Longevity

BIRTHDAY CANDLES ARE SOLD IN PACKS OF 50: Americans' average life expectancy has crept up to 80 (back in 2010 it was 78). But the generation born this year might live much longer — even forever, in a sense. Experts foresee a time, still years on the horizon, when we might enjoy a kind of virtual immortality: Our minds could be "uploaded" into supercomputers whose artificial intelligence far outpaces our own brainpower.

That space-age scenario, dubbed the Singularity and popularized by futurist Ray Kurzweil, predicts that computers — which have been getting more powerful every year — will soon outsmart the human mind, ushering in an epoch of explosive technological progress. In The Singularity Is Near: When Humans Transcend Biology, Kurzweil describes the possibilities of man-plus-machine: Tiny "nanobots" will repair aging cells, radically extending life spans; "Human Body Version 3.0" will let us change our appearance at will; and our conscious selves will eventually dwell inside the digital realm, safely stored in supercomputers for, well, forever.

So when will all this happen? Not until the 2030s at the earliest. And maybe never, say skeptics.

"Kurzweil expects that progress in our understanding of biology will become exponential, like our understanding of the capability of computers," says neuroscientist David Linden, of Johns Hopkins. "But I just don't see that kind of acceleration of knowledge."

Our bet: For the foreseeable future, human beings will still be living, breathing, thinking, and dying in the time-honored ways of old.