Physicists simulated a black hole in the laboratory. Then it started to glow. Science alert

A black hole counterpart could tell us a thing or two about the elusive radiation theoretically emitted by the real thing.

Using a string of atoms in a single coil to simulate the event horizon of a black hole, a team of physicists in 2022 observed the equivalent of what we call Hawking radiation — particles generated from perturbations in quantum fluctuations caused by a black hole's penetration. Free time.

They say this could help resolve the tension between two currently irreconcilable frameworks for describing the universe: general relativity, which describes the behavior of gravity as a continuous field known as spacetime; and quantum mechanics, which describes the behavior of discrete particles using the mathematics of probability.

For a unified theory of quantum gravity that can be applied universally, these two immiscible theories need to find a way to fit together somehow.

This is where black holes come into the picture, perhaps the strangest and most extreme objects in the universe. These massive objects are so dense that, within a certain distance from the black hole's center of mass, there is not enough speed in the universe to escape. Not even the speed of light.

that distance, uneven It is called the event horizon, depending on the mass of the black hole. Once an object crosses its borders, we can only imagine what happens, as nothing returns vital information about its fate. But in 1974, Stephen Hawking proposed that the interruption of quantum fluctuations caused by the event horizon leads to a type of radiation very similar to thermal radiation.

If Hawking radiation exists, it is too faint to be detected yet. It is possible that we will never sift it from the stillness of the universe. But we can verify its properties by creating black hole analogues in laboratory settings.

This has been done before, but in November 2022, a team led by Lotte Mertens of the University of Amsterdam in the Netherlands tried something new.

The one-dimensional chain of atoms served as a path to To “jump” from one position to another. By adjusting the ease with which this jump can occur, physicists can cause certain properties to disappear, effectively creating a kind of event horizon that interferes with the wave-like nature of electrons.

The impact of the false event horizon produced a temperature rise consistent with theoretical predictions for an equivalent black hole system, the team said. But only when part of the chain extends beyond the event horizon.

This could mean that entanglement of particles extending across the event horizon is instrumental in generating Hawking radiation.

The simulated Hawking radiation was only thermal over a certain range of jump amplitudes, and under simulations it began to mimic a type of spacetime considered “flat.” This suggests that Hawking radiation may only be thermal in a range of situations, when there is a change in the warp of spacetime due to gravity.

It's not clear what this means for quantum gravity, but the model offers a way to study the appearance of Hawking radiation in an environment that is not affected by the wild dynamics of black hole formation. Because it is so simple, it can be applied in a wide range of experimental settings, the researchers said.

“This could open the way to explore fundamental aspects of quantum mechanics along with gravity and curved spacetime in various condensed matter settings.” The researchers wrote.

The research was published in Physical review research.

A version of this article was first published in November 2022.