PhD exams and Werner Heisenberg

Physicists can be divided into two big groups: experimentalists and theorists. The first lot (to which I belong) know what a vacuum pump is, the second lot write long equations.

Werner Heisenberg was a theoretician, and so good that he could even write short equations. He has a great (if true, I can't find any reliable source for it) epitaph, applying the inability to exactly locate a particle, as defined in his uncertainty principle, to his own body.

Er liegt irgendwo hier

meaning "He's buried somewhere/anywhere round here". I will try to check this out the next time I'm in Munich. It sounds somehow too good to be true.

Anyway, before he died, and before he developed his nobel-prize winning quantum mechanics, he wrote a thesis titled "On the Stability and Turbulence of Fluid Flow" that concerned the flow of the River Isar through Munich. In Google Maps the flow looks distinctly turbulent in parts, but maybe it's changed since 1925.


Größere Kartenansicht

Well, having done whatever he'd done in the Isar (I can't imagine that he spent much time wading in it) and writing his thesis, Heisenberg had to pass an oral exam. He had four examiners: A theoretician (Arnold Sommerfeld, his PhD adviser), a mathematician, an astronomer and an experimentalist (Wilhelm Wien). Being a theoretican, Heisenberg knew little about experimental matters, and was torn apart in that part of the exam. The bad news for experimentalists is that the theoreticians have been seeking their revenge ever since.

My exam was pretty much a mirror image of Heisenberg's, but without the mathematician. I had a theoretician, an experimentalist (also my PhD advisor) and an astronomer asking the questions, and almost drowned in the theory section. I passed, but only just. This happens to everyone I've ever heard of.

My only suggestion to future experimentalists is to make a formal apology to the theoretician at the start of the exam, explaining your regret for Heisenberg's treatment. Say how cruel it was to confront such a brilliant mind with trivialities of technical equipment, and profess that great thinkers don't need to know how vacuum pumps work. Suggest that you abandon the exam, pick a grade out of a hat and crack open the champagne, drinking to a reconciliation in the world of physics.

Links

I lifted most of this post from this site on Heisenberg's career.

Arnold Sommerfeld is the unluckiest physicist of all time.

That theoretician may be the train that Gajo-Simpatico is fearing.