8: Exercises
( \newcommand{\kernel}{\mathrm{null}\,}\)
At a time when many physicists were considering giving up on even the possibility of developing an understanding of particle physics using the techniques that had worked so well with QED, Gell-Mann, in 1961, discovered the importance of group theory, which gave him a mathematical tool to classify the plethora of new elementary particles according to their symmetry properties.…In Gell-Mann’s scheme …, the different particles fell into sets of representations whose properties …could be graphed so that they formed the vertices of a polyhedron, and all of the particles in each polyhedron could then be transformed into each other by symmetries, which could effectively rotate the polyhedron in different directions. Lawrence Krauss, Quantum Man, p. 288