Since yesterday was Independence Day and many of us saw a fireworks display, shot off our own fireworks, or both, I thought it would be timely to describe how fireworks actually work. All fireworks have one thing in common: they give off heat from some sort of chemical reaction.
Most fireworks also give off light, and most also emit some sort of sound. Notable exceptions to this are sparklers which have little sound, smoke “bombs”, and the large set pieces that display shapes like an American flag or some such. We shall focus on the ones that give off light and sound.