A survey of anti-cryonics writing

(This was originally a link to a post on my blog, A survey of anti-cryonics writing. Eliezer asked me to include the entire text of the article here.)

For its advocates, cryonics offers almost eternal life. To its critics, cryonics is pseudoscience; the idea that we could freeze someone today in such a way that future technology might be able to re-animate them is nothing more than wishful thinking on the desire to avoid death. Many who battle nonsense dressed as science have spoken out against it: see for example Nano Nonsense and Cryonics, a 2001 article by celebrated skeptic Michael Shermer; or check the Skeptic's Dictionary or Quackwatch entries on the subject, or for more detail read the essay Cryonics–A futile desire for everlasting life by "Invisible Flan".

That it seems so makes me sad, because to my naive eyes it seems like it might work and I would quite like to live forever, but I know that I don't know enough to judge. The celebrated Nobel prize winning physicist Richard Feynman tells a story of a US general who spoke to him at a party and explained that one big challenge in desert warfare is keeping the tanks fuelled given the huge distances the fuel has to travel. What would really help, the general said, would be if boffins like Feynman could invent a sort of engine that was powered by sand. On this issue, I'm in the same position as the general; in the same way as a tank fuelled by sand seems plausible enough to him, it makes sense to me to imagine that however your brain stores information it probably has something to do with morphology and chemistry, so there's a good chance it might not evaporate right away at the instant of legal death, and that freezing might be a way to keep the information there long enough for future societies to extract it with their future-technology scanning equipment.

And of course the pro-cryonics people have written reams and reams of material such as Ben Best's Scientific Justification of Cryonics Practice on why they think this is exactly as plausible as I might think, and going into tremendous technical detail setting out arguments for its plausibility and addressing particular difficulties. It's almost enough to make you want to sign up on the spot.

Except, of course, that plenty of totally unscientific ideas are backed by reams of scientific-sounding documents good enough to fool non-experts like me. Backed by the deep pockets of the oil industry, global warming denialism has produced thousands of convincing-sounding arguments against the scientific consensus on CO2 and AGW. Thankfully in that instance we have blogs like Tim Lambert's Deltoid, RealClimate, and many others tracking the various ways that the denialists mislead, whether through cherry-picking evidence, misleading quotes from climate scientists, or outright lies. Their hard work means that denialists can barely move or speak without someone out there checking what they have to say against science's best understanding and pointing out the misrepresentations and discrepancies. So before I pony up my £25 a month to sign up to cryonics life insurance, I want to read the Deltoid of cryonics - the articles that take apart what cryonics advocates write about what they do and really go into the scientific detail on why it doesn't hang together.

Here's my report on what I've found so far.

Nano Nonsense and Cryonics goes for the nitty-gritty right away in the opening paragraph:

To see the flaw in this system, thaw out a can of frozen strawberries. During freezing, the water within each cell expands, crystallizes, and ruptures the cell membranes. When defrosted, all the intracellular goo oozes out, turning your strawberries into runny mush. This is your brain on cryonics.

This sounds convincing, but doesn't address what cryonicists actually claim. Ben Best, President and CEO of the Cryonics Institute, replies in the comments:

Strawberries (and mammalian tissues) are not turned to mush by freezing because water expands and crystallizes inside the cells. Water crystallizes in the extracellular space because more nucleators are found extracellularly. As water crystallizes in the extracellular space, the extracellular salt concentration increases causing cells to lose water osmotically and shrink. Ultimately the cell membranes are broken by crushing from extracellular ice and/or high extracellular salt concentration. [...] Cryonics organizations use vitrification perfusion before cooling to cryogenic temperatures. With good brain perfusion, vitrification can reduce ice formation to negligible amounts.

Best goes on to point out that the paragraph I quote is Shermer's sole attempt to directly address the scientific claims of cryonics; once the opening paragraph has dispensed with the technical nitty gritty, the rest of the piece argues in very general terms about "[blind] optimistic faith in the illimitable power of science" and other such arguments. Shermer received many other responses from cryonics advocates; here's one that he considered "very well reasoned and properly nuanced".

The Quackwatch entry takes us little further; it quotes the debunked Shermer argument above, talks about the cost (they all talk about the cost and a variety of other issues, but here I'm focussing specifically on the issue of technical plausibility), and links to someone else making the same already-answered assertions about freezing damage.

