Odd Lots, July 2019, "What Bitcoin Has To Do With The Dream Of Cryonics (Podcast)" – "... we speak with NYU professor Finn Brunton, who is the author of the new book "Digital Cash: The Unknown History of the Anarchists, Utopians, and Technologists Who Created Cryptocurrency." Brunton talked to us [about] Bitcoin’s pre-history, and about how and why there was a major crossover between digital currency believers and people who want to freeze their bodies in order to live forever."

New York Times, July 2019, "Scientists Are Giving Dead Brains New Life. What Could Go Wrong?" – "According to later reports, Sestan, referring to the most recent ECoG data, stressed that he was confident that the brains in his experiment were “not aware of anything.” Still, he went on, he could not speak to what other scientists might do with the research. “Hypothetically, somebody takes this technology, makes it better and restores someone’s [brain] activity,” he said."

The Greg Gutfeld Show on Fox News, June 2015, "Montana man sues cryonics company to get his father's frozen head back" – "TIMPF: I stand firmly with the head freezing company. GUTFELD: Yes."

The Telegraph, June 2019, "US man sues cryonics organisation to return his father's head" – ""At the end of the day this case is really about whether a child can overrule a parent's wishes about what they want with their body. Laurence Pilgeram unequivocally committed his life to being cryonically preserved. So who should win in that case? The parent or the surviving children?""

Gizmodo, May 2019, "California Man Becomes the First ‘Death With Dignity’ Patient to Undergo Cryonic Preservation" – "A terminally ill patient who opted for assisted death has undergone cryonic preservation at the Alcor Life Extension Foundation. This preservation—the first of its kind—signifies an important milestone for cryonics advocates, who argue that the right to death, paradoxically, is a potential pathway to an eternal life."

Nature, April 2019, "Restoration of brain circulation and cellular functions hours post-mortem" – "These findings demonstrate that under appropriate conditions the isolated, intact large mammalian brain possesses an underappreciated capacity for restoration of microcirculation and molecular and cellular activity after a prolonged post-mortem interval."

Stat, January 2019, "After ghoulish allegations, a brain-preservation company seeks redemption" – "Glutaraldehyde fixation, far from being “terrible,” “almost certainly preserves long-term memories,” he said: It “locks down” everything thought to constitute the biological basis of memories.", December 2018, "Report Finds a Strong Relationship Between Crypto-Advocates and Life Extension" – "Bitcoin historians will recollect that the early cryptocurrency pioneer Hal Finney was a person who believed in life extension and chose to be frozen in cryopreservation. Now a recent report shows that a good number of well-known blockchain advocates are also convinced that an ‘extropian-like’ technology may extend the lives of humans in the future."

Breaker, December 2018, "The Bitcoiners Who Want to Defeat Death" –" there’s a “type of mind” common to cryptocurrency and longevity enthusiasts that doesn’t focus on the short-term horizon, but thinks about big-picture transformational change. “If they see a new technology, they tend to extrapolate,” he says of those with a crypto-cryo mindset. “You can see where it’s all going to go, and that’s why people get so excited.”"

Society for Cryobiology, November 2018, "Society for Cryobiology Position Statement: Cryonics" – "The Society for Cryobiology sometimes receives inquiries regarding its position on the practice of cryopreserving human cadavers or brains with the aim of eventual reanimation, known as cryonics.

The Society recognizes and respects the freedom of individuals to hold and express their own opinions and to act, within lawful limits, according to their beliefs. Preferences regarding disposition of postmortem human bodies or brains are clearly a matter of personal choice and, therefore, inappropriate subjects of Society policy. The Society does, however, take the position that the knowledge necessary for the revival of live or dead whole mammals following cryopreservation does not currently exist and can come only from conscientious and patient research in cryobiology and medicine. In short, the act of preserving a body, head or brain after clinical death and storing it indefinitely on the chance that some future generation may restore it to life is an act of speculation or hope, not science, and as such is outside the purview of the Society for Cryobiology."

