Cryonics

Promotional photo of Alcor technicians playing with dead bodies. Here lies Maximum Transhuman - not dead, only a broken braincell mush with billions of dendrites shattered by freezing.

Cryonics is the industry of freezing dead bodies in liquid nitrogen in hopes of a future resurrection at the hands of advanced medical technology. The essential idea is to quick-freeze the body (or, for less money, the head alone) and preserve it for as long as possible (possibly centuries), with the goal of bringing the subject back to life with as-yet-unknown medical technology. Sufficiently advanced nanotechnology is the current favoured prospect for implementing "and then a miracle occurs," which is all steps past the initial freezing.

Scientists will admit that some sort of cryonic preservation and revival is not considered provably impossible. But they stress that, in practical terms, freezing and reviving dead humans is so far off as to hardly be worth taking seriously and the present cryonics industry is based on speculation at best and pseudoscience at worst. However, cryonicists will accept considerable amounts of your money right now for a business based only on vague science-fiction-level speculations, with no scientific evidence whatsoever that any of their present actions will help achieve their declared aims.

Legally, cryonics is largely considered an extremely elaborate form of burial, and cannot be legally performed on someone who has not been declared medically dead.

Cryonics should not be confused with cryobiology (the study of living things and tissues thereof at low temperatures) or cryogenics (subjecting things to cold temperatures in general).

History

Robert Ettinger, a physics and maths teacher, published The Prospect of Immortality in 1964. He then founded the Cryonics Institute and the related Immortalist Society. Ettinger was inspired by "The Jameson Satellite" by Neil R. Jones (Amazing Stories, July 1931). Lots of science fiction fans and early transhumanists then seized upon the notion with tremendous enthusiasm.

The current state of cryonics

Cryonics for dead humans is still a process of freeze and hope for a miracle to be developed. As the Society for Cryobiology put it :

The Society does, however, take the position that cadaver freezing is not science. The knowledge necessary for the revival of whole mammals following freezing and for bringing the dead to life does not currently exist and can come only from conscientious and patient research in cryobiology, biology, chemistry, and medicine.

(Note that Smith et al 1957 did manage to drop mice into LN2 and revive them.)

As normal freezing damages cells with expanding ice crystals, the body is frozen rapidly in a bath of liquid nitrogen, which is around -196°C. The body is also given large doses of anti-clotting drugs, as well as being infused with cryoprotectant chemicals that cause the water within the body to freeze in a glassy form (vitrification), so as to avoid it crystallizing and puncturing cells. Note that the cryopreservatives are themselves toxic.

Cryonics enthusiasts will allow that you're 100% dead dead when you reach "information-theoretic death," where the information in your mind is beyond recovery. Neural net information (your mind) appears to be preserved in strengths of neuron connections in dendrites. (Rather than electrical activity - coma patients and sufferers of severe hypothermia frequently come back from near-zero brain activity with memory, intelligence and personality intact.) So they work hard to preserve that at the least.

Cryonicists have not scientifically shown that any of what they do will in fact make revival any easier or even that it does preserve the neural information — they just think it sounds like a plausible hypothesis that it will. There is no evidence whatsoever that anything that cryonicists do will be any better at allowing a future resurrection of the long dead than the preservation technology the ancient Egyptians used on their pharaohs.

Ben Best, CEO of the Cryonics Institute, supplies in Scientific Justification of Cryonics Practice a list of cryobiology findings that suggest that cryonicists might not be completely wrong, with considerable "then a miracle occurs" mixed in, which is not quite what the title promises. His assertions as to what cited papers say also vary considerably from what the cited papers' abstracts assert.^{[citation needed]}

Alcor Corporation calls cryonics "a scientific approach to extending human life" and compares it to heart surgery. This is a gross overstatement of the state of both the science and technology and verges on both pseudoscience and quackery.

Technical problems

These would all need to be solved to bring a frozen head back to life. Cryonicists do acknowledge many of these problems.

