Theoretically possible microscopic wormholes

Wormholes play a key role in many science fiction films, often as a shortcut between two distant points in space. In physics, however, these tunnels in space-time have remained purely hypothetical. An international team led by Dr Jose Luis Blázquez-Salcedo from the University of Oldenburg has now presented a new theoretical model in the scientific journal Physical examination letters this makes microscopic wormholes appear less exaggerated than in previous theories.

Wormholes, like black holes, appear in the equations of Albert Einstein’s General Theory of Relativity, published in 1916. An important postulate of Einstein’s theory is that the universe has four dimensions – three dimensions space and time as the fourth dimension. Together, they form what is called space-time, and space-time can be stretched and bent by massive objects such as stars, just as a sheet of rubber would be bent by a ball of metal s ‘sinking into it.

The curvature of space-time determines how objects like spaceships and planets, but also light, move in them. “In theory, space-time could also be bent and curved without massive objects,” says Blázquez-Salcedo, who has since transferred to Complutense University in Madrid in Spain. In this scenario, a wormhole would be an extremely curved region in space-time that looks like two interconnected funnels and connects two distant points in space, like a tunnel. “From a mathematical point of view, such a shortcut would be possible, but no one has ever observed a real wormhole,” explains the physicist.

Moreover, such a wormhole would be unstable. If, for example, a spaceship flew as one, it would instantly collapse into a black hole – an object in which matter would disappear, never to be seen again. The connection it was providing to other places in the universe would be cut. Previous models suggest that the only way to keep the wormhole open is to use some form of exotic matter which has negative mass, or in other words weighs less than nothing, and which only exists in theory. . However, Blázquez-Salcedo and his colleagues Dr. Christian Knoll from the University of Oldenburg and Eugen Radu from the Universidade de Aveiro in Portugal demonstrate in their model that wormholes could also be traversable without such material.

The researchers chose a relatively simple “semi-classical” approach. They combined elements of the theory of relativity with elements of quantum theory and classical electrodynamic theory. In their model, they consider certain elementary particles such as electrons and their electric charge as the material that must pass through the wormhole. As a mathematical description, they chose the Dirac equation, a formula that describes the probability density function of a particle according to quantum theory and relativity as a so-called Dirac field.

As the physicists report in their study, it is the inclusion of the Dirac field in their model that allows the existence of a wormhole traversable by matter, provided that the ratio between the electric charge and the mass of the wormhole exceeds a certain limit. In addition to matter, signals – for example electromagnetic waves – could also pass through tiny tunnels in space-time. The microscopic wormholes postulated by the team would likely not be suitable for interstellar travel. Additionally, the model would need to be further refined to determine whether such unusual structures might actually exist. “We believe that wormholes can also exist in a complete model,” says Blázquez-Salcedo.

Provided by the University of Oldenburg