Answers With Joe, October 1, 2018, "Afterlife Insurance: Is Cryonics Really That Crazy?" – "Our medical technology has progressed by leaps and bounds over the years and along the way our notions of death has changed as well. We no longer see it as a state, but a process. And some have taken this notion to extremes and believe that you can freeze that process indefinitely so that future medicine can cure you. This is cryonics." "Whether this process will actually work is unknown, but it's a bet cryonicists are willing to take."

Estate Planning, August 2018, "Preserving Assets in Trusts for Clients Considering Cryonics" – " “Revival trusts”— a term used in this article to describe a trust created to hold assets for a person upon his or her legal death pending the individual’s revival to life— have been around for decades. Grantors have created revival trusts that currently hold assets and that will receive significantly greater assets upon their deaths. Well known and well-regarded institutions are serving as trustees of these revival trusts, and more institutions are coming on board.

Universal-Sci, June 22, 2018, "New Model Predicts That We’re Probably The Only Advanced Civilization In The Observable Universe" – "The Fermi Paradox remains a stumbling block when it comes to the search for extra-terrestrial intelligence (SETI). Named in honor of the famed physicist Enrico Fermi who first proposed it, this paradox addresses the apparent disparity between the expected probability that intelligent life is plentiful in the Universe, and the apparent lack of evidence of extra-terrestrial intelligence (ETI)."

Cryonics, May-June & July-August, 2018, "Revival of Alcor Patients" – "At an abstract level, the revival process might use any of three primary means: in situ repair, scan-and-restore, or scan-to-WBE (Whole Brain Emulation). In situ repair will require the development of medical nanorobots capable of operating in cryopreserved tissues (“cryobots”), while scan-and-restore and scan-to-WBE could benefit from this technology."

Doklady Biological Sciences, May 2018, "Viable Nematodes from Late Pleistocene Permafrost of the Kolyma River Lowland" – "The viable soil nematodes Panagrolaimus aff. detritophagus (Rhabditida) and Plectus aff. parvus (Plectida) were isolated from the samples of Pleistocene permafrost deposits of the Kolyma River Lowland. The duration of natural cryopreservation of the nematodes corresponds to the age of the deposits, 30 000–40 000 years."

Newsweek, February 10th, 2018, "Where do you go when you die?" – "Noble found that certain animals' cells, post-mortem, remained viable for weeks. The research suggests a "step-wise shutdown," by which parts of us die gradually, at different rates, rather than all at once.", December 20th, 2017, "Do Zombies Pay Taxes?" – "The more likely result is that the IRS wouldn’t accept the revived grantor as the same person, because the IRS would challenge any claim that a cryopreserved individual wasn’t deceased." "Assuming that the revived grantor would be treated as a new person, he or she would also be treated as an unrelated person for purposes of the generation-skipping transfer tax."

Superhuman Summit 2017, October 21st, 2017, "I’m getting frozen when I die, and so should all of you" – "So let's all do it. Together. So I don't have to wake up alone. Dare to dream with me." (youtube)

ABC15, September 25, 2017, "Scottsdale lab freezes bodies in hopes of bringing you back from the dead" – "ALCOR Life Extension practices the science of cryonics. Big metal containers at ALCOR hold bodies of people who are legally dead, but considered lives on hold by ALCOR cryopreservation."

Motherboard, May 8, 2017, "This AI Company Offers Cryogenic Freezing With Its Health Plan" – "Currently most Numerai employees have signed up, though Craib says that some have opted out for religious or philosophical reasons. Those who retained the coverage have the chance to join the likes of Hal Finney, computer scientist and bitcoin pioneer, whose body currently rests in the Alcor vaults."

Humanist Community Forum, April 30, 2017, "Cryonics – Preserving Ourselves for the Future" – "Cryonics is an experiment. Do you want to join the control group, or the experimental group?" Ralph C. Merkle

Insider Monkey, January 13, 2017, "10 Most Interesting Companies In The World" – Alcor is one of the top 10 most interesting companies in the world, along with Google, Apple, Tesla, Facebook, Amazon, Illumina, SpaceX, Editas Medicine, AeroMobil and Monsanto, according to Insider Monkey.

