The universe is not only expanding but accelerating away from us. Now a new theory suggests all this could stop sooner than anyone imagined.
For cosmologists, the origin of the universe is clear. They can see that galaxies are accelerating away from each other and when they play this motion in reverse, the universe contracts to a single event. This suggests it all began some 14 billion years ago in an event we now call the Big Bang.
Now Cosmin Andrei from Princeton University and a couple of colleagues, have investigated this issue using theoretical models that are consistent with current observations. And they say it could begin sooner than we think, perhaps on a time scale measured in millions rather than billions of years. In one scenario they say the minimum time remaining before the end of expansion is roughly equal to the period since life has existed on Earth. That’s 3 or 4 billion years.In another scenario, they calculate that “the time interval remaining before the end of acceleration is less than the time since the Chicxulub asteroid brought an end to the dinosaurs.” That’s just 65 million years—the blink of an eye in cosmological terms.