3.2.1.4
Four fundamental interactions govern all particle physics
Particles, Antiparticles & Photons — AQA A-Level Physics
- There are four fundamental interactions: gravity, electromagnetism, strong nuclear, and weak nuclear.
- The strong interaction is the strongest. Gravity is the weakest.
Ranges of the fundamental forces
- Electromagnetic and gravitational: infinite range.
- Weak nuclear: up to $\sim 10^{-18}$ m.
- Strong nuclear: $\sim 10^{-15}$ m (0.5 to 3.0 fm).
What each force affects
- Gravity: all particles with mass (negligible at particle scales).
- Electromagnetic: all charged particles.
- Strong: hadrons only (particles made of quarks).
- Weak: all particles.