Why Fireworks Depend on Geology


America is about to blow up a bunch of stuff for its 238th birthday. I love it! Who doesn’t love fireworks? Well, aside from my childhood dog, who invariably hid under the bed in cowering terror. And people who have had enough of explosions to last them a lifetime. People who don’t like loud bangs. People who are phobic about fire. All right, so there’s a long list of people and other animals and possibly plants who don’t like fireworks. But hopefully most of this audience does, and even if you can’t stand ‘em, perhaps you like geology, chemistry, physics, and pretty colors. Fireworks have got them all.

Fantastic fireworks display, courtesy of Bayasaa on Flickr.

Fantastic fireworks display, courtesy of Bayasaa on Flickr.

Oh, yeah, definitely geology. There’d be no fireworks without geology. Geologist High Maintenance Mom provides a great overview of the science of fireworks, explaining in kid-friendly ways how physics, chemistry and geology combine to create pyrotechnic magic. She’s a great resource to start with if you want to make your trip to see the fireworks show a fun teachable moment for your kids.

    A very gorgeous burst of fireworks by Nigel Howe on Flickr.

A very gorgeous burst of fireworks by Nigel Howe on Flickr.

For a more adult-oriented overview, see this excellent article on Geology.com. Lots of diagrams and nifty information, including this section regarding how geology fits in. Those beautiful colors wouldn’t be there if geologists weren’t finding the minerals that create them:

What Causes the Colors?

Chemistry holds the secrets to the color of a fireworks burst. The colors that you see in the sky are determined by metal salts that are deliberately added in very small amounts to the stars when they are manufactured.

As the stars burn the metal atoms absorb energy, become excited and emit a specific color of light. Some of the metals that produce the colors of fireworks are tabulated here.

Image is a table of colors caused by different metals. Red: strontium, lithium. Orange: calcium. Yellow: sodium. White: magnesium, aluminum. Green: barium. Blue: copper. Purple: a blend of strontium and copper. Silver: titanium, magnesium, aluminum.Go memorize that article so that you can pull a complete geek on your friends. While other people are screaming “Oooo! Ahhhh! Wow!” you can shout, “Titanium! Copper! Strontium!”

Ooo, I know this one! Image courtesy Nigel Howe on Flickr.

Ooo, I know this one! Image courtesy Nigel Howe on Flickr.

Strontium plus copper! Copper! Maybe some sodium!

Speaking of sodium, did you know you can do an awesome flame test using stuff you can pick up at the grocery store? Check out llinois State Museum Geology Online’s “A Burst of Light (pdf)” lesson – this is something you can, with proper precautions, do safely at home or in the classroom. And there’s more information on the minerals and colors in fireworks at this pdf from the U.S. Bureau of Mines.

So take a geology field trip if you’re in the States today and go see a fireworks display. Raise a beer to the geologists whose ability to unearth (ha) minerals made the whole thing possible. And drink a toast to the chemists and physicists and pyromaniacs who also helped.

A golden grand finale. Image courtesy Karen Blaha on Flickr.

A golden grand finale. Image courtesy Karen Blaha on Flickr.

Science: making awesome things awesomer since humans invented it.

 

Originally published at Scientific American.

Comments

  1. Mobius says

    Chemistry in action!

    Who says that science takes away from the wonder of the world?

  2. rq says

    I once did a project on stained glass and its colours. My biggest surprise was that, to get a good red shade, they use gold. (Which shouldn’t be much of a surprise, I mean – look at copper and the shades of blue it can turn things!)

  3. StevoR : Free West Papua, free Tibet, let the Chagossians return! says

    Actually (at least in one way of interpreting “fireworks!”) the biggest fourth of July fireworks ever could be said to have appeared in the sky on that day in 1054 CE :

    http://tripcyclone.wordpress.com/2011/07/04/july-4th-1054/

    And that event (well okay not exactly *that* one yet but other much earlier ones before our daytime star even formed) are what created geology!