Quantum_ Einstein, Bohr and the Great Debate About the Nature of Reality - Manjit Kumar [51]
With the manuscript finally completed and safely packed away, Niels and Margrethe boarded the train to Manchester. On meeting his bride, Ernest and Mary Rutherford knew that the young Dane had been lucky enough to find the right woman. The marriage indeed proved to be a long and happy one that was strong enough to endure the death of two of their six sons. Rutherford was so taken with Margrethe that for once there was little talk of physics. But he made time to read Bohr's paper and promised to send it to the Philosophical Magazine with his endorsement.5 Relieved and happy, a few days later the Bohrs travelled to Scotland to enjoy the remainder of their honeymoon.
Returning to Copenhagen at the beginning of September, they moved into a small house in the prosperous coastal suburb of Hellerup. In a country with only one university, physics posts rarely became vacant.6 Just before his wedding day, Bohr had accepted a job as a teaching assistant at the Lreanstalt, the Technical College. Each morning, Bohr would cycle to his new office. 'He would come into the yard, pushing his bicycle, faster than anybody else', recalled a colleague later.7 'He was an incessant worker and seemed always to be in a hurry.' The relaxed, pipe-smoking elder statesman of physics lay in the future.
Bohr also began teaching thermodynamics as a privatdozent at the university. Like Einstein, he found preparing a lecture course arduous. Nevertheless, at least one student appreciated the effort and thanked Bohr for 'the clarity and conciseness' with which he had 'arranged the difficult material' and 'the good style' with which it had been delivered.8 But teaching combined with his duties as an assistant left him precious little time to tackle the problems besetting Rutherford's atom. Progress was painfully slow for a young man in a hurry. He had hoped that a report written for Rutherford while still in Manchester on his nascent ideas about atomic structure, later dubbed the 'Rutherford Memorandum', would serve as the basis of a paper ready for publication soon after his honeymoon.9 It was not to be.
'You see,' Bohr said 50 years later in one of the last interviews he gave, 'I'm sorry because most of that was wrong.'10 However, he had identified the key problem: the instability of Rutherford's atom. Maxwell's theory of electromagnetism predicted that an electron circling the nucleus should continuously emit radiation. This incessant leaking of energy sends the electron spiralling into the nucleus as its orbit rapidly decays. Radiative instability was such a well known failing that Bohr did not even mention it in his Memorandum. What really concerned him was the mechanical instability that plagued Rutherford's atom.
Beyond assuming that electrons revolved around the nucleus in the manner of planets around the sun, Rutherford had said nothing about their possible arrangement. A ring of negatively-charged electrons circling the nucleus was known to be unstable due to the repulsive forces the electrons exert on each other because they have the same charge. Nor could the electrons be stationary; since opposite charges attract, the electrons would be dragged towards the positively-charged core. It was a fact that Bohr recognised in the opening sentence of his memo: 'In such an atom there can be no equilibrium [con]figuration without the motion of electrons.'11 The problems that the young Dane had to overcome were mounting up. The electrons could not form a ring, they could not be stationary, and they could not orbit the nucleus. Lastly, with a tiny, point-like nucleus at its heart, there was no way in Rutherford's model to fix the radius of an atom.
Whereas others had interpreted these