Developed by Richard Feynman, these are visual tools used to calculate the probability of particle interactions. Lines represent particles, and "vertices" represent where they meet and exchange energy. Licensed by Google Three Basic Actions
In QED, the electromagnetic force isn't a "static" field, but rather an exchange of photons . When two electrons repel each other, they are effectively "tossing" photons back and forth.
An electron emits or absorbs a photon at a specific place and time. Why It Matters