An open letter to scientific critics of cryonics
The focus of this article is the technical plausibility of cryonics; though there are many non-technical objections, I’d like to treat the technical issue in depth before moving on to the non-technical.
Though many experts in cryogenics and other relevant fields are quoted in the media as condemning cryonics practice, none have written at greater length to explain their reasons. The closest thing to such a reason I can find is Michael Shermer’s article “Nano Nonsense and Cryonics”, but the reason he gave was one that he knew at the time of writing was contrary to scientific reality, and in response to my email asking where I could learn more he recommended three authors all of whom consider cryonics technically plausible. The only other anti-cryonics expert to respond to my email asking for more detail was John Bischof, but his replies didn’t carry the detail I was hoping for. (See my earlier blog posts A survey of anti-cryonics writing and More on anti-cryonics writing for details). Strikingly, even when the Society for Cryobiology passed their 1982 by-law barring cryonicists from membership, they produced no detail to back up their claim that “it is the Board’s scientific judgement that the prospects for re-animation of a frozen human, particularly a legally dead human, are infinitesimally low.” (see Society for Cryobiology statements on cryonics).
If cryonics really is nonsense dressed as science, this lack of detail is surprising, and in sharp contrast to pseudosciences such as homeopathy, on which volumes have been written pointing out its dodgy provenance, scientific implausibility and evidential defeat. It’s also very frustrating: I’m left trying to make a judgement call on a debate that only one side is participating in.
So this is my plea to the scientific critics of cryonics:
Please criticise cryonics.
If you thought that someone else had done it, if you thought that the article you’d want a cryonics hopeful to read had already been written, I hope that the surveys above show you that it really hasn’t. If it has, and I either haven’t found it or haven’t treated it fairly, I welcome your comments.
I’ve been trying to think about the reasons why someone like David Pegg would feel strongly enough about cryonics to take part in drafting that 1982 by-law using such strong language in his draft statements and his statements to the media on the subject, yet have nothing to say in reply to an email asking what he would recommend I read to see the other side of the argument. The only hint I currently have from critics is this remark in personal email from John Bischof:
I think the distinction is between a tissue being dead vs. alive at the time of freezing. I don’t believe there is anything I can possibly write that would further clarify that distinction.But thinking about that remark, and other suggestions that friends have made on why they don’t see the need for such an article, I’ve thought of ten reasons an expert might give for its absence, and tried to answer them.
- It’s perfectly obvious.
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You are experts in your fields; what is obvious to you is not necessarily obvious to everybody. In particular, a lot of us are thinking of the brain as something a bit like a computer, and so it seems perfectly reasonable to imagine that if old bits can sometimes be read from hard drives despite being overwritten, and if Ed Felten can freeze computer RAM chips, take them out, and read the data on them, then maybe someday someone will be able to read out the state of frozen brains with future technology. Part of what is being a good teacher is understanding how others fail to grasp what is obvious to you and being able to make it obvious to them too.
- If you’re crazy enough to need persuading on this score, you’re already beyond the reach of reason.
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Have you ever argued with someone who, when you finally persuaded them that everything is not fine, turned around and argued that everything was hopeless? In these instances, it’s striking that they go straight from the region where things are so good that no action is required to the region where things are so bad that no action is worthwhile, without it seems passing through the band where action is a good and worthwhile response.
In this instance, there must surely be people inbetween, who have so far only heard from one side of the argument and perhaps could be won around if they heard from you. You may be convinced despite my protestations that I’m lost to reason, but even in that case, what about the people I’m going to speak to next? I’m going to be using your relative silence on this issue to help persuade them. Please, write for those people.
- You’re asking for a scientific response to an unscientific claim
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If so, that’s hardly unusual. Scientists respond to all sorts of unscientific claims; consider the response massed against creationism/”intelligent design”, or against homeopathy or vaccine scares.
Cryonics isn’t hiding in some separate magisteria; it makes claims that science is clearly best placed to evaluate. And cryonics advocates make lots of scientific claims about all sorts of things, like the extent of ischemic or freezing damage, the toxicity of their vitritification solutions, or the likely anatomical basis of memory or personality, all of which are ripe for scientific challenge.
