Cryonics
David Gerard (Talk | contribs) (→Problems) |
David Gerard (Talk | contribs) (→Problems) |
||
| Line 45: | Line 45: | ||
* Reattaching a severed head or transplanting the brain. | * Reattaching a severed head or transplanting the brain. | ||
** Alternately: reading the patterns from the original brain and writing those to the cloned brain. | ** Alternately: reading the patterns from the original brain and writing those to the cloned brain. | ||
| − | * Neural net information appears to be preserved in strengths of neuron connections in dendrites. These 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?). This is a problem even with "vitrification." | + | * Neural net information (your mind) appears to be preserved in strengths of neuron connections in dendrites. These 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?). This is a problem even with "vitrification." |
* 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."<ref>[http://ouroboros.wordpress.com/2010/02/05/corpsicles-in-the-new-yorker/ Corpsicles in the ''New Yorker''] (Ouroboros, 5 Feb 2010)</ref> | * 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."<ref>[http://ouroboros.wordpress.com/2010/02/05/corpsicles-in-the-new-yorker/ Corpsicles in the ''New Yorker''] (Ouroboros, 5 Feb 2010)</ref> | ||
* Cure the disease or other condition that originally killed the subject. | * Cure the disease or other condition that originally killed the subject. | ||
Revision as of 22:05, 14 February 2010
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 favourite prospect.
Some sort of cryonic preservation and revival is not considered provably impossible. But in practical terms, it's so far off as to hardly be worth taking seriously. Though cryonicists are quite happy (in all sincerity, one must note) to accept considerable amounts of your money right now.
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.
Contents |
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).[1]
In popular culture
Cryonics in various forms has become something of a trope of science fiction, either as a serious plot device (the Alien tetralogy), a source of humor (Futurama, Sleeper), or sheer boneheaded incomprehensibility (Vanilla Sky).
Mainstream scientific opinion of cryonics
Cryobiology is a real science, the study of how living things react at low temperatures. Cryonics, however, is not considered a part of it, and cryobiologists consider cryonicists annoying clowns. The Society for Cryobiology banned cryonicists in 1982, specifically those "misrepresenting the science of cryobiology, including any practice or application of freezing deceased persons in anticipation of their reanimation."[2] 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.
It can be difficult to find scientific critics willing to bother detailing why they think cryonics is silly.[3]
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."[4]
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 and that charging you $50-120,000 for this is an excellent investment in the far future. There is little deliberate fraud going on. (Modulo one facility that ran out of money and the owner just neglected to restock the liquid nitrogen, leading to the frozen heads thawing. The cryonics movement as a whole was outraged and facility operators are more careful these days.)
The current state of cryonics
Cryonics for dead humans is still a process of freeze-and-hope. The present recovery process involves "and then a miracle happens." 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.
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 meant to cause the water within the body to freeze in a glassy form ("vitrification"), so as to avoid it crystallizing and puncturing cells.
Not that cryonicists actually know if any of what they do will in fact make revival any easier, they just think it sounds like a plausible hypothesis that it will. There is no evidence whatsoever that what cryonicists do will be any better at allowing a future revival than what the ancient Egyptians did to their pharaohs with a similar goal.
Problems
These would all need to be solved to bring a frozen head back to life:
- Cloning most of a body from recoverable DNA. (We're pretty close to this one.)
- Fixing the freezing damage to the original frozen brain.
- Reattaching a severed head or transplanting the brain.
- Alternately: reading the patterns from the original brain and writing those to the cloned brain.
- Neural net information (your mind) appears to be preserved in strengths of neuron connections in dendrites. These 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?). This is a problem even with "vitrification."
- 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."[5]
- Cure the disease or other condition that originally killed the subject.
- Once you've fixed the body cells and the brain paths, you have to resurrect the dead. Tricky.
Cooling processes known to work
The basic notion of freezing and reviving an animal, e.g. a human, is far from completely implausible.
Humans
- Cryonics 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.)
Non-humans
- A bacterium was revived after 120,000 years in a Greenland ice sheet.[6]
- Flies and insects freeze and revive pretty well.[7] Freezing and reviving houseflies is reliable enough to make a nice magic trick.[8]
- Frogs have been frozen and revived quite reliably, and actually appear to have evolved to survive freezing.[9]
- Experiments have been done involving suspended animation at temperatures higher than freezing, in which the life processes of a mammal subject [10] are reduced to almost nothing for a short period then brought back. Pigs can be taken down to 10°C and revived.[11]
See also
Footnotes
- ↑ Cryonics Robert T. Carroll, Skeptic's Dictionary
- ↑ "Upon a two-thirds vote of the Governors in office, the Board of Governors may refuse membership to applicants, or suspend or expel members (including both individual and institutional members), whose conduct is deemed detrimental to the Society, including applicants or members engaged in or who promote any practice or application which the Board of Governors deems incompatible with the ethical and scientific standards of the Society or as misrepresenting the science of cryobiology, including any practice or application of freezing deceased persons in anticipation of their reanimation. [Sec. 2.04 of the bylaws of the Society for Cryobiology]". Note that the quote is on the site of cryonics company Alcor.
- ↑ An open letter to scientific critics of cryonics (Paul Crowley, blog post, 14 February 2010)
- ↑ Quackwatch
- ↑ Corpsicles in the New Yorker (Ouroboros, 5 Feb 2010)
- ↑ Resurrection bug' revived after 120,000 years (Andy Coghlan, New Scientist, 15 June 2009)
- ↑ Frozen Flies Safeguard Research, Screwworm Eradication Efforts (ScienceBlog, 04 Feb 2005)
- ↑ Reviving a Dead Fly Magic Trick
- ↑ Ask the expert: Jon Costanzo (NovaScience Now, PBS, April 2005)
- ↑ Most notably Miles the Beagle, suspended for an hour in 1987. (dead link - anyone got a good ref?)
- ↑ Stuck Pig (Bijal P. Trivedi, Wired 14.07)