jj@alice.UUCP (12/14/84)
>From allegra!ulysses!burl!clyde!bonnie!akgua!whuxlm!harpo!decvax!mcnc!philabs!cmcl2!seismo!harvard!wjh12!foxvax1!brunix!lems!ltn Wed Dec 31 19:00:00 1969 >In article <alice.3140> jj@alice.UUCP writes: >>... >>I hereby propose that the threshold of "darkness" is calculated >>in the following manner: >> >>Consider a spherical shell, of interior radius 1 meter, with the >>interior of the shell representing a perfect black body. Consider >>that that shell is at exactly 373 degrees K. Measure, with a >>probe that has no effect on the EM radiation, ... >> >Sorry. Ever hear of quantum mechanics? There is no such thing as a probe >that has no effect on the thing being measured. > >-les niles Yeah, well, Les, maybe I DO understand that. The POINT is that I was trying to provide a a defination that can be THEORETICALLY calculated, Les. You don't NEED a "perfect probe" because you can, and MUST, calculate the flux in question from first principles. What's that got to do with quantum mechanics? (Other than the obvious uses of quantum mechanics in the calculations, that is.) Measurement of an actual space clearly is less easy, but still within the reach of a good photon counter, I think. Also, given a "normal" space, I think that the effects of absorbing the photons in your very small pickup space will be easily calculated and minor. <What's the ratio of the energy lost to the probe as a percentage of the room's photon loss?