[dixieflatline]

Originally Posted by Quiksand

Fine, we can’t measure everything, so we won’t be able to know where things are and how they are moving. But they still are somewhere, and they still are moving, right? So they still do, in fact, have all those various physical interactions with one another, even if we cannot measure them in any practical way.

So, if that’s the case… how do we escape from the clockwork universe concept? I buy Heisenberg’s uncertainty in measurement, but it doesn’t (intuitively, at least) translate to reality for me.

Sorry to get to this late. I was talking to a friend about similiar things and stumbled on a couple of very useful webpages that might help the confusion if you haven't figured everything out yet.

Your first question is basically is: even if we can't measure all the variables about a particle as long as it they still exist then the particles should behave in known(clockwork) way.

Young did an experiment where he shot a beam of electrons through a double slit looking for diffraction. If he found diffration then electrons had to behave like waves going through the slits. That is exactly what he saw, the electrons were interacting with each other, like waves, causing a diffraction pattern to emerge. From reading your first post it sounds like you already have some grasp on this but now the fun part.

Young took his apparatus and shot single electrons through the slits. With nothing else to interact with the electrons should just go through a slit and hit his detector. But that isn't what he saw. He again found diffraction patterns. It took a while but the single electrons gradually built up to the same pattern as before. Some really neat pictures of his detector here


What's going on here? It turns out that the electrons were interacting with themselves. As the electrons pass through the slits it is equally likely to go through each slit. Once on the other side the two wavefuctions are combined again but combined like waves producing diffraction. If the world was clockwork then the elctrons would have had a specific position and velocity and gone through exactly one slit and when combining the wavefuction on the other side it would be 100% from one and 0% from the other. The only way this experiment works out is if you combine the wavefuctions 50%/50%. So which slit did the electron go through? It's just not a question that we can answer.

It seems that my scientific believes aren't exactly in high reguard so for those at home that don't believe in this wave/particle duality here is an experiment you can do at home to show quantum mechanics is necessary in understanding the universe.

Take three high quality pairs of polarized sun glasses. Setup two pair of glasses next to a light source such that no light passes through. One pair of glasses is now only letting light polarized up and down go through( | ) and the other pair is only letting light polarized left and right go through ( - ). Now add a third pair of glasses polarized at a 45 degree angle ( / ) in between the first two. Rotate the middle pair if you can't tell what direction 45 degrees is you will find it. Remarkably light now passes through all three pair. This cannot be explained classically only with wavefuctions and quantum mechanics.