Originally posted by Johnny Boy:
Originally posted by MBroderick:
[QUOTE]How about I take a perfect box filled of a perfect reflective material, and shoot into it a beam of light. I then close the box. The box doesn't move , and thus the system is stationary with concern to momentum. Will the box not gain a very small amount of mass?
I believe that the answer to your question could be as follows: The light will be reflected between the walls to form standing waves; each standing wave is formed by two wave components moving with speed c (relative to the box) into opposite directions. The light waves thus still have kinetic energy which can be equated to mass. This will cause the weight of the box to increase. It thus seems as if the light under these conditions has a rest mass which adds to the total mass; however, light on its own do not have rest mass. It seems that in order for light energy to add to the mass of another material (like the box), the light has to be confined (as it is within the box). I believe that this is also what happens when light (a "photon") is absorbed by an atomic "electron". The incoming light-wave coalesces (entangles) with the electron-wave (orbital), becomes confined, and thus adds to the mass. The electron orbital then has to "morph" into a higher enery orbital; i.e. one with more mass. This makes much more sense, and I know understand where you were coming from in your earlier posts. Confinement of the wave is possible due to its size, but would you say that this confinement is an entaglement of two waves, or a change of phase, or something altogether unrelated to the typical ideas of wave interaction?
