[Physics] Mirror problem of radiation pressure


If two perfect mirrors are placed facing one another and they are in proximity, and photons (don't ask me how) are traveling between them and toward one of them, what is to keep the radiation pressure from reaching incredible amounts?

I might be way off of base here because I am new to this field. I heard that the radiation pressure doubles on a mirror.

If this is the case, a laser beam focused on a mirror at any angle will cause the mirror to accelerate one of two ways– no more.

This also violates energy conservation and thus isn't valid.

Best Answer

It takes twice the momentum to bounce a photon back from where it came, as it does to just absorb it. So the radiation pressure from reflecting a photon is double that of absorbing a photon. So, two opposing mirrors have simply twice as much radiation pressure as two absorbing surfaces. The pressure doesn't continue to grow.

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