Experience can of course guide us in our choice of serviceable mathematical concepts; it cannot possibly be the source from which they are derived; experience of course remains the sole criterion of the serviceability of a mathematical construction for physics, but the truly creative principle resides in mathematics.
Lecture by Einstein, ‘On the Method of Theoretical Physics’, in Oxford, June 1933
Einstein’s second stay in Oxford, from late April to late May 1932, was less eventful as compared with his busy and much-publicised visit exactly a year earlier. This time he avoided giving lectures in England, except for the Rouse Ball lecture on mathematics on 5 May in Cambridge, which provided him with a welcome opportunity to meet Eddington. (But he did agree at this time to give the Herbert Spencer lecture during Oxford’s Trinity term in mid-1933.) He also kept largely clear of politics, giving only one press interview, to the Jewish Chronicle. Asked by its reporter in his college rooms at Christ Church whether or not ‘Jews as a race make good scientists’ and ‘possess peculiar gifts in the sphere of music’, Einstein replied that while Jews had always taken an interest in intellectual problems, they had excelled more in science. But, he said, ‘I do not believe in any special gifts among the Jews. It is more an inclination towards a particular occupation.’ Pressed on his view of Palestine and Jewish–Arab relations, he added that the Jewish situation there would remain a problem. ‘The coexistence of human beings with different traditions always constitutes a problem.’ Most of his time in Oxford seems to have been spent quietly working on physics and mathematics in his new college, taking walks about the city and playing music with amateurs and professionals, including Marie Soldat, at the Denekes’ house, Gunfield. On one occasion, they finished the last note of the Brahms Piano Quintet at 11.20 p.m. Einstein called out: ‘The gate at Christ Church is locked at eleven – what am I to do now?’ Having rushed to the telephone and called the porters’ lodge, they discovered the college would remain open until midnight (perhaps in Einstein’s honour?). Before hurrying into the Denekes’ car, Einstein scribbled a postcard to Sir Donald Tovey thanking their musicologist friend for the gift of his book on the art of the fugue. ‘Marie Soldat felt our evening had been merrier than any were last year,’ noted Margaret Deneke happily. ‘The professor was more sans gêne and we others had overcome the shyness of having him as our guest.’
THE COMING TO POWER OF THE NAZIS
In Germany, however, May 1932 had been an eventful month. When Einstein returned to Berlin, he found a city that was ominously different from the one he had left a month earlier. Political events in his absence had involved a secret deal on 8 May between an influential military leader, General Kurt von Schleicher, and Adolf Hitler, head of the Nazi Party. This was followed on 30 May by the official removal of the chancellor, Heinrich Brüning, and the appointment of a new, ultra-right-wing chancellor, Franz von Papen, with Schleicher as his minister of defence – all at the behest of the aged president, Field Marshal Paul von Hindenburg. On 2 June, a German Christian leader and Nazi deputy, Wilhelm Kube, announced to the Prussian Diet that ‘when we clean house the exodus of the Children of Israel will be a child’s game in comparison’, adding that ‘a people that possesses a Kant will not permit an Einstein to be tacked onto it’. Thus began the slide towards the Nazi seizure of power less than a year later and the subsequent exile of Einstein from his native country, which would propel him back to Oxford for his final stay in May–June 1933.
During that summer of 1932, when a professor visiting Einstein at his lakeside villa at Caputh near Berlin expressed the hope that the army might curb the Nazis, Einstein responded firmly: ‘I am convinced that a military regime will not prevent the imminent National Socialist revolution. The military dictatorship will suppress the popular will and the people will seek protection against the rule of the Junkers [the Prussian landed nobility] and the officers in a right-radical revolution.’ When he and his wife Elsa locked up their Caputh house in early December 1932, to board a ship in Antwerp heading for California, he told her: ‘Before you leave our villa this time, take a good look at it.’ ‘Why?’ she asked. ‘You will never see it again,’ Einstein quietly replied. His wife thought he was being rather foolish, because they had made plans to return to Berlin in March. Yet it turned out that he was being prescient.
On 10 March 1933, Einstein made his first public statement about the newly arrived power of Nazi Germany, as a major earthquake shook him at the California Institute of Technology. ‘As long as I have any choice in the matter, I shall live only in a country where civil liberty, tolerance and equality of all citizens before the law prevail,’ he told a New York newspaper reporter. ‘Civil liberty implies freedom to express one’s political convictions, in speech and in writing; tolerance implies respect for the convictions of others whatever they may be. These conditions do not exist in Germany at the present time.’ The truth of this analysis was soon forthcoming: Einstein’s house at Caputh was reported to have been broken into, allegedly in search of concealed arms. ‘The raid,’ said Einstein in a statement issued from on board ship to Europe, ‘is but one example of the arbitrary acts of violence now taking place throughout Germany. These acts are the result of the government’s overnight transfer of police powers to a raw and rabid mob of the Nazi militia.’
On arrival in Antwerp on 28 March, the Einsteins decided to stay in Belgium, where Einstein had friends, including the royal family. (He and Elisabeth, the unconventional and artistic Queen of Belgium, enjoyed playing violin together.) That very day, he resigned by letter from the Prussian Academy of Sciences, just before the Nazis held their first national day boycotting German Jews on 1 April.
