Saturday, May 23, 2009

Stephen Hawking

In the 1970s, however, Dr Hawking, a physicist at Cambridge University, used quantum mechanics to predict that black holes are not, in fact, completely black. ...

But near a black hole’s event horizon things can go wrong. A virtual particle or antiparticle may be captured by the black hole’s gravity. Once within the event horizon, it cannot escape and its abandoned partner has no option but to become real. The energy needed for this “realisation” comes from the black hole itself, which thus shrinks and eventually evaporates. Meanwhile, the newly real particles decay, giving off (among other things) light, X-rays and gamma rays. --The Economist, Dumb insolence: Black holes on a desktop, June 18, 2009

The problem is that one of the basic laws of quantum mechanics is that information cannot be lost. (I should point out that in quantum mechanics the term "information" has a technical meaning, and that losing it is more of a problem than, say, losing the shopping list you need at the supermarket.) In the case of the evaporating puddle, for example, it is theoretically possible to reconstruct the puddle by looking at the air molecules above the spot where it used to be. Hawking argued, however, that with the material that evaporated from the black hole, no such thing is possible, that the information simply disappeared.--James Trefil, What Goes In The Black Hole Stays In The Black Hole. OK? A Relatively Big Mystery, The Washington Post, Sunday, September 7, 2008, review of The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics, by Leonard Susskind

To make sense of Hawking’s paradox one must consider how much information, measured in bits, the 1s and 0s of binary code, can fit inside a black hole. The amount, it turns out, does not depend on the black hole’s volume, as one might expect, but on the area of its “horizon” — the flat, funnel-like mouth of the cosmic rabbit hole. --George Johnson, The Theory That Ate the World, The New York Times, August 22, 2008, review of The Black Hole War: My Battle With Stephen Hawking to Make the World Safe for Quantum Mechanics, by Leonard Susskind

Professor Hawking is not convinced that the so-called “God particle”, which theory suggests gives matter its mass, actually exists, and in 2000 he backed his judgement by making a $100 (£50) wager with Professor Kane, who thinks it will soon be found.

Should the Higgs bosun [sic] exist, it is almost certain that the LHC [Large Hadron Collider] will identify it.
--Mark Henderson,, Stephen Hawking's £50 bet on the world, the universe and the God particle, Times Online, September 9, 2008

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