Physicists agree that the universe is not only expanding, but that this expansion is accelerating. But for how long? A new study by three Princeton scientists floats the provocative idea that expansion could end "surprisingly soon," as lead author Paul Steinhardt writes in the Proceedings of the National Academy of Sciences. Specifically, the study suggests that expansion could end in 65 million years and that the universe could actually start contracting in 100 million years, reports Live Science. This represents a minority view in physics, according to a post at IFLScience. The prevailing sentiment among physicists—based on current understanding of "dark energy"—is that no such contraction could ever happen again.
But this new scenario "is not far-fetched," writes Steinhardt. "In fact, it fits naturally with recent theories of cyclic cosmology and conjectures about quantum gravity." Indeed, a physicist not involved with the study tells Live Science that the scenario—one of three put forth in the study—is plausible though currently untestable. The biggest surprise is the relatively short timeline in which it theoretically unfolds, given that 65 million or even 100 million years is not long in the grand scheme of things. And what happens if the universe does, in fact, contract in on itself? It gets a little mind-boggling. As Live Science describes it, the end result, billions of years from now, could be "the death—or perhaps the rebirth—of time and space." (More discoveries stories.)