[Paleopsych] Slate: Theory of Anything? - Physicist Lawrence Krauss turns on his own.
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Theory of Anything? - Physicist Lawrence Krauss turns on his own. By
[I am quite patient and will be glad to wait for string theorists to come up
with something testable.]
Theory of Anything?
Physicist Lawrence Krauss turns on his own.
By Paul Boutin
Posted Wednesday, Nov. 23, 2005, at 11:44 AM ET
Lawrence Krauss, a professor of physics and astronomy at Case Western
Reserve University, has a reputation for shooting down pseudoscience.
He opposed the teaching of intelligent design on The NewsHour With
Jim Lehrer. He penned an essay for the New York Times that dissed
President Bush's proposal for a manned Mars mission. Yet in his latest
book, Hiding in the Mirror, Krauss turns on his own--by taking on
string theory, the leading edge of theoretical physics. Krauss is
probably right that string theory is a threat to science, but his book
proves he's too late to stop it.
String theory, which stretches back to the late 1960s, has become in
the last 20 years the field of choice for up-and-coming physics
researchers. Many of them hope it will deliver a "Theory of
Everything"--the key to a few elegant equations that explain the
workings of the entire universe, from quarks to galaxies.
Elegance is a term theorists apply to formulas, like E=mc^2, which are
simple and symmetrical yet have great scope and power. The concept has
become so associated with string theory that Nova's three-hour
2003 series on the topic was titled The Elegant Universe (you can
watch the whole thing online for free here).
Yet a demonstration of string theory's mathematical elegance was
conspicuously absent from Nova's special effects and on-location
shoots. No one explained any of the math onscreen. That's because
compared to E=mc^2, string theory equations look like spaghetti. And
unfortunately for the aspirations of its proponents, the ideas are
just as hard to explain in words. Let's give it a shot anyway, by
retracing the 20^th century's three big breakthroughs in understanding
Step 1: Relativity (1905-1915). Einstein's Special Theory of
Relativity says matter and energy (E and m in the famous equation) are
equivalent. His General Theory of Relativity says gravity is
caused by the warping of space due to the presence of matter. In 1905,
this seemed like opium-smoking nonsense. But Einstein's complex math
(E=mc^2 is the easy part) accurately predicted oddball behaviors in
stars and galaxies that were later observed and confirmed by
Step 2: Quantum mechanics (1900-1927). Relativistic math works
wonderfully for predicting events at the galactic scale, but
physicists found that subatomic particles don't obey the rules. Their
behavior follows complex probability formulas rather than graceful
high-school geometry. The results of particle physics experiments
can't be determined exactly--you can only calculate the likeliness of
each possible outcome.
Quantum's elegant equation is the Heisenberg uncertainty
principle. It says the position (x) and momentum (p) of any one
particle are never completely knowable at the same time. The closest
you can get is a function related to Planck's constant (h), the
theoretical minimum unit to which the universe can be quantized.
Einstein dismissed this probabilistic model of the universe with his
famous quip, "God does not play dice." But just as Einstein's own
theories were vindicated by real-world tests, he had to adjust his
worldview when experimental results matched quantum's crazy
predictions over and over again.
These two breakthroughs left scientists with one major problem. If
relativity and quantum mechanics are both correct, they should work in
agreement to model the Big Bang, the point 14 billion years ago at
which the universe was at the same time supermassive (where relativity
works) and supersmall (where quantum math holds). Instead, the math
breaks down. Einstein spent his last three decades unsuccessfully
seeking a formula to reconcile it all--a Theory of Everything.
Step 3: String theory (1969-present). String theory proposes a
solution that reconciles relativity and quantum mechanics. To get
there, it requires two radical changes in our view of the universe.
The first is easy: What we've presumed are subatomic particles are
actually tiny vibrating strings of energy, each 100 billion billion
times smaller than the protons at the nucleus of an atom.
That's easy to accept. But for the math to work, there also must be
more physical dimensions to reality than the three of space and one of
time that we can perceive. The most popular string models require 10
or 11 dimensions. What we perceive as solid matter is mathematically
explainable as the three-dimensional manifestation of "strings" of
elementary particles vibrating and dancing through multiple dimensions
of reality, like shadows on a wall. In theory, these extra dimensions
surround us and contain myriad parallel universes. Nova's "The Elegant
Universe" used Matrix-like computer animation to convincingly
visualize these hidden dimensions.
Sounds neat, huh--almost too neat? Krauss' book is subtitled The
Mysterious Allure of Extra Dimensions as a polite way of saying String
Theory Is for Suckers. String theory, he explains, has a catch: Unlike
relativity and quantum mechanics, it can't be tested. That is, no one
has been able to devise a feasible experiment for which string theory
predicts measurable results any different from what the current wisdom
already says would happen. Scientific Method 101 says that if you
can't run a test that might disprove your theory, you can't claim it
as fact. When I asked physicists like Nobel Prize-winner Frank
Wilczek and string theory superstar Edward Witten for ideas about
how to prove string theory, they typically began with scenarios like,
"Let's say we had a particle accelerator the size of the Milky Way
..." Wilczek said strings aren't a theory, but rather a search for a
theory. Witten bluntly added, "We don't yet understand the core idea."
If stringers admit that they're only theorizing about a theory, why is
Krauss going after them? He dances around the topic until the final
page of his book, when he finally admits, "Perhaps I am oversensitive
on this subject ... " Then he slips into passive-voice
scientist-speak. But here's what he's trying to say: No matter how
elegant a theory is, it's a baloney sandwich until it survives
Krauss should know. He spent the 1980s proposing formulas that worked
on a chalkboard but not in the lab. He finally made his name in the
'90s when astronomers' observations confirmed his seemingly outlandish
theory that most of the energy in the universe resides in empty space.
Now Krauss' field of theoretical physics is overrun with theorists
freed from the shackles of experimental proof. The string theorists
blithely create mathematical models positing that the universe we
observe is just one of an infinite number of possible universes that
coexist in dimensions we can't perceive. And there's no way to prove
them wrong in our lifetime. That's not a Theory of Everything, it's a
Theory of Anything, sold with whizzy PBS special effects.
It's not just scientists like Krauss who stands to lose from this;
it's all of us. Einstein's theories paved the way for nuclear power.
Quantum mechanics spawned the transistor and the computer chip. What
if 21^st-century physicists refuse to deliver anything solid without a
galaxy-sized accelerator? "String theory is textbook post-modernism
fueled by irresponsible expenditures of money," Nobel Prize-winner
Robert Laughlin griped to the San Francisco Chronicle earlier this
Krauss' book won't turn that tide. Hiding in the Mirror does a much
better job of explaining string theory than discrediting it. Krauss
knows he's right, but every time he comes close to the kill he stops
to make nice with his colleagues. Last year, Krauss told a New York
Times reporter that string theory was "a colossal failure." Now he
writes that the Times quoted him "out of context." In spite of
himself, he has internalized the postmodern jargon. Goodbye,
Department of Physics. Hello, String Studies.
Related in Slate
Superstring theory is "currently the only plausible candidate for a
Theory of Everything," according to this 1996 article by Jim Holt.
In 2004, Amanda Schaffer labeled Elegant Universe author and
string theory aficionado Brian Greene "the closest thing physics has
to a pop star." David Greenberg debunks the myth that Einstein's
theory begat moral relativism and artistic modernism. Holt writes
about the end of the universe here. Learn about "quantum
weirdness" in this dialogue.
Paul Boutin is a Silicon Valley writer who spent 15 years as a
software engineer and manager.
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