D O C . 3 0 5 C O M M E N T O N B O S E 3 0 9
namely, both being equally probable. The probabilities of both transitions must
therefore depend on the radiation density, that is, on Nv, contrary to Bose’s hypoth-
esis. Planck has discussed in detail in the last edition of his book on radiation theory
the extent to which quantum theory has classical theory as a limiting
case.[4]
Second, according to Bose’s hypothesis, a cold body would have to possess an
absorption potential dependent on the radiation density (diminishing with it). In the
cold state, the bodies should absorb “non-Wien” radiation more weakly than less
intensive radiation from the validity range of the Wien radiation formula. This
would certainly already have been discovered for the infrared radiation of hot light
sources if it behaved that
way.[5]
A. Einstein.