The Skeptic's Dictionary entry is no advance. Again, it refers erroneously to a "mushy brain". It points out that the technology to reanimate those in storage does not already exist, but provides no help for us non-experts in assessing whether it is a plausible future technology, like super-fast computers or fusion power, or whether it is as crazy as the sand-powered tank; it simply asserts baldly and to me counterintuitively that it is the latter. Again, perhaps cryonic reanimation is a sand-powered tank, but I can explain to you why a sand-powered tank is implausible if you don't already know, and if cryonics is in the same league I'd appreciate hearing the explanation.

It does link to the one article I can find that really tries to go into the detail: Cryonics–A futile desire for everlasting life by "Invisible Flan". It opens on a curious note:

If you would like my cited sources, please ask me and I will give them to you.

This seems a very odd practice to me. How can it make sense to write "(Stroh)" in the text without telling us what publication that refers to? Two comments below ask for the references list; no reply is forthcoming.

And again, there seems to be no effort to engage with what cryonicists actually say. The article assets

it is very likely that a human would suffer brain damage from being preserved for a century or two (Stroh).

This bald claim backed by a dangling reference is, to say the least, a little less convincing than the argument set out in Alcor's How Cold is Cold Enough? which explains that even with pessimistic assumptions, one second of chemical activity at body temperature is roughly equivalent to 24 million years at the temperature of liquid nitrogen. Ben Best quotes eminent cryobiologist and anti-cryonics advocate Peter Mazur:

...viscosity is so high (>1013 Poise) that diffusion is insignificant over less than geological time spans.

Another part of the article points out the well-known difficulties with whole-body freezing - because the focus is on achieving the best possible preservation of the brain, other parts suffer more. But the reason why the brain is the focus is that you can afford to be a lot bolder in repairing other parts of the body - unlike the brain, if my liver doesn't survive the freezing, it can be replaced altogether. Further, the article ignores one of the most promising possibilities for reanimation, that of scanning and whole-brain emulation, a route that requires some big advances in computer and scanning technology as well as our understanding of the lowest levels of the brain's function, but which completely sidesteps any problems with repairing either damage from the freezing process or whatever it was that led to legal death.

Contrast these articles to a blog like Deltoid. In post after painstaking post, Lambert addresses specific public claims from global warming denialists - sometimes this takes just one graph, sometimes a devastating point-by-point rebuttal.

Well, if there is a Tim Lambert of cryonics out there, I have yet to find them, and I've looked as best I can. I've tried various Google searches, like "anti-cryonics" or "cryonics skeptic", but nearly all the hits are pro-cryonics. I've asked my LiveJournal friends list, my Twitter feed, and LessWrong.com, and found no real meat. I've searched PubMed and Google Scholar, and again found only pro-cryonics articles, with the exception of this 1981 BMJ article which is I think more meant for humour value than serious argument.

I've also emailed every expert I can find an email address for that has publically spoken against cryonics. Sadly I don't have email addresses for either Arthur W. Rowe or Peter Mazur, two giants of the cryobiology field who both have strongly anti-cryonics positions; I can only hope that blog posts like these might spur them into writing about the subject in depth rather than restricting themselves to rather brief and unsatisfactory remarks in interviews. (If they were to have a change of heart on the subject, they would have to choose between staying silent on their true opinions or being ejected from the Society for Cryobiology under a 1982 by-law.) I mailed Michael Shermer, Steve Jones, Quackwatch, and Professor David Pegg. I told them (quite truthfully) that I had recently started talking to some people who were cryonics advocates, that they seemed persuasive but I wasn't an expert and didn't want to fall for a scam, and asked if there was anything they'd recommend I'd read on the subject to see the other side.

The only one of these to reply was Michael Shermer. He recommended I read David Brin, Steve Harris and Gregory Benford. This is a pretty surprising reply. The latter two are cryonics advocates, and while Brin talks about a lot of possible problems, he agrees with cryonics advocates that it is technically feasable.

I expanded my search to others who might be knowledgable: Society of Cryobiology fellows Professor Barry Fuller and Dr John G Baust, and computational neuroscience Professor Peter Dayan. I received one reply: Dayan was kind enough to reply very rapidly, sounding a cautionary note on how much we still don't know about the structure of memory and referring me to the literature on the subject, but was unable to help in my specific quest for technical anti-cryonics articles.

In his 1994 paper The Molecular Repair of the Brain, cryptology pioneer Professor Ralph Merkle remarks

Interestingly (and somewhat to the author's surprise) there are no published technical articles on cryonics that claim it won't work.

Sixteen years later, it seems that hasn't changed; in fact, as far as the issue of technical feasability goes it is starting to look as if on all the Earth, or at least all the Internet, there is not one person who has ever taken the time to read and understand cryonics claims in any detail, still considers it pseudoscience, and has written a paper, article or even a blog post to rebut anything that cryonics advocates actually say. In fact, the best of the comments on my first blog post on the subject are already a higher standard than anything my searches have turned up.

If you can find any articles that I've missed, please link to them in the comments. If you have any expertise in any relevant area, and you don't think that cryonics has scientific merit - or if you can find any claim made by prominent cryonics advocates that doesn't hold up - any paragraph in Ben Best's Scientific Justification of Cryonics Practice, anything in the Alcor Scientists’ Cryonics FAQ or the Cryonics Institute FAQ, or anything in Whole Brain Emulation: A Roadmap (which isn't directly about cryonics but is closely related) - then please, don't comment here to say so. Instead, write a paper or a blog post about it. If you don't have somewhere you're happy to post it, and if it's better than what's already out there, I'll be happy to host it here.

Because as far as I can tell, if you want to write the best anti-cryonics article in the world, you have a very low bar to clear.

Related articles: Carl Schulman links to Robin Hanson's What Evidence in Silence or Confusion? on Overcoming Bias, which discusses what conclusions one can draw from this.

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The allegation that cryonics is pseudoscience reminds me of the allegations that Singularitarianism/Transhumanism are "atheist religion", "the rapture for nerds", etc. That confusion, I think, comes when people see the questions we're investigating — "Could we live forever?", "Could we end suffering?", etc. — and assume that we're answering the questions in a way similar to how religion does... or they don't even think to remember why they believe religion is bad, and they assume that it's the questions rather than the answers. Obviously, the problem with religion isn't the questions it asks, nor their motives for asking those questions; the problem is the way religion acquires answers to those questions. The same applies to seeking eternal life. Eternal life as a goal isn't wishful thinking; it's wishful thinking when people mistakenly believe that the goal is easy or has already been reached ("you can live forever if you believe in Jesus", etc.). Yet it's not surprising that many perfectly intelligent people buy into these memes. They are used to hearing completely bullshit answers to these completely legitimate questions, so they get to the point where the questions themselves set off their bullshit alarms, even in the context of attempting to investigate them within a rigorous scientific/rational framework.

The "singularity == religion" and "cryonics == pseudoscience" memes are comparable to someone in the early 1960s comparing the Apollo program to the story of the Tower of Babel, and then dismissing the program on that basis as a technically infeasible religious fantasy.

Actually the Apollo program was quite well supported by the advancing missile technologies that were developed from the 1940s and onwards. Those early and ongoing tests made clear demonstrations of the ability to launch man-made objects into orbits around the earth and the moon. There's no such similar testing that has been done for cryonics. That analogy is really exaggerating things.

If you think that the Apollo program was better supported by missile evidence than cryonics is by the rabbit kidney vitrification, you're going to have to show your workings. You should do so in more than a comment, though, since whatever you post will as I show above be the best anti-cryonics article in the world.

Reading this back, I have to add that the Apollo program was much better supported by missile evidence than cryonics is by the rabbit kidney vitrification. However, I don't think the difference is qualitative.

I've also encountered people who criticize the predictions surrounding the singularity, which misses the point that the singularity is the point beyond which predictions cannot be made.

edit: Didn't mean that as a comprehensive definition.

That is not the most common usage here. See Three Singularity Schools and the LW wiki page.

EDIT: The parent comment does not deserve to be at -4. This is a reasonable thing for an inexperienced commenter to say.

Thanks for saving me from karmic hell, but I still don't see the conflict. I seem to follow the Vinge version, which doesn't appear to be proscribed.

I may have been too categorical, obviously one can make all the predictions he likes, and some with a high percentage of certainty, for instance "If cryorevival is possible then post singularity it will be trivial to implement" but that still doesn't give us any certainty that this will be so, for instance a post singularity paperclip maximizer would be capable of cryorevival but have no interest in it.

If that were true about the Singularity, then wouldn't it be correct to criticize the people who make predictions about it?

Depends on your objectives. If you believe the singularity is something that will happen regardless then it's harmless to spin scenarios. I gather that people like Elizier figure that the Singularity will happen unavoidably but that it can be steered towards optimum outcomes by setting down the initial parameters, in which case I suppose it's good to have an official line about "how things could be/how we want things to be"

There is no "point beyond which predictions cannot be made". That is a SF fantasy.

God forbid someone might mistake our hypothetical discussions about future smarter than human artificial intelligences for science fiction.

I've also encountered people who criticize the predictions surrounding the singularity, which misses the point that the singularity is the point beyond which predictions cannot be made.

I dispute that point.