- But the assertion that we will “someday” have the technology to reanimate is completely unfalsifiable
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Falsifiability is Karl Popper’s effort to set out what distinguishes a theory that science can examine from one such as the dragon in Carl Sagan’s garage, and the linked Wikipedia article sets out some of the problems with applying this criterion. In practice, future discoveries could certainly put an end to cryonics. If, for example, we came to better understand the mechanism of memory and it were shown that freezing inevitably causes what cryonicists call information theoretic death, that would destroy the practice of cryonics at a stroke.
- It’s like trying to argue with a marshmallow
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I know the feeling, and I sympathise. Sometimes for example large parts of an argument can be taken up simply with trying to pin down your counterpart to a claim that can sensibly be debated. As an atheist and skeptic, this is often how it feels arguing with religious people and other supernatural believers. I think of Sam Harris’s memorable line in his online debate with Andrew Sullivan:
I now feel like a tennis player, in mid-serve, who notices that his opponent is no longer holding a racket.
From this, though, we see that people do often have some success in arguing with the marshmallow. Harris’s response is exactly one such, and it doesn’t stop there but continues for nearly a further 2000 words; and that’s just one return in a longer discussion. If cryonicists are using the tactics of marshmallow debate, you could do the world a service by calling them on it.In addition, cryonics advocates make lots of very specific claims. Best’s “Scientific Justification of Cryonics Practice” is full of them, for example. You don’t have to write the Final Great Refutation of Cryonics; refuting any claim made by cryonics firms would be a big step forward.
- Surely the burden of proof is on cryonicists to show that it can be done?
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Again, this is true of a great many things that scientists in practice put great energy into arguing against.
The burden of proof is on those who argue for the theory of heliocentrism, but in that instance the burden is not only met but overmet to a truly supendous degree, and now anyone who wants to argue against it has a tremendous burden to meet. Cryonics is of course vastly short of that standard, but you can hardly argue that cryonicists have made no effort to serve this particular ball — there are absolutely reams and reams of material arguing in favour of cryonics. If you don’t feel that it goes any way towards meeting their burden of proof, it seems like it should be possible to say a few words about why.
- Extraordinary claims require extraordinary evidence
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Cryonics claims are certainly emotionally extraordinary. The idea that it might be possible to take people who are legally dead today and transport them into a second life in the unforeseeable future certainly knocks most people’s socks off. However, to require extraordinary evidence a claim has to be scientifically extraordinary — it has to be such that were it true, many settled scientific facts would need to be re-examined. If there’s any settled science that cryonics goes against, I’m not aware of it, and would very much appreciate knowing about it.
- How do you criticise “Then a miracle occurs”?
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If cryonics really is like the famous “then a miracle occurs” mathematical proof, surely an expert could tell us more about which difficult but reasonable-seeming steps in cryonicists descriptions of possible future means of reanimation hides what is actually a huge chasm of difficulty that it is fantasy to posit we might one day bridge.
The ideal article I’d hope to find on the subject would:
- Explicitly address the best literature of cryonics providers
- Use probabilistic reasoning
- Discuss the question of information-theoretic death
- Discuss both bodily reanimation and scanning/WBE approaches to reanimation
But you don’t have to meet that bar to advance the debate — practically any expert writing on the subject would vastly increase the quality of the pool of anti-cryonics writing out there. If you’ve written for example blog comments that criticise technical feasibility, please turn them into articles that are designed to stand alone; if you’ve nowhere to host them I’m happy to host sufficiently good articles here. The best article I’m currently aware of is that by Chris Patil, for more on which see this discussion; I’m hoping also to get an article out of criticisms my friends have made of the Brain Emulation Roadmap.
It is incredible to me that I can beg cryonics critics for reading material in email and receive so little back. If what you say is true, then thousands of people are spending tens of millions of dollars pursuing a ridiculous dream, and new people are signing up all the time. You could save some of those people from wasting their money and their hope; though you might not believe it, you could even save me. Please, I beg you on bended knee, please actually criticise cryonics.
COMMENT POLICY As before, comments should directly address the subject of this post. If you have a comment to make about cryonics that isn’t specifically to do with what I address here, please sit on it for now; hopefully a future post will be more on topic for those thoughts.
Comments
FWIW, the RationalWiki article is nice: http://rationalwiki.com/wiki/Cryonics
Conceptually, it’s possible that they’ve started with the equivalent of stating that their goal is science-fiction level strong AI and they just need to, ahh, do the century of hot and fast-moving innovation to get anywhere near that.
