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Today marks the 238th celebration of Independence Day in America—the day the United States came into its own right, with the signing of the Declaration of Independence, as a country independent of the nation formerly-known-as the Kingdom of Great Britain.

(As an homage to America’s history, check out artist Jeff Koons’ recently unveiled 3D-scanned and computer-milled Liberty Bell replica—a study of details eight years in the making—here.)

Most Americans’ schedules this weekend will be dominated by picnics, parties, festivals, and—my personal favorite—fireworks. It’s the one time I feel really happy that things around me are catching fire and blowing up.

Fireworks have a long history that dates back to 7th century China, and they have been mesmerizing societies and celebrating events ever since. Some countries even host national fireworks competitions, where teams come together to out-do each other for the title of best pyrotechnic display.

Have you ever thought about the science behind those impressive explosions in the sky? Well, it all boils down to simple chemistry–different compounds produce different colors. But the setup to get those chemicals in the sky may be a lot simpler than you thought.

In this video from the American Chemical Society, pyrotechnic expert John A. Conkling explains the science behind the bright bursts.

Credit: ACS Reactions; YouTube

Feature image credit: 柏安 蘇; Flickr CC BY-NC-SA 2.0