# 1948

## Quantum electrodynamics

## The book of science

Tom Sharp

Tom Sharp

Hans Bethe, Julian Schwinger, Shin'ichirō Tomonaga, Freeman Dyson, Richard Feynman quantum mechanics |

- Electrically charged particles
- move, interact, emit and absorb
- photons, create force fields,
- act like waves, act like particles,
- within certain probabilities
- consistent with special relativity.
- Now these behaviors can be
- described, formulated, renormalized,
- quantified with extreme precision,
- and illustrated with Feynman diagrams.

- Every alternative happens at once,
- every state superimposed in time, so
- to calculate the probability of an electron
- moving from here to there, one would need
- to consider all paths including intermediate
- events, which is impractical; however,
- virtual particles in closed loops return
- particles to their real states, so we can
- cut the Gordian knot. Increasingly
- complicated calculations eventually
- increasingly diminish in importance.

- Does any
- virtual particle
- escape to
- become actual?
- Hopes come true;
- dreams awaken;
- silliness
- persists.
- Many agree
- God has a sense
- of humor, like
- a zen potter
- who deliberately
- adds a flaw.
- Fun to tease
- these things out.

A Feynman diagram does not show how a particle moves from one point to another; the particle’s path, speed, dimensionality, and nature are still mysteries, although quantum electrodynamic theory describes the probabilities that it undergoes events, such as when an electron absorbs or emits a photon, or when a quark-antiquark pair radiates a gluon. Quantum electrodynamics is a part of quantum field theory; a field is a function that assigns a value for each point in a space (of some kind).

See also in

The book of science:Electromagnetism—Hans Christian Ørsted, André-Marie Ampère, Michael FaradayMaxwell’s equations—James Clerk MaxwellQuanta—Max Planck, Albert EinsteinSpecial relativity—Albert EinsteinAtom—Ernest Rutherford, Niels BohrWave-particle duality—Werner Heisenberg, Louis de Broglie, Erwin SchrödingerAntimatter—Paul Dirac, Carl David AndersonNuclear fission—Otto Hahn, Fritz Strassmann, Lise Meitner, Otto Robert Frisch, Rudolf Peierls, Enrico FermiParity violation—Tsung-Dao Lee, Chen-Ning YangReadings on wikipedia: