WEST LAFAYETTE, Ind.–You might have seen fireworks a lot in your life, but do you know the science behind how they function? Marcy Towns is a chemistry professor and the associate dean for the College of Science at Purdue University. She explains what really makes a firework work.
The Anatomy of a Firework
Towns says first you have to understand the anatomy of a firework. “So first of all, you have a tube that the charge goes down into, and there’s a fuse, and you ignite the fuse. When the fuse burns down, it hits a black powder charge that propels the firework up into the sky. And it also sets off a timing fuse. And as that timing fuse burns down, what then happens is the middle of the firework ignites and ignites the material in it, and it explodes out into beautiful colors and shapes that we call fireworks,” said Towns.
You often see fireworks with different colors. Towns says the fireworks are colored based on their chemical compounds they are composed of. “So if you see a red firework, it has strontium in it. If you see a beautiful yellow firework, which is pretty common, that has sodium in it. If you see a green firework, it has barium in it. If you see a blue firework — and blue is the hardest color to make — it has copper compounds in it. And then last but not least, the sparkles that come out are pieces of aluminum, titanium and/or magnesium,” said Towns.
Sparkles and Flashes
Many fireworks create sparkles and flashes. Those are based on the particle size. “And these particles are usually aluminum, titanium or magnesium. If they’re a really fine, powdery particle size, then in just a flash, they burn really fast. There’s lots of surface area and that just goes. If it’s a little bit longer and you’re seeing them sparkle as they drift toward the ground, it’s just that the particles are slightly larger,” said Towns.
Fireworks often create a loud boom. “Big booms are created by having a powdery substance that rapidly burns and releases gases. And it just, it creates a sound wave that sounds like a big boom. And frequently there’s also little, tiny pieces of aluminum or magnesium or titanium to do a flash. So it’s a bang-flash kind of thing. But there are also whistles. And whistles are really cool. It’s a different material that you pack into a tiny little tube, and as it burns and goes out of the tube, it creates a whistling sound, almost like you’re blowing across the top of a bottle. And then there are things that crackle as well. Those are actually bigger particles that are made primarily of bismuth, and they fall out of the sky kind of crackling,” said Towns.
Towns also recommends that you follow the appropriate safety measures such as: Never allow children to play with or ignite fireworks, including sparklers, Light fireworks one at a time and then move back quickly, Never use fireworks while impaired by alcohol or drugs, Keep a bucket of water or a garden hose handy in case of a fire or other mishap.
Original reporting: 93.1 WIBC (Indianapolis) — read the source article.