Alternately, that there’s a faster-than-light step in there they haven’t accounted for, i.e. actually impossible.
Not that I actually know anything about it or anything.
In the best case, it seems that by getting reanimated you’d be an only slightly brain-addled version of your old self emulated in a computer with a virtual body, serving as a pet to super-advanced beings who found your cognitive skills utterly pathetic and unhelpful, long after everybody you knew was long since dead.
Gee, that doesn’t sound so appealing.
It would be very interesting to hear some serious commentary on information theoretic death. In particular I wonder if there’s any strong reason to think that all that fancy antifreeze in the bloodstream stuff is particularly helpful. The strongest case against information theoretic preservation I’ve seen is all that cracking which happens during the freezing process, which is undoubtedly destroying tons of information, in particular severing a lot of dendrites, and the question is really whether there are a small enough amount of such cracks that it would be reasonable to figure out what dendrites led where before the cracking, or there’s so much of it both on a micro and macro scale that such tricks look hopeless.
@Bram — indeed. There’s a whole pile of problems like that that would all need to be solved for it to work. “I suppose it’s not impossible, now go away and solve all these obvious problems before you expect me to spend one second of my life thinking about it” is an entirely reasonable response.
OTOH, freezing your head is pretty much a desperation move anyway.
Not all the problems stack in the way you are imagining. In fact, they all boil down to one thing: we cannot yet repair things on a nanoscopic scale.
If we could do so already, cryonics would be unnecessary.
I’m also adding problems as a list to the RationalWiki article.
Is Homeopathy really a good analogy?
They can write detailed criticisms of Homeopathy because they can see, feel, touch, and test it and all of its facets, and come to a conclusion.
You can’t write a detailed criticism on something that centers around currently nonexistent technology, with no process in place, an only an inkling of “what might be”. With such a lack of material, the most one could do is vaguely disagree with its potential.
So Im not sure that Homeopathy Criticism Documents are a good comparison. There really is no detail for them to delve into and criticize right now. At the very most, the best they could do is criticize the theory and the “10,000 foot view” overall concept. And that’s pretty much what they do.
What do you have in mind when you say this? As far as I have been able to tell, what they do is restrict themselves to bald statements that it is fantasy; if they’ve said more I’ve been unable to find it. Part of the point of this article is that even from 10,000 feet, it should be possible to say a little more than that.
Responding to Bram’s comment — i love that there are still people who aren’t famliar with vitrification …. and that people still comment on Cryonics as if its an ice crystalization cracking destructive cooling process. Lets get past 1985 in our education of cryonics before we speak, folks! The cracks you speak of due to “freezing” are not a factor anymore.
@CryoBurger: The skeptics have claimed that the position is so implausible as to border on fraudulence. Have they really supported that assertion? Indeed, can such an assertion be supported to the same degree that it can with homeopathy?
There is unfortunately still quite a bit of real freezing in sub-ideal cryonics cases (meaning most of them) and vitrification does cause cracking when you go below -136C. But this is an argument for investing in better cryonics infrastructure (so that we aren’t reliant on the boiling temperature of LN2 which is -196C), not an argument against cryonics.
@David: Strong AI is not ruled out by the fundamental geometry of spacetime, so it is not impossible in the same way that (we assume) FTL is. But it is also a tad irrelevant since fully automated non-conscious drexlerian nanobots can concievably do the job of cellular repair. And further, direct cellular repair may not even be necessary when neurovitrification is accomplished under ideal conditions — just regrowth and reintegration of the surrounding body parts. That could be quite a bit nearer term, judging by advances in stem cell tech.
@Bram: Regrowing damaged brain tissue is a near-future possibility (thanks to stem cells), so being stuck brain-addled isn’t that likely. A more likely issue is that you would lose memories and acquired personality traits due to a failure to recover some fraction of the essential information. It is hard to say how much you are likely to lose, but even losing 90% of your brain’s information might not be enough to kill your sense of self-continuity.
As to lacking marketable skills for the new civilization full of superior beings, it seems to me that unless they unfairly prohibited the practice you would be free to upgrade your own mental capacities. Immigrants from less developed to more developed societies may not be as well off as those born there, but would not be better off dead, generally speaking. (Anyway, that is not relevant to the main topic of feasibility.)
