If photons bounce off of surfaces (get reflected), why does it immediately go dark after we switch off the lights?

Question

If photons bounce off of surfaces (get reflected), why does it immediately go dark after we switch off the lights?

In: Physics

Answer 1

>ELI5: If photons bounce off of surfaces (get reflected), why does it immediately go dark after we switch off the lights?

Because only a fraction gets reflected. The rest gets absorbed by the material and turned into thermal energy. Since that absorption happens on every bounce eventually 100% of all light that does not go on an infinite journey into outer space gets absorbed at some point (sooner rather than later, since it moves at light speed).