Rayleigh-Jeans formula based on equipartion theoreom, which says that each degree of freedom

"gets" .5kT energy. This theory predicts intensity proportional to frequency^2

Plank's photon proposal => f^3 / ( exp(hf/kT) -1 )

> plot({x^2,x^3/(exp(x)-1)},x=0..0.3,title="works well at low freq");

> plot([x^2,x^3/(exp(x)-1)],x=0..8,y=0..3,axes=boxed,title="Ultraviolet Catastrophe",color=[black,blue],labels=[frequency,""],labelfont=[TIMES,BOLD,18]);

>