I would like to hear more from experts on fracturing. But I don’t see how fracturing of a solid object would cause much actual information loss.
You could make a new version of me with a ‘sense of self-continuity’ using 0% of my existing brain matter. The fact that such a sense would be a delusion wouldn’t change the subjective impression of the entity which had it.
Having one’s brain be made superintelligent as a way of overcoming the whole brain damage thing is a nice fantasy, but we don’t run Commodore 64 OS on any modern hardware, even though I’m sure that old OS would appreciate it. There’s no ethical or legal requirement that the remnants of a corpse be treated with any particular respect, and it’s far more plausible that one’s addled brain would be used as is as AI for some cannon fodder in a super-advanced version of Quake as that the future will want you to live out some heavenly fantasy.
Please can we keep the focus on technical feasibility for now. I want to thrash out this point more before moving on to other objections to cryonics.
We could easily get into a general discussion of the merits or otherwise of cryonics here. If possible, I’d like to stay focussed on the specifics of what the article sets out — why the relative absence of papers, articles etc that make a detailed case against cryonics?
Dunno about papers, but here’s Penn and Teller calling cryonics a scam and saying why they think so:
http://www.youtube.com/watch?v=bVPCGMYmQjw
Is that useful?
Video requires quite an investment of time for me to watch — could you say a little about what it argues so I know whether to spend time on it?
I have watched it (cos I’m at work and I like listening to Penn and Teller snark). It doesn’t say much that’s substansive. The only actual arguments are: “they’re banking on someone in the future solving thawing”, and “it costs a lot of money”.
Thought it might be that sort of thing. Many thanks for checking and commenting!
Sorry if I got off topic.
I think you raise an important point that the obvious fact that cryonics is an emotionally extraordinary claim does not automatically and obviously make it a scientifically extraordinary claim.
I suspect the reason that there are so many scientific critiques of homeopathy vs. cryonics is that homeopathy is used on people who are currently alive, and not beyond the help of ‘proper medicine’ whereas cryonics entirely revolves around people who are, at least in the current state of medical technology, already beyond help.
Where it’s easy to see some value in preventing deaths or further illness in people relying on the placebo effect alone to eg. cure cancer, the value of preventing cryonics lies solely in saving a few bereaved people some money, and (arguably) forcing a few poor dupes blinking out into the light of day.
So the cost/benefit ratio is hugely different. Opponents of homeopathy see themselves as saving lives. Opponents of cryonics, I suspect, just see themselves as saving people money and false hope. Which is far less of an incentive to go to war. Especially when your daily work involves other things that do save lives.
Me, I’m not going to say it’s not possible. Just as it’s not impossible that the egyptians who got themselves mummified, internal organs removed, and so on may also some day be reanimated by some not yet imagined future process (okay, maybe this is less likely still, but possibly more interesting). I’m probably not going to invest in it either.
@Maxine — the trouble in the pharaohs’ case is that putting a brain in a jar for six thousand years is not very information-preserving. Livers just aren’t that important to personhood, it turns out.
The Ben Best paper (where he grossly distorts the claims of two out of two of the referenced papers I’ve look up so far) appears to be the current cryonics industry’s best shot at claiming a scientific rationale for the current cryonics industry’s activities. I’ve asked the RationalWiki crowd to research the papers in question and compare what they actually say to the claims in Best’s paper.
(The one where Best claims a rat hippocampus was frozen and put back into place in working order is a complete lie, for example, which doesn’t augur well for the rest. The rabbit’s kidney claim is grossly exaggerated by best. Etc.)
Note that David no longer considers the paper to be lying about the rat hippocampus thing.
No indeed — on rereading, I think Best has misrepresented the paper saying “well, the cells don’t look trashed in their frozen state” as it saying “woohoo, the cells are viable!”
I think you are suffering from a failure of relinquishment here, “learning as little as possible from each error”. However, if you really think there’s substance to this, don’t just stick it into the RationalWiki article next to all the dross in there — write a proper article-length exposition on the problem and post it as a blog post. If you don’t feel it’s appropriate for any of your blogs I could post it here.
Going through each of Best’s references and comparing them to the original paper is on the to-do list.
