The Purest Soul's Beautiful Quantum Mechanics

Shortly after Heisenberg's return from Heligoland where he had come up with the first results in the direction of matrix mechanics, he was invited to present a lecture to the Kapitza Club at the Cavendish Laboratory in Cambridge. The title of his talk was Term Zoology and Zeeman Botany. At the end of his talk he briefly mentioned his new results on matrix mechanics. In the audience was another young physicist, Paul Adrien Maurice Dirac (1902 – 1984) who, although this work should have been of extreme interest to him, paid no attention to it. As Dirac himself later explained, the seminars at the Cavendish Laboratory were held at two o'clock in the afternoon. "After a good lunch, this time was more suitable for a snooze than concentrated attention on a speaker"…