Universe May Not End in 30 Billion Years—It May Have Babies Instead
In the Woody Allen movie Annie Hall , nine year-old Alvy Singer is depressed and has stopped doing his homework because, "Well, the universe is everything, and if it's expanding, someday it will break apart and that would be the end of everything!"
Actually, the 1977 movie was prescient because cosmologists had not yet discovered dark energy and the fact that the expansion of the universe is accelerating. In recent years, cosmologists havepostulated that the Big Rip in which all matter–galaxies, stars, planets, and even atoms–is torn apart into nothingness could be only 30 billion years away.
Well, there may be good news of a sort. According to a press release, University of North Carolina physicists argue that there may be a reprieve:
During expansion, dark energy—the unknown force causing the universe to expand at an accelerating rate—pushes and pushes until all matter fragments into patches so far apart that nothing can bridge the gaps. Everything from black holes to atoms disintegrates. This point, just a fraction of a second before the end of time, is the turnaround.
At the turnaround, each fragmented patch collapses and contracts individually instead of pulling back together in a reversal of the Big Bang. The patches become an infinite number of independent universes that contract and then bounce outward again, reinflating in a manner similar to the Big Bang. One patch becomes our universe.
"This cycle happens an infinite number of times, thus eliminating any start or end of time," [UNC physicist Paul] Frampton said. "There is no Big Bang."
The whole paper is at the physics pre-print arXiv.
So time may be endless and every universe fecund, so there's no excuse for not doing your homework kids. Now what's the public policy angle on this one?