As early as 200 B.C., the Chinese began roasting bamboo to ward off evil. Bamboo pops noisily when heated due to its hollow air pockets.
Between 600 and 900 A.D., Chinese alchemists mixed saltpeter, charcoal, sulfur and other ingredients, yielding an early form of gunpowder, which produced an even louder bang.
Soon, paper tubes replaced bamboo, giving rise to firecrackers, then to rockets, which were converted for use in war. Different chemicals and fuses led to colorful explosions, fired to celebrate military victories.
In medieval England, firework assistants were called “green men” because they wore caps of leaves to protect their heads from sparks. Green men doubled as jesters to both entertain and protect the crowd, much like rodeo clowns today. It was dangerous work, with many green men dying or being injured by bad detonations.