PROFESSOR V.~CLAV VOTRUBA'S SIXTIETH BIRTHDAY

On December 19th, 1969, RNDr. V~iclav V o t r u b a D.Sc., Professor of Theoreti- cal Physics and Corresponding Member of the Czechoslovak Academy of Sciences celebrates his sixtieth birthday.

Professor V o t r u b a was born in Slav&in on the Oh~e, near Louny, in Bohemia. He studied at the Faculty of Natural Sciences of Charles University in Prague. During his graduate studies he was a pupil of Professor Z~ivigka and afterwards be- came Assistent Professor at the De- partment of Theoretical Physics headed by Professor Z~ivigka. During the war he taught at various Prague grammar schools.

After the reopening of the Czech uni- versities in 1945 he was charged with lecturing instead of the deceased Pro- fessor Z~ivigka. In 1946 he left for a one-year stay in Zurich where he wor- ked in the group of Professors Wentze l and Pauli . Here he started to work on the problem of electron-positron pair creation at photon-electron collisions. The results (Bulletin Int. de l'Acad. Tcheque des Sci. 49 (1948), No. 4, 1-31; Phys Rev. 73 (1948), 1468) of his investigations later became the basis of his habilitation thesis, and now are amongst the standard references in textbooks and monographs on quantum electro- dynamics.

Shortly after his return from Zurich he was appointed Reader and since 1954 he has been acting as a Full Professor of Theoretical Physics at the Faculty of Mathematics and Physics of Charles University in Prague. In 1956-59 period he was Deputy Director of the Joint Institute for Nuclear Research in Dubna.

Mention should be made of Votruba's pioneering activity in the field of particle systematics. For instance, already in 1949 after the first reports on the possible exis- tence of other particles than leptons, mesons and nucleons, V o t r u b a suggested treating these new particles as excited states of nucleons and mesons. He solved the problem of the mass-spectrum of these new particle in an original way by introducing mass-operators into the Dirac and Kemmer equations (Bulletin Int. de l'Acad. Tcheque des Sci. 50 (1949), No. 12, 1-18). A similar theory was presented independently by Pais in 1952, i.e. at a time when these new particles had been sufficiently explored.

Czech. J. Phys. B 19 (1969) 1469

Another of Votruba's original contributions was the consistent introduction of isotopic spin, which had hitherto been ascribed only to nucleons, as a fundamental characteristic of all elementary particles (Czech. J. Phys. 2 (1953), 1). Some of his further results in this field were presented at the IV th Rochester conference on High Energy Physics (USA, 1955) and at the International High Energy Physics Conference in 1958 (Geneva).

Similarly to his activity as a scholar, his pedagogical activity too has fundamentally influenced the development of Czechoslovak physics. It is no exaggeration to say that nearly all Czechoslovak theoretical physicists working in nuclear and high energy physics are his pupils.

Thus it remains to conclude with our sincere wishes to Professor V o t r u b a for good health and a long life and that he will be able to continue contributing to Czechoslovak physics.

The Editors

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