Fire Stoppers

New tech fights fire with sound

-  -Vanessa Bates Ramirez

A WILDFIRE BURNS IN THE HILLS of a Los Angeles suburb, leaping from one patch of dry brush to another as it approaches a cluster of homes. The landscaping at the first house burns, but the house itself stubbornly refuses to catch fire: any small flames that start along its walls or roof quickly die out. There’s no water in sight—the flames are being quenched by sound waves. This kind of acoustic fire suppression may soon play a vital role in fighting wildfires.

The key ingredients for a fire are heat, fuel and oxygen; take one of these away, and the flames are extinguished. Sound waves can stifle a fire by pushing oxygen molecules away from the fuel, preventing the fire from getting the air it needs to continue its combustion reaction.