On the International Scene

Abstract

1960’s was a golden age for theoretical (particle) physicists, in the sense that the universities were competing to become the very best in the area and were looking for the most competent and promising scientists. Källén was an obvious candidate. It was known that Källén, as he himself had stated, could not be tempted to take up a permanent position anywhere outside Sweden. But perhaps he could be tempted to come for some time? His correspondence (in the Källén Collection) shows that he had quite a few invitations to go to several places in the USA. Here below, we quote a few of his last “offers”. For example, he received a letter of invitation, dated 30 October 1967 and signed by Alfred Schild, Austin, Texas (with copies to Yuval Ne´eman and Harold P. Hanson) stating:

“I am writing now to ask you if you would like to come during the next academic year [1968–9], preferably for both semesters, otherwise for one. If you do, I am confident that the University of Texas would make an attractive offer.”

From Wisconsin he received the news (from Hiroomi Umezawa, dated 24 April 1967):

“The University of Wisconsin-Milwaukee has become extremely interested in establishing a strong group of theoretical physicists. … We would be extremely happy if you would agree to come to Milwaukee on this visiting professorship.”

T. A. Pond, the Chairman of Department of Physics, State University of New York at Stony Brook wrote to him on 3 November 1967 (with copies to President Toll, Professor Yang, and Professor Dresden):