A long time ago some co-workers and I were discussing a sphere (of any size really) made of a perfect one-way mirror, such that light (photons) could enter, but never leave. The question what would happen.
One co-worker suggested a black hole would be created as the mass continually increased as more and more photons were trapped.
Today I learned (or re-learned possibly) that photons have no mass., of course it is never as simple as it seems. Technically they have no rest mass. It gets complicated.
So any thoughts on what would happen with a photon trapping sphere?
