What’s wild is that most things having to do with light, magnetism, and/or electricity are interchangeable and reversible. Put electricity through a wire and it’ll create a magnetic field, or wave a magnetic field near a wire and it’ll create electricity. That means that putting electricity into an LED creates light and a magnetic field, or putting light into the LED creates electricity and a magnetic field, or waving a magnetic field near it will create electricity in the wires and light from the LED. Granted for that last one you’ll need a spinning magnetar nearby, or just add some more wire to the LED and it becomes a kitchen counter experiment.

Same interchangeability with solar panels, transformers, thermoelectric devices, etc. The effect might be big or small, depending on the setup, but the physics is happening either way.

I’ve spent time lost in space thinking about how much stuff is really just a copper wire in various configurations.

Have a copper wire - it’s an antenna, magnet, inductor, fuse, thermometer, heater, and strain gauge.

Put another copper wire near it - it’s a capacitor.

Curl one more than the other - it’s a transformer.

Put iron on it - it’s a thermocouple.

Put electricity through it - it’s a peltier cooler.

Add salt water - it’s a battery.

Put electricity through it - the iron is now a permanent magnet.

Wave the permanent magnet near it - it’s a generator and a microphone.

Put electricity through it again - it’s a motor and a speaker.

Heat it up and it’ll make Cuprous Oxide - it’s a solar panel and a diode.

Put electricity into it - it’s an LED.

Same with LEDs, they can be reversed to generate electricity.

What's their spectrum?