LARS ONSAGER - The National Academies Press

LARS ONSAGER 189
may seem strange that a man who could see so deeply into
physical reality should have been so conspicuously lacking in
imagination when it came to reading other minds, but almost
everyone who met him became immediately aware of this
disability.
"I won't say he was the world's worst lecturer," Professor Cole continues,
"but he was certainly in contention. He was difficult to understand anyway,
but he also had the habit of lecturing when his back was to the students
and he was writing on the blackboard. To compound matters, he was a big
man, and students had to peer round him just to try and see what was
being written."
Onsager's problems in communicating with lesser mortals
were certainly not due to impatience or arrogance. The theoretical
chemist Julian Gibbs, of Brown University, who got to
know him some years later describes Onsager as a "very, very
friendly man" who would always assume that his listeners
were as advanced in their thinking as he was. "He assumed
that if he knew it, others in the field automatically knew it,"
whatever the subject under discussion.
Yet it was not only students who found Onsager difficult
to understand; his colleagues had the same difficulty. Oliver
Penrose, who worked with him as a postdoctoral associate,
recalls a lecture to the Kapitza Club in Cambridge, many
years later, at which Onsager was explaining his joint work
with Bruria Kaufman on the Ising lattice. He had been
warned that non-theoreticians would be present and that he
should phrase his talk in not too technical language. He
plunged, nevertheless, into the mathematics of spinor algebras.
After about twenty minutes, one of the many experimentalists
in the audience had the courage to ask him what
a spinor was. Onsager replied, thoughtfully: "A spinor—no,
a set of spinors—is a set of matrices isomorphic to the orthogonal
group." With that he gave the famous Onsager grin,