A friend of mine ran across the following PDE in some notes from an old friend of theirs:
$$ \theta \frac{d^2\theta}{dt^2} + \delta\frac{d\theta}{dt} + \frac{dL}{d\alpha}(\rho_1-\rho_2)\alpha = \frac{dR}{dB}S_2B\,. $$ The $L$ here might be a different character, it's garbled in the writing.
I like a good math mystery so I did some poking around for it but couldn't find anything. They indicated it might have something to do with balancing things that wobble, possibly rockets. Any ideas?
