After 29 years of thinking about it, Stephen Hawking says he was
wrong about black holes. The renowned Cambridge University physicist
formally presented a paper on July 14 arguing that black holes, the
celestial vortexes formed from collapsed stars,
preserve traces of objects swallowed up and
eventually could spit bits out "in a mangled form."
Hawking's radical new theory caps his
three-decade struggle to explain a paradox in scientific thinking: How can
objects really "disappear" inside a black hole and leave no trace, as he
long believed, when subatomic theory says matter can be transformed but
never fully destroyed?
Hawking had previously insisted that black holes destroy all molecular
fingerprints of their contents and emit only a generic form of radiation.
But at the 17th International Conference on General Relativity and
Gravitation, Hawking presented mind-boggling
new calculations that suggest black holes are able to cast out their
contents - and that there's only one way in and one way out.
Hawking, 62, said he no longer believes a 1980s theory that black holes
might offer passage into another universe, a rival explanation for
identifying where matter and energy go when consumed by a black hole.
Hawking now sides with particle physicists who have long insisted that
any matter swallowed by a black hole can't just disappear but must
eventually generate a specific output. The latest theory offers hope that
scientists one day may identify the history of what a black hole has taken
in over the eons - by decoding what it emits.
"There is no baby universe branching off
(inside a black hole), as I once thought. The information remains
firmly in our universe," Hawking said in a speech to about 800 physicists
and other scientists from 50 countries. "I'm sorry to disappoint science
fiction fans, but if information is preserved, there is no possibility of
using black holes to travel to other universes.
"If you jump into a black hole, your mass energy will be returned to
our universe, but in a mangled form, which contains the information about
what you were like, but in an unrecognizable state."
Hawking's new theory produced waves of skepticism and puzzlement from
leading physics professors. Two in the front row - William Unruh of the
University of British Columbia and Robert Wald of the University of
Chicago - shrugged and shook their heads in disbelief as Hawking spoke.
"Hawking is completely revising his prior belief that what goes into a
black hole is washed out. Now he believes that anything emitted from a
black hole can be identifiable back to its source," said Wald, an expert
on black holes. "He's running away from what we still believe."
Unruh said: "Part of the problem is he's providing so few details, so
it's impossible to know whether we can believe these calculations. Stephen
Hawking's not stupid, so we're going to take what he says seriously ...
but the whole theory we're hearing seems extremely speculative."
(Agencies)