• Freezing frozen organs recoverably. (We can actually do this with rabbit kidneys and embryos.)
• Cloning most of a body from recoverable DNA. (We're closer to this one than any of the others below.)
  • In most cases this removes the need to cure what killed you -- bad heart? Just clone a new one.
  • Prosthetic organs are a hypothetical option, but cloning is probably technically easier.
• Nanobots. Present nanotechnology has no idea how to get there from here. Computer-controlled nanoscopic miracle workers are still pure speculation.
  • And they won't resemble the popular image of macroscopic industrial robots a millionth of the size with their own built-in supercomputers. They'll be much more like cells or enzymes - carefully designed chemicals. Things are different at nanoscale.
  • "Nanobots!" is not the magic answer to everything. Humans would still need to know how to actually fix whatever it was to program the nanobots.
• Fixing the freezing damage to the original frozen brain.
  • The dendrites (10,000 connections for each of the 100 billion neurons) are cracked badly by the freezing process - "acoustic fracturing events," like when you drop an ice cube into a drink. How do you fix a frozen brain that's cracked into several, or hundreds of, pieces, with dendrites shattered at a microscopic level? (Usual answer: handwavium nanobots.) This is a problem even with vitrification.
  • The damage may not be mappable, let alone repairable. Saying "nanobots" won't change the energies required to scan at 5nm resolutions, where things start going quantum.
  • Cryonics companies presently cool to and store at LN2 phase change temperature, -196°C, for easy maintenance of thermal stability, whereas vitrification only requires -135°C.
• Reattaching a severed head or transplanting the brain.
  • Alternately: reading the patterns from the original brain and writing those to the cloned brain (uploading and downloading minds). Cryonicists speak of mind-uploading as if it's a mere technical detail that's just around the corner.
  • This is part of the "clone the rest of the organs" problem.
• The cryopreservatives, that prevent ice crystal damage, are themselves toxic and would need to be removed from the cells.
• Preserve cells at ~100% viability. "~99% ain't gonna cut it. We're barely there even in ideal situations like loose cells in rich media loaded with antifreeze compounds."
  • As those who work with stroke victims know, large chunks of personality and memory can go out the window. They are generally considered to be the same person afterward (occupying the same body and all that), but cryonics needs to preserve the entire person if it is to live up to its promise.
• Cure the disease or other condition that originally killed the subject.
  • If this was located below the neck, it's already done at this point. If you died of a stroke or gunshot to the head, it is going to be a bit... messier. Kind of like the whole cracking problem previously mentioned.
• Once you've fixed the body cells and the brain paths, you have a recovered corpse. Your next task is to resurrect the dead.
  • Perhaps a defibrillator or artificial stimulation/support will get the heart pumping. A respirator will move oxygen into the lungs. Will the presence of oxygen bearing blood "cause" the liver to start doing its thing again, and so on for other organs? We need to get all (or enough of) the parts working again.

Specific scenarios that would keep today's cryonics from working

• Nanobots, uploading, or other "reanimation" tech never being invented.
  • This includes if they are impossible due to some physical law, as well as if we simply never get around to it.
• Insufficient information being preserved by today's cryonics for such tech to be useful to current patients.
  • In other words, maybe someday cryonics will work but it doesn't today.
• Reanimation tech taking so long to develop that other unpredictable factors (social upheaval, global warming, etc.) prevent it from being carried out.
  • We might already be preserving people well enough, and the technology might get developed eventually, such that it would have worked, but unfortunately someone has pulled the plug early or crashed a plane into the cryonics facility first.

Organisational problems

The existing two cryonics facilities are small and financially shaky. The Chatsworth facility ran out of money and the frozen bodies thawed.

In popular culture

Cryonics in various forms has become something of a fictional trope, either as a serious plot device (the Alien tetralogy), a source of humor (Futurama, Sleeper), or sheer boneheaded incomprehensibility (Vanilla Sky). Its usual job is one-way time travel, the cryonics itself being handwaved (as you are allowed to do in science fiction, though not in reality) as a pretext for one of various Rip Van Winkle scenarios.

As a speculative concept, cryonics is distinct from the science-fictional concept of suspended animation, despite cryonicists' frequent use of the term "suspension" to describe being frozen. In fiction, "cryogenics" generally refers to a not-yet-invented form of suspended animation rather than cryonics, in that the worst technical issue to be resolved (if at all) in the far future is portrayed as aging, or whatever killed you.

Timothy Leary was famously interested in the "one in a thousand" chance of revival and signed up with Alcor soon after it opened. Eventually, though, the cryonicists themselves creeped him out so much he opted for cremation.

