In physics we do things and afterwards worry about whether they worked
I would like to pay tribute to the great physicist, Nicola Cabibbo who died on Monday at the age of 75.
He was mainly known for his work on weak interactions. He explained why the transitions between up and down quarks, electrons and electron neutrinos, muons and muon neutrinos had similar quantum amplitudes by postulating weak universality. He also explained why transitions with a change in strangeness had about a quarter the amplitude of those with no change in strangeness through the mixing angle (also called Cabibbo angle).