In response, a German newspaper published an anti-Semitic cartoon on 1 April. It showed a sharp-nosed Einstein on his hands and knees being kicked out of a German consulate by a large boot. According to its satirical caption: ‘The concierge of the German embassy in Brussels is authorised to cure an Asiatic [i.e. an East European Jew] of the delusion that he is a Prussian.’ After Einstein formally applied for release from German citizenship on 4 April, the irritated Nazi regime took almost a year to enact his expatriation.
A Nazi view of Einstein. This anti-Semitic cartoon published in the Deutsche Tageszeitung, 1 April 1933, the day of Germany’s first national day boycotting its Jews, shows Einstein being booted out of the German embassy in Brussels. (See text above the cartoon for a translation of the German caption.) Shortly after the cartoon’s publication, Einstein applied for release from German citizenship, having relocated his residence from Germany to Belgium.
As for the Prussian Academy, it immediately bowed cravenly to what the majority of its members assumed their furious government expected from them – by publicly accusing Einstein of ‘atrocity propaganda’ against Germany. A horrified Max Planck informed the acting secretary of the academy on 31 March: ‘Even though in political matters a deep gulf divides me from him, I am, on the other hand, absolutely certain that in the history of centuries to come Einstein’s name will be celebrated as one of the brightest stars that ever shone in our Academy.’ In a personal response to Planck, Einstein, while denying the allegation of ‘atrocity propaganda’, added prophetically: ‘But now the war of extermination against my Jewish brethren has compelled me to throw the influence I have in the world into the balance of their favour.’ Planck, ever the social conservative, replied equat-ing such persecution of the Jews with Einstein’s pacifism and refusal of military service: ‘Two ideologies, which cannot coexist, have clashed here. I have no sympathy with the one or the other.’ It was a sad and very bitter way to end the long and loyal friendship between these two great physicists. When Planck died in 1947, Einstein wrote to his widow: ‘The hours which I was permitted to spend at your house, and the many conversations which I conducted face to face with that wonderful man, will remain among my most beautiful memories for the rest of my life. This cannot be altered by the fact that a tragic fate tore us apart.’
During 1933–35, the German government officially seized all of the Einsteins’ assets in Germany. First to go were their bank deposits, ‘in order to maintain public security and order and also to prevent future anticipated subversive Communist activities’, according to an official letter sent to Einstein by the Office of the Secret State Police on 10 May. Then it was the turn of their villa in Caputh and Einstein’s beloved sailboat, Tümmler (Porpoise). Happily, the boat was sold in error not to a Nazi Party member, as intended by the Prussian prime minister, but to a man who forbade his son from joining the Hitler Youth and would support five orphans of an anti-Fascist executed by the People’s Court in Berlin in 1944. But attempts by Einstein, as a long-time Swiss citizen, his relatives and their lawyers, to enlist the help of the Swiss government in rescuing his German assets during 1933, failed completely, because the Swiss did not want to upset the Nazis.
Some Belgian colleagues had offered the Einsteins temporary accommodation in an old country house near Antwerp. Since they were likely to be staying in Belgium for some time, they decided to rent a holiday house, the Villa Savoyard, in Le Coq sur Mer, a small seaside resort near Ostend, without servants and without a telephone. Though less spacious than their house in Caputh, its magnificent situation among coastal sand dunes appealed to Einstein. Not only was it isolated enough to discourage unwanted callers, it was also fine for solitary walking and reflection – both on science and on politics. In due course, it would also prove practical for the protection of Einstein by an armed contingent of Belgian police.
INTRODUCING OLIVER LOCKER-LAMPSON
Around the time he moved to Le Coq, Einstein received a surprising letter in German from an Englishman, a complete stranger based in London. Dated 28 March 1933, it was sent from the House of Commons. Prompted by the press coverage of Einstein’s homeless predicament, Commander Oliver Stillingfleet Locker-Lampson, a Conservative member of parliament since 1910, wished to offer Einstein his private residence in London as a refuge from the Nazis for a year, at any time that suited his guest. He put it like this:
It was at the time of your presence in Oxford – when Lord Haldane was still with us – that I had the honour to make your acquaintance – and that is what I would like to refer to now.
My letter today is, above all, inspired by the wish to assure you, dear Professor, how sincerely a large number of my countrymen take part in the suffering that your fellow-believers in Germany have to endure.
The fact that ‘Einstein is without a home’ has deeply moved me, and perhaps this may serve as a justification for daring to approach you with a suggestion that, as a modest member of the public, would otherwise not be appropriate to the greatest scholar of our time. And I hope, therefore, that you, dear Professor, will see in my little offer nothing but a genuine sign of my unreserved respect and desire to serve you in my own way.
Coming down to brass tacks, Locker-Lampson explained that his London house consisted of a hallway, dining-room, living-room and lounge, two or three bedrooms, three bedrooms for employees and well-equipped kitchen facilities. Both running costs and servants would naturally be included in his offer. Then he concluded: ‘My house may not be as comfortable as yours, of course, but who knows, whether the “Ether-Atmosphere” of our English love of “Fair Play” might not help you to penetrate even deeper into the “Relativity-Mysteries”.’ (‘Ether-Atmosphere’, ‘Fair Play’ and ‘Relativity-Mysteries’ appear in English in the German original.)
