Black holes may dodge the speeding 鈥渂ullets鈥� that would otherwise strip them naked 鈥� and pose problems for Einstein鈥檚 theory of general relativity.
The finding is good news for physicist Stephen Hawking, who has wagered that such naked singularities are a physical impossibility.
The event horizon surrounding a black hole means nothing, not even light, escapes. But in 2009, physicists Ted Jacobson and Thomas Sotiriou at the University of Maryland at College Park calculated that, under some circumstances, an incoming particle might cause a spinning black hole to rotate so fast that this horizon is destroyed, allowing light to escape.
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The trouble is, the theory of general relativity and other laws of classical physics break down around the resulting 鈥渘aked singularity鈥�.
Now , also at the University of Maryland in College Park, and his colleagues reckon that such incoming particles needn鈥檛 strip spinning black holes.
Hawking wager
The problem with the previous study, says Barausse, is that it did not include so-called 鈥渟elf-force鈥� effects that stem from the gravity of incoming matter. By estimating these effects, Barausse鈥檚 team calculates that the incoming particles in question should distort a spinning black hole鈥檚 gravity so that the black hole 鈥渟hrinks away鈥� from the particles.
These particles then speed on past instead of falling in. 鈥淭he black hole basically dodges the bullet,鈥� Barausse says.
The accuracy of this assertion might become clearer in a few years, as various groups are running computer simulations to calculate the self-force of particles orbiting spinning black holes, says Barausse.
If the hypothesis turns out to be correct, Stephen Hawking will be a happy man. In 1997, he bet physicists John Preskill and Kip Thorne of the California Institute of Technology in Pasadena that .
What happens if he loses the wager? According to the terms of the bet: 鈥淭he loser will reward the winner with clothing to cover the winner鈥檚 nakedness. The clothing is to be embroidered with a suitable, truly concessionary message.鈥�
Reference: http://arxiv.org/abs/1008.5159
