‘Nova’ Reveals Secrets of Fireworks

It began with Chinese alchemists mixing compounds more than 1,000 years ago, but the enduring, evolving art of fireworks seems picture-perfect for today’s world of big-screen TV. An eye-catching “Nova” explores the history, science and artistry of “Fireworks!” (tonight at 8, PBS).

Modern fireworks makers and exhibitors still rely on ancient alchemy and old family secrets, but they also use such high-tech tools as digital launch controls to create pyrotechnic symphonies for crowds with ever-rising expectations.

Steve Pelkey, the man behind last year’s Independence Day gala in Boston, explains how much more there is than meets the eye. Those mad splashes of color don’t choreograph themselves to each piano stroke of “Great Balls of Fire.”

While coordinating 3.5 tons of pyrotechnics, Pelkey has to sweat wind conditions, crowd control and other headaches. No wonder he carries a container of Advil.

Then there’s Wally Glenn, Web designer by day, “Pyroboy” by night: Donning a Kevlar suit and a harness full of explosives, he becomes a dancing pyrotechnic display. The key, he says, is in knowing enough about chemicals to create brilliant blues and greens while avoiding spontaneous combustion.

These pros take their incendiary craft seriously. Says one fireworks planner: “We’re responsible for sucking the emotion out of every man, woman and child.”

In true “Nova” style, the show has just enough science to satisfy a layperson’s curiosity. We learn the once elusive secret to color (using potassium chlorate for a fiercer burn) and the varied shapes that help make fireworks screech, whistle and bang on cue.

Half a year before the Fourth of July may seem like an odd airdate but, with its spirit of celebratory patriotism, this episode couldn’t be more timely.