Locker-Lampson, though largely forgotten today, was a well-known politician in Britain in 1933. The antithesis of Einstein in almost every respect, he was the son of a Victorian man of letters and poet who had been friendly with Alfred Lord Tennyson and Oscar Wilde; a wealthy landowner with properties in London, Norfolk and Surrey; and a decorated war veteran, who had commanded a British armoured column on the Russian front fighting on behalf of Tsar Nicholas II, with the political backing of his family’s friend, Churchill. Tall, lean, dashing, maverick, mercurial – and, when crossed, vindictive – the strongly anti-Bolshevist commander had previously praised the up-and-coming Nazis, in common with a wide variety of upper-class Englishmen during this pre-war decade. They ‘despatched their children to Nazi Germany in droves’ and ‘many openly admired Hitler – for the way he had pulled his country up by its bootstraps and particularly for his determination to defeat Bolshevism’, according to a recent historical study, Travellers in the Third Reich. But now that Hitler was actually in power, Einstein had apparently become Locker-Lampson’s hero.
What were Locker-Lampson’s real motives in making his undoubtedly generous offer? With someone of his dissembling contradictions it is difficult to be sure, as we shall constantly discover while his intriguing and crucial relationship with Einstein unfolds during the second half of 1933.
There is an unintentional clue in the letter’s opening paragraph. Locker-Lampson claims vaguely to have met Einstein in person in Oxford ‘when Lord Haldane was still with us’. That is, during Einstein’s flying visit to Oxford in 1921 (not in 1931), given that Haldane died in 1928. But this supposed memory is extremely unlikely to be true, since Einstein met virtually no one in Oxford (not even the vice-chancellor), other than his host Lindemann, during the few hours he spent in Oxford on 14 June 1921. Perhaps Locker-Lampson misremembered and actually met Einstein in London in June 1921, maybe at Haldane’s private reception or the official dinner after Einstein’s speech at King’s College? But if so, there is no record of his presence in the detailed contemporary newspaper and magazine reports listing distinguished guests and visitors at these events, despite the fact that Commander Locker-Lampson was by 1921 a fairly well-known political figure: a long-time friend of Winston Churchill, and the parliamentary private secretary of the chancellor of the exchequer, Austen Chamberlain, in 1919–21, with whom he had attended the 1919 Versailles peace conference. So it seems most probable that Locker-Lampson’s claimed encounter with Einstein in England was simply a convenient fantasy.
Much stronger evidence of his tendency to embroider historical facts comes from Locker-Lampson’s bizarre article, ‘Adolf Hitler as I know him’, published in late September 1930, shortly after the Nazi Party made its first major electoral gains in Germany, in the Daily Mirror, which was then a right-wing national newspaper. So bizarre, in fact, that the article is worth discussing at considerable length – given the importance of Locker-Lampson’s coming role in Einstein’s life in England during September 1933.
It began with a tantalising tale about Hitler, the war of 1914–18 and cricket. ‘My first recollection of Herr Hitler is remote and casual.’ Locker-Lampson was then supposedly in south Germany, talking to some British officers who had been prisoners of war in Germany. Hitler was much on their minds because of the latest news of his failure to grab power in the 1923 Munich Putsch. They recalled that he had been in hospital while they were in a prisoner-of-war camp on parole. One day Hitler had come to them and asked if he might watch a cricket eleven at play, so as to initiate himself into the mysteries of the British national game. They welcomed him, and wrote out the rules ‘in the best British sport-loving spirit’. With these, Hitler vanished. However, he returned a few days later and announced that he was already training a German team and was looking for an early opportunity to challenge his British instructors. ‘I believe they even played a friendly match.’
Even more significantly, Hitler returned again with the astonishing information that he had reflected over the rules of cricket, and wished to alter them radically to suit serious-minded Teutons rather than hedonistic British people. Among his essential improvements were the discontinuance of pads, which he dismissed as ‘unmanly and un-German’, and the introduction of a bigger and harder ball. In other words, Hitler saw cricket not as his ‘innocent’ British instructors did, but instead as ‘a possible medium for the training of troops off duty and in times of peace’.
Then Locker-Lampson gave a laudatory analysis of Hitler the up-and-coming politician (though without lending any support to anti-Semitism), apparently based on personal knowledge. Before his current fame, ‘he seemed just an ordinary German officer with . . . tooth-brush moustache in the latest military style, a soft collar always united with a pin shaped like a swastika, and eyes hidden behind loaded lids – suggestive of hidden fire and fury. Even when he spoke in his deep guttural voice, we were not necessarily thrilled.’ However, ‘after a few hours in his company any honest observer must admit that folk become electrified. The temperature of the room rises in his presence. He enhances the value of life. He makes his humblest follower feel twice the man.’
That said, the political difficulties in Hitler’s way were still formidable, Locker-Lampson conceded, in a country with fifteen parties, in which his own party – the Nazi Party – comprised more than the usual ragbag of competing views and ambitions. How to unite these when his party got into power might prove even trickier for Hitler than how to reconcile them out of office. ‘But he means to ride off on the patriotic ticket, and play for a tear-up of the treaties and a rip-up of reparations. That is his soul’s consecration – that is what makes him a legendary hero already.’
Finally, the article reverted to cricket. Hitler’s ‘motto’, suggested Locker-Lampson, might be the German motto he had suggested during the world war to his British cricketing friends when he was rewriting the old game’s rules: ‘Ohne Hast, ohne Rest’ (without haste, without rest). ‘Only I doubt his ability to wait – or his country’s wish that he should.’
