One of physicist Stephen Hawking’s most famous paradoxes may finally be resolved: New research shows that black holes can actually store information about the massive stars that created them. According to the study, this information could be hidden in the radiation around black holes, colloquially known as “quantum hairs,” and could theoretically be inferred to tell the origins of these black holes. These findings may finally solve a difficult problem that Hawking was working on in the last years of his life.
black hole problem
According to Stephen Hawking’s work, radiation gradually “leaks” from black holes in the form of thermal energy known as “Hawking radiation”. However, due to its thermal nature, this radiation cannot carry information. This means that when black holes evaporate, they methodically destroy all information about the stars that created them. This contradicts the laws of quantum mechanics, which state that information cannot be destroyed and that the final state of an object can give clues about its initial state. This problem has plagued cosmologists for decades and is known as “Hawking’s paradox of information.”
“[Це дослідження] “It’s the final nail in the coffin of the paradox because we now fully understand the physical phenomenon in which information escapes a collapsing black hole,” said Xavier Calmet, professor of physics at the University of Sussex and lead author of the study. sister publication Space. Live Science by email. He proposes a modification of Hawking radiation that renders it “non-thermal” so that it can carry information from the black hole’s ultimate fate with it.
Black holes are such massive objects that nothing, not even light, can escape gravity. They form when massive stars run out of fuel and collapse on themselves.
Calmet said that in classical physics, black holes are “very simple objects.” “So simple that they can be characterized by three numbers: their mass, angular momentum, and electric charge.”
Famous physicist John Wheeler described this lack of distinguishing features by saying that “black holes do not have hairs”. However, Calmet explained that while the ultimate black hole is very simple, the primordial star that gave birth to it was a complex astrophysical object made up of a complex mix of protons, electrons, and neutrons that combined to form the elements. the composition of this star
Although black holes do not carry the “memory” of the stars they once were, the rules of quantum physics state that information cannot simply be erased from the universe. In 1976, Hawking met this cosmic balm and showed that this information cannot be stored indefinitely in black holes sealed from the outer universe. Applying the rules of quantum mechanics to black holes, Hawking suggested that they emit a type of thermal radiation, later called Hawking radiation. Over long periods of time, leakage of this radiation causes black holes to evaporate completely, leaving only a void. In this way, the information is irretrievably lost.
“However, quantum physics, which suggests that this black hole’s ‘life’ film can be rewinded, does not allow for this,” said Calmet. “Starting with radiation, we can recover the original black hole and eventually the star.”
Searching for the “hair” of a black hole
Calmette has been working with her colleague Steve Hsu, professor of theoretical physics at the University of Michigan, to resolve the Hawking paradox since 2021. The team found black holes in a previous study published in March 2022. to really have “quantum hair”,in the form of a unique quantum trace in the gravitational fields surrounding them.
In their new study, the team re-evaluated Hawking’s 1976 calculations, but this time took into account the effects of “quantum gravity” – a definition of gravity according to the principles of quantum mechanics – that Hawking did not.
“While these quantum gravity corrections are small, they are crucial for the black hole to evaporate,” Calmet said. Said. “We were able to show that these effects change the Hawking radiation to become non-thermal. In other words, given quantum gravity, the radiation May contains information”.
While the quantum hair proposed in Calmet and Hsu’s previous work is an abstract mathematical concept, the team has now described the precise physical phenomenon in which information escapes a black hole via Hawking radiation and how it can be received by an outside observer (opens in new tabs). This is currently impossible, as it would require a sufficiently sensitive instrument to measure Hawking radiation, which is currently purely theoretical.
Calmet acknowledged that there is currently no real way for astrophysicists to measure the effect that the researchers suggested because it was small. Instead, he suggests, one way to develop this theory is to study black hole simulations in laboratories on Earth. The team’s mathematical modeling of Hawking radiation and black holes could prove invaluable in this simulation.
Source: Port Altele