CBC News, November 25, 2016, "B.C. man signs first-of-its-kind Canadian cryonic contract" – "Macintosh's claim says the province is the only place in the world to outlaw cryonics. In its legal response, the province has said the only cryonics vendors barred by the legislation are those who imply that customers may "expect" to be brought back to life in the future."

Rolling Stone, August 2016, "Inside Steve Aoki's Quest for EDM Immortality" – "Alcor promises to preserve Aoki's earthly form at a sufficiently low temperature so that – should technology ever advance to the point that Aoki hopes it will – he can be reanimated and/or his consciousness can be uploaded to a computer, granting him something like digital immortality. Aoki, who's 38, set this plan into motion after reading the work of famed futurist Ray Kurzweil, who speculates on the imminence of such scenarios becoming scientific fact."

SciShow, July 2016, "Cryonics: Could We Really Bring People Back to Life?" – "It's an age-old sci-fi trope, but there are scientists out there working on making cryonics a reality!"

Faders, April/May 2016, "What A Time To Be Alive — Forever" – "Do you want to live forever? Yes? OK. Here’s how. Call up one of the currently operational centers of cryonics. That’s the industry-preferred term for the practice of freezing one’s body after [legal]death in order to one day, once the necessary technology arrives, be thawed out and reanimated."

National Geographic Channel, April 3, 2016, "Cryopreservation Explained" – "Dr. Max More, CEO of Alcor Life Extension Foundation, explains how they preserve people’s brains in hopes of waking them up in the future when scientists can restore their body."

Worth ReadingWait but Why, March 2016, "Why Cryonics Makes Sense" – "At the beginning of my research, my question was, “Is cryonics an okay thing to do?” By the end, the question was, “Is it okay to not sign up a dying child for cryonics, or will future people view that the way we see a parent refusing to allow life-saving medical treatment to their child for religious reasons?”"

Cryobiology, December 2015, "Aldehyde-stabilized cryopreservation" – "We describe here a new cryobiological and neurobiological technique, aldehyde-stabilized cryopreservation (ASC), which ... has the unique ability to combine stable long term ice-free sample storage with excellent anatomical resolution. ... we perfuse-fixed rabbit and pig brains with a glutaraldehyde-based fixative, then slowly perfused increasing concentrations of ethylene glycol over several hours in a manner similar to techniques used for whole organ cryopreservation. Once 65% w/v ethylene glycol was reached, we vitrified brains at −135 °C for indefinite long-term storage."

Science Alert, February 10, 2016, "A mammal's brain has been cryonically frozen and recovered for the first time" – "For the first time, researchers have cryonically frozen a whole mammalian brain and recovered it in near-perfect condition, with the cell membranes, synapses, and intracellular structures all intact."

Brain Preservation Foundation, 201x, "Overview of 21st Century Medicine’s Cryopreservation for Viability Research" – "21CM’s “straight” cryopreservation\cryonics technique for whole brain preservation eliminates ice crystal formation but does so at the cost of severely shrinking the brain through osmotic dehydration." ..."similar cryoprotectant formulas and protocols applied to half millimeter thick slices of living brain have shown good ultrastructure preservation and amazingly good recovery of function after rewarming from weeks of -130 degrees C storage."

The Economist, February 6, 2016, "Wait Not In Vain" – "After decades of piecemeal progress, the science of cryogenically storing human organs is warming up" "Venture capitalists, charities and individual philanthropists are queuing up to add to the rising pile of cash." "The cryopreservation race is on, then. And the winning post is the organ bank."

Scientific American, February 1, 2016, "Can Our Minds Live Forever?" – Editorial comment: This is a change for Shermer, who wrote a 2001 editorial in Scientific American titled "Nano Nonsense and Cryonics."

Emily M. Scott, December 23, 2015, "The Best Stories I Read in 2015" – “A Dying Young Woman’s Hope in Cryonics and a Future” "... was probably my favorite piece of the year, and an incredible piece of science journalism." "This story has everything for me: a clear explanation of the science behind it, a discussion of the ethics surrounding the issue, as well as anecdotes that drew me in."

