DARPA is the acronym for Defense Advanced Research Projects Agency. You never heard of it? It’s the central research and development organization for the United States Department of Defense. The internet is probably the best known product to come from DARPA and, in fact, what you’re using at this moment was called darpanet before it was called internet.
DARPA sponsors research in many fields, some of them scary, many of them not known to the public, even though the agency itself is not remarkably or unnecessarily secretive. One of their not-so-secretive projects is fire suppression. As it says on their web site “Fire in a combat vehicle or other confined space puts warfighters at risk. DARPA’s Instant Fire Suppression (IFS) program seeks to establish the feasibility of a novel flame-suppression system based on destabilization of flame plasma with electromagnetic fields, acoustics, ion injection, or other novel approaches.”
In other words, they’re interested in learning how to put out fires instantly with a blast of electro-magnetism or sound. And, in fact, in response to DARPA’s challenge, scientists have had some success. In Professor George Whiteside’s lab at Harvard University this year scientists were able to snuff out a flame a foot and a half tall by directing a strong electric field at it. When you have a fire, some of the fuel is separated into positively and negatively charged particles swirling in the gas that makes up the flame. And it’s been known for a long time that a static electric field could bend flames. Instead of using a static field, Whitesides’ group used an oscillating field. They pointed a wire wand, which had a high-voltage field flowing from its tip, at a flame and the flame was shoved so far from it’s source of fuel that it instantly went out. Extinguishing a flame in a laboratory isn’t the same as putting out an uncontrolled fire in the outside world, but it’s a start. If you’d like to read more, here’s a link to an article about the experiment in Harvard Magazine.