Walt Disney, who is often thought to have had his head or body frozen, died in December 1966, a few weeks before the first cryonicist freezing in early 1967. He also failed to get the Supreme Court to extend his life so that his copyrights would never, ever run out.

Mainstream scientific opinion of cryonics

Cryonics is not considered a part of cryobiology, and cryobiologists consider cryonicists nuisances. The Society for Cryobiology banned cryonicists from membership in 1982, specifically those "misrepresenting the science of cryobiology, including any practice or application of freezing deceased persons in anticipation of their reanimation." As they put it in an official statement:

"The act of freezing a dead body and storing it indefinitely on the chance that some future generation may restore it to life is an act of faith, not science."

The Society's planned statement was actually considerably toned down (it originally called cryonics a "fraud") after threats of litigation from Mike Darwin of Alcor.

It can be difficult to find scientific critics willing to bother detailing why they think what the cryonics industry does is silly. Mostly they consider that cryonicists are failing to acknowledge the hard, grinding work to advance the several sciences and technologies that are prerequisites for their goals. Castles in the air are a completely acceptable, indeed standard, part of turning science fiction into practical technology, but you do have to go through the brick-by-brick slog of building the foundations underneath. Or, indeed, inventing the bricks.

Mainstream medical opinion of cryonics

National Council Against Health Fraud president William T. Jarvis said: "Cryonics might be a suitable subject for scientific research, but marketing an unproven method to the public is quackery." Mostly, doctors ignore cryonics and consider it a nice but expensive long shot.

Cryonics advocacy

Demographics

Demographically, cryonics advocates tend to intersect strongly with transhumanists — almost all well-educated, mostly male, mostly atheist or agnostic but with some religious, and disproportionately involved in mathematics, computers, or physics.

Hardly any celebrities have signed up to be brought back to life in the far future. Which may be a net win.

Discussion tropes

In argument, cryonics advocates tend to freely confuse technologies we have any idea of how to get to with science-fiction-level speculation that is only somewhat plausible, and speak of "first, achieve the singularity" as if it were a minor detail that will just happen, rather than a huge amount of work by a huge number of people solving the many, many prerequisite tiny details.

The proposals and speculations are so vague as to be pretty much unfalsifiable. Solid objection to a speculation is met with another speculation that may (but does not necessarily, or sometimes even probably) escape the problem. You will find many attempts to reverse the burden of proof and demand that you prove a given speculation isn't possible.

Cryonicists also tend to assert unsupported high subjective probability estimates for as yet nonexistent technologies. Figures are derived on the basis of no evidence at all, concerning the behaviour of systems we've built nothing like and therefore have no empirical understanding of.

Take care to distinguish the statement "some sort of cryonic suspension and revival may be possible with as yet unrealised future technologies" from "there is any evidence that what the cryonics industry does right now does any good at all." Cryonics advocates tend to hear the second questioned and answer by asserting the first.

When you ask about a particularly tricky part and the answer is "but, nanobots!" take a drink.

Not deliberate fraud (mostly)

Cryonicists are almost entirely scarily sincere, exceedingly smart and capable people and really believe that freezing your freshly-dead body is the best current hope of evading permanent death (maybe it is) and that the $50-120,000 this costs is an excellent investment in the far future (a little less certain). There is little deliberate fraud going on.

• The Chatsworth facility, run by Robert Nelson, ran out of money and the frozen bodies thawed. The cryonics movement as a whole was outraged and facility operators are much more careful these days.
• In widely-reported allegations by their ex-COO, Alcor have been incredibly careless with the frozen heads in their care. Alcor denies all allegations, tried to get his book blocked from publication and has threatened further legal action. Considering that cryonics people are by and large absolute fanatics, the allegations are, on the surface, about as plausible as a Palestinian/Israeli peace conference held in BaconWorld theme park.

Pascal's wager

Cryonics enthusiasts are fond of applying a variant of Pascal's wager to cryonics and saying that being a Pascal's Wager variant doesn't make their argument fallacious. Ralph Merkle gives us Merkle's Matrix:

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

The questionable aspect here is omitting the bit where "sign up" means you pay $120,000 of present-life money for the chance at an afterlife, the details of which completely lack scientific backing for the obvious hard bits.

Cooling processes known to work

The basic notion of freezing and reviving an animal, e.g. a human, is far from completely implausible.

