Cryo-Preservation for Future Life

Abstract

Cryonics is an effort to save lives by using temperatures so cold that a person beyond help by today's medicine might 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 word death occurs when the chemistry of life becomes so disorganized that normal operation cannot be restored. (Death is not when life turns off. People can and have survived being "turned off".) How much chemical disorder can be survived depends on medical technology. A hundred years ago, cardiac arrest was irreversible. People were called dead when their heart stopped beating. Today death is believed to occur 4 to 6 minutes after the heart stops beating because after several minutes it is difficult to resuscitate the brain. However, with new experimental treatments, more than 10 minutes of warm cardiac arrest can now be survived without brain injury. Future technologies for molecular repair may extend the frontiers of resuscitation beyond 60 minutes or more, making today's beliefs about when death occurs obsolete. Ultimately, real death occurs when cell structure and chemistry become so disorganized that no technology could restore the original state. This is called the information-theoretic criterion for death. Any other definition of death is arbitrary and subject to continual revision as technology changes. That is certainly the case for death pronounced on the basis of absent "vital signs" today, which is not real death at all.