Man, this scepticism stuff, it’s work …
That sounds like useful work, but what I’m suggesting is that you narrow your focus even further, to just this one discrepancy you perceive, and write that up. As far as I can tell, no critic of cryonics has ever tried to actually respond to the actual words of a cryonics advocate before, except in the form of blog comments. So just this one article on this one paragraph on this one reference would represent a huge step forward.
Bringing egyptian mummies back is extraordinary by existing scientific standards. If you were to claim that enough information is present in the hollowed-out skull of a mummy to bring back the personality of the individual, it would be very surprising in terms of today’s science. Can the same really be said of cryonics?
@Luke — what I’m noting is that, for information preservation, the Egyptians pretty clearly screwed the pooch. Because the science behind their preservation technology wasn’t actually good science.
So too, the cryonics industry has shown no evidence that what they do to frozen heads does not similarly screw the pooch. Are the dendrites preserved in a state where their strengths can be measured? How many of them are? For a computer science question: what proportion of interconnects can you randomly trash in a neural net and have it still work usefully?
Or is it like running a CD through a grinder, then asserting that nanobots will some day exist that can read the pits and reassemble the music, and expecting people to pay you to run CDs through a grinder and save the pieces?
The comparison to egyptian mummification is a clear case of dramatization. Anyone with the hindsight of today’s science can plainly see that there is no comparison, as mummification does not even keep the brain around.
The science of cryonics may or may not be “sufficiently good” but the case for it not being sufficiently good is not anywhere near as strong as the case against egyptian methods of preservation.
Putting a CD through a grinder would separate and mix the pieces quite a bit. If they were intact, and sufficient context remained to put them back together like a puzzle (in other words, the CD contained predictable data, or the shapes of the plastic fragments were well preserved) it might be possible to reconstruct it even so. With cryonics we have an additional advantage, in that the pieces are still in more or less the same place they originally were.
If you take out the assumption of eventual nanotech capable of repairing dendrites and such, cryonics (i.e. present-day attempts) does look like a scam. But advocates do not see it as particularly reasonable to assume the converse, given the fact that cryonics opens the door to thousands of years of technological advancement as a possible resolution.
They’ve already acknowledged that they probably screwed the pooch on the earliest frozen heads, which are likely crystal-broken mush now. Where is the evidence that what they’re actually doing now is any better?
Calling it a “scam” is a tricky one — the cryonics industry is, generally speaking, not actually engaged in knowing, deliberate fraud. But there’s no evidence it’s not presently profound foolishness to bother spending a large sum of money on.
Could you provide a reference for that please?
Look up James Bedford, the first man frozen. They didn’t use any cryoprotectants. Pretty much all cells will be ice crystal mush, let alone the dendrites. They acknowledge this one as “very tricky”. No shit.
OK, so they haven’t actually come close to saying that they “screwed the pooch”. The closest they’ve actually come to saying it is that they think that he might be the last to be reanimated. Please stop misrepresenting what they say.
Not that it matters directly to cryonics, but a CD put through a meat grinder is information theoretically speaking most likely completely intact. CDs by design use error correcting codes for handling scratches, and the coding itself is so far overkill that usually when a CD skips it’s because it lost tracking not because the error correction failed, and tracking is a physical reading device problem rather than an information theoretic problem. The arc of the tracks and the shape of the pieces should make it easy to narrow down the number of possibilities of how the pieces go together to a reasonable amount, and then the data is recoverable.
Granted, CDs are explicitly designed to handle scratches, while the human brain isn’t designed to handle incisions, and the size of structures in CDs is vastly larger than dendrites, but the CD in a meat grinder example is a better argument in favor of information theoretic preservation than against it.
The ‘what it’s designed for’ criterion is quite substantive. I’m pretty sure one could breed creatures which could survive freezing after a few million generations, but we humans weren’t bred that way, so we can’t.
e.g. some frogs, which have already evolved to survive partial freezing! http://www.pbs.org/wgbh/nova/sciencenow/3209/05-ask.html
What if we had a less scratch-resistant sort of CD and froze it at LN2 temperatures, then shattered it? Would most of the information be recoverable in theory? My thought is that it would be, since the plastic pieces would take unique enough shapes (undistorted thanks to the cold temperature) that they could be pieced back together like a puzzle.
