Happy Fourth of July! To celebrate our nation's Independence Day, and to pay tribute to one of childhood's greatest pastimes, I'd like to share some interesting tidbits I've discovered about fireworks. The first — where do the colors of fireworks come from? This neat chart shows us exactly which chemical(s) contribute to each color you'll see in the sky tonight: (via Boing Boing) The second is a video which describes the science behind fireworks — featuring John Conkling, a leading expert in the field of pyrotechnics, this clip talks about the chemical composition of fireworks, how mortars work, and how colors are formed. I hope you guys have a great holiday, and be sure to think back to what you've learned here as you see...