More seriously, not only is the question the same, the answer is the same too: "Why yes, you can live forever! And it's easy! Just pay this reasonable fee to the Organization, and we will take care of it."

If religion teaches us anything, it is that people really don't want to die, and will happily be convinced by very poor arguments that they aren't going to.

Therefore, the fact that a given person is convinced that cryonics will work is much weaker evidence about whether cryonics will work or not than if that that person were convinced it will not, since it would require less high-quality evidence to convince him or her in the "yes" direction.

This argument holds even if the person is yourself -- we should be more doubtful about our convictions if they happen to be the kind of thing that we are inherently predisposed to believe.

Therefore, the fact that a given person is convinced that cryonics will work is much weaker evidence about whether cryonics will work or not than if that that person were convinced it will not, since it would require less high-quality evidence to convince him or her in the "yes" direction.

No it isn't. The similarity to religion means that people will be more easily convinced it will not work, unless it happens to be the mainstream belief.

Very true! So a clever man will know that the cryonist was convinced against the odds, and so the fact that the cryonist was convinced is strong evidence; clearly the clever man should believe also. But! this must have been how the cryonist reasoned, which explains why he was easily convinced with a minimum of evidence. That means that it is actually very easy to be convinced about effectiveness of cryonics, so other peoples' belief is weak evidence after all. So I can clearly not believe in cryonics!

A classic blunder!

Yes, getting hugely tangled up in meta-level arguments instead of looking at the actual arguments and evidence and object-level way-the-world-is would indeed be a classic blunder.

This is the best anti-cryonics argument I've heard so far. I largely agree with the replies about why it's wrong, but at least it's an argument rather than a gut "ewww..." or "blasphemy!" or "crazy talk!" reaction.


Your reply really is excellent!

Still - and I've been noting this a lot - not to do with technical feasibility. A word I have finally been learning to spell what with writing it so much.

It may seem weird to be so focussed on this one thing what with all the other ways that cryonics can fail, but feasibility is what creates the seriousness barrier. As soon as you think that it stands a really good chance of working, you're over the line with us wacky people, and you're arguing about economics or whether the future wants us or suchlike with real skin in the game.

I'm surprised. I'd have though the biggest barrier to it being taken seriously is the comfort of normality barrier. That is most people are comfortable with the narrative of birth-life-death and anything that takes them outside that makes them uncomfortable and is ignored.

Yes, that's what motivates people to come to a negative conclusion, but I think it's the plausibility issue that allows them not to worry about the conclusions. Not many people say "if my heart stops, don't resuscitate me".

I don't think it is the coming back from the dead that makes people uncomfortable so much the world and technology that is supposed in the future to enable it. The eternal life from that point on also drastically changes the narrative.

Whoops, I just sent off a "you should join LW" message to Earendil on the board without noting that Earendil was the one who posted the link here!

+1 rationality point for reading comments without checking the author. -1 social point for the faux pas.

I find this to be a silly argument, as it assumes that not much will change about the methods of teaching, or of rejuvenation by the time that these people (who have been frozen) are re-constituted in one manner or another.

True, we would be antiquated and ignorant by the standards of the day, but just going into the process of freezing gives us a mind-set that shows us that we must be ready to abandon just about everything we know when and if we wake again. The Man from 1400 discussed in the article did not have that mindset and it was discussed as if his freezing had been an accident rather than an act of intention.

Plus, there is another reason to thaw the people out who have been frozen: Rule of Law. These people have all signed contracts based upon their conception that when and if we develop the technology to reanimate them, that we will do so. I have not examined a contract from Alcor or another cryonics program, so this may be an implicit assumption of the process.

If that is the Best anti-cryonics argument heard so far, then it is a lousy argument.

Edit: Also, if, when revived, the person is going to have an indefinitely long life, then any re-training would be trivial in terms of cost.

The one in the link.

Basically, that the cost of reviving and taking care of large numbers of frozen people will exceed the value of those people to the future, so there won't be very many frozen people revived.

How do you work that out? We're talking about a future society that can revive a cryonics patient, how can you be so certain that cost would be an issue for them?

Interestingly (and somewhat to the author's surprise) there are no published technical articles on cryonics that claim it won't work.

Also interestingly, there appear to be no published technical articles that claim that it will.

Last week, I searched for articles on how mammalian cryopreservation is done. I found nothing. Not a single journal article on any of the techniques Alcor uses. There are many articles on cryopreserving sperm, and embryos; there are studies on attempting to preserve other types of tissue samples. But I could not find a single article on methods to attempt to cryopreserve adult mammals. Not even in the journal Cryobiology, which is entirely about cryopreservation.

