Your favorite equations.

(Yay! Nerdiest thread evar!)

My personal fav. is Minkowski's "c = i".  I.e. the speed of light is equal to \sqrt{1} as a dimensioned constant.

>>1
That's a rare/antiquated view of special relativity.  Nowadays, people prefer pseudoriemannian manifolds over complex riemannian manifolds.  ie instead of making time imaginary, one just has a metric that is not positive definite.  I can't think of any other reason why one would want c to equal i.