This is available on a t-shirt from xkcd.com - the mouseover on the website says 'bonus points if you can identify the science'. Neal took one look, muttered something about blackbody radiation and is now explaining the maths and telling the tragic tale of Boltzmann's Constant, which helps explain why this curve isn't a straight line (his critique of classical physics was vindicated a couple of months after his death - the little k is his constant in this equation). It plots the energy carried by a photon of light by its frequency (though light's a particle too). A blackbody radiator radiates all the heat/light it absorbs.
I shall buy Neal the t-shirt in honour of his superior nerding.
