Tuesday, May 31, 2011

Science Creates Potential For Supervillany Through Mirrors & Light

If you take two flat mirrors and place them very close together, the virtual particles that pop into existence between the mirrors will actually force them together. But that's nothing compared to when mirrors approach the speed of light.

What they're talking about "virtual particles", but for our purposes all we really need to know is that, according to present understanding of quantum mechanics, pairs of particles and their corresponding antiparticles will pop into existence, then almost immediately annihilate each other. These are known as quantum fluctuations.

So how do the mirrors come into it? Basically, if the two mirrors are close enough together, the distance between them actually becomes smaller than the wavelengths of the virtual particles. This in turn creates an imbalance between the vacuum pressure inside the mirrors and that on the outside, creating an attractive force that brings the two mirrors together. This is known as the static Casimir effect, and it was experimentally demonstrated in 1998.

Still, that's downright normal compared to the dynamic Casimir effect. This can only come into play if a mirror is traveling at relativistic speeds, which is roughly speaking 10% of the speed of light or faster. Technology Review's arXiv blog explains what theoretically happens here:

At slow speeds, the sea of virtual particles can easily adapt to the mirror's movement and continue to come into existence in pairs and then disappear as they annihilate each other. But when the speed of the mirror begins to match the the speed of the photons, in other words at relativistic speeds, some photons become separated from their partners and so do not get annihilated. These virtual photons then become real and the mirror begins to produce light.

Sure enough, scientists have spotted microwave photons emerging from the moving mirror, just as predicted.

Microwave lasers out of vibrating mirrors. Laser bomb?

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