|
|||
Mead says that Bohr and his followers were largely wrong about quantum mechanics. It's important, however, to understand what he is and what he isn't criticizing. There are really two levels of science involved, best typified by Kepler and Newton. Kepler spent years analyzing data collected over years by Brahe. Brahe kept track of the movements of the planets as positions in the sky, and Kepler wanted to try to work out what their orbits were and how they moved in space. And he succeeded: he determined that the planets moved in ellipses, that the Sun was at one focus of the ellipse, and that they moved at higher speeds when closer to the Sun than when further away. He developed a series of mathematical models which permitted predictions of planetary motion, and they were right; it was a tremendous achievement, and Kepler is rightfully renowned as one of the gods of classical physics. But notably absent from Kepler's work was any explanation of why the planets actually behaved the way they did. It was a very practical model. Newton, on the other hand, achieved a more fundamental understanding with his Universal Law of Gravitation. By the same token, Quantum Mechanics has a lot of formulas which describe how certain fundamental particles will act in various situations; those formulas are true as best we can determine, and their use has lead to such amazing creations as semiconductors, lasers and polymer chemistry. But it's one thing to describe how something will act, and another thing to understand why it happens that way. Mead is not disputing the formulas or the predictions (he'd have to be a fool to do so, and he isn't). But Bohr and his followers went further and tried to create a mental model of physical reality and that is what Mead is complaining about. This is and is not important. It's not important in the sense that it's not going to change those formulas; a hell of a lot of important work has been done with them absent any fundamental understanding of what they mean. As long as they keep providing the right answers, the polymer chemists and semiconductor physicists and a lot of other people are going to continue to use them to turn out new miracles. On the other hand, your mental model can affect how you think about the next advance. Quantum Mechanics is still not complete; it still needs to be unified with General Relativity, for one thing. I'm also not sure I'd agree with Mead's characterization of the 20th century as a new dark age in Physics. That's a bit harsh (though I think he's saying that for shock value). I'd put it a different way: occasionally in Science there will be an advance which expands your horizons, breaks you out of your old domain, and forces you into a whole new level of mystification. In order to make sense of something, you have to be confused about it first. Such periods are times of great ferment, but they're not useless by any means. There was such an interval which commenced with the Michelson-Morley experiment, which shattered the "ether" theory of light, and ended with the development of Quantum mechanics. But in a sense that moved us into a new degree of confusion. (As one wag put it: we're still confused, but we're confused on a much higher level, about much more important things.) That's actually an exciting time. If we're lucky, we'll always be confused at ever increasing levels of complexity and significance. It would really be boring if we understood everything. (discuss) |
|||
