What is cryonics?

Many people confuse the terms cryogenics, cryobiology, suspended animation, cryonic suspension, and cryonics. Here are my definitions of these terms, which I believe are pretty much standard.

Cryogenics
The study of materials at very low temperatures (near absolute zero). Cryogenics is a branch of physics.
Cryobiology
The study of the effect of low temperatures (below the freezing point of water) on biological systems. A primary goal of this field is the preservation and long term storage of organ systems such as hearts, kidneys, etc. for use in transplantation. This goal has not yet been reached and currently only individual cells and organisms consisting of only a very few cells (such as embryos) can be successfully treated, stored, and revived.
Suspended animation
This term refers to the ability to start and stop, at will, a biological system (usually a person) through some physical means (usually the use of cold temperatures). Suspended animation does not currently exist.
Cryonic suspension
A (currently non-standard) medical technique for attempting to prevent the permanent cessation of life in individuals on the brink of death. It involves the use of low temperatures to halt metabolic decay. A person who is cryonically suspended can not be revived by current medical technology. The freezing process does too much damage. What is accomplished is that once frozen the person's biological state does not change. The reason for performing a cryonic suspension is the belief that science, technology, and society will advance to the point where revival of the person is both possible and desirable.
Cryonics
A branch of science that aims to develop reversible suspended animation. Until suspended animation is achieved, most cryonicists favor the use of cryonic suspension as a last ditch effort for people whose medical options have run out.

If this sounds interesting, check out the excellent introduction to cryonics (available as a hypertext document, no less) maintained by Tim Freeman, tsf@cs.cmu.edu . Other sources of information include Kevin Brown's kqb@whscad1.att.com CryoNet mailing list and the sci.cryonics newsgroup.


Here are some cryonics related cartoons: