It’s long been an urban legend that you can put out fire with the sound of your voice. Apparently DARPA, in its ongoing desire to be absolutely insane, had decided it’s going to make that a reality.
OK, so the real reason is that they want to be able to extinguish fires using physics instead of chemicals. Chemicals are riskier than using fire’s own properties against it. But the problem is mostly figuring out how to actually do that.
DARPA’s technique involves surrounding the flame with speakers. The speakers generate an acoustic field that surrounds the flame and puts it out in two ways. The sound increases the air speed, which thins out the atmosphere a bit and helps disrupt combustion. It also shakes up the fuel, disrupting the surface and driving down the overall temperature. Here it is in action:
https://c.brightcove.com/services/viewer/federated_f9?isVid=1
This isn’t the first time DARPA has used physics to put out fire. They’ve also created an ionic wind with an electric field because it’s awesome, that’s why.
We’re looking forward to DARPA’s further efforts in fire extinguishing, probably involving nuclear radiation, magnetism, or generating a tiny black hole to suck it away.
image courtesy nikolaii666 via Flickr