PBS, November 18, 2015, "The Brain with David Eagleman: Episode 6 | Cryonic Preservation of the Brain and Body" – "David visits Alcor Life Extension Foundation where CEO Max More explains that the team’s aim is to give people a second chance at life."

MIT Technology Review, October 19, 2015, "The Science Surrounding Cryonics" – "Direct evidence that memories can survive cryopreservation comes from the roundworm Caenorhabditis elegans ..." "Similarly, it has been shown that long-term potentiation of neurons, a mechanism of memory, remains intact in rabbit brain tissue following cryopreservation."

Alcor, August 7 2015, "Cryonics Testimonial: Alcor Member Professor Gregory Benford" – "I became interested in cryonics because it's the only scientifically plausible answer to the problem of death, and death is the big human problem. It shapes all of human psychology."

California Magazine, Summer 2015, "Into the Deep Freeze: What Kind of Person Chooses to Get Cryonically Preserved?" – "[Max] More [Alcor's President] comes across as a reasonable man who is acutely aware that most people think his ideas are insane, or repugnant, or both. Like most of the cryonicists I spoke to, he frames his points as appeals to logic, not emotion. His confidence is infectious."

Hopes & Fears, May 11, 2015, "I freeze people's brains for a living" – "For me, cryopreservation was an obvious mechanical problem. You’ve got molecules; why not lock them in place so that somebody can fix them later?" "I was an ENT physician, but I haven’t practiced for about five years now. I still have my license. My participation in the cryonics field happened very gradually."

ESPN, May 5, 2015, "The Greatest Hitter Who Ever Lived On" – "In her book, Claudia writes what her father told the doctor. “ ... I'd like to have some more time with my two kids.” "

Specter Defied, April 25, 2015, "How to sign up for Alcor cryo" – "This article is intended for those who already think cryopreservation is a good idea but are putting it off since they don't know exactly what needs to be done."

The Dr. Oz Show, March 10, 2015, "Why Larry King Wants to Freeze His Body" – "I think when you die, that's it. And I don't want it to be it. I want to be around. So I figure the only chance I have is to be frozen. And then, if they cure whatever I died of, I come back."

The List, March 12, 2015, "Live Forever by Freezing Your Body" – "First and foremost I look forward to the future, I think it's going to be a great place. I want to live as long as possible." "Many pay for their cryonic treatment by naming the company itself, Alcor, as their life insurance beneficiary."

The Journal of Medical Ethics, February 25, 2015, "The case for cryonics" – " insofar as the alternatives to cryonics are burial or cremation, and thus certain, irreversible death, even small chances for success can be sufficient to make opting for cryonics a rational choice."

Journal of Critical Care, December 2014, "The Future of Death" – "If future technologies come to include nanotechnological interventions to enter cells and reverse structural and molecular changes that prevent natural return to normal cell function, then even neuronal cell death as currently understood is not a loss of the capacity to return to consciousness. Whether a patient is living or dead depends on time, place, and circumstances as much as it does on biology."

The Onion, October 15, 2014, "Facebook Offers To Freeze Female Employees’ Newborn Children" – "“We recognize the many challenges women face starting a family and balancing a career, which is why our company will provide extensive support to female employees who want to preserve their infant in a frozen state of suspended animation until they’re ready for child-rearing,” said Facebook spokesperson Mary Copperman, ..."

The Atlantic, August 26, 2014, "For $200,000, This Lab Will Swap Your Body's Blood for Antifreeze" – "Cryopreservation is a darling of the futurist community. The general premise is simple: Medicine is continually getting better. Those who die today could be cured tomorrow. Cryonics is a way to bridge the gap between today’s medicine and tomorrow’s."

The Huffington Post, June 23, 2014, "Should Cryonics, Cryothanasia, and Transhumanism Be Part of the Euthanasia Debate?" – "Approximately 40 million people around the world have some form of dementia, according to a World Health Organization report. About 70 percent of those suffer from Alzheimer's. With average lifespans increasing due to rapidly improving longevity science, what are people with these maladies to do? Do those with severe cases want to be kept alive for years or even decades in a debilitated mental state just because modern medicine can do it?" "In the 21st Century--the age of transhumanism and brilliant scientific achievement--the question should be asked: Are there other ways to approach this sensitive issue?" "Recently, some transhumanists have advocated for cryothanasia, where a patient undergoes physician or self-administered euthanasia with the intent of being cryonically suspended during the death process or immediately afterward. This creates the optimum environment since all persons involved are on hand and ready to do their part so that an ideal freeze can occur."

