There's an episode of the old-time radio series Lights Out Everybody , from the pen of creative luminary Arch Oboler. The plot of The Immortal Gentleman rather startled me when, as a kid, I first listened to it, alone upstairs in my darkened bedroom. It is the future. Or, at least, we think it is. A man from the present day falls asleep in an auditorium during a boring lecture, and "wakes up" to find himself in the remnants of the very same auditorium. He is soon tagging-along with a band of people who are on a mission. In the future --- in their time --- people live forever. And they're seeking to end that, by any means necessary. The moral of Immortal Gentleman --- that humanity should live and then die, making way for newer, younger people --- has always stuck with me. When we're young, we rarely seem to think about death. If we do, it's typically something we don't look favorably upon. The idea of living forever is an inviting one. But at what c...