Science Fair Project Encyclopedia Cryonics is the practice of
preserving organisms, or at least their brains, for possible
future revival by storing them at cryogenic temperatures where
metabolism and decay are almost completely stopped. An organism
held in such a state (either frozen or vitrified) is said to be
cryopreserved. Barring social disruptions, cryonicists believe
that a perfectly vitrified person can be expected to remain
physically viable for at least 30,000 years, after which time
cosmic ray damage is thought to be irreparable. Many scientists
in the field, most notably Ralph Merkle and Brian Wowk, hold
that molecular nanotechnology has the potential to extend even
this limit many times over. To its detractors, the justification
for cryonics is unclear, given the primitive state of
preservation technology. Advocates counter that even a slim
chance of revival is better than no chance. In the future, they
speculate, not only will conventional health services be
improved, but they will also quite li