So what exactly is the difference between (a) a hot gold ingot; and (b) the Sun?
Why is one a blackbody, but the other isn't?
How can they "measure" or "determine" that the Sun absorbs 100% of the radiation incident upon it? What kind of experiments do they do to confirm this?
So this is something that had always been a bit of a stumbling block for me, but I think I'm starting to grasp it .. at least partially.
What we really have going on is two distinct bodies: (a) the "radiator" itself, which might be the walls of an oven (i.e., the actual "solid" object that...
I'm reading from an introductory text on quantum physics, and came across this sentence:
It's the second sentence that I don't understand: how can the energy in the EM field be responsible for the ability of a hollow cavity to absorb heat?