July 3, 2002 -- This Fourth of July, fewer communities out West will be "oohing" and "ahh-ing" beneath sizzling fireworks shows.
Instead, many will be watching a more modern version of patriotic displays — laser light shows set to programmed music. The computerized animations, which are directed into the sky or at oversized mesh screens, use highly focused lasers that are far less likely to spark a fire in the dry tinderbox-like terrain of Western states.
Colorado and Arizona have endured the largest wildfires in each state's history this year and officials are taking extra precautions to keep fire risks low.
"We have been flooded with phone calls," says Rikki Rothenberg-Klein, vice president for sales at Laser Fantasy International, a Seattle-based laser show company. "For many communities, this offers a very very safe way to put on a show."
Rothenberg-Klein says her company has had to turn down requests and is producing twice as many shows than last year. It's handling spectacles in Sonora, Calif., Helena, Mont., and two in Colorado, where firework displays were banned this year because to wildfire concerns.
Bob Tory of Minneapolis-based Lasertainment says the laser show company has enjoyed a significant "bump in demand." And at South Dakota's Mount Rushmore, the usual brilliant fireworks show will be replaced by a laser display.
Instead of relying on black powder to create bright displays, laser light shows use mirrors, gas or crystals and agitated atoms.
John Neese, an engineer at the University of Michigan's Center for Ultrafast Optical Science, explains light show lasers, which are highly focused beams of light with similar wavelengths, are usually generated within a tube of inert gas, such as argon or krypton.
A high-voltage current is directed through the tube, which agitates the atoms that make up the gas. The atoms eventually return to their normal state and as they do, they release energy in the form of photons — or light.
Mirrors at each end of the tube capture these photons and direct them into a single beam. Different gasses release photons of different wavelengths, which creates different colors. Krypton emits light in red green and blue. Argon releases light in mostly green and blue.
Laser light show artists mix these colors on a screen or in the air to create displays of all colors. They also use tools like grated plates, networks of mirrors and computer programs to direct the lasers into intricate designs or animations.
They can generate words by projecting lasers in a connect-the-dot-like outline. Since the lasers move so fast, the dots are blended into smooth lines as the lights lingers in a spectator's vision.
Traditional fireworks displays have become more technical in recent years, with some companies using computer chips inside firecracker shells to help orchestrate timing. But laser shows rely on much more technology and energy and so remain a pricey alternative.
A typical 30-minute show can cost $15,000 to $25,000 and larger performances can run more than $100,000. Still, many cities are willing to pay the price for safety. Neese explains the lasers used in light shows are no more volatile than most workplace fluorescent lights.
"Workplace fluorescent lights put out about 40 watts," he says. "Most lasers in light shows put out about 20 watts. They could theoretically start a fire, but they'd have to be focused on a pinpoint for a long time."
Although laser shows aren't likely to trigger fires, they do post another risk — distracting pilots who may be flying overhead. In 1995, the U.S. Food and Drug Administration imposed a temporary ban on outdoor laser shows in Las Vegas when pilots complained they had been "blinded" by the displays.
That problem has since been resolved by requiring laser light show companies get clearance from the Federal Aviation Association before proceeding with a show. Companies must also employ aircraft spotters who can notify operators when any aircraft is approaching the area of a display.
"We have aircraft spotters and do everything possible to ensure a safe show," says Rothenberg-Klein.
Light laser shows may be a safer alternative, but they can't offer the thunderous booms and burned smells of Fourth of July fireworks.
"Lasers can be impressive," says Neese. "But I think the smoke in the sky from fireworks offers a better backdrop. I'd still rank laser shows second to fireworks."