Is death inevitable? True, everyone born before Aug. 4, 1900, has proved mortal (the world's oldest-known living person, a Japanese woman named Nabi Tajima, was born on that date). But the past is only an imperfect guide to the future, as the effervescent present is ceaselessly teaching us.

Must we die? We ourselves probably must. But our children, our grandchildren — or if not them, theirs — may, conceivably, be the beneficiaries of the greatest revolution ever: the conquest of death.

Immortality is an ancient dream. A Chinese king of the third century B.C. dispatched a sage, Xu Fu by name, on a quest for the elixir of life. He was to receive it from a race of immortal beings who lived on a certain mountain. His armada of 60 ships failed to reach the mountain. It reached instead, legend has it, Japan, which Xu and his crew settled and enriched with Chinese wet-rice agriculture, marking the end of Japan's 12,000-year-long hunter-gatherer Jomon Period culture.