Wormholes may not exist – we’ve found they reveal something deeper about time and the universe |
Wormholes are often imagined as tunnels through space or time — shortcuts across the universe. But this image rests on a misunderstanding of work by physicists Albert Einstein and Nathan Rosen.
In 1935, while studying the behaviour of particles in regions of extreme gravity, Einstein and Rosen introduced what they called a “bridge”: a mathematical link between two perfectly symmetrical copies of spacetime. It was not intended as a passage for travel, but as a way to maintain consistency between gravity and quantum physics. Only later did Einstein–Rosen bridges become associated with wormholes, despite having little to do with the original idea.
But in new research, my colleagues and I show that the original Einstein–Rosen bridge points to something far stranger — and more fundamental — than a wormhole.
The puzzle Einstein and Rosen were addressing was never about space travel, but about how quantum fields behave in curved spacetime. Interpreted this way, the Einstein–Rosen bridge acts as a mirror in spacetime: a connection between two microscopic arrows of time.
Quantum mechanics governs nature at the smallest scales such as particles, while Einstein’s theory of general relativity applies to gravity and spacetime. Reconciling the two remains one of physics’ deepest challenges. And excitingly, our reinterpretation may offer a path to doing this.
The “wormhole” interpretation emerged decades after Einstein and Rosen’s work, when physicists speculated about crossing from one side of spacetime to the other, most notably in the late-1980s research.
But those same analyses also made clear how speculative the idea was: within general relativity, such a journey........