Robert Krulwich revisits the mysterious but true Gompertz Law of Human Mortality, named for the British actuary who had originally discovered this mathematical fact back in 1825.

via NPR:

Obviously, when you’re young (and past the extra-risky years of early childhood), the chances of dying in the coming year are minuscule — roughly 1 in 3,000 for 25-year-olds. (This is a group average, of course.)
But eight years later, the tables said, the odds will roughly double.  ”When I’m 33 [the chances of my dying that year] will be about 1 in 1,500.”
And eight years after that…the odds double again: “It will be about 1 in 750.”
And eight years later, there’s another doubling. Looking down the chart, you’ll see that keeps happening and happening and happening. “Your probability of dying during a given year doubles every eight years.”

A helpful, if horrifying, chart: