Dark night, bright flashes, ooooh, ahhhh….hmmmm, how does that work? Here is a collection of how those flashy bangs and pops do their thing.
How Stuff Works does a typically thorough job explaining the hows and whys of fireworks.
When the fuse burns into the shell, it ignites the bursting charge, causing the shell to explode. The explosion ignites the outside of the stars, which begin to burn with bright showers of sparks. Since the explosion throws the stars in all directions, you get the huge sphere of sparkling light that is so familiar at fireworks displays.
Pyrouniverse is up for giving the abstract on how they are loaded, but keep their lips sealed on the ancient family secrets.
Fireworks tubes are made by rolling thick paper tightly around a former, such as a dowel. Though they can be made by hand, most firework/tube factories use machinery to manufacture tubes.
The shells that hold the individual charges are loaded with various metals and other ingredients.
Inside a shell are pellets that, when burning, produce the colors in a fireworks explosion. Various compounds create various colors — strontium gets you red; barium, green; copper, blue; sodium, yellow. Aluminum, titanium and magnesium brighten the flames.
The Boston fireworks show has a tradition of drawing huge, potentially panic attack producing crowds. Each of the charges have been built and are planned and manufactured for months in advance. When the time comes, they will be fired off in coordination with the music emanating from the stage.
They downloaded the soundtrack onto a specially designed computer system and began the time-consuming work of matching their arsenal of Roman Candles, Comets, Meteors, Spinning Wheels, and other fireworks with the rhythm of the music.
“You judge what to use by the feel of the music,” Art Rozzi said. “You have to know what you’ve got. You have to know if you’re going to shoot a lot or a little. And you have to keep in mind the finale, so you’re not giving anything away.”
Though many cities have fireworks shows, lots are also dampening the fuse this year because of the expense and budget priorities. For the lucky remainders, people have been prepping the sites for the past few days and weeks.
Each firework is encased in a shell that looks like an oversized light bulb wrapped in brown paper. Inside, one fuse launches the firework like a rocket, while another has a time delay that makes it burst in the air.
The fireworks are made of gunpowder and beads that form various shapes and colors depending on the chemical pigments and how they are arranged inside. They come from all over the world, though most are from China.
The color of a compound in a firework will be the same as its color in a flame test. Not all compounds that produce a colored flame are appropriate for coloring fireworks, however. Ideal colorants will produce a pure, intense color when present in moderate concentration.
Check out the wikipedia entry for more details, and a trip around the world detailing ways that fireworks are used in other cultures.
Share with us in the comments your experiences of making and deploying fireworks.
Image above from Wikipedia