Electroweak interaction Updated +Created
Video 1.
Electroweak Theory and the Origin of the Fundamental Forces by PBS Space Time (2020)
Source. Unsatisfactory, as usual.
Feynman diagram Updated +Created
I think they are a tool to calculate the probability of different types of particle decays and particle collision outcomes. TODO Minimal example of that.
And they can be derived from a more complete quantum electrodynamics formulation via perturbation theory.
At Richard Feynman Quantum Electrodynamics Lecture at University of Auckland (1979), an intuitive explanation of them in termes of sum of products of propagators is given.
Pauli exclusion principle Updated +Created
Initially a phenomenological guess to explain the periodic table. Later it was apparently proven properly with the spin-statistics theorem, physics.stackexchange.com/questions/360140/theoretical-proof-of-paulis-exclusion-principle.
And it was understood more and more that basically this is what prevents solids from collapsing into a single nucleus, not electrical repulsion: electron degeneracy pressure!
Bibliography:
Video 1.
The Biggest Ideas in the Universe | 17. Matter by Sean Carroll (2020)
Source.