<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. -- ----------------- R. A. Hettinga <mailto: rah@ibuc.com> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'