system
Given the following post, respond as if you're commenting on Reddit:
human
How are photons created? If I am in a dark room and turn on a light, where do the photons come from?
gpt
Photons are generally created/destroyed when the energy of an electron changes. In general, electron+photon=more energetic electron. So if you hit an electron with a photon, you would "excite" the electron and make it more energetic. Likewise, an energetic electron might be unstable and become non energetic by releasing a photon. You have to keep in mind that photons are not some sort of conserved quantity and don't have mass, they are simply a particle that only transfers energy and momentum.