Physics
Feynman was an amazing physicist. He was well known for
his work in Quantum Electrodynamics (QED). QED is not a simple subject. Basically
as far as I can see it QED is based on the interaction of charged point particles
such as positrons, electrons and photons.
Feynman designed a relatively simplistic way of understanding these interactions.
The Feynman diagram shows the interactions between electrons, positrons, and
photons in a two-dimensional time related processes. There are Feynman rules
for using these diagrams which can accurately calculate the interactions between
the particles.
The rules basically state:
1 Draw all possible diagrams for a specific number of photons.
2 Calculate the amplitude for all possibilities (this part is very messy)
3 Add the amplitude factors for all possible paths.
The diagrams look as follows. Arrows to the right represent electrons. Arrows
to the left represent positrons. Wavy lines represent photons.
an electron emits a photon and another electron obsorbs the photon
The time of these diagrams moves from left to right.
Representations of these diagrams can be found at:
http://www2.slac.stanford.edu/vvc/theory/feynman.html