Biographical Memoirs: Volume 62 (1993)
Chapter: Bristol
hydrogen by Heitler and London. His conclusion was that the bond energy in Li2 is considerably smaller than in H2, not because of the repulsion of the K shells but because the bond electrons were two s electrons (1930a). Max recently averred that this topic turned out to be a nightmare for him because of the complexity of the mathematics involved and that he had never dared to look at his thesis again (1); but nevertheless it won him his Ph.D. Degree in 1930.
EARLY CAREER IN PHYSICS (1929-32)
Bristol
John E. Lennard-Jones, Professor of Theoretical Physics at the new H. H. Wills Physics Laboratory, University of Bristol, England, spent some months at Göttingen in 1929 and was anxious to attract to Bristol two of Max Born's students for whom research grants had been provided. Gerhard Herzberg, then a postdoctoral Fellow, and Max Delbrüick were appointed. Max remained at Bristol for 18 months and became very friendly with Cecil F. Powell, with whom he roomed. Among other friends at that time were P. M. S. Blackett, later to become President of the Royal Society, P. A. M. Dirac and H. W. P. Skinner. Of these early associates four were later to win Nobel Prizes, three in physics (Dirac, Blackett and Powell) and one in chemistry (Herzberg).
An unpublished history of the Bristol Department, written by the late Professor A. M. Tyndall, related that "M. Delbrück, Prussian by birth but cosmopolitan by nature, a theoretical physicist recommended by M. Born, brought with him intellectual stimulus, critical judgement and social entertainment which gave help and pleasure to many and sundry." Another member of the department at the time, who remembers him quite well (J. Burrow, quoted by
