system
Given the following post, respond as if you're commenting on Reddit:
human
If light is a constantly shifting electric/magnetic field, why does it not interact with other external electromagnetic fields?

I understand that photons themselves lack charge, and light  interacts with things like other photons and electrons etc. but why don't the electric and magnetic field interact with, say the magnetic field around a magnet?
gpt
Maxwell's equations are linear, which means that EM fields obey the superposition principle. If you bring together two sources of electromagnetic fields, the net field at any point in space is simply the sum of the two individual fields.