In truth I know very little about the subject, so this is somewhat an ignorant speculation, and I invite other insight, and comments. However I have recently been doing some self motivated research. To me the hidden variables theory makes the most sense, yet it seems most people are more inclined to believe Indeterminism reigns supreme at the quantum level. It seems outlandish to me that so many would presume there is no causal factors explaining some uninterpretable phenomenon regarding quantum particles, and that they would rather explain it away by saying particles act on chance to some degree. I've done a little bit of reading on Schrödinger's cat, Bell's theorem, and the de Broglie-Bohm theory. Can anyone lead me to good evidence that quantum mechanics is, or is not, determinate?
Hah yeah, I was a bit skeptical about the title at first, too - but it's not what it sounds like it is. It is quite a bit of speculation, but if you're reading Brian Greene and can tolerate his description of string theory, it's pretty much at the same level as that.
Ah! How could I forget about Michio Kaku?! Definitely read "Physics of the Impossible".
I get the feeling that perhaps modern quantum mechanics is a close approximation based on evidence, and formulated to reproduce that evidence as closely as possible. However is still missing some fundamental variables.
I would be very grateful if you could provide a source from a scientific publishing that outlines the experiment you've described, especially regarding the pattern being different when observed prior to hitting the screen.
Yep. This is essentially what I mentioned in one of my previous posts. Hidden variables are virtually ruled out as likely explanations for any and all of this phenomena. We'd have to make a hell of a lot more assumptions were we to assume hidden variables, and that would just be incredibly bad science.
You can read almost any "popsci" physics book, and it has a description of that experiment usually, Brian Greene's (who is a very good theoretical physicist) Fabric of the Cosmos has a good description of it in the chapter "Time and Quantum". Here is a quote from it: "When a single photon hits a beam splitter, classical intuition says that it will either pass through or will be reflected. Classical reasoning doesn't even allow a hint of interference, since there is nothing to interfere: all we have are single, individual, particulate photons passing from source to detector, one by one, some going left, some going right. But when the experiment is done, the individual photons recorded over time do yield an interference pattern. According to quantum physics, the reason is that each detected photon could have gotten to the detector by the left route or by going via the right route. Thus, we are obliged to combine these two possible histories in determining the probability that a photon will hit the screen at one particular point or another. When the left and right probability waves for each individual photon are merged in this way, they yield the undulating probability pattern of wave interference... you can insert additional detectors, but if you do, you will find two things. First, each electron and each photon will always be found to go through one and only one of the detectors; that is, you can determine which path each electron or photon follows, and you will find that it always goes one way or the other, not both. Second, you will also find that the resulting data recorded by the main detectors have changed. Instead of getting the interference patterns, you get the results expected from classical physics."
At this point, there's no reason to think there are hidden variables - no evidence points to it whatsoever. It very well might be the case that there are in fact hidden variables, but again there's never been any trace of these variables in any experiments thus far. It doesn't intuitively make sense, but it works, and all the experimental data points towards it, and that's all that matters until evidence to the contrary comes along.
Ninja, if you're still not satisfied you can easily find information on other important experiments in QM. The book by Heisenberg I mentioned earlier has a whole chapter dedicated to outlining these important experiments: (C.T.R. Wilson Experiments, more diffraction experiments, emission, absorption and dispersion of radiation, interference & conservation laws, Compton Effect, radiation fluctuation phenomena, ...)