Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: 33.2 The Four Basic Forces The four basic forces and their carrier particles are summarized in the Table 33.1. Feynman diagrams are graphs of time versus position and are highly useful pictorial representations of particle processes. The theory of electromagnetism on the particle scale is called quantum electrodynamics (QED). Answer: quantum electrodynamics
Output:
What do we call the theory of electromagnetism on the particle scale?