The most beautiful equation ever
It is said that one day, when the great German mathematician Leonhard Euler was at the Court of Catherine the Great, a friend asked him for a proof of the existence of God. Euler is supposed to have replied with what is now called the Euler Identity and then essentially said Q.E.D.
Euler's Identity is indeed beautiful because the five parts of the equation come from vastly different origins, and each with roles in mathematics that can’t be overstated and that they should be connected by such a simple relationship, is simply stunning.
One would have to think that Euler’s identity will appear, to the arbitrarily advanced mathematicians thousands of years hence, to remain as beautiful and stunning as the day it was first written.