- Fireworks first appeared around 1000 A.D., in Chinese religious ceremonies.
- Various metal salts are used to create the colored explosions. Barium makes green, copper makes blue, and aluminum is responsible for the sparkle.
- To make different shapes, a chemical mixture is glued to wax paper in the form that it will take when it explodes. Next, the paper is put inside a spherical shell made of cardboard or some other paper. Several are fired off at the same time to give the appearance of three dimensions.
- The U.S. imported around $217 million worth of fireworks in 2007, with $207 million of that coming from China, according to the U.S. Census Bureau.
[ via Kristin Appenbrink, Real Simple magazine, July 2008 ]