File:Feynman'sDiagram.jpg

Summary
Picture of a Feynman diagram, inscribed by Richard P. Feynman to me, in my copy of Volume 3 of his Feynman Lectures on Physics (Quantum Mechanics). Picture taken by self.

if you can't read the symbols, they are $$\gamma_\mu$$ to $$\gamma_\mu$$  and  $$1/q^2$$