Källén and the Ettore Majorana Centre in Erice

Gunnar Kallen was genuinely interested in the education of young people. He took his teaching duties very seriously and seemed to enjoy them. His lecture notes were typed and made available to students. Phrases such as “it can be shown”, “it has been found that” did not exist in his frame of reference. He would start from the “fundamentals” and successively build up the required theoretical framework. The students were expected to have a solid theoretical ground to stand on. He gave courses on classical mechanics, electricity and magnetism, quantum mechanics, etc., never giving the same course twice. Therefore, the students often had to learn the material by themselves, consulting his lecture notes and those few books that were available, such as Dirac’s book on quantum mechanics. Kallen wrote a large number of recommendation letters for his students to attend “summer schools”, to acquire further knowledge. Therefore, he was very supportive of the establishment of the School of physics at Erice, Italy, that later on developed into the “Ettore Majorana Centre in Erice” [1].