Where do light particles “go?”

Question

Where do light particles go? If a person is in a dark room, and they open a curtain, light illuminates the room from outside. But then, when the curtain is closed, the room is dark again, and the light is no longer there. Where did it go?

I probably have a flawed understanding of how light particles work.

In: 10

Answer 1

Since no material is perfectly reflective, some of the light bouncing around a room is absorbed every time it hits an object. Bright white paint only reflects ~90% of the light that falls on it, absorbing the other ~10%. After just 100 bounces off of white paint, only 0.003% of the original light will remain—and light moves so fast that it can travel across an ordinary room millions of times per second.