As far as I have been able to detect, Einstein and Jaumann never met, and the former seems never to have mentioned the latter. The converse is not true. In 1913, Gustav Mie, needling Einstein as was his wont, defended the priority of Max Abraham’s gravitational theory over the Entwurf. (Einstein objected, noting that the theories were different, so priority was not really at issue.) A few months later, Jaumann wrote in to a journal that his own theory had priority even over that of Abraham. “The fundamental idea of my gravity theory is that the Poisson differential equation is the rudiment of an effective physical equation and must be completed through introduction of the fluxion of some physical variables,” he stated, “more precisely the total fluxion of the first order of the gravitational potential itself to an effective physical law, which thus also represents the temporal propagation of gravitational effects.”87 There was no reaction. When reviewing the literature on this topic in 1914, Abraham remarked that Jaumann’s work was so far afield that he was going to omit it in his analysis.88 The only credence the scientist from Brno’s priority received was in a laudatory obituary upon his death in 1924.89
* * *
Einstein left Prague as he had come: without a workable theory of general relativity. But the city proved essential to the transformation of his research profile by giving him the conceptual (and literal) space to detach himself from the pressures of the ever-growing quantum theory and enabling him to follow a hunch from several years earlier about the equivalence principle and gravitation. The theory he produced between the fall of 1911 and the spring of 1912—the static theory—ended up foundering on its own assumptions, but not without teaching Einstein a few valuable points. The first was that some implications of any theory of general relativity, such as the bending of starlight around a gravitational body such as the sun, would be amenable to empirical verification, a realization that led him to use his contacts in Prague to connect with Erwin Freundlich in Berlin and initiate an eclipse expedition. Although the understanding of the precise magnitude of the bending of this light would change as the final theory of general relativity took form, the centrality of this phenomenon would not—indeed, it would form the catalyst of Einstein’s global celebrity.
Second, the constant back-and-forth in letters to colleagues and in printed duels with Abraham considerably refined his understanding of the equivalence principle and its limitations. The initial insight about the need to modify special relativity’s insistence on the constancy of the speed of light when faced with a changing gravitational potential, however, did not. The Entwurf theory carried over this central finding: “In earlier works I have shown that the equivalence principle implies that in a static gravitational field the speed of light c depends on the gravitational potential. […] c is not to be understood as a constant, but as a function of the spatial coordinates that represents a measure for the gravitational potential.”90 In the spring of 1912, Einstein realized—almost certainly in conversations with Georg Pick—that he might have to relinquish flat spacetime in favor of a Riemannian geometry, an idea he pursued with vigor with Grossmann in the fall.91
The very success of general relativity in the form in which it was presented in Berlin in 1915–1916 has served to occlude the significance of the physicist’s time in Prague, the moment when he first began to work in earnest on gravitation. As a collaboration of historians over the past 15 years has shown, Einstein pursued in Zurich and then in Berlin two parallel routes toward general relativity: one physical and one mathematical. His eventual triumph encouraged him to emphasize the mathematical route—the quest for general covariance—over the physical intuitions that had guided him in his first ventures in 1907 and then again in Prague. This was how Einstein related the history of the theory that made him unimaginably famous, and an effect of this presentation has been to diminish the apparent significance of the months he spent in Prague.92 It is important not to overstate the contrary point: if Einstein had died in that freak horse cart accident in the wake of his fight with Abraham, we might associate gravitation more with a modified Nordström theory than with Einstein—the theory as of summer 1912 was not an embryonic form of general relativity. On the other hand, it is hard to see how he could have reoriented himself so single-mindedly on this path without the experience of splendid isolation that he had enjoyed in Prague.
