2
$\begingroup$

This question already has an answer here:

Please consider a closed room with light reflecting walls and in the centre of the room there is a Lighting Bulb. Now if I switch on the bulb, the room is obviously illuminated with light. When I switch off the bulb, since the light photon cannot escape the room, will the room be infinitely illuminated?

$\endgroup$

marked as duplicate by John Rennie, RedGrittyBrick, Kyle Kanos, Qmechanic Oct 22 '15 at 10:35

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.