Prior to Planck's work, it <answer>h</answer>ad been assumed t<answer>h</answer>at t<answer>h</answer>e energy of a body could take on any value w<answer>h</answer>atsoever – t<answer>h</answer>at it was a continuous variable. T<answer>h</answer>e Rayleig<answer>h</answer>–Jeans law makes close predictions for a narrow range of values at one limit of temperatures, but t<answer>h</answer>e results diverge more and more strongly as temperatures increase. To make Planck's law, w<answer>h</answer>ic<answer>h</answer> correctly predicts blackbody emissions, it was necessary to multiply t<answer>h</answer>e classical expression by a complex factor t<answer>h</answer>at involves <answer>h</answer> in bot<answer>h</answer> t<answer>h</answer>e numerator and t<answer>h</answer>e denominator. T<answer>h</answer>e influence of <answer>h</answer> in t<answer>h</answer>is complex factor would not disappear if it were set to zero or to any ot<answer>h</answer>er value. Making an equation out of Planck's law t<answer>h</answer>at would reproduce t<answer>h</answer>e Rayleig<answer>h</answer>–Jeans law could not be done by c<answer>h</answer>anging t<answer>h</answer>e values of <answer>h</answer>, of t<answer>h</answer>e Boltzmann constant, or of any ot<answer>h</answer>er constant or variable in t<answer>h</answer>e equation. In t<answer>h</answer>is case t<answer>h</answer>e picture given by classical p<answer>h</answer>ysics is not duplicated by a range of results in t<answer>h</answer>e quantum picture.
In making Planck's law, what was in both the numerator and denominator of the formula that was used?
h