Stephen Hawking was the first to propose that not everything that comes in contact with a black hole succumbs to its immense gravity and inevitable nothingness. In fact, tiny particles of light, known as photons, are sometimes ejected back out of the black hole, robbing it of energy. This gradual loss of mass over time means that every black hole eventually evaporates out of existence.
Credit: Alain r/Wikimedia
The energy of these tiny particles that escape from black holes, known as Hawking radiation, has answered a lot of questions about how these mysterious phenomena actually work. However, because this radiation is so delicate, it is impossible to detect it from thousands of light-years away. So far, no one has actually been able to prove it exists.
Jeff Steinhauer, professor of physics at the Technion university in Haifa, believes he has got around this problem by creating a laboratory-sized “black hole” made out of sound, and watching particles steal energy from its fringes.
In a paper posted on the physics website arXiv, he describes how he cooled helium to a shade above absolute zero and churned it around fast enough to make a barrier that no sound should be able to cross; the equivalent of a black hole’s event horizon. Professor Steinhauer said he had found signs that phonons, the very small packets of energy that make up sound waves, were leaking out of his sonic black hole just as Hawking’s equations predict they should.
The results have yet to be replicated elsewhere and scientists say they will want to check the effect is not caused by another factor.
If confirmed, it would strengthen Prof Hawking's case for Nobel Prize.
Watch: Black Holes Explained
"The experiments are beautiful," physicist Silke Weinfurtner from the University of Nottingham in the UK, who is running his own Earth-based experiments to try and detect Hawking radiation, told The Telegraph. "Jeff has done an amazing job, but some of the claims he makes are open to debate. This is worth discussing."
Meanwhile, a paper published in Physical Review Letters last month has found another way to strengthen the case for Hawking radiation. Physicists Chris Adami and Kamil Bradler from the University of Ottawa describe a new technique that allows them to follow a black hole’s life over time.
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