No reliable evidence exists for the accuracy of Locker-Lampson’s cricket story. Notwithstanding a claim made in The Times in 2010 that the story is ‘true’, it is very unlikely to be factual, according to current historians of early Nazism (such as Thomas Weber, author of Becoming Hitler: The Making of a Nazi), given the authoritative details of Hitler’s war record and his probable lack of knowledge of conversational English in 1914–18. Nor is there any evidence, including the draft for Locker-Lampson’s unwritten memoirs, that he ever met Hitler in person in Germany during the 1920s, although such a meeting is certainly conceivable, given his open sympathy at this time for both Germany and Fascism – in Italy, as well as Germany – if not for anti-Semitism. In 1931, Locker-Lampson founded a short-lived patriotic movement with semi-Fascist leanings, the Sentinels of Empire, also known as the Blue Shirts. It held mass rallies in London’s Albert Hall, led by Locker-Lampson, who composed its anthem, ‘March on!’ (set to music from the British Gaumont film, High Treason), which he sent to Benito Mussolini on a 78-rpm phonographic record along with Blue Shirts silver and blue-enamelled cufflinks and a badge. And he himself received a gold cigarette case, a gift from an influential Nazi ideologue, Alfred Rosenberg, as a ‘token of his esteem’ (an item that Locker-Lampson, to his credit, did not accept). Yet, Time magazine joked, after attending a Blue Shirts Albert Hall rally, that few people expected Locker-Lampson to become ‘in more than nickname “Britain’s Hitler”, much less “Britain’s Mussolini”’. Nonetheless, there can be little doubt that he worshipped, and wanted for himself, some of the glamour of famous people. In 1930, his icon was apparently Hitler; by mid-1933, it had certainly become Einstein.
Had Einstein been aware of Locker-Lampson’s Daily Mirror article, he would presumably have avoided any kind of association with him. Even the public letter Locker-Lampson now addressed to Hitler, printed in The Times on 1 April 1933 as a postscript to the newspaper’s long report on the ‘Nazi boycott of Jews’, could hardly have appealed to Einstein. While sounding a new note of warning about Nazi anti-Semitism, Locker-Lampson’s letter retained some of the commander’s earlier praise for the German leader in its opening phrase: ‘As a member of Parliament and former officer who has always and openly stood for Germany’s claims to military equality and territorial revision and who has been for years your sincere admirer . . .’. But it continued less positively: ‘I take the liberty of calling your attention to the fact that the decision to discriminate against the German Jews has had a most damaging effect upon the good feeling for Germany which was growing stronger and which culminated on your accession to power.’ Then it reverted to praise: ‘We hoped to see Germany strengthened under your leadership . . .’. But it concluded: ‘This action against the Jews is making the work of myself and other friends of Germany almost impossible. Forgive me, Chancellor, for these frank words of an Englishman who has often cheered you in your meetings in Germany.’ (When Locker-Lampson stepped up his public campaign in the mid-1930s, and became a noted sponsor of desperate German-Jewish refugees, Hitler eventually retorted by calling Locker-Lampson ‘a Jew and a Communist’!)
Einstein in Tom Quad, the main quadrangle of Christ Church, Oxford, the college where he lived in June 1933. By now, Einstein was a refugee from Germany, his houses and bank account having recently been confiscated by the Nazi regime.
However, it seems that Einstein was ignorant of Locker-Lampson’s politics at the time of the commander’s invitation. At any rate, he had no wish to abandon his independent life by the sea in Belgium and move to metropolitan London. While thanking Locker-Lampson for his offer, he declined it. Yet, he and his wife would keep the possibility of such an English refuge in mind.
Instead, Einstein began to plan a further month in Oxford, as well as a visit to Glasgow in Scotland, where he had agreed to give a lecture on the history of general relativity at the University of Glasgow on 20 June. During early May, there was a revealing exchange of letters between Einstein in Le Coq and Lindemann in Oxford, mixing science with politics.
RETURN TO OXFORD
It started with a brief letter from Einstein on 1 May about returning to England. He began: ‘I am sitting here in my very pleasant exile with Professor Mayer.’ He would be in Glasgow on 20 June. Could he visit Oxford again that month? Might Christ Church be able to offer him a small room? It need not be so ‘grand’ as his previous lodgings in 1931 and 1932. Then Einstein abruptly switched subjects and alluded to politics: ‘You have probably heard of my little duel with the Prussian Academy. I shall never see the land of my birth again.’ Finally he mentioned physics: he had worked out with Professor Mayer ‘a couple of wonderful new results of a mathematical-physical kind’.
Lindemann replied immediately on 4 May, saying that he would have written earlier but had had no address for Einstein, and that he gathered from the newspapers that ‘there was not much prospect of a letter to Berlin being forwarded’. He naturally welcomed Einstein’s visit, but suggested that, since Oxford’s Trinity term would end on 16 June, Einstein should arrive at the end of May, so that his visit to Glasgow would fall ‘at the end of your stay instead of in the middle of it’. A set of rooms would be available, but ‘as we did not know your plans I am afraid they will be somewhat smaller than last year’.
