This is so cool:
With water, powder, foam and chemicals, there are already many means of dousing a flame, so it may be hard to imagine what sense it makes to add a new one.
But putting out a blaze usually leaves behind a big mess — chemical residue in every cranny, or gushing water that ruins what flames failed to devour.
Sound waves are much cleaner.
Tran envisions the new extinguishers starting out small, perhaps mounted over stovetops to put out grease fires. Or astronauts could deploy them.
“In space, extinguisher contents spread all over. But you can direct sound waves without gravity,” Robertson said.
