To get the real meaning you have to consider subatomic particles, in order to know where something is or how fast it is going you have to interact with it - e.g. shine a light on it ,or if it is charged pass it through an electromagnetic field perhaps. By doing so you give the "thing" a small amount of energy which may alter it's speed or position. So you have the situation - was it where we see it now before we shone the light on it ? Try measuring something without adding to, or taking away some of , it's energy - very difficult. Want to make some real money and a Nobel prize ? -Sort that lot out. Geoff. ----- Original Message ----- From: "Roger Merchberger" <zmerch(a)30below.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk(a)classiccmp.org> Sent: Friday, October 31, 2003 6:40 AM Subject: Re: Is there a physicist in the house? '50 speed meaningless... school...),

And if you have such an argument and it _is_ right, all you've shown is that Newtonian mechanics and Heisenberg are incompatible, that they cannot both be right. Which, if either, _is_ right is a question for experiment, not theorizing. (My money would be on Heisenberg in such a case.) That's part of it; the Pauli exclusion principle is also related. The exclusion principle says that particles with non-integer spin (fermions, such as electrons with their spin ??) cannot be identical: two such particles must differ in location, or spin, or some such. This is why atoms have electron shells that can fill up - for example, the first shell is spatially symmetric, and thus can tolerate only two electrons, one with spin +? and one with spin -?; the next shells are lobed, with three such available (one for each spatial dimension), holding two electrons each. Fermions display Fermi-Dirac statistics, I think the term is. Particles with integer spin (bosons, such as photons with their zero spin) can be as identical as they care to; they are said to display Bose-Einstein statistics. As you say, when particles get very cold, their momentum becomes very small, to a high degree of precision, which means their position becomes correspondingly _un_certain: they fuzz out, to put it loosely. But if you try this with fermions, they resist overlapping because of the exclusion principle[%]; you have to do it with bosons to get anything really interesting. (This is why helium-4 becomes superfluid but helium-3 doesn't: that extra neutron makes the difference between the nuclei being fermions and their being bosons.) With fermions, all you get is zero-point motion (particles still jiggling around some regardless of how close to absolute zero you get; they refuse to sit still because that would give them very precise position _and_ velocity, and fuzzing out into a B-E condensate would make them overlap with other fermions.) [%] Actually, "because of" is a very imprecise way of putting it. We do not know _why_ the world works this way; we do not know even that there _is_ a "why". All we know is _that_ it does, and the exclusion principle is just a description of one aspect of the way the world works. To say that the exclusion principle is _why_ something happens is, strictly speaking, mistaking description for causality. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse(a)rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

Jerome Fine replies: Ummmmm ... I think the problem, Fred, is that the English language was being used - perhaps that might be the reason why you ... I don't normally jump in on these "discussions", but this was one response I could not seem to resist. Actually, I probably did not understand the explanation any more than Fred did, however, I do realize that VERY small concentrations of energy / matter are being discussed - and that is what makes all the difference between what is ordinary and what takes place at a level that is (almost?) totally beyond normal human senses. As stated in this discussion, a lot of what is observed is not actually understood as to the reasons WHY! Perhaps some theories might explain some observations in a few centuries, but right now I seem to understand that even electricity can't actually be explained, only observed and measured. Part of the reason is that the universe is a VERY delicate balance. Change a few of the constants by even a small percentage and life as we observe it here on the Earth could not exist. Just one example is H2O. It is one of the few compounds which is lighter in the normal (or usual) frozen state than in the liquid state with which is is in contact. Ice bergs FLOAT!! I don't know or understand enough to provide other specific examples, let alone describe even a few of the states of frozen H2O. At the other end of the spectrum, the VERY (IMPOSSIBLY?) LARGE, other very interesting things (phenomenon) also occur. Black holes are just one example. Our universe is extremely interesting! Sincerely yours, Jerome Fine -- If you attempted to send a reply and the original e-mail address has been discontinued due a high volume of junk e-mail, then the semi-permanent e-mail address can be obtained by replacing the four characters preceding the 'at' with the four digits of the current year.