
Darpa creates sound-based fire extinguisher - evo_9
http://www.extremetech.com/extreme/132859-darpa-creates-sound-based-fire-extinguisher
======
Zenst
I have a friend who will be pleased about this for all the wrong reasons as he
can not setup a sound system in a forrest and have an excuse, enough said.

I do wonder how practical but there again the first mobile phones were hardly
practical, so its a good start. Will be usefule when combined with some of the
technolody that turns natural surfaces into speakers and in that windows would
be the ideal way to implement this as alotof buildings have them and they
could act as speakers perhaps for this type of fire suppresion. Not totaly
sure on the health aspects, but there again it may be another halon type
affair were it is not too good for human exposure either.

I like the insight into fire being cold plasma and in many ways having gone
from cavemen we are still learning about fire, amazing when you think of it
that way.

------
stephengillie
This is a much better fire suppression idea than Star Trek's _surround it with
a force field and let it use up all the oxygen_ system.

~~~
JoeAltmaier
Though that was often a fire in a plasma conduit or something; not sure
exactly what was going on there.

------
jawns
I'd like to know more about the characteristics of cold plasmas -- the article
doesn't go into it much.

Also (having not watched the video): Just how loud does this have to be to
work? And does it need to work in audible frequencies?

~~~
stephengillie
_A plasma is sometimes referred to as being "hot" if it is nearly fully
ionized, or "cold" if only a small fraction (for example 1%) of the gas
molecules are ionized, but other definitions of the terms "hot plasma" and
"cold plasma" are common._

<https://en.wikipedia.org/wiki/Plasma_(physics)#Temperatures>

------
ximeng
<http://www.darpa.mil/NewsEvents/Releases/2012/07/12.aspx>

(source)

