Cryonics is an effort to save lives by using temperatures so cold that a person beyond help by today's medicine can be preserved for decades or centuries until a future medical technology can restore that person to full health.
Cryonics sounds like science fiction, but is based on modern science. It's an experiment in the most literal sense of the word. The question you have to ask yourself is this: would you rather be in the experimental group, or the control group?
Cryonics is justified by three facts that are not well known:
1) Life can be stopped and restarted if its basic structure is preserved.
Human embryos are routinely preserved for years at temperatures that completely stop the chemistry of life. Adult humans have survived cooling to temperatures that stop the heart, brain, and all other organs from functioning for up to an hour. These and many other lessons of biology teach us that life is a particular structure of matter. Life can be stopped and restarted if cell structure and chemistry are preserved sufficiently well.
2) Vitrification (not freezing) can preserve biological structure very well.
Adding high concentrations of chemicals called cryoprotectants to cells permits tissue to be cooled to very low temperatures with little or no ice formation. The state of no ice formation at temperatures below -120°C is called vitrification. It is now possible to physically vitrify organs as large as the human brain, achieving excellent structural preservation without freezing.
3) Methods for repairing structure at the molecular level can now be foreseen.
The emerging science of nanotechnology will eventually lead to devices capable of extensive tissue repair and regeneration, including repair of individual cells one molecule at a time. This future nanomedicine could theoretically recover any preserved person in which the basic brain structures encoding memory and personality remain inferable, which typically occurs well after spontaneous function has been lost.
- If survival of structure means survival of the person;
- If cold can preserve essential structure with sufficient fidelity;
- If foreseeable technology can repair injuries of the preservation process;
Then cryonics should work, even though it cannot be demonstrated to work today. That is the scientific justification for cryonics. It is a justification that grows stronger with every new advance in preservation technology.