Although it comes from the same root, kryos, the Greek word for cold, cryonics is not to be confused with the mainstream sciences of cryogenics or cryobiology. These involve freezing of metals or of simple organisms. Metals get stronger after deep freezing, while the freezing and thawing of cancerous tissue can be a good way to kill it. But cryonics seeks to do the opposite. Anyone who has ever put beer in the freezer and then forgotten about it can grasp the problems facing cryonics enthusiasts today.
Ice is less dense than water.
So far, there have been no great breakthroughs, despite the enthusiasm on the various cryonics Web sites. Scientists a thousand years ago probably would have scoffed at the idea of cloning, space travel or the Internet. For those interested in making arrangements for cryonic preservation, there is little choice. The established cryonic facilities are all in the United States, although Alcor now has an outlet near London, which prepares bodies for the ride to Arizona and their plunge into a giant thermos of liquid nitrogen. Those set on cryonic preservation need to take as much care as they can about where they die.