In a universe where faster-than-light travel isn’t possible, wormholes—hypothetical shortcuts across spacetime that link one part of the universe with another —give hope to romantics who wish to jump millions of light years in a single bound. But are wormholes more than a sci-fi portal to zip us between galaxies? Recent research suggests that they actually describe microscopic channels between particles all around us.
As far-out as wormholes sound, they are described by of Einstein’s theory of general relativity, the same theory that describes the force of gravity. General relativity expresses gravity as the smooth bending of space and time. For example, the sun creates a dimple in the fabric of spacetime; the planets “roll” around the periphery of the dimple. A wormhole is more than a dimple, though. It is like a tunnel between two parallel sheets of spacetime.
The details about wormholes remain fuzzy, but new research suggests that they may be fundamentally related to quantum entanglement. Quantum entanglement is a phenomenon where pair of objects are bound together. No matter how far apart they fly, they will “know” about each other—even if they are on opposite sides of the galaxy. Which, when you think about it, sounds a lot like a wormhole.
A pair of independent teams arrived at the same conclusion. Here’s Katia Moskvitch, writing for AAAS Science Now:
Kristan Jensen of the University of Victoria in Canada and Andreas Karch of the University of Washington, Seattle, start by imagining an entangled quark-antiquark pair residing in ordinary 3D space, as they described online on 20 November in Physical Review Letters. The two quarks rush away from each other, approaching the speed of light so that it becomes impossible to pass signals from one to the other. The researchers assume that the 3D space where the quarks reside is a hypothetical boundary of a 4D world. In this 3D space, the entangled pair is connected by a kind of conceptual string. But in the 4D space, the string becomes a wormhole.
Julian Sonner of the Massachusetts Institute of Technology in Cambridge then builds upon Karch’s and Jensen’s work. He imagines a quark-antiquark pair that pops into existence in a strong electric field, which then sends the oppositely charged particles accelerating in opposite directions. Sonner also finds that the entangled particles in the 3D world are connected by a wormhole in the 4D world, as he also reported online on 20 November in Physical Review Letters.
Such pairs of particles are ubiquitous, though we don’t know for certain whether wormholes exist between them. For now, these findings remain theoretical. We haven’t even found hard evidence of large wormholes yet, let alone microwormholes. Both remain hypothetical objects of thought experiments, but as we learned from Einstein, such musings can lead to great revolutions in physics.