The latest scientific paper by Stephen Hawking has been published and deals with one of the central topics of the 56-year career of the physicist.

The work was completed in the days before Hawking's death in March.

Discuss the question of whether black holes preserve information about the things that fall into it.

Some researchers believed this information was destroyed, but others said it violated the laws of quantum mechanics.

These laws propose that everything in our world can be divided into information, such as a string of 1

But Hawking, based on the work of Albert Einstein, showed that black holes have a temperature. And since hot objects lose heat in space, black holes eventually evaporate – disappearing from existence.

Black holes are regions in space where gravity is so strong that nothing can enter.

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Written in the Guardian, one of the co-authors of the study, Malcolm Perry, of the University of Cambridge, he said: "What Hawking discovered that in the physics of black holes there seemed to be an even greater uncertainty than in quantum mechanics."

He added: "This may not have mattered – except that black holes are true objects. the centers of many galaxies. "

If an object has a temperature, it will also have a property known as entropy.

"Entropy is a measure of how many different ways an object can be made from its microscopic ingredients and always looks the same," said Professor Perry.

He says that he discussed the document with Hawking just before he died but did not know that the professor was ill.

"Stephen was very hard to communicate and I was put on a speaker to explain where we'd come in. When I explained it, he produced a huge smile," Professor Perry explained.

The new article shows mathematically that the entropy of a black hole can be recorded by the light particles (photons) that surround the horizon of the black hole events. The event horizon is a limit, or point of no return, in which the escape from the gravitational attraction of the black hole becomes impossible – even for light.

The patina of light around the black hole has been dubbed "soft hair". "What this paper does is show that" soft hair "can explain entropy," said Professor Perry.

But he added that: "We do not know that Hawking's entropy is responsible for everything you could throw on a black hole, so this is really a step along the way."

## The most important discoveries by Hawking

- With the Oxford mathematician Roger Penrose, he showed that if there had been a Big Bang, it must have started from an infinitely small point – a singularity
- Black holes radiate energy known as Hawking radiation, while gradually they lose mass. This is due to quantum effects near the edge of the black hole, a region called the event horizon
- He predicted the existence of mini black holes at the time of the Big Bang. These tiny black holes would have been incredibly hot, scattering masses to disappear – potentially ending their lives in a powerful explosion.
- In the 1970s, Hawking considered if the particles and light entering a black hole were destroyed if the black hole had evaporated. Initially Hawking thought that this "information" was lost from the universe. But the US physicist Leonard Susskind is not on agreement. These ideas became known as the paradox of information. In 2004, Hawking admitted that the information had to be kept.
- With the physicist James Hartle, he tried to describe the history of the cosmos in a single mathematical expression. But quantum theory shows that the distinctions between space and time are not clear. As a result, the proposal showed that it was not appropriate to ask what happened before the Big Bang.

Now the prof. Perry and the other authors must find out how the information associated with the entropy of a black hole is physically stored in the soft hair,

The research is based on previous works published in 2015, which suggested that information may not turn into a black hole, but is kept at its borders.

Professor Marika Taylor, a theoretical physicist from the University of Southampton, said: "The authors must make different non-trivial assumptions, so the next steps will be to prove that these hypotheses are valid."

Previously, Professor Hawking had proposed that photons could be emitted from black holes due to quantum fluctuations, a concept known as Hawking radiation. Information from the black hole might be able to escape through this route, but it could be in a chaotic and useless form.

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