Brains seem to be redundant in nature. When you think about it, they have to store the same information in multiple places to be able to communicate between the various parts effectively. Some stroke victims have lost an entire hemisphere, iirc. Their remaining hemisphere took over, relearned what they needed to know. How much better would it be if you could simply regrow the lost parts?
I think if you lose 50% of your data you are probably the same person by a reasonable estimation. The less data is preserved the more likely we would be to think of you as a clone/progeny rather than the same person. But even that is worth something I would think.
Even with perfect jigsaw powers, some sections of the original CD really will be pulverized, and have to be recovered using error correction. Human brains appear to have a lot of redundancy, but no error correcting codes in the sense that CDs have them, so all damage to a human brain causes some information loss.
Yes, it seems certain that there will be some information loss; the question is how this compares to the observed natural processes that cause information loss in living people.
“Scientific critics of cryonics” I briefly read through this thread after stumbling upon this looking for something totally different. I found it interesting because it doesn’t seem, to me, that anyone responding to this is actually an expert in anything related to what Paul was asking. I thought he was asking for expert opinions on why cryogenics is not plausible. I am an expert in an affiliated area and have worked with cryogenics just to perform my work. @ Paul, this is in no way to sound harsh or condescending, but it is implausible and the way to find these studies is to actually be an expert and have access to places such as medline instead of wikipedia. I can’t even begin to go into why cryogenics (in the magnitude you are describing) won’t work because it would be out of your realm of knowledge from what I read that you posted. That said, I could be wrong because I don’t know you. I understand your frustration on wanting to know why, but it is so completely complicated and with not having the appropriate background, I myself can’t even begin to explain to you why. That is not to belittle you in any way as I am sure you are an expert in an area I am not. The take away point is that there is a TON of evidence/studies on the subject matter, but it’s just not readily available for the lay person that doesn’t study it. Some believe it shouldn’t be available for that very reason. Point in case: @ Luke- do you really know what a stem cell is? I honestly cringe when the topic comes up in mainstream society because it’s pretty much like cancer. I didn’t understand what cancer REALLY was until after med school and then training beyond that specifically dealt with cancer. That’s how complicated it is. As far as stem cell research goes, WE HAVE ACCESS TO STEM CELLS WITHOUT USING EMBRYOS- THEY DO EXIST AND SOME OUTSTANDING RESEARCH HAS BEEN PERFORMED USING THEM!!! Case in point here is Dolly the sheep. She was cloned. What alot of people don’t know is there are several forms of clones. She was the first of a certain type and was begat from her own somatic cell mammary tissue- not an embryo. The whole thing was a fluke bc they forgot to feed the cells and the result was they went into another stage of replication (dormant) that NO ONE was looking at as an alternative for cloning. Stem cells are not the end all for everything. Their use for diseases and the such is understandable. When you get into cloning people and preserving your body to be revived later, that’s just plain narcissism and quite frankly against nature itself. If everyone lived forever, they’d die of cancer. It’s how the body works. There is a certain error in cell replication and you can’t change that. This has nothing to do with nano repair and fracturing from freezing. Your body can only take so much and you die for a reason. So basically, in a nutshell, get access to medline or some authentic peer reviewed medical/research journals and you will find your answers, but good luck understanding it. It takes years of training and TONS of experience to do what these guys do in their work. For anyone that wants to pop off about this answer, examine yourself before you do so because it would be out of sheer insecurity if done.
Don’t worry — my field is crypto and I know what you mean, I don’t think this is patronising.
Could you write an article that explains the problem in your own language? I might not be able to understand it, but I can look for someone who can.
Thanks!
The “lucid dream” option in Vanilla Sky is completely fictional. Real cryonics companies do not make big promises like in Vanilla Sky, and there is not yet any technology to reverse cryogenic damage or to influence dreams.
I can’t figure out if this comment is spam or real! On the one hand, it’s relevant to cryonics, but on the other hand, it doesn’t have anything to do with the content of this article, and the name and link are incredibly spammy. I’ve taken a middle route of leaving it up but removing the link to the website, so that if it is spam the spammer doesn’t benefit.
It looks familiar to me. I think it is something I wrote in reply to a question on Yahoo Answers. Someone must be copying stuff based on keywords.
You’re right, I should have Googled it. Here it is. Thanks! Will leave it up so this discussion makes sense, but be ruthless in future.