Mystery of levitation 'solved'

CarpBrain said:
Here's a question about the Casimir force that struck me recently:

If the Casimir force is caused by lower density vacuum fluctuations, and the force causes two parallel plates to move toward one another, then where does the energy come from to do the work on the plates?

If it comes from the vacuum fluctuations, then there needs to be a corresponding decrease in energy elsewhere in the system. I'm seeing this explanation as analogous to Hawking radiation along the event horizon of a black hole, where the production of the radiation causes a mass evaporation effect on the black hole. I've been digging around the archives, but haven't found anything that satisfactorily explains this. Any thoughts from our other resident physicists?

If I remember correctly, the Casimir energy is negative and diverges as the separation vanishes. So the KE of the plates' motion should be compensated by a decrease in the Casimir energy (it gets more negative). I'll try to remember to look this up tomorrow at work.
 

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freebfrost said:
Nor was there evidence of gravity prior to Newton, correct?

No. There was evidence for gravity before Newton - things were observed falling to the ground for thousands of years prior to his birth, but had been explained incorrectly. Newton looked at the observed phenomena, and figured out why it was actually happening.

The analogy you want is Einstein - there was effectively no evidence that the speed of light in a vacuum was constant before he considered that as an axiom for the theory of special relativity. Nobody had thought to bother, and the devices required to test with sufficient accuracy and precision had not yet been built.

Our experience with reality is bounded by our current perceptions of reality. We can only attempt to prove what we know - we can't prove what we do not yet know. Heck, we still can't explain gravity.

Incorrect. The scientific method, in fact, is a series of attempts to prove things we do not know - many fail, some succeed. We cannot attempt to prove that which we cannot imagine, but imagining a thing and knowing it are two different things. Ask any sci-fi author if you don't believe me. Our imaginations are not strictly bounded by our current knowledge - if that were true, we could never have new knowledge.

Are you asking me a Schrodinger's Cat question here?

No, I am not. Schrodinger's Cat does not apply - it applies to events and measurements, not to the physical law itself. The results of the laws of the universe may be indeterminate until you look at them, but there's no evidence the laws themselves are indeterminate.

Or, to put it in gamer terms, we don't live in the World of Darkness game of Mage: the Ascension, where the dominant paradigm belief determines how the Universe does it's business. Gravity worked before Newton - things fell to the ground. Quantum Mechanics worked before Schrodinger - and so millions of years ago stars emitted with certain spectra for us to see now. And so on.
 

You know, I was going to ignore that post, but you stated things well enough, Umbran, that I just want to second you there.
 


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