http://online.wsj.com/article_print/0,,SB109953476293464515,00.html
The Wall Street Journal
November 4, 2004
COMMENTARY
Bush and a Butterfly
By MICHIO KAKU
November 4, 2004; Page A14
Another squeaker -- almost. Once again, the presidential election seemed to
teeter -- if only briefly -- on a razor's edge. But for scientists, even
political events can raise scientific questions. Here, one is tempted to
ask something that no one raised on Fox News or CNN: What is the smallest
event necessary to tip the balance?
Meteorologists sometimes talk about the butterfly effect, that even the
flapping of a butterfly's wings might, at critical junctures, tip a storm
cloud into unleashing a downpour. But quantum physicists ask a deeper
question: Can even tiny quantum events tip a presidential election? If so,
then perhaps the entire universe itself splits in half. In one universe,
there is rejoicing in the White House. In another quantum universe, there
is rejoicing in the streets of Paris and Berlin. Both would be possible
universes.
* * *
According to the quantum theory, which rules the sub-atomic world, one can
only calculate probabilities, not definite outcomes. According to the "many
worlds" quantum theory, the universe splits in half each time a quantum
event takes place, creating a cascading "multiverse" of possible universes.
Even the smallest quantum event (like the impact of a cosmic ray) can have
catastrophic consequences. What might have happened if a cosmic ray went
through the womb of Hitler's mother. She might have suffered a miscarriage,
and Hitler would never have been born. Imagine a world in which Napoleon,
Alexander the Great, Julius Caesar, Gandhi, Churchill -- or even George W.
Bush -- were never born due to a tiny quantum event. The mind is sent
swimming by the possibilities. (We physicists like to tell the story of a
Russian physicist who, witnessing the decadence of Las Vegas for the first
time, put all his money on the first bet. When told what a foolish strategy
that was, he replied, "Yes, but in one quantum universe, I shall be rich
beyond imagination!")
But since we cannot make contact with these parallel universes it might
appear that this is just idle talk. Instead of debating how many angels can
dance on the head of a pin, it seems as if physicists are asking how many
universes can spin off from one quantum event.
But there is one very important practical application: the future of
computers and the wealth of nations. By 2020, Silicon Valley may become a
Rust Belt. Moore's law will finally collapse, causing massive disruption in
the world's economy. All things must pass, even the miniaturization of
computer chips, the engine of the world's prosperity.
Why? The Pentium chip today is so compact that it has a layer only about 20
atoms across. By 2020, this layer might become only five atoms across, in
which case the Uncertainty Principle takes over, you don't know where the
electrons are any more, and the chip short-circuits.
Silicon chips are useless at the atomic level. Instead, physicists are
frantically investigating "quantum computers," which compute on individual
atoms. Spinning atoms are like tops, and their axis can be aligned up,
down, or to any angle in between. Bits (like 0s and 1s) are replaced by
"qubits" (quantum bits, which can be 0, 1, and anything in between). What
makes quantum computers so powerful is that they compute not just in our
universe, but in other quantum universes simultaneously. Even the CIA is
interested in quantum computers, since they are so incredibly powerful they
might be able to crack any known code.
Quantum computers are still many decades away. But eventually, the nation
which dominates the world economy may be the one which masters the nano
world of atomic, and quantum computing. Then quantum events, instead of
being the idle talk of quantum philosophers, will be the source of the
world's wealth.
The Silicon Age is coming to a close. Welcome to the Quantum Age, where
even button-down bankers will have to learn the mysteries of the
multiverse. Not to mention those who do the exit polls at American
presidential elections!
Mr. Kaku, the Henry Semat Professor of Theoretical Physics at the City
University of New York, is the author of "Parallel Worlds," forthcoming in
January from Doubleday.
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R. A. Hettinga