A team of researchers, including physics professor João Marto, from UBI, suggests that Einstein-Rosen bridges function as a mathematical connection between two directions of time: one that advances and another that recedes. The idea could solve the black hole Information Paradox.
The concept of Einstein-Rosen bridge is often understood as a cosmic shortcut, similar to a tunnel that connects distant points in space-time. While this image works well in science fiction, a new study shows that it doesn’t match the real physics behind this concept.
recently published in Classical and Quantum Gravitysuggests that the original bridge theory did not describe a wormhole, but rather a mathematical characteristic the way time is structured.
The results of the study, led by professor Enrique Gaztañagafrom the University of Portsmouth, in collaboration with K. Sravan Kumarfrom the same university, and João Martoprofessor of physics at the University of Beira Interior, could help solve a persistent problem of physics.
The researchers suggest that the bridge works like a mathematical link between two directions of time: one that advances and the other that retreats.
Albert Einstein e Nathan Rosen never directly proposedin his original 1935 theory, that his “bridge” was a shortcut through space, notes .
Instead, they studied the behavior of quantum fields under conditions of extreme gravity. To keep the equations coherent, they described a connection between two copies of spacetime that are mirror images from each other.
The interpretation as a “wormhole” emerged much later. In the original formulation, the bridge collapses too quickly so that something can cross it, which makes it unusable as a passagem. Despite this, the idea of a literal tunnel ended up becoming popular.
Gaztañaga and his team re-examined the original idea. They do not see the bridge as a path through space, but as a mechanism linked to the way the quantum mechanics works in curved spacetime.
Their conclusions suggest that to fully describe what happens near black holes, it is necessary consider both directions of time, and not just the one that advances and that we experience.
This finding is relevant to one of the greatest puzzles in physicsknown as the Black Hole Information Paradox.
Em 1974, Stephen Hawking demonstrated that black holes slowly emit thermal radiation, apparently destroying all information about the matter that fell into them. This directly contradicts the ideacentral to quantum mechanics, that information cannot be destroyed.
The study authors state that the paradox only arises when we think about black holes from a single direction of time.
When both directions are included in the quantum frame, the information persists on the event horizon rather than disappearing. It continues to evolve in the time-reversed component of the quantum state. From our perspective we can’t see it, but the information is still there.
The implications of the hypothesis go beyond black holes. If, at the quantum level, time has two mirrored directions, the Big Bang may not have been the beginning absolute. It could rather represent a quantum transition from a contracting universe to an expanding universe, each with its own direction of time.
In this scenario, our universe could be inside a black hole formed into an even larger cosmos.
Researchers point to a possible clue in the observations. The cosmic background radiation presents a persistent imbalance that standard models have difficulty explaining. Models with mirrored quantum components fit observational data better, but the researchers emphasize that this still does not confirm the theory.
Gaztañaga does not intend this study replace the theory of relativity Einstein or conventional quantum mechanics. Rather, it proposes that both ideas gain strength when we take the complete and balanced structure seriously in the time of quantum mechanics.
What the Einstein-Rosen bridge could actually describe is not a shortcut between galaxies, but a window into the hidden structure of time itselfsay the study authors.
