Stephen Hawking’s Final Scientific Paper on Blackholes Has Just Been Released

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Physicists who last worked with the renowned British cosmologist Stephen Hawking before his passing in March earlier this year have now written up the last parts of his final paper and published it online.

Hawking had spent the better part of his career finding out what happens to information when objects fall into black holes. Nearly 60 years later, Stephen Hawking argued that black holes also have a temperature.

The paper named Black Hole Entropy and Soft Hair, tackles with what happens to information when it falls into a black hole, a problem that theoretical physicists refer to as ‘the information paradox,’ said researchers from Cambridge University in the UK.

In 1915, Albert Einstein published his theory of general relativity, which described how gravity arises from the spacetime-bending effects of matter. However, Einstein made important predictions about black holes too, notably that a black hole can be completely defined by only three features: its mass, charge, and spin.

This paper proposes a way to understand entropy for astrophysical black holes based on symmetries of the event horizon. The authors have to make several non-trivial assumptions so the next steps will be to show that these assumptions are valid,” said Marika Taylor, professor of theoretical physics at Southampton University and a former student of Hawking’s.

Since hot objects lose heat into space, the ultimate fate of a black hole is to evaporate out of existence. However, the rules of the quantum world dictate that information is never lost. So what happens to all the information contained in an object when it tumbles into a black hole.

In the latest paper, Hawking and his colleagues showed how some of the information may be preserved. Days before Hawking died, Perry was at Harvard working on the paper with colleagues. He was not aware of how ill Hawking was and called to give the physicist an update. It may have been the last scientific exchange Hawking had.

“It was very difficult for Stephen to communicate and I was put on a loudspeaker to explain where we had got to. When I explained it, he simply produced an enormous smile. I told him we’d go somewhere. He knew the final result,” Perry said.