@HDE226868 neat article! I was confused by just one thing -- in the formula you say T is central temperature, and then you start talking about critical temperature, and I'm not sure how those relate. (And temperature isn't part of the later graph.) Can you clarify that?
Also, even though all the other stuff in the formula is constants, I for one would appreciate it if you could say (or link to something about) what the others are. The subscripts are particularly mysterious.