Decades ago, Einstein concocted a theory in which space doesn’t just curve, but swirls like a cyclone. Now it is making a comeback because it could fix several of the biggest problems in cosmology
13 October 2021
LONG ago, people thought that empty space was just what it sounds like: a featureless void. But the more we have studied seeming emptiness, the more we have shown that this is far from the truth. The air around us is full of jostling gas molecules. In space proper, beyond our atmosphere, there are quantum fields and particles of light. Even the emptiest corner of interstellar wilderness isn’t devoid of character because space itself can warp and curve.
But what if we still haven’t got to the bottom of what space is like? In the middle of his career, Albert Einstein became convinced that general relativity, his great theory of space and time, had missed a trick. Yes, space did warp and curve – but not in the way he had thought. If the true twistiness of space was accounted for, he reckoned, it might bring us closer to a grand unified theory of physics.
Einstein never quite cracked the idea, and it has been largely left to languish for almost a century. But now there is fresh cause to revive it. Physicists are struggling with a raft of devilish problems in cosmology that are forcing us to question the basics of even our most well-established theories. Dark energy, the unidentified stuff that seems to be pushing the universe apart at an ever accelerating rate, is just one example.
Some physicists are asking whether the answer to all these problems could be to once again tweak our understanding of space itself. This time the goal isn’t to unify all of physics. But if we give space the right kind of …