Question: What is the standard model of physics?

Daniel Scully answered on 16 Nov 2011:

The Standard Model is the name given to our current theory of Particle Physics.

It contains 12 “matter” particles – which combine to make up atoms and everything the Universe is made of. Then there are 4 “force” particles – which allow the matter particles to interact with each other.

For example, the photon, carries the electro-magnetic force – so when two magents repell each other, it’s photons travelling between the magnets which push them apart.

The Standard Model doesn’t predict what particles and forces exist, we put those in. But it does allow us to make predictions of how those particles and forces then behave. Those predictions have been checked with experiments to such accuracy that it is the most accurately tested theory in the history of science!

There are still some questions to be answered in the Standard Model though. The most well known is that it doesn’t allow the particles to have mass, which we know they do! The Higgs force was suggested to solve this problem. That’s why the LHC at CERN is looking for the “Higgs Boson” which would prove the Higgs force exists.

(There are other “Standard Models” in physics too. Like the Standard Model of Cosmology. But they’re completely different things.)