Quantum field theory
Theory · 1927 to 1970s, Europe and the United States · Physics, stage 2: Map the theories
Quantum field theory combines quantum mechanics with special relativity by treating particles as excitations of fields that fill all of space. Dirac took the first step in 1928 with an equation for the electron that respected relativity and predicted antimatter. Making the theory finite took another twenty years, until Feynman, Schwinger, and Tomonaga produced quantum electrodynamics, whose predictions for the electron's magnetic moment match measurement to more decimal places than any other result in science. Extending the same method to the nuclear forces produced the Standard Model, which classifies all known particles and three of the four forces. Gravity has resisted this treatment, which is the outstanding problem in the field.
What it claims
- Particles are excitations of underlying fields rather than independent objects.
- Particle number is not fixed, since energy can create and destroy particles.
- The form of each interaction is fixed by the symmetries the theory is required to respect.
- The method covers the electromagnetic, weak, and strong forces but not gravity.
Key ideas
People
Sources
- Quantum field theory English Wikipedia
- Quantum Field Theory Stanford Encyclopedia of Philosophy
- Standard Model English Wikipedia
