The sun formed 4.5 billion years ago, but it’s got around 6 billion years more before its fuel runs out. It will then flare up, engulfing the inner planets. And the expanding universe will continue—perhaps forever—destined to become ever colder, ever emptier. To quote Woody Allen, eternity is very long, especially toward the end.
By Martin Rees | NAUTILUS
Any creatures witnessing the sun’s demise won’t be human—they’ll be as different from us as we are from a bug. Posthuman evolution—here on Earth and far beyond—could be as prolonged as the Darwinian evolution that has led to us—and even more wonderful. And evolution will speed up; it can happen via “intelligent design” on a technological timescale, operating far faster than natural selection and driven by advances in genetics and in artificial intelligence (AI). The long-term future probably lies with electronic rather than organic “life.”
In cosmological terms (or indeed in a Darwinian time frame) a millennium is but an instant. So let us “fast forward” not for a few centuries, or even for a few millennia, but for an “astronomical” timescale millions of times longer than that. The “ecology” of stellar births and deaths in our galaxy will proceed gradually more slowly, until jolted by the “environmental shock” of an impact with the Andromeda Galaxy, maybe 4 billion years hence. The debris of our galaxy, Andromeda, and their smaller companions—which now make up what is called the Local Group—will thereafter aggregate into one amorphous swarm of stars.