Alcor, December 19, 2013, "Dr. Michio Kaku and Cryonics: Why Michio Kaku's Critique of Cryonics is Bogus" – "You'd expect that a man of that learning, and knowledge, and experience ... would have done his research and get things right. Unfortunately, just about every single point in that video was incorrect."

BBC, October 31, 2013, "Will we ever bring the dead back to life?" – "The woods’ cool temperature, it turned out, had prevented the woman’s cells from breaking down as quickly as they would have in a warmer environment, allowing her to lay dead in the forest for around four hours, plus survive an additional six hours between the time the passerby called the ambulance and the time her heart began beating again. Three weeks later, she left the hospital, and today she is happily married and recently delivered a baby."

The Guardian, September 20, 2013, "Cryonics: the people hoping to give death a cold shoulder" – "Scores of Brits have also signed up for what the movement has dubbed "a second chance at life""

Singularity Weblog, September 12, 2013, "My Video Tour of Alcor and Interview with CEO Max More" – "During our visit CEO Dr. More walked us through the Alcor facilities as well as the process starting after clinical death is proclaimed, through the cooling of the body and its vitrification, and ending in long term storage."

Science Omega, July 1, 2013, "Exploring cryonics: Could science offer new life after death?" – "Medical advances have made it possible – given favourable circumstances – for physicians to bring patients, who are clinically dead, back to life." ... " cryonics has been viewed as somewhat of a fringe science since its inception. However, advances within fields such as regenerative medicine and nanomedicine have caused some experts to acknowledge the field’s growing potential. Last month, for example, three academics from the University of Oxford revealed that, once dead, they will be cryogenically preserved until it becomes possible to bring them back to life."

The Independent, June 9, 2013: "Academics at Oxford University pay to be cryogenically preserved and brought back to life in the future" –

"Nick Bostrom, professor of philosophy at the Future of Humanity Institute [FHI] and his co researcher Anders Sandberg have agreed to pay an American company to detach and deep freeze their heads in the advent of their deaths.

Colleague Stuart Armstrong is instead opting to have his whole body frozen. Preserving the full body is technically more difficult to achieve and can cost up to £130,000.

Bostrom, Armstrong, Sandberg are lead researchers at the FHI, a part of the prestigious Oxford Martin School where academics complete research into problems affecting the globe, such as a climate change."

"“It costs me £25 a month in premiums to cover the cost of getting cryo-preserved, and that seems a good bet,” he [Armstrong] said. “It’s a lot cheaper than joining a gym, which is most people’s way of trying to prolong life.”"

BuzzFeed, June 6, 2013, "The Immortality Business" – "The richest vein of professed cryonicists is, not surprisingly, in the world of technology." Alcor’s "public-facing members include prolific inventor and Singularity cleric Ray Kurzweil; nanotechnology pioneer Ralph Merkle; and Marvin Minsky, co-founder of MIT’s artificial intelligence laboratory."

Worth ReadingThe Observer, April 6th, 2013: "Sam Parnia – the man who could bring you back from the dead" – '"The longest I know of is a Japanese girl I mention in the book," Parnia says. "She had been dead for more than three hours. ... Afterwards, she returned to life perfectly fine and has, I have been told, recently had a baby."' "One of the stranger things you realise in reading Parnia's book is the idea that we might be in thrall to historical perceptions of life and death and that these ultimate constants have lately become vaguer than most of us would allow."

Discovery Channel, April 16th, 2013: "Maria Entraigues Discovery Channel interview" – In Spanish. "Alcor is the place where I will take a little nap so that I can wake up in the future..."

Cryonics, January 2013: "Alcor-40 Conference Review" – "From the science of cryopreservation to the implications of neural network research on cryonics to strategies for preserving your assets as well as yourself, no stone was left unturned and no question unasked."

Phoenix New Times, September 17th, 2012: "Best Second Chance - 2012: ALCOR Life Extension Foundation" – "ALCOR ... specializes in cryonics, the science of preserving bodies at sub-zero temperatures for eventual reanimation, possibly centuries from now."

William Maris interview on CNBCCNBC, September 20th, 2012: "William Maris: Google Ventures Managing Partner" – "What's the most exciting areas right now?" ... "There are two areas. One, I'm interested in macro trends that are 5 or 10 years out, things like radical life extension, cryogenics, nanotechnology, and then there are trends that are occuring sooner." ... "So go back to cryogenics, how realistic is that idea at this point?"... " we're looking for entrepreneurs that have a healthy disregard for the impossible. If I start from a place by saying that's not realistic, or not possible, we won't make any investments. So I think it's very realistic." ... "I want to know if this is a reality that we could see sometime in my lifetime?" "It's a reality now, there are companies that specialize in cryogenics."

Metro, August 24th, 2012: "The Cryonic Man: How Alcor Life Extension preserves your dead body" – Alcor chief executive Max More says: " hospital staff are usually fascinated and want to help in any way they can."

OraTVnetwork, July 17th, 2012: "Seth MacFarlane & Larry King on Cryonics" (41 seconds) – Larry King: "How about we get frozen together?" Seth MacFarlane: "Let's do it!"

PBS Newshour, July 10th, 2012: "As Humans and Computers Merge ... Immortality?" – Ray Kurzweil, co-founder, Singularity University: "People say, oh, I don't want to live past 100. And I say, OK, I would like to hear you say that when you're 100."

Newsmax Health, December 7th, 2011: "Larry King's Vow to Freeze His Dead Body Is Not Crazy, Experts Say" – "the 78-year-old King stated, “I wanna be frozen, on the hope that they’ll find whatever I died of and they’ll bring me back.”"

Worth ReadingSENS5 Conference, September 3rd, 2011: "Cryonic Life Extension" – "Cryonics enables the transport of critically ill people through time in an unchanging state to a time when more advanced medical and repair technologies are available" said Max More, President and CEO of Alcor Life Extension Foundation.

Science Channel's Through the Wormhole (Season 2), July 15th 2011: "Cryogenic Preservation" – "Cryogenic freezing is a process that could successfully preserve a human body over an extended period of time."

Time, February 10th 2011: "2045: The Year Man Becomes Immortal" – "Old age is an illness like any other, and what do you do with illnesses? You cure them."

Rolling Stone, December 2010: "Life on the Rocks: can you bring people back from the dead?" (slow site) – "Isn't it a leap of faith to believe in something that hasn't happened yet? 'The comparison's more like talking to someone 150 years ago and saying, "In a little while, humans are going to have flying machines."'"

Lightspeed, October 2010: "Considering Cryonics" – Author and Physics Professor Gregory Benford looks at cryonics, and says "’s a rational gamble, especially when you consider that cryonicists buy life insurance policies which pay their organization upon their death..."

Worth ReadingSingularity Summit 2010, August 15th, 2010: "Modifying the Boundary between Life and Death" – Lance Becker, MD, Director, Center for Resuscitation Science, Emergency Medicine, University of Pennsylvania: "Our initial results are very encouraging. We have taken 6 dead people ... plugged those patients into cardiopulmonary bypass and we have a 50% survival rate out of those 6 patients". On cryonics: "I look forward to seeing that field [cryonics] be synergistic with some of what we're doing."

New York Times, July 5th, 2010: "Until Cryonics Do Us Part" – Cryonics can produce hostility from spouses who are not cryonicists.

Colorado Court Order, March 1, 2010: "IN THE MATTER OF THE ESTATE OF: MARY ROBBINS" – "The Court finds that the evidence clearly shows Mary's decision in 2006 for Alcor to preserve her last remains by cryonic suspension was an informed and resolute one." "Alcor shall have custody of Mary's last remains..."

