for National Geographic News
In a nondescript office building near the airport in Scottsdale, Arizona, the Alcor Life Extension Foundation is selling a shot at immortality.
Inside, 67 bodiesmostly just severed headslay cryogenically preserved in steel tanks filled with liquid nitrogen, waiting for the day when science can figure out a way to reanimate them.
But is deathlessness really a scientific possibility?
Joseph Waynick, Alcor's president and chief executive, certainly thinks so. "When physicians first wanted to transplant a heart from one person to another, they were laughed at and told it was impossible," he said. "I have no doubt the technology [to revive life] will become available."
Many cryobiologists, however, scoff at the idea, contending that the practice is little more than a pipe dream and that current "patients" will never be successfully revived.
"Even if, in our wildest dreams, this proved possible in the future, the end result would be the preservation of a dead body, not the suspended animation of a person," said Michael Taylor, a Charleston, South Carolina-based cryobiologist with Organ Recovery Systems, a company specializing in transplant medicine.
The prospect of cheating death raises a host of philosophical, moral, and religious questions. But let's consider only the scientific aspects.
Even proponents of cryonics, the practice of storing entire organisms (or at least their brains) for future revival, admit there is no scientific evidence that a cryopreserved human will ever be revived. No one even knows what technology would have to be developed to reverse the preservation.
Many questions surround the cryopreservation process itself. In cryopreservation, cells and tissues are stored at frigid, cryogenic temperatureswhere metabolism and decay are almost stoppedfor future revival at normal temperatures.
But scientists have long known that the freezing process creates ice crystals, which destroy cells and cellular structures.
A few years ago, cryobiologists discovered a new preservation process, called vitrification, which virtually eliminates ice-crystal formation. Rather than freezing the tissue, vitrification suspends it in a highly viscous glassy state. In this mode, molecules remain in a disordered state, as in a fluid, rather than forming a crystalline structure.
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