That isolation had benefits but also costs. Both family and professional disappointments induced Einstein to start exploring ways out of Bohemia a semester after he arrived. In late August 1911, the university in Utrecht wrote inquiring whether he would be interested in a position there. It only took Einstein four days to respond decisively in the negative: “I have been here in Prague only 4 months and am now happy to have adapted somewhat to the foreign conditions. Thus I much regret that I must ask you to consider another colleague for the vacant position, and I give you my heartfelt thanks that you wanted to place me in your milieu.”93 His Dutch contact, Willem Julius, tried again in late September, and Einstein once again turned the proposal down. He wrote his Zurich friend Heinrich Zangger “that I however right away declined for the reason that I could not so soon again decide to change my residence.” (Although, in this same letter, he also told Zangger that his refusal had nothing to do with a newly acquired fondness for the city: “But that I would abandon half-barbaric Prague with a light conscience, that is certain.”)94 Or, as he wrote Julius at greater length, after commenting on his enjoyable interactions with Dutch colleagues: “These pleasant personal experiences have made my decision to remain here truly difficult; but I am now resolved to do so. Think of yourself in my present situation! Here I have a spacious institute with a magnificent library and I don’t have to struggle with the difficulties of the language, which with my awful ponderousness in learning languages comes heavily into consideration for me!”95 It is quite telling that Einstein, a professor in a bilingual city where his own tongue was in the overwhelming minority, thought of Prague as essentially Germanophone.
Utrecht persisted. In November, Einstein somewhat modified the answer he had been consistently offering. “Before I left my Zurich homeland [Heimat] for Prague,” he wrote Julius, “I promised privatim in Zurich to communicate with them before I took any other position so that the administration of the Polytechnic could be allowed to make an offer in the event they found that a good idea.”96 He asked Zangger and Grossmann to make inquiries back in Switzerland—not at the University of Zurich that he had left, but at his alma mater, the ETH.97 After a lengthy exchange of letters with administrators in Zurich, including a debate about whether they would come to Prague to negotiate with Einstein or he would make the trip to Zurich (in the end, Einstein traveled), he received an official call in late January 1912.98
What had changed from his earlier determination to remain in Prague? The most likely cause was his experience in Brussels at the Solvay Conference. Whatever his privately dismissive comments about the intellectual results of the gathering, it seems that the experience of engaging in conversation with the luminaries of his field registered with Einstein. He made an impression on several of them as well. Much as the German University in Prague had earlier asked Max Planck for his endorsement of this former patent clerk, the ETH bureaucracy contacted Marie Curie in Paris. “In Brussels, where I attended a scientific congress in which Mr. Einstein took part, I was able to appreciate the clarity of his mind, the comprehension of his writings, and the depth of his knowledge,” she responded. “If one considers that Mr. Einstein is still very young, one is correct to base on him the greatest hopes and to see in him one of the premier theoreticians of the future.”99 Einstein now looked around Prague and, instead of seeing quiet where he could concentrate on gravity, lamented the absence of colleagues against whose intellect he could sharpen his pathbreaking ideas. What had just a few months earlier appeared as an exciting new adventure in this Germanic outpost among the Habsburg Slavs had come to seem provincial, even backward. Once he saw Prague this way, he could never unsee it
, and Zurich’s invitation proved impossible to resist.
CHAPTER 3
Anti-Prague
Since then I must always, when I want to write something about a foreign region, think: “Better to forgo the local color, you will only disgrace yourself.” Yes, it turns out as though the residents formally have a right for the exclusive representation of their homeland.
Almost all good travelers have also respected that and cannot stress often enough that their comments are only meant subjectively; no dependable exact account, only a mistaken attempt—and an interesting one precisely through its mistakes. Precisely because of the fact that these observers refuse in advance any ethnographic and scholarly whitewashing, they obtain the courage to present directly their coincidental experiences unaffectedly, without responsibility and, where they seem to establish laws, one softly hears the skeptical, almost ironic undertone.
—Max Brod1
From Albert Einstein’s point of view, especially in later years, the most significant thing he took away from Prague was something he had left behind: the static theory of gravitation. It had not been a success in terms of leading directly to a full-blown theory of general relativity, but it had provided a passage out of the quantum rut and set him on a course to one of the most remarkable developments in the history of physics. In this way of looking at things, Prague was simply a backdrop, a city in which he happened to live while working on a particular set of equations, but he might as well have been in Bonn or Königsberg or Vienna—any university town where he could function seamlessly in German, shuttling back and forth from his apartment to his offices at the local physics institute. Yet this was not Einstein’s actual experience of the city, which impinged on his thoughts and shaped his life in countless ways—even if he wasn’t conscious of them.
