We’ll need three lengths: the radius of the sun \(R\ns_\odot=6.96\times 10^8\,\Rm\), the radius of the earth \(R\ns_\Re=6.38\times 10^6\,\Rm\), and the radius of the earth’s orbit \(a\ns_\Re=1.50\time...We’ll need three lengths: the radius of the sun \(R\ns_\odot=6.96\times 10^8\,\Rm\), the radius of the earth \(R\ns_\Re=6.38\times 10^6\,\Rm\), and the radius of the earth’s orbit \(a\ns_\Re=1.50\times 10^{11}\,\Rm\). This is known as the ultraviolet catastrophe, since the divergence comes from the large \(\nu\) part of the integral, which in the optical spectrum is the ultraviolet portion.
