Quantum_ Einstein, Bohr and the Great Debate About the Nature of Reality - Manjit Kumar [59]
Just as Part I of the trilogy was published in July 1913, Bohr had finally been appointed to a lectureship at Copenhagen University. Before long he was unhappy, as his major responsibility was to teach elementary physics to medical students. At the beginning of 1914, with his reputation on the rise, Bohr set about trying to establish a new professorship in theoretical physics for himself. It would be difficult, as theoretical physics as a distinct discipline was still poorly recognised as such outside Germany. 'In my opinion Dr Bohr is one of the most promising and able of the young Mathematical Physicists in Europe today', wrote Rutherford in the testimonial to the Department of Religious and Educational Affairs in support of Bohr and his proposal.45 The immense interest that his work had attracted internationally ensured that Bohr received the backing of the faculty, but once again the university hierarchy chose to postpone any decision. It was then that a dejected Bohr received a letter from Rutherford offering an escape route.
'I daresay you know Darwin's tenure of readership has expired, and we are now advertising for a successor at £200', Rutherford wrote.46 'Preliminary inquiries show that not many men of promise are available. I should like to get a young fellow with some originality in him.' Having already told the Dane that his work showed 'great originality and merit', Rutherford wanted Bohr without explicitly saying so.47
In September 1914, having been granted a year's leave of absence, as any decision on the professorship he wanted was unlikely before then, Niels and Margrethe Bohr arrived in Manchester to a warm welcome at their safe arrival after a stormy voyage around Scotland. The First World War had begun and much had changed. The wave of patriotism that swept the country had virtually emptied the laboratories as those eligible to fight signed up. The hope that the war would be short and sharp receded by the day as the Germans smashed through Belgium and into France. Men who had only recently been colleagues were now fighting on opposing sides. Marsden was soon at the western front. Geiger and Hevesy had joined the armies of the Central Powers.
Rutherford was not in Manchester when Bohr arrived. He had left in June to attend the annual meeting of the British Association for the Advancement of Science, being held that year in Melbourne, Australia. Recently knighted, he visited his family in New Zealand before travelling on to America and Canada as planned. Once back in Manchester, Rutherford devoted much of his time to anti-submarine warfare. Since Denmark was neutral, Bohr was not allowed to take part in any war-related activities. He concentrated largely on teaching, and what research was possible was impeded by the lack of journals and the censorship of letters from and to Europe.
Originally planning to spend just a year in Manchester, Bohr was still there when in May 1916 he was formally appointed to the newly created post of professor of theoretical physics in Copenhagen. The growing recognition of his work had secured the post, but despite its successes there were problems that the quantum atom could not solve. The answers it gave for atoms with more than one electron failed to tally with experiments. It could not even account for helium with just two electrons. Worse, Bohr's atomic model predicted spectral lines that could not be found. In spite of the introduction of ad hoc 'selection rules' to explain why some lines were observed and others were not, all the central elements of Bohr's atom were accepted by the end of 1914: the existence of discrete energy levels, the quantisation of