The hypothetical torch

[Supernick]

What would happen if I sat in a perfectly reflective ball, covered in perfectly reflective material, and turned a torch on and off. Would there still be light after the torch had gone off as the light bounced around? Obviously very hypothetical, but would it also get unbearably bright if I kept my torch on?

[trilobite]

Yes, until you opened your eyes to see it, Whereupon the light would be absorbed by your retinas. The same would apply if you stuck a camera in to film the event.

It's a bit analagous to the perfect vacuum. Can't exist because as soon as you put something in to measure it, it's no longer a vacuum.

[bruce-lucie]

In a hypothetical sense it makes sense, but it cant be possible because you are in the ball, and it can never be tested so i guess its all stuck in the mind!

[helghast]

wouldn't only some light be reflected as the rest would be refracted out

[Potatoman]

surely youy body would absord the light. I see you point tho. Looks like im gonna up all night wondering about this! Cheers for that! Light comes millions of miles from the sun and 'fizzle' out, so the ball should (in theory) glow for a short while. My head hurts, already!

[booksworth]

Anything that radiates energy, such as the filament in your torch bulb, also absorbs energy. So all the light will get mopped up back in the torch filament, which will warm up a bit. -.-.-.- Incandescent lights are very inefficient, so the effect of this heating will produce very little additional radiated light. Therefore, you won't get ever-increasing brightness, and it will all go dark as soon as you switch off the torch, at least so far as a human can detect.

[anthomson]

What if you put the torch in a smaller ball constructed from a perfect one mirror so the light could escape in to the larger ball but not re-enter it. Be good if could be made to work - make a great battery.