CSflim

Basically, Quantum Mechanics appears to be random. Most physicist would tell you that indeed it is random.

Bohm likes quantum randomness to the pseudo-randomness of Brownian motion...if you place a tiny particle into a glass of "still" water, it will jump and dodge all over the place, in an apparently random manner, and apparently defying Newtons deterministic laws of mechanics.

But we know the brownian motion is not random. It just requires a deeper understanding of what exactly a liquid is. It is a whole bunch of particles bouncing around off each other. We can now see that the apparenty randomness of Brownian motion is in fact perfectly deterministic...just very difficult to predict, given the fact that you cannot take the liquid to be "uniform" instead you need to take into account the position of every single particle that makes up that liquid.

Bohm argues that the pseudo-randomness of quantum mechanics is the same. Rather than accepting the randomness, we need to search for a "deeper reality" behind it.
So he proposed the idea of "hidden variables" to account for quantum mechanical behavior, the idea being that the quantities that we can measure are just manifestations of some unmeasurable quanties.

It seemed as good an interpretation of quantum reality as any. Then along came Von Neumann, and other nay-sayers. Von Neumann, the superb mathematician (directly responsible for the architechture of the computer you are using to read this post) came up with his "impossibility proof", a theorem, showing that NO system of hidden variables, could account for the observed effects of quantum mechanics. And so "hidden variables" was pretty much unanimously disregarded by all within the scientific community. Determinism was dead. Quantum randomness ruled.

But Von Neumann HAD NOT in fact disproved the principle of hidden variables. He had made one unfounded assumption. As a result his "impossibility proof" disproves the correctness of any LOCAL hidden variables interpretation. It did not disprove the possibility of a non-local reality. And it is from this that I believe that this thread's main article spawns.

If you let go of your preconcieved notion of "space" and "distance", then it is possible to formulate a theory of hidden variables. This is what Bohm proves in this book. He is not saying that: Here is how the deeper reality of hidden variables works, but rather he is saying: Here is a mathematical model of a non-local reality, which can be shown to be in agreement with quantum mechanical observations.

So in essence, this chapter proves Von Neumann wrong. It is possible to define a reality of "hidden-variables", albeit a non-local one.

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