Standard Model

The Standard Model is the theoretical framework that describes the fundamental particles of nature and the forces that act between them.

  • The Standard Model is a quantum field theory, which means that it uses the principles of quantum mechanics to describe the behaviour of matter and energy at the atomic and subatomic levels.
  • The Standard Model is based on two fundamental theories:
    • Quantum mechanics provides a description of the physical properties of nature as interactions between fields of energy at the scale of atoms and subatomic particles. It is the foundation of all quantum physics.
    • Special relativity is a theory of space and time developed by Albert Einstein in 1905. It states that:
      • The laws of physics are invariant (i.e., identical) in all inertial frames of reference.
      • The speed of light in a vacuum is the same for all observers, regardless of the motion of the light source or observer.
  • The Standard Model describes three of the four fundamental forces:
    • Electromagnetic force: The force that attracts or repels charged particles.
    • Strong nuclear force: The force that binds quarks together into protons and neutrons.
    • Weak nuclear force: The force that is responsible for radioactive decay.
    • Despite being perhaps the most familiar fundamental interaction, gravity is not described by the Standard Model, due to contradictions that arise when combining general relativity, the modern theory of gravity, and quantum mechanics.
  • The Standard Model describes 17 fundamental particles:
    • Quarks: Up, down, charm, strange, top, and bottom.
    • Leptons: Electron, muon, tau, and their 3 corresponding neutrinos.
    • Bosons: Photon, gluon, W and Z bosons, and the Higgs boson.
  • Arguably, the Standard Model stands as the most successful theory created so far by human beings in our attempts to comprehend the totality of existence – the Universe, the world around us, and every aspect of our own physical being.
  • Whilst the model has been able to explain the presence of three of the the four fundamental forces, the behaviour of subatomic particles, and the structure of the atom, it remains a work in progress, with physicists continuously seeking to refine it.
  • The following scientists have received a Nobel Prize for their work on the Standard Model:
    • Richard Feynman, Julian Schwinger, and Yoichiro Nambu (1965 Nobel Prize in Physics) for their work on quantum electrodynamics.
    • Murray Gell-Mann (1969 Nobel Prize in Physics) for his classification of elementary particles.
    • Steven Weinberg, Sheldon Glashow, and Abdus Salam (1979 Nobel Prize in Physics) for their unification of the weak and electromagnetic forces.
    • Peter Higgs and François Englert (2013 Nobel Prize in Physics) for their discovery of the Higgs boson.