Then he discussed his own recent visit to Berlin, for four or five days in mid-April over Easter, when he had seen many of Einstein’s German colleagues. About the Prussian Academy’s condemnation of Einstein and the wider political situation he commented:
The general feeling was much against the action taken by the Academy, which was the responsibility of one of the secretaries without consultation with the members. I can tell you more about it when you come. Everybody sent you their kind regards, more especially Schrödinger, but it was felt that it would be damaging to all concerned to write to you, especially as the letter would almost certainly not be forwarded. Conditions there were extremely curious. It seems, however, that the Nazis have got their hands on the machine and they will probably be there for a long time.
Lindemann went on to consider what could be done to help some of the German-Jewish physicists, by trying to find them positions at Oxford. ‘I need scarcely say that very little money is available and that it would cause a lot of feeling, even if it were possible to place them in positions normally occupied by Englishmen.’ He specified two promising individuals, Hans Bethe and Fritz London (the first of whom would win a Nobel prize), recommended to him by Einstein’s non-Jewish colleague, the theoretical physicist Arnold Sommerfeld. Lindemann asked whether Einstein would be willing to recommend Bethe and London too, while adding characteristically: ‘Perhaps there are others whom you might consider better, but I have the impression that anyone trained by Sommerfeld is the sort of man who can work out a problem and get an answer, which is what we really need in Oxford rather than the more abstract type who would spend his time disputing with the philosophers.’ This was the launch of Lindemann’s historic campaign to obtain funding for notable refugee experimental physicists to come to Oxford in 1933–34. He would help a group of distinguished Jews, including the low-temperature physicist Franz (later Sir Francis) Simon, who became a professor at Oxford, worked on the atomic bomb project and eventually took over from Lindemann as head of the Clarendon Laboratory.
Einstein responded on 7 May, advising that he would try to reach England on 21 May. Lindemann should not go to any bother about his accommodation because he would need only ‘one room’ in order to be comfortable. About politics, he added ominously, ‘I think that the Nazis have got the whip hand in Berlin.’ He had been told on good authority that the Nazis were hurriedly collecting war materiel, notably aeroplanes. ‘If they are given another year or two the world will have another fine experience at the hands of the Germans.’ As for the two physicists mentioned by Lindemann, he recommended London as ‘a great source of strength’ but said he knew too little about Bethe to express an opinion. Regardless of which individuals might be chosen, he was very grateful to Lindemann for his efforts to relieve refugee physicists. He offered to give a third of his salary that year to help his threatened German-Jewish colleagues.
Then, on 9 May, Einstein wrote again very briefly, announcing that he would not be able to arrive in Oxford until about the 26th because his younger son had been taken seriously ill. If he were to have any mental peace in England, he could not wait six weeks before seeing him in Zurich. ‘You are not a father yourself, but I know you will certainly understand.’ Not long before heading for Oxford in late May, he would see his son, Eduard, a long-term psychiatric patient suffering from schizophrenia, who was being looked after by his ex-wife, Mileva, and by professional clinics, in Zurich. Einstein chose to stay with Mileva. ‘There is no written evidence about Einstein’s feelings when he visited his son,’ noted Einstein’s German biographer Albrecht Fölsing. ‘No doubt he was profoundly shaken, and he certainly determined to make sure his son’s future was financially secure.’ Although Einstein would remain in touch with Eduard by letter, he would never see his son, or his ex-wife, again. (Eduard Einstein survived his father, dying in a Swiss psychiatric hospital in 1965.)
The landing card completed by Einstein on arrival in Britain at Dover, 26 May 1933. It notes his nationality at birth as German, but his current nationality as Swiss; and that his British residence will be in Oxford.
One decidedly puzzling omission from this May correspondence with Lindemann was the Herbert Spencer lecture in Oxford, which Einstein had agreed to give in Trinity term 1933, during his Oxford visit in May 1932. Neither Einstein nor Lindemann refers to the lecture at all. (Nor was it mentioned in a substantial report on ‘Einstein as an Oxford don’ published in the Manchester Guardian on 17 April 1933, which noted that Einstein was expected in Oxford during the summer term.) Although the lecture actually took place at Rhodes House on 10 June 1933, it would appear that this date must have been settled by Einstein at the very last minute, relatively speaking – either shortly before he left Le Coq in mid-May or perhaps soon after he arrived in Oxford on 26 May. Whichever was the case, the lecture must surely have been prepared under conditions of much personal and professional stress for Einstein, exacerbated by the Nazi announcement in mid-May of the seizure of his and his wife’s German financial assets.
As he informed Max Born – who had just escaped from Germany to the Italian Alps and would soon settle in Britain – on 30 May, in a letter sent from the cloistered calm of Christ Church: ‘You know, I think, that I have never had a particularly favourable opinion of the Germans (morally and politically speaking). But I must confess that the degree of their brutality and cowardice came as something of a surprise to me.’ He concluded: ‘I’ve been promoted to an “evil monster” in Germany, and all my money has been taken away from me. But I console myself with the thought that the latter would soon be gone anyway.’
