🚀 go-pugleaf

In article <baz> jbaez@riesz.mit.edu (John C. Baez) writes:
   In article <bar> sichase@csa1.lbl.gov (SCOTT I CHASE) writes:
   >In article <foo>, slovick@Apple.COM (Linda Slovick) writes...
   >>2.) Is a flame a plasma?
   >Yes. 

   Anyone know HOW ionized a campfire flame is?

Not very.  If you assume that the ionization potential of a typical
air molecule is ~10V, (Nitrogen's is 14V, according to my handy CRC),
you'd need to get ~10eV/particle of thermal energy to ionize most of
the gas.  The temperature is just 10eV/Kb, or 110,000K (210,000F).
This is about a factor of 20 times hotter than a typical campfire
flame!

Campfire flames glow because they're hot enough (~3,000K) to give off orange
light by blackbody radiation, not because their charges are re-associating.

The best/most common places to see plasmas on the Earth are (a) fluorescent
lights, including most city street lights, and (b) spark discharges 
(lightning, spark plugs in cars, etc.).


	
--
Craig DeForest -- astrophysicist for hire.   DoD#314159; PhD#271828