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Old 09-08-2003, 03:13 PM   #13 (permalink)
CSflim
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Quote:
Originally posted by filtherton
Doesn't quantum uncertainty essentailly boil down to the idea that you can't at the same time know where exactly something is, and it's velocity.
Maybe i'm a dummy, but how does our inability to currently understand the behavior of certain subatomic particles have to do with determinism?
As i understand it determinism has to do with the idea that everything that will ever happen was set in motion unchangably by the big bang at the beginning of the universe, while quantum uncertainty simply states that we can't know exactly what is going on down there.
I guess that i don't understand how our ability to understand the behavior subatomics has anything to do with the idea that everything that will ever happen was determined the moment the universe exploded.
The universe does what it does regardless of whether we can understand it.
Hmmmm...depends who you ask.
David Bohm would liken the randomness of quantum mechanics to the pseudo-randomness of Brownian motion: i.e. apparent randomness occurring due to (deterministic) occurrences at a deeper level.

This is what led Bohm to put forward his theory of Hidden Variables i.e. that the randomness apparent in quantum mechanics is only a manifestation of some deeper reality at a sub quantum level. However the hidden variables theory has been largely discounted, most notably by Niels Bohr and John Von Neumann, who disproved the possibility of a hidden variables system as originally put forward by Bohm.
Because of this most physicists do not accept Bohm's conjecture.
However, Bohm describes a system of hidden variables that do not suffer from the same assumptions that allowed Von Neumann and Bohr to discredit his previous proposal. However to me this revised hidden variables seems to really stretch the boundaries of believability, as it requires such a radical change in our picture of reality. To be honest with you, I would reject Bohm's theory on the basis of Occam's razor...for now.
Bohm's theory could be validated. He describes possible experiments to carry out to verify his theory. One of these would break Heisenberg's Law...which would certainly shake up the quantum physics community! However Bohm did not describe a means to carry out these said hypothetical experiments, and they are currently beyond our means.
So for the moment at least it seems that randomness is an inherent property of nature!

So to answer your question: For the vast majority of the physicist community, yes quantum events are random, and not just random to the extent of our inability to measure accurately enough.

To give a solid example, take a radioactive atom. We know that in time it will disintegrate, giving out radiation. The question is when. It seems that there is no way to predict this...it is random.

For more information on Bohm's Hidden Variable's theory, check out Order and The Implicate Wholeness by David Bohm. (requires at least a layman’s understanding of quantum mechanics, and gets a bit heavy on the maths at times, but for the most part, the maths can be skimmed over without any major loss to the overall narrative).
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