According to Feynman’s formulation, the entire universe of QED can be boiled down to three simple actions: A photon goes from one place and time to another. An electron goes from one place and time to another.

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.

Beyond being a mathematical masterpiece, QED provided the blueprint for the of particle physics. It showed scientists how to combine quantum mechanics with special relativity and successfully handle "renormalization"—a mathematical technique to remove the "infinities" that previously broke earlier theories.

is the relativistic quantum field theory that describes how light and matter interact. It specifically focuses on the interactions between electrically charged particles (like electrons and positrons) and the electromagnetic field (represented by photons). The "Jewel of Physics"

An electron emits or absorbs a photon at a specific place and time. Why It Matters