FIREWONK: Very few people set out to be pyrotechnicians -- you can't major in it in college. I got involved when I started helping one of my college professors with his projects, and I've devoted myself to the science of fireworks ever since: I got a doctorate in chemistry, taught, and even headed the American Pyrotechnics Association for 25 years. While having a science background helps, being a pyrotechnician is really about artistry and passion. If you don't have a love for lighting the fuse and hearing the crowd go wild, you're in the wrong profession.

THE BIG BANG: Pyrotechnic shows today are much different than they were 20 years ago. Back then, only one shell -- the container that houses the chemicals and explodes in the air -- went off at a time. Shows lasted an hour. Now, we create 15- to 20-minute displays that combine colors and use different types of fireworks together -- everything from gentle fountain sprays to roman candles to really big shells that burst up to 1,200 feet in the air. And we time the fireworks to music lyrics. No one wants to see a slow-paced show that's all red bursts.

POP ART: Because of advances in chemical mixing, our color palette isn't limited to red, white and blue anymore. And green isn't just green, either. All different shades can be produced. One real crowd-pleaser is the use of pattern shells. They allow us to create shapes including hearts, stars -- even wedding rings, which we used at my daughter's wedding seven years ago. Now we're trying to tackle letters. It's difficult because when you do a big show, not everyone in the crowd is looking at the sky from the same angle, so the words might not make sense. Or you could end up spelling something inappropriate! But we'll figure it out someday.

HALF LIT: The pros look at fireworks displays much differently than spectators do. Good-quality fireworks are supposed to have completely symmetrical, full patterns. If you only see half a starburst, it didn't ignite properly. Since we're shooting so many off at once, it's hard to spot the duds. That's why you'll sometimes see pyrotechnicians out the next day combing the grounds for shells that didn't defuse properly.

SPARKLE SAFELY: Fireworks contain explosives, so you have to treat them with respect. If you want to light some at home, the most important rule is to make sure you buy them from a licensed supplier. Don't get fireworks from a van you see on the street corner. In this area, it's illegal to set off anything that explodes or fires into the air, so stick to sparklers and fountains. And make sure the person shooting them off is sober. Dealing with explosives after you've downed a six-pack just isn't a good idea.

As told to Michelle Hainer

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Proud pyro: Conkling and one of his babies.