〈 Berger | Dillon 〉

His dream was to find a Lie algebra whose representations could model the observed baryons and mesons. You see, much earlier Heisenberg had invented a theory like this based on the Lie algebra su(2). This could account for all baryons and mesons known at the time. (2/n)

But later, "strange" baryons and mesons were discovered - quite a zoo of them. So Gell-Mann wanted to find a bigger Lie algebra to explain them. He wanted it to contain the 3-dimensional Lie algebra su(2), since he wanted his theory to include Heisenberg's. (3/n)