On Thu, 16 Aug 2001, Steve Thompson wrote:
Quoting Anonymous (nobody@paranoici.org):
If a block of a metal is hollowed out and a small port is drilled to see in, the radiance of the cavity is substantially higher than that of the surface of the metal. As if that weren't shocking enough, it turns out that the radiance of cavities is the same no matter what kind of metal is used. (This is so counterintuitive that I almost don't believe it!)
This is actually a phenomenal result. If one makes a large enough apparatus so that the cavity is very, very large with a correspondingly small port is drilled, you've then got the makings of a great beam weapon.
You're missing the parameter where the walls have to be kept at a temperature T. This implies that your environment around the ball is controlled. In a lab environment you'd wrap the cavity in some sort of heater blanket. To help you get a better grasp of the scale of the effect, consider the odds of a single photon entering the cavity port from the outside. What is the odds that that photon will be re-emitted? Almost nill. It effectively absorbs radiation at all frequencies (hence the 'black' term). Now, consider the inverse, what is the odd that a photon of a given wavelength will be emitted? The odds that a perfect black body absorber would radiate a photon from inside the cavity to the outside environment is also low. So, to make a black body radiator into a beam weapon implies so much energy keeping the cavity at the temperature required that it would be simpler to use that energy directly instead of trying to create a high energy photon stream from a very(!) inefficient emission process. The Dynamics of Heat Fuchs ISBN 0-387-94603-9 -- ____________________________________________________________________ natsugusa ya...tsuwamonodomo ga...yume no ato summer grass...those mighty warriors'...dream-tracks Matsuo Basho The Armadillo Group ,::////;::-. James Choate Austin, Tx /:'///// ``::>/|/ ravage@ssz.com www.ssz.com .', |||| `/( e\ 512-451-7087 -====~~mm-'`-```-mm --'- --------------------------------------------------------------------