Here is a relevant question I have had in my mind for some time. It will likely reveal a fundamental misunderstanding of blackbody radiation on my part.
A gedanken experiment:
Imagine two boxes, one a "true"blackbody radiator (such as the box with aluminum foil referred to by John D.) and the other a collection of tunable lasers. These lasers are tuned and have intensities in such a way that when someone plots the intensity verus wavelength of the light coming out of the box the resulting curve matches that of a blackbody.
Now if a thermometer is used to measure the temperature inside the two boxes the temperature of the first box, the one with the "true" blackbody in it, will correspond to the peak wavelength according to Wien's law, whereas the second will not.
This is an apparent paradox to me. What is wrong?
Justin Parke
Oakland Mills High School
Columbia, MD