[tt] NYTBR: Leonard Susskind: The Black Hole War

[Premise Checker]

Leonard Susskind: The Black Hole War
http://www.nytimes.com/2008/08/24/books/review/Johnson-t.html

The Theory That Ate the World
By GEORGE JOHNSON

THE BLACK HOLE WAR
My Battle With Stephen Hawking to Make the World Safe for Quantum 
Mechanics
By Leonard Susskind
470 pp. Little, Brown & Company. $27.99

This is your universe on acid: 10 dimensions of space, seven of
which we cannot see, filled almost entirely with dark matter and
dark energy -- invisible thought stuff that serves to make the
cosmologists' equations come out right.

The cosmologists are stuck, with the rest of us, in Dimensions 1
through 3, and we are all made from what Earthlings quaintly regard
as ordinary particles, the tiny fraction of matter that radiates and
reflects mysterious waves called light. Compounding the indignity,
this afterthought of an existence may be only an illusion -- a
holographic projection of some two-dimensional flatland that
stretches like a timpani skin across the very edge of space. Plato
had it backward. It's the shadows on the wall that are real.

At night when our brains are unplugged from our senses and
error-correction is off, we dream furiously. And so it is with
21st-century physics. Undeterred by experimental data -- it would
take a particle accelerator as big as the galaxy to test some of the
latest cosmological contrivances -- theorists have found a new role
as entertainers, scientific Scheherazades.

Leonard Susskind, a professor of theoretical physics at Stanford, is
one of the wiliest. Three years ago in "The Cosmic Landscape: String
Theory and the Illusion of Intelligent Design," he spun a tale of a
multitude of different universes -- nooks and crannies of a
transcendent multiverse, or "landscape," each ruled by a different
physics. This is probably the most controversial interpretation of
superstring theory (some of Susskind's colleagues absolutely hate
the idea), but it has its appeal. With so many universes out there,
the fact of our own existence need not inspire worship and awe. We
just happen to occupy one of the niches where the laws are favorable
to carbon-based life.

In his new book, "The Black Hole War: My Battle With Stephen Hawking
to Make the World Safe for Quantum Mechanics," Susskind's cosmos
gets even weirder. Black holes already seemed scary enough, with
their ability to swallow everything, including light. For a while,
we learn, physicists were faced with the possibility that these
cosmic vortexes might also be eaters of order, sucking up and
destroying information. Like the Echthroi, the evil demons of
entropy in Madeleine L'Engle's novel "A Wind in the Door," black
holes might be chomping their way through the universe, ploughing
sense into nonsense.

The story of how Susskind and a colleague, the Dutch physicist
Gerard 't Hooft, disproved (or at least undermined) the theory
begins in 1983 at a San Francisco mansion owned by, of all people,
Werner Erhard, the New Age entrepreneur who had made his fortune
with a profitable cult called EST. Erhard, we're told, was also a
"physics groupie," and he presided over salons in which some of the
world's great theorists came to butt minds.

The trouble began when Stephen Hawking made an astonishing
prediction about what happens when information -- a book, a
painting, a musical recording or any pattern of matter or energy --
falls into a black hole. Earlier, Hawking had proved that black
holes eventually evaporate -- at which point, he now claimed,
everything inside them disappears from the universe.

That might not sound like such a big deal. Just find another copy of
whatever was lost. But that, Susskind realized, was not the point.
Among the fundamentals of physics is that information must always be
conserved. Even if you throw a DVD into a wood chipper, it is
possible in theory (important weasel words) to chase down the
splinters and recover the songs. Burned books can be reassembled
from the smoke and ashes. Physics, in other words, dictates that
everything that happens must be reversible. And that means
information cannot be allowed simply to vanish.

Even worse, quantum mechanics predicts that empty space seethes with
tiny "virtual black holes," popping in and out of existence and
gobbling up bits. If Hawking was right, Susskind concluded, "the
foundations of our subject were destroyed."

Not everyone was quite so alarmed. But Hawking's information
paradox, as it came to be called, opened an arena in which two great
theories of physics -- general relativity, describing gravity, and
quantum mechanics, describing everything else -- duked it out.

I was eager to learn how, in the end, Susskind and company showed
that Hawking was probably wrong -- that information is indeed
conserved. But first I had to get through a 66-page crash course on
relativity and quantum mechanics. Every book about contemporary
physics seems to begin this way, which can be frustrating to anyone
who reads more than one. (Imagine if every account of the 2008
presidential campaign had to begin with the roots of Athenian
democracy and the heritage of the French Enlightenment.)

Finally we get to the heart of the story, and it turns out to be a
mind-bender. 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.

Susskind explains this dizzying notion about as clearly as is
probably possible. Every time a bit falls into a black hole, its
opening expands by one square Planck length -- an area billions and
billions of times smaller than a proton. It is because of this
phenomenon, Susskind contends, that the information isn't lost. A
description of everything that falls into a black hole, whether a
book or an entire civilization, is recorded on the surface of its
horizon and radiated back like imagery on a giant drive-in movie
screen. As with a hologram, three dimensions are contained within
two.

Strangest of all, we learn, this holographic conjecture -- elevated
in the book, perhaps prematurely, to the holographic principle --
may apply to the entire universe. Hence the notion of our own
reality as an illusory projection of some flatlanders' membrane
world. It's as though the pixilated people we see on television are
real and the actors are only secondary manifestations.

Or something like that. How this all fits together is still pretty
murky. "Getting our collective head around the holographic principle
is probably the biggest challenge that we physicists have had since
the discovery of quantum mechanics," Susskind admits. He speculates
at one point that our big bang of a universe is some kind of
"inside-out black hole" -- one that spews everything outward instead
of sucking it in.

But wait. Maybe it just looks that way because time is moving
backward! Or -- who knows? -- maybe our universe is really a 3-D
projection of a 4-D world falling through some hyperdimensional
gullet!

Toward the end of the book Susskind quotes Hawking: "We are just an
advanced breed of monkeys on a minor planet of a very average star.
But we can understand the universe."

Maybe. But not without a lot more data.

George Johnson is the author of Fire in the Mind: Science, Faith,
and the Search for Order. His most recent book is The Ten Most
Beautiful Experiments.