Scientists claim to have solved one of the greatest paradoxes in physics. A new theorem bridges a contradiction first brought to light by noted British scientist Stephen Hawking. So-called ‘quantum hair’ plays a leading role in this.
Dating back to the 1970s, the Hawking paradox revolves around black holes: dead, imploded stars with such a massive gravitational pull that not even light can escape.
Hawking pointed out a problem to his colleagues. According to Einstein’s general theory of relativity, nothing can escape from a black hole, but according to quantum mechanics, it is impossible. That paradox presented scientists with the dilemma that one of the two theories, both fundamental to modern physics, may not be quite right.
No ‘hair’ is it?
If nothing can escape from a black hole, no information about what is happening inside the black hole can get out. In the 1960s, the American physicist John Wheeler came up with the following description of black holes: objects with only a mass, a rotational speed and charge, but otherwise devoid of any other physical property. They were supposedly ‘bald’ and Wheeler’s theorem was therefore called the ‘No-Hair Theorem’.
A team of physicists has now shown that components of the dead star leave an imprint in the black hole’s gravitational field. They call that print ‘quantum hair’, and their thesis the ‘Well-Hair theorem’.
The new theorem, published in Physical Review Letters, bridges the gap between general relativity and quantum mechanics, according to the scientists. The quantum hair makes it possible for information about the black hole to get out, without violating the principles of both theories.
“The problem has been cracked!” Professor Xavier Calmet, one of the researchers, told the BBC. He says it’s a simple, elegant solution to the problem, “but it will take some time to accept.”
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