Quantum_ Einstein, Bohr and the Great Debate About the Nature of Reality - Manjit Kumar [116]
Heisenberg could not stop himself from lamenting later that Sommerfeld, who had witnessed the whole incident, had 'succumbed to the persuasive force of Schrödinger's mathematics'.66 Shaken and dejected at being forced to retire from the arena vanquished before battle had been properly joined, Heisenberg needed to regroup. 'A few days ago I heard two lectures here by Schrödinger,' he wrote to Jordan, 'and I am rock-solid convinced of the incorrectness of the physical interpretation of QM presented by Schrödinger.'67 He already knew that conviction alone was not enough, given that 'Schrödinger's mathematics signifies a great progress'.68 After his disastrous intervention, Heisenberg had sent a dispatch to Bohr from the front line of quantum physics.
After reading Heisenberg's version of events in Munich, Bohr invited Schrödinger to Copenhagen to give a lecture and participate in 'some discussions for the narrower circle of those who work here at the Institute, in which we can deal more deeply with the open questions of atomic theory'.69 When Schrödinger stepped off the train on 1 October 1926, Bohr was waiting for him at the station. Remarkably, it was the first time they had ever met.
After the exchange of pleasantries, battle began almost at once, and according to Heisenberg, 'continued daily from early morning until late at night'.70 There was to be little respite for Schrödinger from Bohr's continual probing in the days ahead. He installed Schrödinger in the guest room at his home to maximise their time together. Although usually the most kind and considerate of hosts, in his desire to convince Schrödinger that he was in error, Bohr appeared even to Heisenberg to act as a 'remorseless fanatic, one who was not prepared to make the least concession or grant that he could ever be mistaken'.71 Each man passionately defended his deeply-rooted convictions concerning the physical interpretation of the new physics. Neither was prepared to concede a single point without putting up a fight. Each pounced on any weakness or lack of precision in the argument of the other.
During one discussion Schrödinger called 'the whole idea of quantum jumps a sheer fantasy'. 'But it does not prove that there are no quantum jumps', Bohr countered. All it proved, he continued, was that 'we cannot imagine them'. Emotions soon ran high. 'You can't seriously be trying to cast doubt on the whole basis of quantum theory!' asked Bohr. Schrödinger conceded there was much that still needed to be fully explained, but that Bohr had also 'failed to discover a satisfactory physical interpretation of quantum mechanics'. As Bohr continued to press, Schrödinger finally snapped. 'If all this damned quantum jumping were really here to stay, I should be sorry I ever got involved with quantum theory.' 'But the rest of us are extremely grateful that you did,' Bohr replied, 'your wave mechanics has contributed so much to mathematical clarity and simplicity that it represents a gigantic advance over all previous forms of quantum mechanic.'72
After a few days of these relentless discussions, Schrödinger fell ill and took to his bed. Even as his wife did all she could to nurse their house-guest, Bohr sat on the edge of the bed and continued the argument. 'But surely Schrödinger, you must see …' He did see, but only through the glasses that he had long worn, and he was not about to change them for ones prescribed by Bohr. There had been little, if any, chance of the two men ever reaching a concord. Each remained unconvinced by the other. 'No real understanding could be expected since, at the time, neither side was able to offer a complete and coherent interpretation