At the heart of modern physics is a gulf that scientists have spent more than a century trying to bridge. Quantum mechanics gives an apparently flawless description of the forces that dominate at the atomic scale. Albert Einstein’s theory of general relativity has never been proven wrong in its predictions of how gravity shapes cosmic events. But the two theories are fundamentally incompatible.
Now, scientists have proposed a framework that they say could unify these two pillars of physics, through a radical rethink of the nature of spacetime. Instead of time ticking away predictably, under the “postquantum theory of classical gravity”, the rate at which time flows would wobble randomly, like the ebb and flow of a stream.
