At the quantum scale, physics is?

At the quantum scale, physics is?
There is no point in a poll. Quantum mechanics only predicts probabilities.Originally Posted by GiantEvil
What you have in quantum mechannics a deterministic evolution of a set of probability measures. In order to make a measurement you invoke the probability measures, so the theory is stochastic.
You know that, I know that. But there are people out there, wandering around with Stephen Hawking book's under their arm's, saying different. What do I tell them?so the theory is stochastic.
Who are these people? If only I really did see people wandering around carrying physics books under their arms.
I thik he means this post:http://www.thescienceforum.com/viewt...hlight=#247001Originally Posted by saul
I'm confused too.
I've carried a physics book around before. Even read it. Have you?Originally Posted by salsaonline
Have I what? Read a physics book?Originally Posted by GiantEvil
Be careful who you pick on. Salsaonline has most definitely read a physics book or three, and quite a few more mathematics books. You are fighting WAY outside your weight cloass.Originally Posted by GiantEvil
if you observe exactly what dr rocket said. it is a deterministic prediction of propabilities. the propabilities only come in from the measurements we take. as he said here:Originally Posted by GiantEvil
in my post on another topic that you saw fit to refute not in front of me but off on another topic, i had merely stated this fact. if you have a measurement that is 100% accurate then the system is deterministic. and i also stated that we have no such measurement through my reference to the uncertainty principle.What you have in quantum mechannics a deterministic evolution of a set of probability measures. In order to make a measurement you invoke the probability measures, so the theory is stochastic.
in the future if you see it fit to argue what i say without fully understanding it, at least do so in front of me. a private message asking me to explain what i said would have cleared this whole deal up.
You misunderstood what I said.Originally Posted by saul
Quantum mechanics is inherently stochastic.
The probability measure evolves deterministically, but all observables are random variables.
One does not get the same outcome for repeated experiments under the same conditions. One only gets outcomes that are consistent with the probability calculated for those outcomes. Take a tunnel diode, a device that utilizes an inherently quantum mechanical phenomena. One cannot predict which electrons will pass through the potential barrier and which will not. One can only predict the likelihood that tunneling will occur.
The critical difference between quantum mechanics and classical physical theories, including general relativity, is that quantum mechanics only predicts probabilities. It is an inherently stochastic theory.
It does not matter how accurate your measurement might be in principle. If you could measure postion precisely, then what the uncertainty principle would tell you is that you no idea whatever what the momentum might be. A precise measurement does not change the stochastic nature of quantum mechanics, it only makes uncertainty in the complimentary variable unbounded.
I was in a combative mood when I read your above statement, and there projected my own hostilities. Sorry. I see that actually, it is a wistful statement of a better world. And I concur.Originally Posted by salsaonline
P.S. I have not yet voted in this poll. Check the result's.
Edit; Sun, May 23, 12:12 PM; Okay, now I've voted.
I like to tell them that Einstein said "God does not play dice.", then got into debate after debate with Neils Bohr and the other Quantum physicists until one day Bohr finally cornered him and he had to admit he was wrong.Originally Posted by GiantEvil
That's kind of generalized, because I think Einstein kept holding on to his determinism as best he could, but he was never able to gain ground in his debates over it after that.
Bohr told Einstein to refrain from telling God what to do.Originally Posted by kojax
I don't think that Einstein ever really gave up his philosophy that physics should be deterministic. He did not live to see the results of the EPR experiments.
Even today there are serious physicists pursuing deterministic models. I don't think many people, even some of these researchers, hold out much hope. Nature, at the quantum level really does appear to be stochastic. Recent experiments do nothing to dispel the "weirdness", only reinforce it.
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