Grand Unified Theories

I was talking to a guy the other day about Grand Unified Theories, and I thought I ought to say something about them. The Wikipedia Grand Unified Theory article gives a fair account. It says a GUT is a model where “at high energy, the three gauge interactions of the Standard Model that define the electromagnetic, weak, and strong interactions, or forces, are merged into a single force”. You’ve doubtless seen the picture: Image from the particle adventure That’s from the particle adventure website. They say this: “one of the major goals of particle physics…

Continue Reading

Electroweak theory

The weak interaction is said to be responsible for beta decay, muon decay, and some other decays. For example it’s said to be responsible for charged pion decay, but not for the more rapid neutral pion decay. That’s said to be caused by electromagnetism. However the electroweak interaction is said to be a unification of the weak interaction with electro-magnetism, and thus is said to cover all pion decays. The beginnings of unification As to when this unification began, it’s hard to say. Some might say…

Continue Reading

A partial history of the weak interaction

The weak interaction is said to be responsible for beta decay, where a neutron decays into a proton, an electron, and an antineutrino. All four of these particles are said to be fermions. Fermions are of course named after Enrico Fermi, who proposed what’s now known as the Fermi interaction. That was in his 1933 paper Attempt at a theory of β rays. It was famously rejected by Nature, then published in both Italian and German in 1934. The Fermi Interaction The Fermi Interaction is “the…

Continue Reading
Close Menu