Every year we look forward to the flash and bang of a stellar fireworks display to celebrate the Fourth of July. But how do those glorious bursts of color work to light up the night sky? The answer lies with chemistry.
Each aerial firework is basically a tube of color pellets called stars packed tightly around a series of explosives and fuses. When the primary fuse is lit, the explosives propel the tube into the air and light a secondary fuse that triggers the firework’s explosion seconds later when it reaches a desired height.
The color and effect of a firework are all determined by chemistry. Each pellet or star is packed with a different combination of chemicals that will reveal a different color when set on fire. Strontium for red and barium for green are the easiest colors to make, while a much trickier blue can be created with chlorine compounds and copper.
Magnesium creates white light and also can be used to create a flashing, sparkling effect. Gold and silver burn more slowly and can be used to give a firework a tail like a comet that can keep burning almost all the way back down to the ground.
And those hearts and smiley faces we sometimes see? When pyrotechnicians design fireworks, they pack the stars into the tubes in a certain shape, but upside down and backwards so that when they explode in the sky, we see the picture right side up and facing us.
Fireworks have been delighting crowds since their invention in the 7th century in China where they were used to publicly celebrate a variety of events. Sometimes they’re called Chinese flowers in honor of their birthplace.
In the Middle Ages, fireworks spread west through the Islamic world along with gunpowder technology. And in 1749, George Frideric Handel celebrated their timeless glory with his “Music for the Royal Fireworks.”
This summer, you can catch the fireworks at Davis Community Park, 14th and F streets, at a free annual community event hosted by the city of Davis. The fireworks will begin around 9:30 p.m., capping off a day full of fun. Remember, it is illegal to purchase or use any fireworks within the city of Davis; leave the pyrotechnics to the professionals.
Explorit’s coming events:
* Explorit’s “Beautiful World: Science and Art” exhibition is open to the public from 1 to 5 p.m.every Wednesday, Saturday and Sunday, and every Friday from 3 to 6 p.m. Admission is $5 per person; Explorit members, teachers and children 2 and under are free.
* Interested in membership? Think your Explorit membership may have lapsed? Call Explorit at 530-756-0191 to check or sign up!
* Birthday parties are back at Explorit! Call Explorit at 530-756-0191 for more information or to book your party.
* Don’t miss Explorit’s summer field trip to the Discovery Museum’s Challenger Center on Aug. 6 for fifth-, sixth- and seventh-grade students. Search “Explorit” on brownpapertickets.com.
* Save the date: Sunday, Sept. 7! Our exciting Final Blast Festival and Chemistry Show once again will wow you and your kids. This event celebrates the end of Explorit’s Summer Science Camp season and is a fun way to start the new school year.