Werner Heisenberg was one of the greatest physicists of the twentieth century. He is best known as a founder of quantum mechanics, the new physics of the atomic world, and especially for the uncertainty principle in quantum theory. He did cut a controversial figure according to many during World War II. After which he became active in the field of elementary particle physics and West German science policy.
This story is about him earning his doctorate from Ludwig-Maximilians-Universität München under the mentorship of William Sommerfeld.
Physics in those days still meant primarily experimental physics. Theoretical physics, though rising in status, had not yet reached full acceptance as a branch of physics equal to experimental research. So Heisenberg also had to take the four-hour laboratory course in experimental physics offered by Prof. Wilhelm Wien, where he struggled badly much to the great Prof. Weins displeasure. Meanwhile he carried on with his thesis on a very difficult problem in hydrodynamics. He submitted a 59 page thesis on the same to the University faculty on the same which was duely accepted and published in the journal edited by Wein.
But he still had to acquire the desired grades in the orals to get through with his doctorate. And this was where trouble began. The oral examining committee consisted of Sommerfeld and Wien in physics, along with representatives in Heisenberg's two minor subjects, mathematics and astronomy: one grade for each subject and one for overall performance. The grades ranged from I (equivalent to an A) to V (an F). So obviously much was at stake.
He tackled Sommerfeld's physics and the Mathematics questions quite easily. But then came astronomy where he stumbled and finally fell flat on his face in Wein's experimental physics. Where others had studied and learnt about the Fabry-Perot interferometer extensively, Heisenberg failed to derive the resolving power of a normal telescope! The angry professor then asked him the working principle of a storage battery and he was still the same dumb! Naturally Wein who held the idea that one needs to be an expert in experiments to do physics saw no reason to pass the 21 year old, and gave him the lowest grade , a F!
An argument arose between Sommerfeld and Wien over the relative importance of theoretical physics in relation to experimental physics. The result was that Heisenberg received a C, in physics and for the overall grade for his doctorate. Both of these grades were probably averages between Sommerfeld's grade (an A) and Wien's grade (an F)!
Accustomed to being among the top in his class, Heisenberg was distraught with this mediocre grade. Heisenberg skipped the party arranged by Sommerfeld and went straight to Max Born who had hired him as his teaching assistant for the next season. He summarised Born about his miseries and asked, "I wonder if you still want to have me."
Though born let his offer stand, a worried Heisenberg's father wrote to famed experimentalist James Frank to impart some knowledge in that field to his son. Frank tried hard, but somethings aren't just meant to be. Heisenberg's gargantuan lack of interest in it made him give up, which meant if he had to do physics all he could live on was theory. And he did just that!