Technology & Science

Hawking admits he was wrong on black holes

Stephen W. Hawking on Wednesday put forward a radically-revised version of his theory on the nature of black holes

Renowned physicist Stephen Hawking on Wednesday put forward a radically-revised version of his theory on the nature of black holes, which formed where stars collapse.

He told a Dublin conference that black holes did not destroy everything they consumed but instead eventually fired out "mangled" matter and energy.

Until now, he had argued that matter sucked into the gravitational vortex of a black hole was completely destroyed and no information about it ever reappeared apart from a generic form of radiation, now called "Hawking radiation."

That conflicted with an elemental law of quantum physics, which holds that information can never be completely lost.

But in Wednesday's presentation, entitled "The Information Paradox for black holes," Hawking posited that black holes hold their contents for eons. He said the black holes eventually deteriorate and die.

As they disintegrate, he said, the black holes emit their transformed contents back into the universe.

His new theory has wide-ranging intellectual implications for other fields of study.

Previously, Hawking had also held out the possibility that disappearing matter could travel through the black hole into a parallel universe, a concept much beloved in some branches of philosophy and in science fiction.

"There is no baby universe branching off, as I once thought. The information remains firmly in our universe...," he said.

"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," Hawking explained in his speech.

"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," he argued.

Hawking, Lucasian Professor of Mathematics at Cambridge University, achieved international fame with the 1975 theory that pioneered black hole science and was later popularized in his book A Brief History of Time.

The 62-year old scientist who travels to speaking engagements around the world has had amyotrophic lateral sclerosis since his mid-20s. He communicates by using a hand-held device to select words on his wheelchair's computer screen, then sends them out through a speech synthesizer.

Hawking also settled another matter almost three decades old. He had made a bet with Caltech astrophysicist John Preskill, who insisted in 1975 that matter consumed by black holes couldn't be destroyed.

Hawking conceded he had lost the bet and presented Preskill with a reference work, Total Baseball, The Ultimate Baseball Encyclopedia, after having it specially flown over from the United States.

He said he could not convince Preskill of the "superiority of cricket."