Moreover, at a public event in Oxford’s University Museum on 2 June Einstein appeared sorely in need of public reassurance. He had been invited to offer a vote of thanks for a lecture by Rutherford to the Junior Scientific Society on ‘The Artificial Transmutation of the Elements’. Not only was Rutherford a Nobel laureate, like Einstein, he was also a peer of the realm, the 1st Baron Rutherford, and, in addition to his honours, a big booming extrovert with a voice loud enough to disturb sensitive scientific experimental apparatus – according to a standing joke among his Cavendish Laboratory co-workers in Cambridge. Lord Rutherford made quite a contrast with the smaller figure of Einstein, a theoretician who typically worked alone at home or in an office, never in a laboratory, and was naturally unconfident at public speaking in English. According to one of the Oxford undergraduates at the lecture, C. H. Arnold, Einstein seemed ‘a poor forlorn little figure’ beside Rutherford. While Einstein was delivering his speech of thanks, somehow coping with English, ‘it seemed to me that he was more than a little doubtful about the way in which he would be received in a British university’. However, the moment he sat down, he was greeted by a thunderous outburst of applause. As Arnold vividly recalled more than three decades later:
Never in all my life shall I forget the wonderful change which took place in Einstein’s face at that moment. The light came back into his eyes, and his whole face seemed transfigured with joy and delight when it came home to him in this way that, no matter how badly he had been treated by the Nazis, both he himself and his undoubted genius were at any rate greatly appreciated at Oxford.
HERBERT SPENCER LECTURE IN OXFORD
The psychological strain seems to have expressed itself in Einstein’s scientific thinking as well as his personal behaviour. In his lecture on 10 June, ‘On the method of theoretical physics’ – the German manuscript of which lay on his Christ Church desk at the very time he was writing to Born – he tried to escape from the messy physical reality inherent in experimental physics, including quantum mechanics, and substitute for it the paradise of pure mathematics, which he had been pursuing for some years in his unified field theory, most recently with the help of his calculator, Walther Mayer, in Le Coq. ‘The sanctuary from personal turmoil that Einstein sought in physics may also have coloured the extreme rationalist pronouncements in his Herbert Spencer lecture,’ according to the editors of The Cambridge Companion to Einstein. Opinions consequently differ as to the lecture’s value. One Einstein biographer, Fölsing (who originally trained as a physicist), condemned it as ‘a reckless overestimation of the possibility of understanding nature through mathematics alone – a mistake he would not have been capable of in his most productive years’ (while acknowledging that ‘this faith, though ultimately unproductive, sustained him for decades in his search for the unified field theory’). By contrast, another Einstein biographer, Abraham Pais, a practising physicist who knew Einstein personally over a long period, hailed the lecture as ‘perhaps the clearest and most revealing expression of his mode of thinking’.
Einstein (front row, second from left) as a guest at a political debate at the Oxford Union, June 1933. In the second row, third from left, is Michael Foot, then a student at the university, who later became leader of the Labour Party in Britain. Einstein did not speak in the debate, which was about British politics and did not refer to Germany. After a brief stay in Oxford, he left the city, never to return.
Theoretical physics had always been Einstein’s sanctuary, as he revealed on several occasions during his life, including his ‘Autobiographical notes’ written for his seventieth birthday in 1949, which called theoretical physics a liberation ‘from the chains of the “merely personal”’. Back in 1897, when he was eighteen, while breaking up with his first girlfriend he wrote to her mother:
Strenuous intellectual work and looking at God’s Nature are the reconciling, fortifying, yet relentlessly strict angels that shall lead me through all of life’s troubles. . . . One creates a small little world for oneself, and as lamentably insignificant as it may be in comparison with the perpetually changing size of real existence, one feels miraculously great and important, like a mole in his self-dug hole.
And as an adult in 1918, while struggling with wartime privations, divorce and illness that left him bedridden for several months, he made this powerful statement in a speech on the sixtieth birthday of Planck:
I believe with Schopenhauer that one of the strongest motives that leads men to art and science is escape from everyday life with its painful crudity and hopeless dreariness, from the fetters of one’s own ever shifting desires. A finely tempered nature longs to escape from personal life into the world of objective perception and thought. . . . With this negative motive goes a positive one. Man tries to make for himself in the fashion that suits him best a simplified and intelligible picture of the world; he then tries to some extent to substitute this cosmos of his for the world of experience, and thus to overcome it. This is what the painter, the poet, the speculative philosopher, and the natural scientist do, each in his own fashion. Each makes this cosmos and its construction the pivot of his emotional life, in order to find in this way the peace and security which he cannot find in the narrow whirlpool of personal experience.
Einstein’s Oxford lecture opened with an uncharacteristically emotional introduction – at least by his unemotional standards – perhaps hinting at his mental state in early June 1933:
I wish to preface what I have to say by expressing to you the great gratitude which I feel to the University of Oxford for having given me the honour and privilege of delivering the Herbert Spencer lecture. May I say that the invitation makes me feel that the links between this university and myself are becoming progressively stronger?
Then he thanked three colleagues at Christ Church – a philo-sopher, Gilbert Ryle, a classicist, Denys Page and a physicist, Claude Hurst – ‘who have helped me – and perhaps a few of you – by translating into English the lecture which I wrote in German’. (Oddly, he did not mention a role for Lindemann.) This time at Rhodes House, unlike in May 1931, in Einstein’s first-ever lecture solely in English, the audience did not have to struggle with an unfamiliar language – although Einstein’s inimitably accented English, as he read from the dense translation, might sometimes have appeared to have been a foreign tongue. Nor were there any blackboards chalked with baffling mathematics, to be saved by eager science dons. That said, the lecture, as printed, was demanding enough to challenge any listening physicist or philosopher, not to mention the anonymous correspondent of The Times with the unenviable task of trying to summarise its content for a general readership. (The Times report on 12 June was safely, if unimaginatively, headlined ‘Basic concepts in physics’.)
