This van der Waals fluid relationship to heat flow turned out to be really interesting.
The reduced form of the equation of state for any fluid is:
Adding the stefan-boltzmann and exchanging T for T^4 on the right side gives, with T^4=TSI:
Apparently, light can, and maybe should, be treated like a form of fluid. This of course gives my brain some interesting ideas about space and what fills the vacuum, and how massive bodies is affected by it. I´ll probably get back to that in another post.