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Can somebody explain how the idea of randomness and quantum mechanics are often paired up? Why is it that quantum mechanics is random?
Surely the Heisenberg principle implies randomness - due to the uncertainty involved. I.e if the value of a body's position cannot be known exactly then is there not a randomness about that effective position?
Interesting but does it specifically rule out the random element if the outcome is measured in a conventional way?
Or are you implying that what goes on at a level we don't understand and can't measure may, in fact be non-random and capable of being determined exactly?
Is it the reduction to a "simple form" that introduces the random experience?
Can somebody explain how the idea of randomness and quantum mechanics are often paired up?
Why is it that quantum mechanics is random?
ok, so let's say i believe that quantum mechanics is truly random. how is it, then, the the classical world seems so deterministic?
is that just a psychological bias?
also, if the quantum mechanical scale is so small, does/could it have an impact on free will?
The last attempted answer I read was something along the lines that in most large scale situations all the myriad different quantum mechanical things that could happen at the microscopic level all do more or less the same thing in aggregate, so the universe diverges a lot less than you would expect
(for example in the twin slit the photon has gone through *both* slits- it must have done so to give that interference pattern).
If it doesn't actually need to exist whilst the energy is on the way, I say that you needn't actually claim that it is anywhere in particular.Which is the bigger problem to deal with - "it's in two places at once" or "it's nowhere"? It could hurt your brain to reconcile either of those with normal everyday experiences. No need to try.
Well, in the quantum electrodynamics formulation of QM the particle has gone every route to get from the emitter to the receiver, so, yes you can say that it has gone through both.
I think that it will only stop stop hurting brains, when we accept and don't fight against certain ideas. We must stop triumphantly quoting 'paradoxes' and open up to the possibility that paradoxes can always be resolved by altering the way of looking at things. When we can achieve that, QM and the rest will no longer appear to resist us.
Why did the particle have to go through any slits at all?
Careful here, in QED the particle has a vector that rotates as the particle travels. Dyson showed that if you do that correctly then the sum of the vectors is just the wavefunction, so it's equivalent to the normal Schroedinger equation.
I don't think I can accept randomness. Not even a single computer in this world can create a pure random number. It simply doesn't exists.
The randomness of radioactive decay can be made as an example. They say, although we know the exact rate of decay, we don't have any idea which one will decay first. For me, the notion of half life itself shows us that there are actually some system governing it. It wasn't random, it just we don't understand it yet. Otherwise, there won't be any notion of half-lives...
I hope Albert Einstein is still alive today to unscrew quantum mechanic's mess...
You just look at the diffraction pattern, which, really, on its own, shows that it has gone through both slits,
Quote from: wolfekeeper on 07/07/2009 14:09:05You just look at the diffraction pattern, which, really, on its own, shows that it has gone through both slits,Yes, but *what* has gone through both slits? The particle?
Actually there are computers that use quantum effects to generate random numbers. In fact non deterministic electronics is not at all difficult, resistors have significant random noise.
To measure really small stuff in the real world is a very very tough job. Consider this, it have to be in absolute zero temperature, no light, not a single photon, not on earth because of the gravity and magnetic distortion, not to mention the absolute necessary to protect from electromagnetic waves... Just impossible...
QuoteI hope Albert Einstein is still alive today to unscrew quantum mechanic's mess...No, he died, and he had even less luck than other physicists really with QM.
QuoteActually there are computers that use quantum effects to generate random numbers. In fact non deterministic electronics is not at all difficult, resistors have significant random noise.Remember our old friend the hiss in radios? We know now it is actually came from background radiation from outer space. Most probably the same thing happened to resistors.
Quote from: wanhafizi on 08/07/2009 01:58:02QuoteActually there are computers that use quantum effects to generate random numbers. In fact non deterministic electronics is not at all difficult, resistors have significant random noise.Remember our old friend the hiss in radios? We know now it is actually came from background radiation from outer space. Most probably the same thing happened to resistors.Nope, that's not it in this case. There's something called 'shot noise' which is random noise due to the movement of individual electrons through the resistor. It's actually a measureable amount of noise, and electrons are quantum entities.
so, to sum up this thread: evidence for QM randomness is like evidence for god - you can believe in it, but you just don't know if it's actually true or not.is that right?
No. We actually have reproducible experimental evidence for quantum randomness. There is no reproducible experimental evidence for God.
Actually, it's the other way around, external interference acts as a measurement and destroys the interference fringes because the wavefunction loses coherence.
The facts is, we cannot measure any small stuff without 'touching' it. We used electron, photon, magnetic waves to measure by 'touching' what we are measuring. This causes the system being measured to be literally effected.
Otherwise, you, your actions, your mind are really just a summation of of your biology, nerve fibers, electrical charges in your brain and your surroundings.
Well, you have to look at the evidence- if you change your biology in even minor ways (drugs, strokes, surgery), it seems that you change your mind and will; so it seems to me that freewill is a product of biology (at bottom memory is a biological function).
... i am a hard determinist ...