The physics started with some typically Einsteinian humour. He ironically reprimanded himself for claiming more authority for his remarks to come than perhaps he should:
If you wish to learn from the theoretical physicist anything about the methods which he uses, I would give you the following piece of advice: don’t listen to his words, examine his achievements. For to the discoverer in that field, the constructions of his imagination appear so necessary and so natural that he is apt to treat them not as the creations of his thoughts but as given realities.
This statement may seem to be designed to drive my audience away without more ado. For you will say to yourselves, ‘The lecturer is himself a constructive physicist; on his own showing therefore he should leave the consideration of the structure of theoretical science to the epistemologist.’
Having openly voiced this subtle objection, Einstein further warned his listeners that his personal view of the past and present of theoretical physics was bound to be coloured by what he was currently trying to achieve and hoped to achieve in the future – an implicit reference to his ongoing work on the unified field theory (which he would briefly mention later in the lecture). ‘But this is the common fate of all who have adopted the world of ideas as their dwelling-place. He is in just the same plight as the historian, who also, even though unconsciously, disposes events of the past around ideals that he has formed about human society.’
Then Einstein got to grips with the relationship in physics between pure theory, that is the free inventions of the human mind, and the data of experience, that is our observations of physical reality. ‘We honour ancient Greece as the cradle of western science,’ he initially reassured his audience, many of whom were no doubt classically trained. ‘She for the first time created the intellectual miracle of a logical system, the assertions of which followed one from another with such rigour that not one of the demonstrated propositions admitted of the slightest doubt – Euclid’s geometry.’ Thinking of his own boyhood, he added: ‘The man who was not enthralled in youth by this work was not born to be a scientific theorist.’
Yet, for science to comprehend reality, more than Greek thought was required, he reminded his audience:
Pure logical thinking can give us no knowledge of the world of experience; all knowledge about reality begins with experience and terminates in it. Conclusions reached by purely rational processes are, so far as reality is concerned, entirely empty. It was because he recognised this, and especially because he impressed it upon the scientific world, that Galileo became the father of modern physics and in fact of the whole of modern natural science.
Newton, ‘the first creator of a comprehensive and workable system of theoretical physics’, agreed with Galileo’s view, Einstein continued.
[He] still believed that the basic concepts and laws of his system could be derived from experience; his phrase ‘hypotheses non fingo’ can only be interpreted in this sense. In fact, at the time it seemed that there was no problematical element in the concepts of space and time. The concepts of mass, acceleration and force, and the laws connecting them, appeared to be directly borrowed from experience. Once this basis is assumed, the expression for gravity seems to be derivable from experience; and the same derivability was to be anticipated for the other forces.
However, Newton was aware of certain difficulties:
One can see from the way he formulated his views that Newton felt by no means comfortable about the concept of absolute space, which embodied that of absolute rest; for he was alive to the fact that nothing in experience seemed to correspond to this latter concept. He also felt uneasy about the introduction of action at a distance. But the enormous practical success of his theory may well have prevented him and the physicists of the eighteenth and nineteenth centuries from recognising the fictitious character of the principles of his system.
In other words, they did not recognise that the principles were free inventions of the human mind.
On the contrary, the scientists of those times were for the most part convinced that the basic concepts and laws of physics were not in a logical sense free inventions of the human mind, but rather that they were derivable by abstraction, i.e. by a logical process, from experiments.
Then Einstein mentioned his own contribution:
It was the general theory of relativity which showed in a convincing manner the incorrectness of this view. For this theory revealed that it was possible for us, using basic principles far removed from those of Newton, to do justice to the entire range of the data of experience in a manner even more complete and satisfactory than was possible with Newton’s principles. But quite apart from the question of comparative merits, the fictitious character of the principles is made quite obvious by the fact that it is possible to point to two essentially different principles, both of which correspond to experience to a large extent. This indicates that any attempt logically to derive the basic concepts and laws of mechanics from the ultimate data of experience is doomed to failure.
However, said Einstein,
[i]f it is the case that the axiomatic basis of theoretical physics cannot be an inference from experience, but must be a free invention, have we any right to hope that we shall find the correct way? Still more – does this correct approach exist at all, save in our imagination? Have we any right to hope that experience will guide us aright, when there are theories (like classical [i.e. Newtonian] mechanics) which agree with experience to a very great extent, even without comprehending the subject in its depths?
He answered confidently, if controversially: ‘in my opinion there is the correct path and, moreover, that it is in our power to find it’. Then followed the most quoted words in his Herbert Spencer lecture (given below in italics):
Our experience up to date justifies us in feeling sure that in nature is actualised the ideal of mathematical simplicity. It is my conviction that pure mathematical construction enables us to discover the concepts and the laws connecting them which give us the key to the understanding of the phenomena of nature. Experience can of course guide us in our choice of serviceable mathematical concepts; it cannot possibly be the source from which they are derived; experience of course remains the sole criterion of the serviceability of a mathematical construction for physics, but the truly creative principle resides in mathematics.
