New Type of Black Hole, Proposed
Posted by Mike Kremer on Mar 19, 2002 at 20:22
DONUT SHAPED BLACK HOLE
In the 11 March print issue of PRL, researchers propose that five dimensions of space-time can harbor a rotating, donut-shaped "black ring"--the first example of a nonspherical black hole. If we live in a world with extra, hidden dimensions--as many theorists speculate--these rings might even be created in Geneva, at the world's largest particle accelerator, now under construction. Black holes have proved key in the past for checking and improving theories with higher dimensions, and the discovery strengthens the case that these objects obey different rules when lifted from their 4D confines.
Previously theorems from the 1970s proved that 4D black holes can only adopt a spherical shape and are uniquely defined by their mass and angular momentum.
But last year, Roberto Emparan of CERN in Geneva and Harvey Reall of Queen Mary College in London found a ring-shaped black hole solution to Einstein's equations in five dimensions . But this static black ring would need a disk of exotic matter inside it to keep from collapsing. Now they've found that the centrifugal force of a spinning ring balances the pull of gravity all by itself. The authors speculate that a spherical black hole in five dimensions might morph into a black ring if spun fast enough.
"This black ring solution is a remarkable discovery," says Simon Ross of the University of Durham in the UK. "This was widely regarded as a relatively closed field, where the interesting discoveries had already been made." Gary Horowitz of the University of California in Santa Barbara agrees and suspects that thicker rings--more like bagels than hula hoops--will prove stable. As for the future, he says, "[this result] opens up the possibility of a lot of new properties of black holes in higher dimensions."
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What an amazing discovery....made even more amazing
that it was'nt discovered years ago.
Now lets see, by using a bit of hindsight, we could all have theorized about this.
what configuration would a ball of putty or jelly assume if spun fast, about its center?
Answer: A Bagel, or even a Pancake