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What about this well known, tested and well accepted effect: http://en.wikipedia.org/wiki/Casimir_effect http://en.wikipedia.org/wiki/Casimir_effect I'm not s

• Steuard 11y ago
  I'm not sure what you're getting at, either. The Casimir effect is real, absolutely. I think it was an exercise in one of my quantum field theory classes. In particular, the Casimir effect is something that you can compute entirely within the structure of existing physics, and it doesn't violate any conservation laws. Now, if you suggest that I can somehow extract the Casimir energy without having put the same energy into the system first, I'll start arguing about violations of the laws of physics (in much the same way that I have above).
  • btilly 11y ago
    ...and if you did, then you'd be on shaky ground. Extracting energy from the zero-point energy all around us no more violates conservation of energy than extracting energy from E=mc^2 does. And we can no more figure out how to do so than Einstein could figure out how to do so a century ago. Heck, simply finding an efficient way to store lots of energy that way would be a nice trick as well! We know of no reason why you can't beat any existing battery technology by many orders of magnitude! The trick is that we cannot think of any plausible way to do these things. And once you open up the window of, "This would be amazing if we could, and we can't prove you can't," then you've got something of great interest to cranks who convince themselves that they have done so. So you'd be on safe grounds promptly excusing yourself from any conversation where someone is trying to convince you that it has been done. But dismissing them with a general wave of the hand and appeal to conservation laws makes you as wrong as they are.
    • pdonis 11y ago
      > Extracting energy from the zero-point energy all around us Which can't be done because it's the zero point energy--i.e., it's the state with the lowest possible energy. If there were a lower energy state possible, we would be calling that the "zero-point". > We know of no reason why you can't beat any existing battery technology by many orders of magnitude! We know more than that: we know how to store orders of magnitude more energy than existing battery technology. Just use rest mass to store it: equal quantities of matter and antimatter. The problem, of course, is how to do that safely.
      • btilly 11y ago
        Which can't be done because it's the zero point energy--i.e., it's the state with the lowest possible energy. If there were a lower energy state possible, we would be calling that the "zero-point". The Casimir force demonstrates that the zero point of vacuum can be ABOVE the zero point of the same space with a different arrangement of stuff in it. In other words the zero point energy is not necessarily the minimal configuration that can be achieved. Thus the apparently trivial answer isn't necessarily correct.
        • pdonis 11y ago
          > The Casimir force demonstrates that the zero point of vacuum can be ABOVE the zero point of the same space with a different arrangement of stuff in it. Yes, that's because if you arrange stuff in a "vacuum" it's no longer a vacuum. In the case of the Casimir effect, you now have a pair of uncharged plates in what used to be vacuum. The question is, how do you propose to extract net energy using this effect? It takes energy to arrange the stuff in the first place (for example, to put the uncharged plates in place)--in other words, it takes energy to perturb the "vacuum". If you run the numbers, you'll see that there's no way to get back more energy from something like the Casimir effect than it took to arrange the stuff the right way in the first place. Which is just another way of saying that the "zero point" of an actual vacuum--no stuff present at all--is still effectively the lowest energy you can achieve.
          • btilly 11y ago
            When you say, "If you run the numbers", what you mean is, "If you do the calculation for the operation that we know how to do then..." And I agree. We do not know how to perform an operation that extracts net energy from the zero point energy. We have no idea how to go about it. And we have good reason to suspect that this is impossible. We just have no proof of it. For an analogy to a past situation like this, it is like the situation for many decades when it was known that Maxwell's demon could break the laws of entropy, but we were pretty sure it couldn't be built. And there was a century long back and forth on the topic before that was demonstrated.
  • Confusion 11y ago
    A quantum field theory class isn't enough to actually understand and explain a Casimir experiment if you want to go beyond the 'shut up and calculate' approach. Being able to compute the Casimir force is insufficient for understanding and explaining the entire experiment. In a Casimir experiment, which closed system can you define in which you require conservation of energy? How do you calculate the total energy in the system in the 'before' and 'after' configurations? How does separating two plates put energy into that system in such a way that it can subsequently manifest itself as the Casimir force? Does separating the plates increase the zero point energy and is that subsequently decreased by the Casimir force? Is it known to be possible to change the zero point energy like that? Arguing violations of the laws of physics is not very interesting if we can't microscopically pinpoint what happens in the first place. Which can be surprisingly hard: it took decades to properly explain Laplace's demon.