Worth ReadingOrganogenesis, Vol 5 Issue 3, 2009: "Physical and biological aspects of renal vitrification" – "We report here the detailed case history of a rabbit kidney that survived vitrification and subsequent transplantation"

BBC News,October 20, 2008: "Doctors get death diagnosis tips" – "...there is enough ambiguity in diagnosing death that doctors need guidance" " low body temperature when it is inappropriate to confirm death." (audio)

Worth ReadingCryonics, 4th Quarter 2008: "A Cryopreservation Revival Scenario using MNT" – Molecular nanotechnology is the most compelling approach ever put forward for comprehensive repair of cryopreservation injury with maximum retention of original biological information., April 2008, "It's not immoral to want to be immortal" – Arthur Caplan, Ph.D., director of the Center for Bioethics at the University of Pennsylvania says "Nor it is vain or indulgent to want to live longer. Ask your spouse, children, friends or grandchildren if they wish you could live longer. Vanity can drive the dream of immortality, but more often than not it is the desire to live for others that fuels the dream."

Newsweek, July 23, 2007: "Back From the Dead" – "The other is to scan the entire three-dimensional molecular array of the brain into a computer which could hypothetically reconstitute the mind, either as a physical entity or a disembodied intelligence in cyberspace."

Newsweek, May 7, 2007: "To Treat the Dead" – ""After one hour," he says, "we couldn't see evidence the cells had died. We thought we'd done something wrong." In fact, cells cut off from their blood supply died only hours later."

Edge, January 2007: "What Are You Optimistic About" – "Eternal life may come within our reach once we understand enough about how our knowledge and mental processes are embodied in our brains. For then we should be able to duplicate that information — and then into more robust machinery."

Channel 5 (UK), 2006 : "Cryonics – Freeze Me" (A.K.A. "Death in the Deep Freeze") – "Almost every major advance has met with its critics, who have said that it's impossible, unworkable, uneconomical; and then, of course, when it's demonstrated, they announce that it's obvious and they knew it all along." (If you have a link to the video, please email it to me).

Worth ReadingThe Wall Street Journal, January 21st 2006: "A Cold Calculus Leads Cryonauts To Put Assets on Ice" – "At least a dozen wealthy American and foreign businessmen are testing unfamiliar legal territory by creating so-called personal revival trusts designed to allow them to reclaim their riches hundreds, or even thousands, of years into the future."

The Arizona State Legislature is not regulating cryonics.

Guardian Unlimited, January 23rd 2004, "House of the temporarily dead" – "Officially, the building is "the world's first comprehensive facility devoted to life extension research and cryopreservation", a six-acre structure that will house research laboratories, animal and plant DNA, and up to 10,000 temporarily dead people."

The Fifth Alcor Conference on Extreme Life Extension resulted in several articles:

Wired News, November 18th 2002: "Ray Kurzweil's Plan: Never Die" – "Ray Kurzweil, celebrated author, inventor and geek hero, plans to live forever."

Wired News, November 20th 2002: A Few Ways to Win Mortality War – "Discussions among leading researchers in nanotechnology, cloning and artificial intelligence focused on much more than cryonics, the process of freezing the body in liquid nitrogen after death to be later reanimated. Cryonics is basically a backup plan if technology doesn't obliterate mortality first."

Wired News, November 20th 2002: Who Wants to Live Forever? – "Gregory Benford, of the University of California at Irvine, believes the public should know that 'cryonicists aren't crazy, they're just really great, sexy optimists.'", November 22nd 2002: The Alcor Conference on Extreme Life Extension – "Bringing together longevity experts, biotechnology pioneers, and futurists, the conference explored how the emerging technologies of biotechnology, nanotechnology, and cryonics will enable humans to halt and ultimately reverse aging and disease and live indefinitely."

Coverage of cryonics related to the Ted Williams case was voluminous. Here are links to a few contemporaneous articles:

The New York Times, September 26th 2002: "Fight Over Williams May End"
USA Today, July 28th 2002: "Vitrification could keep tissue safe during the big chill"
The New York Times, July 16th 2002: "They've Seen the Future and Intend to Live It"
The New York Times, July 9th 2002: "Even for the Last .400 Hitter, Cryonics Is the Longest Shot"
(Note that the Boston Globe links and others that have gone dead have been deleted).

