CompuServe Messages

The Heisenberg Uncertainty principle really only applies at the sub-atomic level (the micro-scopic as opposed to the macro-scopic), and basically states that you can not know, with complete accuracy, both the position and velocity of a particle. You can know absolutely where a particle is, but nothing about its velocity — or you can have a rough idea of both its position and velocity — or alsolutely know its velocity but have no idea of its position. The more you know about one, the less you can know about the other. Yes, Quantum Mechanics DOES state that the act of observing a system alters that system. The most famous example of this is the mind experiment known as Schroedinger's Cat. You put a cat in a box, along with a mechanism for releasing a poison gas. The poison-trigger is an isotope that has a 50/50 chance of decaying by half in a minute, say. So, if the isotope decays, the cat dies — if not, the cat lives. Now, the question is, what happens if you don't open the box. The theory goes that all the possibilities (in this case two: cat=dead / cat=alive) co-exist simultaneously as wave functions as long as the system (cat/poison) remains unobserved. So until the VERY moment that you open the box, the cat is both alive AND dead. At that precise instant, one waveform collapses and the other is actualized. (Although, in the many-worlds theory, BOTH events happen, as the universe constantly fractures at every decision-point into multiple realities — so suddenly there would be two universes — one where the cat lived and one where the cat died. Again, remember that this is a THOUGHT experiment, and just meant to illustrate a concept. Again, the real theory only applies at the sub-atomic level, so don't try this at home, kids!<g> For those interested in Quantum Mechanics, I'd reccommend the book "The Dancing Wu Li Masters". Dave