Every year on the Fourth, you and the fam pack up your lawn
chairs and head to the best spot for viewing your town’s fireworks display. But
have you ever wondered how they work? You don't have to be a science nerd to dig these deets!
What's it all about?
Those bright lights and loud booms that you’re hearing are
caused by explosions of precise mixtures of chemicals and fuel. The sound shows
up because of the huge amount of energy that is suddenly being let out into the
air, causing a shock wave. And the colors appear when the metal salts within
the fireworks get heated up, because then their specific elements will produce
different amounts of energy. Higher energies will have shorter wavelengths of
light, creating purple and blue mixtures of color. Lower energies make longer
wavelengths, so that red and orange shades appear.
The whole process of igniting firework begins when someone
lights its main fuse. Then, there are actually two fuses that go to work – one
is fast action, and the other is time delay. The fast action is so that those
chemicals get lifted up in the air and away from people ASAP, while the time
delay creeps slowly toward the chemicals. Once the time delayed fuse reaches
those metal salts, the colors and the noise is released, and that moment is
perfectly timed so that it occurs when the fast action fuse runs out. If the
fuses are off for some reason, all that energy might burst out when the
firework is too close to the ground, which could be very dangerous. So if you
wanted an exact science, making fireworks would be it.
Are we there yet?
If you’ve ever wondered why fireworks just can’t get it
together and always have their light and sound happening at different times,
it’s because they’ve run into the same problem as thunder and lightning – sound
just can’t keep up with light. The speed of light is about a million times the
speed of sound. So here’s a trick that you can use to tell how far away the
explosives are: When you see a firework go off, start counting out the seconds.
Stop when you hear the accompanying boom, and divide the number of seconds you
counted by 3. That tells you how many kilometers there are between you and
those gorge colors.
1. Make sure that there are at least 840 feet between you
and the spot where those babies are being ignited. That distance has been
calculated to keep you clear of even the largest fireworks.
2. The fuse should never be lit if winds are over 20 mph, in
case those flying chemicals blow in a direction they shouldn’t. Officials who
run large displays should know that, but check the weather forecast before you
head out, just to be sure.
3. Leave your pets at home when you go to see the fireworks.
You might think Spot will like the pretty colors, but he’ll probably just get
scared when that crazy noise catches up with the light. And you definitely
don’t wanna risk having your pooch run off and get lost.
4. If your fam gets some sparklers to play with at home,
don’t let your sibs or anyone younger than 12 hold ‘em, because those babies
will get hotter than 1000-degrees Celsius.
For more info on the
most exciting part Independence Day, click here. Have a safe, fun time watching the explosions,
BY CARRIE RUPPERT ON 7/2/2012 12:00:00 AM
POSTED IN fun stuff, summer, fourth of july, 4th of July fun