Go to the current issue of Cryobiology and look at the article titles to see what actually is being done in the field. Also notice that the author names are almost all Asian and (non-English/French/German) European. Cryonics for humans is most popular in nations that don't publish on cryonics. (Don't know if it's popular in the Nordic countries.)

Not a single journal article on any of the techniques Alcor uses.

That's forbidden by the Society for Cryobiology by-laws.

Aha. I hadn't been aware of that conflict between cryonics and cryobiologist. I plan to go and read the Alcor page in full, then the letter in full, but right now one thing comes to mind: whatever document justifies the cryobiologists' decision to outright ban cryonics should lay out the most credible extant arguments against cryonics. They wouldn't take such a serious decision on a whim.

[EDIT: the below is wrong.]

As far as I can tell, there is no such document. This I consider very striking evidence on the credibility of anticryonics.

Of course the by-law is 28 years old, so even if there were such a document it would need updating.

Very interesting. I like to synthesize and summarize, so this is my synopsis.

I read that they have one mild moral objection, that they were willing to stand behind over several drafts, and one scientific objection, that they were not willing to reiterate.

1st objection: you shouldn't sell a technological service that hasn't been scientifically demonstrated (presumably, even if the buyer is aware that they're only buying a potential technology)

It is interesting that they would like to call this fraud even though they can't quite:

"the implication of ultimate reanimation borders more on fraud than either faith or science."

(This reminds me of the argument I lost as to whether people would be justified in thinking that cryonics was a scam for some weak interpretation of 'scam' .)

2nd objection: that however people are cryo-preserved now, it is unlikely to be un-doable

in light of current scientific understanding of freezing injury in cells and tissues, even in the presence of cryo-preservatives, it is the Board’s scientific judgment that the prospects for re-animation of a frozen human, particularly a legally dead human, are infinitesimally low.

I don't agree with the first objection: if informed people want to pay for the chance of reanimation, I think that's their decision.

The second objection would be strong, if it were true that cryo-preservation causes irreversible damage (information loss), but that appears currently undecided.

The second objection would be strong, if it were true that cryo-preservation causes irreversible damage (information loss), but that appears currently undecided.

All the arguments I've found so far that are in favour of that position are either very vague on details, or fatally flawed on details. Most cryonics critics don't appear to understand the issue of information theoretic death clearly enough to articulate a position on it.

Thanks. The revision history is particularly interesting.

That's one of the most depressing things I've read in a while >.<

Pretty much agree.

The only thing that gives much comfort is that was written in 1991 so there's theoretically enough time for some of the obstructionist cohort to have retired or run out of steam on the subject. Perhaps the upside of a pessimistic view on scientific progress could be kicking in by now?

I tried to verify the actual current state of the Society for Cryobiology's bylaws to see if they even contain the provisions banning cryonicists or their research any longer. With 20 years for them to have realized that such censorship is at the very least in poor taste, maybe things have settled down? When I tried looking for an online version of the document with the it didn't appear to be something they have on display.

Does anyone else have stronger google-fu than I? It would be neat to track down the document so we could see for ourselves :-)

Wow, I'm actually having a very hard time finding any information on relations between the two more current than the '91 article

Nice link - I added Alcor's side of the story to the question "Is cryonics worthwhile?":


Thanks to everyone's suggestions, there's now 5 sub-debates for cryonics:

  • Is information-theoretic death the most real interpretation of death?
  • Is cryonic restoration technically feasible in the future?
  • Is living forever or having a greatly extended lifespan desirable?
  • Is there life after death?
  • Does cryonic preservation with today's best technology cause information-theoretic death?

Wow, that really stirs up the rebel in me.

I'm curious now to look more into the state of the art in cryopreservation. How close are we to successfully cryopreserving an organ?

I think most cryobiologists are going about it the wrong way, trying to get incrementally better at cryopreserving tissue. The work I'm aware of that seems most promising (I say, having almost no familiarity with the field) is Ken Storey's work with wood frogs. They can freeze and thaw naturally.

I looked into it because I hoped I might be able to move some genes from a wood frog into a mouse, freeze it, thaw it later, and win the Methuselah Mouse prize. But it turns out that the frog has an anti-dessicant response to protect tissue from lack of water, an anti-ischemia response to protect tissue from lack of oxygen, a glucose response to produce glucose as a cryoprotectant, an anti-glucose response to protect cells from the huge amounts of glucose, and a bunch of other mysterious responses. It involves hundreds of genes. It's going to take a large program to import entire gene pathways from one organism to another.