Cryonics is the practice of preserving life by pausing the dying process using subfreezing temperatures with the intent of restoring good health with medical technology in the future.
“At the point where the current legal and medical system gives up on a patient, they aren’t really dead.”
— Eliezer Yudkowsky, You Only Live Twice
The definitions of death change over time as medical understanding and technology improve. Someone who would’ve been declared dead decades ago may still have a chance today. Death used to be when a person’s heart stopped, then when their heart couldn’t be restarted, and is now being extended further.
Death is only permanent when the structures encoding memory and personality (necessary for consciousness) have become so disrupted that it becomes theoretically impossible to recover the person. This is called “information-theoretic death”. Any other definition of death is arbitrary, and subject to revision.
When someone is dying, the transition from alive to dead is not instantaneous. It takes time to die. Doctors can use this time to try and save the person, and are often successful. When it is impossible or inappropriate to reverse the dying process… this is when cryonics becomes relevant.
Cryonics is currently the best-known method for pausing the dying process in a way that allows for potentially restoring good health with medical technology in the future. Cryonics is an ambulance to the future.
“The concept of cryonics is optimistic…many leading experts on nanotechnology anticipate that it will make it possible to reanimate cryonics patients.”
— Nick Bostrom, The Case Against Aging
Cryonics sounds like science fiction, but it’s based on modern science.
Cryonics is 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? The cryonics group has a chance, but the control group has none.
Life can be stopped and restarted if its basic structures can be preserved.
Human embryos are routinely preserved for years at very low temperatures. Adult humans have survived being cooled for up to an hour at temperatures that stop the heart, brain, and all other organs from functioning.
Vitrification can preserve biological structure very well – much better than freezing.
Vitrification is the transformation of a substance into a glassy solid. High concentrations of cryoprotectants permit biological tissue to be cooled to very low temperatures with little to no ice formation. It is now possible to physically vitrify organs as large as the human brain, achieving excellent structural preservation without freezing.
Methods for repairing biological structure at the molecular level can now be foreseen.
Nanotechnology will lead to the capability of extensive tissue repair and regeneration, including repairing individual cells one molecule at a time. This future nanomedicine could theoretically recover any cryopreserved person where the structures encoding memory and personality remain inferable.
