Using Explosives to Put Out Wildfires Is Actually a Great Idea

Picture this: a drought-fueled wildfire is heading for Los Angeles, and fast. Millions of lives are at stake, and water can't stop it. When suddenly, a helicopter—armed with what can only be described as a giant cannon—flies straight for flames and BOOM. There's an explosion, and the fire's gone.

This Michael Bay movie of a situation is not only plausible, it's on the horizon. Australian engineer Dr. Graham Doig recently tested a method that would enable us to put out forest fires with a controlled explosion. More specifically, the controlled explosion produces a shock wave that blows the fire out as if it were a giant birthday cake candle. It's incredible. Just watch:

This is not a new idea. For years, explosives have been used to put out tough-to-tame oil and gas fires. That basically involves sending a shockwave down a well and hoping for the best. It makes good scientific sense. "The sudden change in pressure across the shockwave, and then the impulse of the airflow behind it pushed the flame straight off the fuel source," Doig explained in a release. "As soon as the flame doesn't have access to fuel anymore, it stops burning." Sound can create a similar effect.

The challenge is moving this process into the more unpredictable environment of a wildfire or a forest fire. Doig thinks the way to do it would be to strap the explosives to a helicopter that could swoop in on a moment's notice and stop fires from spreading. Even if the explosion doesn't put out the whole fire, it'll at least slow the beast down. "Fire is very fast moving if it gets up into the tree tops," says Doing. "We're thinking of this as being a potential way to stop a fast uncontrolled fire in its tracks and give you a lot more time to get things under control or evacuate people that are downwind of the blaze."

That's a great idea! Here's the kicker: with existing methods, there's basically nothing the firefighters can do once the flames get into the treetops. They can pray, but that fire will devour whatever fuel is in front of it. You know that phrase, "Fight fire with fire?" It actually works in this case. [Slashdot]