Question: how do light bulbs make light?

Phillip Wilkinson answered on 9 Mar 2013:

By passing electricity through a simple circuit. When the electricity reaches the ‘filament’ (the thick piece of wire in the center of the bulb). It heats up, this heat then starts to give off light as well!

This is why light bulbs are so inefficient. Something like 80% of the energy used in lighting up a bulb is wasted on generating heat. Hence why they are so hot to touch after being on for not that long.

So use energy efficient bulbs instead!