system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does it become dark immediately when I switch off the light? What happened to the photons of light that were emitted by the light source?
gpt
You mean are photons that were emitted just previously still traveling at the instantaneous moment the light turns off? Well, yeah, but they move at the speed of light. In case you don't realize how fast that is, light could circle the earth over 7 times a second.