America is about to blow up a bunch of stuff for its 240th birthday. I love it! Who doesn’t love fireworks? Well, aside from animals like 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 are triggered or kept awake by loud bangs. People who are phobic about fire. All right, so there’s a long list of people and other animals who don’t like fireworks. But hopefully, even if you can’t stand ’em, you’ll be able to enjoy the geology, chemistry, and physics of them. Continue reading “The Geology of Fireworks”
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.
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.
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.
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.
Science: making awesome things awesomer since humans invented it.
Upon getting off work on July 4th, I hurried home and hied me up the hill behind my house.
I love the hill behind my house. For one thing, I suspect it’s a drumlin. For another, I found my garnet mica schist there. And for the third, I can see a whole bunch of fireworks displays from all over the Seattle area from it. Not perfectly, mind, but well enough. And there are no crowds. Just lotsa ba-booms.
As I was headed for the hill, I saw the lovely crescent moon shining in the last of the sunset:
You see, when it’s cloudless here (which is like two days out of the year), you can catch a teensy little glimpse of the Olympics from that hill. And there was one of the higher peaks, silhouetted against the twilight, with things blowing up nearby:
Is that or is that not sweet?
Speaking of sweet, folks launched fireworks in the valley down by the river, so the whole huge drumlin opposite my drumlin would be lit up like, well, the 4th of July. I didn’t catch the really gorgeous explosions, alas, but I managed to catch this one in the act:
Watching those enormous blooms of sparks against the dark forested hill, lighting up the entire valley for just an instant, made my heart leap. So did the ones someone on the hill above me launched – I mean, full-size fireworks going off right above my head, now, that was intense. And more fun than I care to admit.
After a while, the entire valley filled with smoke and the faint smell of cordite. Surreal. I would’ve stayed out there for the finale, but there was this ridiculous long lull in the displays that allowed my extremities to clear their respective throats and say, “You know, Dana, it may be July, but we’re fairly far north, and it is frickin freezing out here, and we’d really like to go back inside.” So we did. I couldn’t feel my fingers or toes for about an hour afterward, but it was worth it.
Evelyn put up red, white and blue rocks in honor of the holiday, which got me to thinking about the Fourth of July and geology. There’s definitely geology involved. Take the whole Battle of Bunker Hill thing. That was fought on drumlins. Having one right behind me, I can understand why the rebels wanted to be on top and why the British had a hard time assaulting those positions. They may not be all that tall, in the relative scheme of things, but when you’re running up a hill in a hail of bullets, they probably seem very tall indeed. And they command a fair view of the surrounding area.
|Breed’s Hill, courtesy of McDee|
That’s where most of the battle was fought, actually, right up there on Breed’s Hill. We rebels wouldn’t have had such a sweet setup if it hadn’t been for the Laurentide Ice Sheet. Somewhere between 80,000-90,000 years ago, this whole area got invaded by Canadian ice. It carved the Boston Basin and dumped some drumlins when it left around 14,000-11,000 years ago. Boston, it seems, aside from not having lovely mountains forced up by a subduction zone, is quite similar to Seattle: glacial outwash and drumlins and moraines, oh my. They’re even similar in age, and for good reason: the Laurentide Ice and the Cordilleran Ice Sheet actually connected to each other. Ice from sea to shining sea.
Most of the glaciers we associate with now are so small it’s hard to believe something as prosaic as a lot of ice left such enormous mounds of gravel, sand and clay, but they did. We’re talking continental glaciers that were hundreds of thousands of square miles in extent and three thousand feet thick. Even wee glaciers make good bulldozers: you can just imagine what these behemoths were capable of. But you don’t have to imagine it. You can go walk around and see the results for yourself, all over the northern bits of North America.
If you go, make sure you pick up a copy of Written in Stone by Chet and Maureen Raymo. ‘Tis handy and slim.
Oh, just one more, then, because a famous drumlin close to sunset is lovely:
|Breed’s Hill, courtesy of Via Tsuji|
And, for the curious, a shot at the drumlin across the Sammamish River valley, taken from my own dear drumlin and favorite fireworks-watching hangout.
Our very own Woozle has written you a birfdai song:
It’s going to be soooo hard not to sing the chorus whilst standing in line for my own personal groping session when next I fly…
America turns 233 today. Sometimes, it’s fun to embarrass the birthday country with a home video unearthed from their parents’ attic. Remarkably, our Founding Fathers had both musical talent and excellent videographers, so we have just that opportunity. Here they are, solemnly choosing the author of the Declaration of Independence:
All humorous history aside, declaring independence was a momentous event. Here’s something with the proper gravitas:
Happy birthday, America.
On this Fourth of July, I just want to let a few of our more courageous politicians say a few words about the freedoms this country was founded on:
Senator Russ Feingold:
Senator Chris Dodd:
Representative Dennis Kucinich:
The Constitution is a huge part of what we’re celebrating. Let’s not forget it.