If a black hole swallows this book, will it disappear?

By Sheilla Jones

The Globe and Mail

September 20, 2008

THE BLACK HOLE WAR: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics

By Leonard Susskind

Little, Brown & Company (Hachette)

470 pages

I can't imagine that there are very many people in the world who would bet Stephen Hawking that his physics was wrong, even fewer who would win such a bet and perhaps only one who would forget making the winning bet in the first place. That would be University of Alberta professor Don Page.

 Page was the first cosmologist to publish a paper disputing Hawking's contention that any information that falls into a black hole - that great cosmic gulper of anything and everything within its gravitational reach - is gone forever, even when the black hole finally radiates away to nothing. Physicists used to think that black holes could only grow as they devoured more and more information (which means light, matter or anything else), but Hawking's most significant contribution to the theory of black holes was to demonstrate in 1976 that they can radiate away heat and simply evaporate.

Hawking went even further. He argued that the information lost to a black hole did not return to the universe via radiation as it shrank, but that it ceased to exist. This was a direct contradiction to the understanding in cosmology that, just as energy can change form but cannot disappear, information can change form but cannot disappear either. Thus, there is both conservation of energy and conservation of information. Or not.

Page and Hawking argued the issue in 1980, while Page was visiting Hawking in England. Neither would budge from his position, so they formalized their differences in writing with a bet of $1, or £1, depending on the winner. Page soon forgot about it.

At that time, Hawking was already an awe-inspiring star in the physics firmament, so there weren't many people who would dare to challenge him so directly. But Page and Hawking had a different relationship. Page lived with the Hawking family while he was doing a post-doc with Hawking from 1976 to 1979, and because Hawking was increasingly disabled by the effects of Lou Gehrig's disease, part of Page's job was to help get him up and get breakfast and on to the physics department in the morning, as well as help him to bed at night. Even more personal-care duties fell to Page when Jane, Hawking's wife, became pregnant with their third child (who would become Page's godchild). Perhaps it's just not possible to be in awe of someone for whom you've provided personal care, no matter how brilliant he might be.

Leonard Susskind begins The Black Hole War in 1983, which may explain why he doesn't mention Page's 1980 paper. His story starts at a gathering of cosmologists at the California mansion of the New Age est founder Werner Erhard, an unabashed physics groupie who could afford to host top scientists from around the world so he could be the proverbial fly-on-the-wall as they bashed heads.

Hawking was there, reiterating his stand on the loss of information in a black hole. Susskind—hearing this idea for the first time—and Dutch physicist Gerard 't Hooft were immediately alarmed at the implications for conservation of information in the universe because, if Hawking were right, the most fundamental of sciences—quantum physics—must be wrong. Not that it seemed to worry the other scientists present. "Rome was burning," Susskind writes, "the Huns were at the gate, and no one noticed."

This kind of over-the-top hyperbole appears regularly throughout Susskind's tale of his dispute with Hawking, which, despite the book's title, was not really a war at all. It was a friendly but very determined dispute over some rather esoteric aspects of black hole physics between Hawking on one side and Susskind, t' Hooft, Cal Tech physicist John Preskill, Page and a few more on the other.

What saves The Black Hole War from being an obscure story that would appeal only to a handful of physics insiders is the way Susskind has presented it. "Writing about physics for a general audience without including the human element," Susskind states in the introduction, "seems to me to leave out something interesting."

That "something interesting" is the personal and emotional colour commentary he provides in what is essentially a science memoir. We learn about Susskind's beginning as a left-wing, New York Jewish plumber-cum-physics student, of his angst-ridden return to Cambridge University, where he had once been the proverbial fish out of water, of his laughing duel with Sir Roger Penrose at Oxford over who would get the last piece of their shared chocolate mousse, and of his confession about how little patience he has had for trying to communicate with Hawking directly because Hawking's responses are careful and slow and presented by his assistant, as well as his annoyance at Hawking's "angelic/devilish smile" of knowing superiority.

Most physics books intended for a general audience provide introductory chapters on the necessary physics, and The Black Hole War is no exception. However, Susskind, a professor of theoretical physics at Stanford University, does a masterful job of translating the incredible complexity of general relativity, quantum physics, string theory and black hole theory into a cheerful romp through the worlds of the very big and the very small. Granted, he does include some equations, because he chooses to respect the intelligence of the reader, but he also makes it possible to skip the equations altogether without harming the story.

I would highly recommend this book to anyone curious about black holes or even just curious about the scientists who devote their lives to such seeming minutiae as whether information that falls into a black hole can ever get out again. This is not to suggest that The Black Hole War is a lightweight book. It deals with some complicated topics, but it also veers off into highly speculative territory when Susskind begins promoting his own theories of the universe.

Hawking did finally announce in 2004 that he had changed his mind and that information did, after all, escape from black holes. It was announced at a press conference, where Hawking paid off a 1997 bet he'd made with Preskill with a baseball encyclopedia. The forgetful Page wondered why he hadn't made a bet with Hawking himself, perhaps suspecting that Hawking would never concede, or because he considered gambling to be a tax on the stupid and Hawking was anything but.

In fact, Page didn't remember his own bet until the spring of 2007, just in time to ferret out the written deal from the floor-to-ceiling stacks of papers crowding his office, meet with Hawking in Texas for an official if reluctant concession that Page had won, and then have it appended to Susskind's book just before it went to press.

Physicists!

Stephen Hawking cheerfully pays off physicist Don Page with a prized "Marilyn Monroe dollar" in December 2007 after losing a bet with Don over whether or not information that falls into black holes is lost to this world forever. Don insisited that would violate the conservation of energy principle, and Stephen eventually conceeded.

Photo courtesy of Don Page

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