Humans

• Cryogenics has proven usably effective for single human cells — it is widely used in in vitro fertilization to store fertilized zygotes for later implantation.
• There are many reported cases of humans (adult and child) who have had a severely lowered core temperature and been brought back to full health once warmed. (Of course, there are quite a lot more reported cases where they just died. And there are, of course, no cases of a human being frozen solid and surviving the process.)
• Therapeutic hypothermia (down to 32°C, from the normal 37°C) is routinely practiced in hospitals as a method of reversing ischemia damage.

Non-humans

• Small mammals freeze and revive surprisingly well. Smith et al (1957) is a sterling piece of mad science, with remarkable success for half a century ago. Mice simply dropped in beakers of LN2 revive fairly reliably with careful warming, artificial respiration and electrical shocks, because they are so small they flash freeze. However, the females are infertile because large oocyte cells are particularly sensitive to ice crystals, and they suffer slightly diminished remaining lifespans for various related reasons. Bushbabies were revived but died within 24 hours.
• Experiments have been done involving suspended animation at temperatures higher than freezing, in which the life processes of a mammal subject are reduced to almost nothing for a short period then brought back. Pigs can be taken down to 10°C and revived.
• Some frogs have been frozen and revived quite reliably, and actually appear to have evolved to survive partial freezing. Cold-blooded animals in general are rather better at dealing with cold than mammals or birds.
• Flies and insects freeze and revive pretty well. Freezing and reviving houseflies is reliable enough to make a nice magic trick.
• A bacterium was revived after 120,000 years in a Greenland ice sheet.

Organs

• Viable eggs are recoverable from frozen mouse ovaries. This is, of course, not the same as recovering a working organ.
• A rabbit kidney (cryobiologists like rabbit kidneys, and experiment on them a lot) was frozen to -135°C and retransplanted, and supported life. Best claims it "functioned well enough as the sole kidney to keep the rabbit alive indefinitely," but the original paper does not go that far. Examination of the correct paper documenting the study, however, shows that the vitrified (not "frozen") rabbit kidney when rewarmed was able to function as the sole functioning kidney (but not "indefinitely", a claim not made by Best).

• Best claims that cryobiologists have taken out a rat hippocampus, frozen it, inspected it and declared that it would possibly be viable (presumably, working when replaced). This would be very promising, except that the abstract of the cited paper does not claim any such success and only claims that the slice looked good. But an examination of Table 1 of "Cryopreservation of rat hippocampal slices by vitrification" shows that the viability of vitrified hippocamal slices was close to 100% within experimental error. The average for the seven listed experiments was just under 100%. The K+/Na+ assay of viability is a very reliable one. If cells cannot pump ions they are not viable. If there is active oxidative phosphorylation with production of ATP, that means that cells are viable. The cells not only can work again, they are working again. The statement made by Best in his paper was fully supported by the hippocampal vitrification paper he cited. (Note: The authors of the paper are cryonicists as well as cryobiologists, but appear to understand what brick-by-brick science and technology entails.)

See also

• Transhumanism

External links

• Mistakes Were Made. An extraordinary episode of radio documentary series This American Life tells the funny, bizarre, and tragic story of a cryonics facility owner and client family for whom things didn't go quite as planned with the frozen body thing. It's an excellent cautionary primer to the complexities of actually running such a business.
• Penn and Teller Call BS on the Cryonics Scam
• Grossman, W.M. (February 14, 2008) "Patients who are frozen in time" Guardian.co.uk
• Choi, J. and Bischof, J.C. (2009) "Review of biomaterial thermal property measurements in the cryogenic regime and their use for prediction of equilibrium and non-equilibrium freezing applications in cryobiology" Cryobiology, in press; review. Excerpt: "It is well accepted in cryobiology that the temperature history and cooling rates experienced in biomaterials during freezing procedures correlate strongly with biological outcome.... Further studies are needed to extract thermal properties of other important biomaterials in the subzero temperature domain and to develop accurate numerical methods which take into account non-equilibrium cooling events encountered in cryobiology when partial or total vitrification occurs." (abstract; emphasis added)
• Ma W., et al. (2006) "Cryopreservation of adherent neuronal networks" Neuroscience Letters, 403(1-2):84-9. Excerpt: "Here is the first report on cryopreservation of mammalian adherent neuronal networks." (abstract)