Richard Feynman quantum mechanics |

## Feynman diagram

- A Feynman diagram graphs
- paths of subatomic particles
- against time, in which
- lines entering from the left
- and leaving to the right
- carry energy, momentum, and spin,
- in which each vertex represents
- where particles interact or split,
- and internal lines are propagators.
- Straight lines are fermions,
- wavy lines are bosons,
- and helical lines are gluons.

## Antiparticles seem to go backwards in time

- Ernst Stueckelberg interpreted the positron,
- the electron’s antiparticular mate,
- as though it were an electron moving backward in time.

## Representation

- A Feynman diagram represents
- a possibility for a set of interacting particles,
- but it doesn’t represent all possibilities,
- which would be almost all
- of an infinite number of diagrams,
- which would be like . . . like . . .

One difference between a theorist and an experimentalist in the field of quantum chromodynamics is that the theorist simplifies to essential interactions, when the actual interactions can be far more complex, containing a profusion of gluons sprouting off quarks and antiquarks and decaying into hadrons.

See also in

The book of science:Antimatter—Paul Dirac, Carl David AndersonQuantum electrodynamics—Hans Bethe, Julian Schwinger, Shin'ichirō Tomonaga, Freeman Dyson, Richard FeynmanReadings in wikipedia:

Other readings:

Quantum Diaries