The 4 July was celebrated as America’s Independence Day in 1777.
Image Credit: Alexey Stiop | Dreamstime.com
Today, fireworks mark celebrations all over the world.
From ancient China to the New World, fireworks have evolved considerably.
The very first fireworks — gunpowder firecrackers — came from humble beginnings and didn’t do much more than pop, but modern versions can create shapes, multiple colors and various sounds.
How fireworks work:
Before diving into the history of fireworks, it is important to understand how they work.
Each modern firework consists of an aerial shell. This is a tube that contains gunpowder and dozens of small pods.
Each of the pods is called a “star.” These stars measure about 1 to 1.5 inches (3 to 4 centimeters) in diameter, according to the American Chemical Society (ACA).
The Pod holds: Fuel, An oxidizing agent, A binder Metal salts or metal oxides for color.
A firework also has a fuse that is lit to ignite the gunpowder. Each star makes one dot in the fireworks explosion.
When the colorants are heated, their atoms absorb energy and then produce light as they lose excess energy.
Different chemicals produce different amounts of energy, creating different colors.
New Year’s Eve Fireworks display at Sydney Harbor, Australia.