system
Given the following post, respond as if you're commenting on Reddit:
human
Could you trap light inside a spherical, perfectly mirrored ball of sorts?

Imagine you have a perfectly spherical hollow ball, the inside of which is a perfect mirror. If one was somehow able to get light inside, would it decay, or just travel inside the mirrored ball forever and ever?

Note: there is no practical application to this question (that I'm aware of), I've just been curious about it for a bit and just found this subreddit.
gpt
No, because there's no such thing as either a perfect sphere or a perfect mirror. The intensity of reflected light is always less than the intensity of incident light, and the difference is made up by the fact that the mirror grows slightly warmer from the interaction.