system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Where does light go?

So if you have a completely dark room, you turn on a lamp and turn it off again, where does that light go? 

Does it get sucked back into the lamp or does it fizzle out into nothing?
gpt
Light moves at 186,000 miles per *second*. When you turn the lamp off, the light that it previously emitted continues to zoom away at that ridiculous speed.

Within a room, it bounces off of every surface, being partially absorbed and partially reflected on every bounce until it's either been completely absorbed or has escaped the room. Since it bounces around faster than you can imagine, it reaches that point of "completely absorbed" so quickly that it's essentially instant as you see it, so the room becomes dark "immediately".