Christopher Hitchens quote, February 15, 2011: "If someone is reported dead on Tuesday, and you see them on Friday, the overwhelming, the obvious conclusion is that the initial report was mistaken."

Howard Lovy's blog August 27th 2003: "Unfrozen Cave Men"

Scientific American, September 2001: "Nano nonsense and cryonics"

Search PubMed for articles on cryonics.

Search Google Scholar for articles on cryonics.

For further information:

Those interested in joining the experimental group can contact:

The Alcor Life Extension Foundation
7895 E. Acoma Dr. Suite 110
Scottsdale AZ 85260-6916

phone: 480-905-1906 or (toll free) 877-462-5267
fax: 480-922-9027

No action is needed to join the control group.

The Alcor FAQ is excellent.

Worth ReadingChapter 9 of Engines of Creation discusses biostasis and cryonics.

Worth ReadingThis YouTube video is an easy introduction to some of the technical issues in cryonics.

Worth ReadingThe 4th Quarter 2008 issue of Cryonics magazine (the MNT articles are available as a PDF) discusses the application of MNT (Molecular NanoTechnology) to cryonics.

Worth ReadingThe arrest of biological time as a bridge to engineered negligible senescence provides a brief overview of the core technical assumptions of cryonics.

The molecular repair of the brain discusses the technical issues surrounding the feasibility of cryonics.

Nanomedicine by Robert A. Freitas provides a technical overview of expected medical applications of nanotechnology.

Ralph Merkle explains why cryonics will work at the 6th Alcor Conference.

How to Cryopreserve Everyone: if millions of people were cryopreserved annually, the combined up-front plus long-term costs could drop to ~$3000 each.

A previous Wikipedia article on Cryonics was quite good, even though an editor at Wikipedia who hates cryonics has since driven it down hill.

Signing Up Your Relatives: after you've signed up, you'll want your friends and loved ones to join you. This is an overview of the practical and emotional issues involved.

LessWrong has an excellent overview page of its discussions on cryonics.

A 2007 article in the Southwestern University Law Review reviews the legal basis for cryonics and proposes changes to the Uniform Anatomical Gift Act (UAGA).

(Best for geeks) Cryonics, cryptography, and maximum likelihood estimation discusses the surprisingly close relationship between cryptanalysis of World War II rotor machines and the problem of inferring neuronal wiring given partial information.

Here is a list of selected journal articles on cryonics. discusses cryonics and related concepts. It provides an excellent overview of the multiple cascading technological changes that will transform our lives in the coming decades.

Timeline of brain preservation is from the Timelines Wiki, and is quite good.

Matt Ridley is also optimistic about the future.

Large scale analysis of neural structures reviews the issues involved in high resolution imaging of the human brain. While not directly applicable to cryonics, it provides useful background about the neuronal structures that we wish to preserve.

The Prospect of Immortality (1965) by Robert C. W. Ettinger, is now available on the web. This book started the cryonics movement.

Jim Halperin's 1998 novel, The First Immortal, is a well researched and entertaining introduction to the subject.

The society for the recovery of persons apparently dead by Steven B. Harris. An essay on people's remarkable ability to ignore new ideas for decades and even centuries, and its relevance to cryonics.

The DMOZ open directory project has many links related to cryonics.

Timeship will pursue research in life extension, cryonics, vitrification (cryopreservation without ice) and related areas.

The growing movement for increasing autonomy and control by the terminally ill patient will likely improve the conditions under which cryopreservation can be performed. The Oregon Death With Dignity Act is one manifestation of this movement. A New England Journal of Medicine article in 2003 described Nurses' experiences with patients who refused food and fluids to hasten death.

Those interested in the Society for Cryobiology are referred to Mike Darwin's article. While published in 1991, it still provides the best summary of their motives and tactics.

Anyone interested in a long and healthy life will also be concerned about the regulatory environment and its impact on health care.

This page is part of Ralph C. Merkle's web site.