Quote:
Originally Posted by The Lone Ranger
Quote:
Originally Posted by davidm
Of course you can set up experiments that amplify quantum probabilities to macro scale; this is the idea behind the famous Schroedinger's Cat thought experiment.
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True, though a lot of people mis-understand Schroedinger's point. He came up with the thought experiment to illustrate the absurdity of thinking of macroscopic objects as being in indeterminant states. His point was that the cat is not in some in-between, neither-dead-nor-alive state, but simply that it's not possible to know which state (dead or alive) it's in until you open the box.
The cat, being a complex system that's well above the level at which quantum indeterminacy applies, will have definitely caused the "collapse" of the wave function, and so will be in one of the two possible states before the box is opened. It's just that it's not possible for an outside observer to know which one before you open the box. |
I'd disagree, Michael. The equation of quantum mechanics are perfectly correct in describing a cat in a quantum-superposition of states. There's
no process by which wave-functions 'collapse' (it's actually completely inconsistent with Schrodinger's equation!), nor do large, complex systems cause any such thing. Browsing wikipedia informs me that we've set up superpositions with objects of ~10 trillion atoms; at what number of atoms should we call this a 'macroscopic' effect?.
Interaction with the environment can lead to a similar thing happening in a smooth sort of way (
quantum decoherence), but that's a practical point, not one of principle. And even then, the 'collapse' is not
perfect; there's always a smidgen of dead-cat superposed with alive-cat, or vice-versa.
Schrodinger's goal was indeed to point out the absurdity of applying quantum mechancis to macroscopic scales; the correct response is that the absurdity is entirely correct. We don't 'experience' such absurdity because quantum mechanics doesn't predict we will. But that doesn't mean such a thing isn't a correct
description of the universe in the language of quantum mechanics.
You should be trying to interpret macroscopic, classical experiences in terms of quantum mechanics, not trying to explain quantum mechancis in terms of macroscopic, classical experiences.