In a certain sense, therefore, I hold it to be true that pure thought is competent to comprehend the real, as the ancients dreamed.
The rest of the lecture was more technical, mentioning some of the mathematical concepts, such as Riemann’s geometry and Dirac’s spinors, that had proved fruitful in general relativity and quantum mechanics, and naming key theoretical contributors to the latter field, such as Born, de Broglie, Dirac, Heisenberg and Schrödinger, during the previous decade. (Bohr, strangely, went unmentioned.) But in his conclusion Einstein made no bones about his by now well-known view of quantum mechanics as being a theory of only transitory significance:
I still believe in the possibility of giving a model of reality, a theory, that is to say, which shall represent events themselves and not merely the probability of their occurrence. On the other hand, it seems to me certain that we have to give up the notion of an absolute localisation of the particles in a theoretical model. This seems to me to be the correct theoretical interpretation of Heisenberg’s uncertainty principle. And yet a theory may perfectly well exist, which though it is in a genuine sense an atomistic one (and not merely on the basis of a particular interpretation), nevertheless involves no localisation of the particles in a mathematical model. . . . Only if this sort of representation of the atomistic structure be obtained could I regard the quantum problem within the framework of a continuum theory as solved.
MATHEMATICS, PHYSICS AND REALITY
Thus, in his Herbert Spencer lecture, Einstein assured his Oxford audience, and by extension the international world of physics, that mathematics, on its own, could provide the basis for understanding nature. He apparently now rejected his own earlier position, as elegantly stated in 1921: ‘As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.’ As evidence of his new belief, he cited his own general theory of relativity, conceived in 1915–16, which he now claimed to have been essentially based on mathematical concepts rather than physical observations – for all its crucial confirmation by British astronomers in 1919. No doubt many theoretical and experimental physicists, especially those working in quantum mechanics, were taken aback and unconvinced by such a bold claim, even coming from Einstein, flying as it did in the face of so much of the history of physics, beginning with Galileo and Newton, that evidently arose from a combination of theory, observation and experiment. But which of them was in a position to contest its validity with general relativity’s world-famous creator?
Perhaps they should have taken Einstein’s initial humorous warning in Oxford more seriously. Was Einstein himself really the best authority on the origins of his own theory? Maybe not, as he himself had hinted. ‘It was not until several decades later that a team of scholars scrutinised his notebooks and demonstrated that he had developed his theory. They saw clear evidence that he used a two-pronged strategy, involving both mathematics and physical reasoning, right up until he completed the theory, yet he subsequently downplayed the role of physical reasoning,’ writes physicist, historian and Dirac’s biographer Graham Farmelo. ‘Einstein appears to have largely based his new philo-sophy of research on distorted recollections of his work in the final month of his search for the correct field equations of gravity.’ According to an associate of the team, Jeroen van Dongen, ‘Einstein overemphasised the part mathematics had played in his development of his theory of gravity, probably to try to persuade his critical colleagues of the value of his way of trying to find a unified theory of gravity and electromagnetism.’
Ironically, there was a clear indication of Einstein’s tendency towards such distorted recollection a mere ten days after his Herbert Spencer lecture, in his lecture in Glasgow on 20 June. Speaking at the university in considerable technical detail, for the second time in English, on ‘The Origin of the General Theory of Relativity’, Einstein commented on the dark days of late 1915, after two years of excessively hard work, when he had felt lost. Finally, he recognised certain errors of thought, and ‘after having ruefully returned to the Riemannian curvature, succeeded in linking the theory with the facts of astronomical experience’. In other words, general relativity rested not only on mathematical concepts but also on physical – in this case astronomical – observations. He closed the lecture with the following memorable statement:
In the light of the knowledge attained, the happy achievement seems almost a matter of course, and any intelligent student can grasp it without too much trouble. But the years of anxious searching in the dark, with their intense longing, their alternations of confidence and exhaustion and the final emergence into the light – only those who have experienced it can understand that.
Little wonder, then, that the origins of general relativity should be an obscure and contentious subject – even to Einstein himself.
For the wider public, of course, even the basics of relativity remained as perplexing in 1933 as they had been on Einstein’s first visit to England in 1921. Glasgow railway station appeared to supply yet another example of this truth. Einstein arrived there from London apparently a day earlier than was expected. He found himself standing on the platform alone, so to speak, in a large crowd – who were awaiting not Einstein but the Hollywood comedy star Thelma Todd (of Marx Brothers fame), who happened to be on the same train. Fortunately, a local newspaper reporter recognised the professor and telephoned the university authorities, who soon rescued him. According to the Manchester Guardian, however, relativity was at work: ‘Professor Einstein is of all living philosophers the one whose name is most widely known to the multitude – but in the matter of railway station receptions even he could not hope to loom so large as a film star. There are “kinks in fame” as it is estimated by the multitude, even as there are “kinks in space” as it is measured by mathematicians.’
Having collected a by now customary honorary doctorate from the University of Glasgow along with a former prime minister of France, Édouard Herriot, near the end of June Einstein left London and returned to his home and his wife in Belgium. Although he could not have anticipated it, he was about to embark on perhaps the most anxious and exhausting period of his life: a direct clash between his personal vision of the world and the dark reality of Nazi Germany, in which England – in the person of the enigmatic Commander Locker-Lampson – would help to save Einstein from being assassinated.
