I Thought experiment: Photons in a box

[kent davidge]

Consider a box whose walls are mirrors. Suppose we trap a bunch (yes, it's vague) of photons inside the box. They will not escape, or assume that a major part of them will not escape the box.

Now suppose we have a way of decreasing the size of the box at our will, but possibly obeying the laws of physics (i.e. not infinetly decreasing the size of the box). As we imagine decreasing the box, some interesting thoughts arise

- At some point there would appear some kind of mini black hole?

- The photons would exert some kind of pressure outwards?

- And possible other possibilites...

I would like to know what/if any of these would be more likely.

OR... remembering that the mirrors are made of atoms, well before those interesting things becoming likely to happen the interaction of the trapped photons with the mirrors atoms would somehow have freed the photons out of the box.

 

[bahamagreen]

The answers are going to be mathematical... as a thought experiment it might be easier if you let the box be replaced by an internally mirrored sphere?

 

[kent davidge]

Yea, a sphere would better fit the story.

 

[rootone]

- At some point there would appear some kind of mini black hole?.

Assuming nothing escapes the walls of your ever reducing sphere then yes a black hole will be the result.
Because at some point there will be X photons existing in a zero volume,
My guess is that your perfect mirror sphere will get very hot and break before that happens,

 

[jtbell]

well before those interesting things becoming likely to happen the interaction of the trapped photons with the mirrors atoms would somehow have freed the photons out of the box.

Bingo!