Take that daily walk to the institute, which was highlighted by all observers as the metronomic backbone of the physicist’s life in Bohemia. Even today, with much greater traffic—there is a busy tram station along the way that holds up pedestrians—the journey lasts about a quarter of an hour if one walks briskly, as Einstein did in those days. The heart of Prague did not suffer too many architectural atrocities across the violent twentieth century, and many of the buildings and landmarks that Einstein would have seen we can still observe today. He left no surviving trace of his constant traverses of what he would certainly have called the Moldau River (known as the Vltava in Czech both then and now), and it is possible that he did not notice much of it, lost in daydreams about the equivalence principle or the numbing blindness of the habitual commute. But we can reveal what he did not deem worth mentioning, perhaps did not even notice, and in doing so we can encounter the real Prague of 1911 and 1912, the Prague in which Einstein lived.
He would have begun this daily walk by descending the stairs of what was then Třebízkého ulice 1215, emerging out of the portico of the new art deco building on the south side of this short residential street in the neighborhood of Smíchov. He would have turned right and walked toward the Moldau, and when he hit it made another right along the banks, heading for the Palackého Most, or Palacký Bridge, which he would take across the river. The bridge was built from 1876 to 1878, according to the designs of Bedřich Münzberger (whose name is a characteristic blend of Czech and German monikers), to solve a pressing problem for the industrial firms located deeper in Smíchov. Factories like the Ringhoffer Machine Works needed a way to move heavy material into the heart of the city, and for that a stone bridge was essential. Chain suspension affairs like the Francis I Bridge would not do, and the ornate towers of the iconic Charles Bridge farther north—today a statue-studded pedestrian thoroughfare bearing throngs of tourists ambling from the castle to the Old Town Square—made it inconvenient for the movement of machinery. The Palacký Bridge was a modern bridge for a modern city.2
As Einstein turned left onto the bridge to cross the river, he would have seen something that is no longer there. In those years the Palacký Bridge was framed by four sculptural groups based on themes from Czech folklore, including the beautiful soothsaying mother of the people, Libuše, and her chosen husband and mythic founder of the first dynasty in Bohemia, Přemysl. They would have greeted Einstein on the Smíchov side of the bridge as he walked to work. The statues had been designed by the canonical Bohemian sculptor Václav Myslbek and installed during the 10 years following 1887. They were thus a later nationalist adornment to what had come to be an increasingly symbolic bridge. (The statues were damaged during a U.S. air raid on the city on Valentine’s Day 1945; after being restored, they were moved from the bridge to the gardens at Vyšehrad, down the eastern bank of the river.) As the city’s chief stone bridge, the fourteenth-century Charles Bridge, became a symbol of Catholicism and Habsburg power—a symbol of the “Germans”—the Palacký Bridge would become the opposite. The stone was subtly blue, white, and red, the national colors of the Crown of Bohemia. Einstein almost certainly did not know who the figures were or what the colors meant; for him, this was simply the easiest way to get to work.
For the entirety of his time in Prague, he would have encountered a bit of trouble as he alit from the bridge to enter the New Town. There was a large construction site there—so large that it is really astonishing that Einstein never commented upon it in letters to distant friends. It must have been an impressive sight, as dozens of workers labored to erect a gigantic monument to František Palacký (1798–1876), historian and central nationalist hero of 1848.3 Palacký remained committed to what eventually became Austria-Hungary—he felt it was the only way to protect the Czechs amid the surges of German nation-building to the west and north and Russian pressure from the east—but he was a constant thorn in its side, leading the Old Czech political party to demand ever greater autonomy within the framework of the Habsburg Empire. After his death, as Czech politics radicalized into increasingly confrontational postures, Palacký was transformed into a convenient emblem of oppositionist politics. His monument would heighten the symbolism of his bridge.
The foundation stone for the monument was laid on the centenary of his birth in June 1898, in a ceremony commemorated by Slavic personalities near and far, such as Grand Duke Konstantin, president of the Academy of Sciences in St. Petersburg (of which Palacký was a member), who sent a sympathetic greeting.4 Stanislav Sucharda, the leading student of Myslbek—designer of the mythic figures on the bridge, and also the statue of Wenceslas in his eponymous square, the most internationally recognizable sculpture in Prague—composed an enormous montage of figures (figure 3). In it Palacký himself, seated in the center and gazing across the river, is overshadowed by his granite backdrop, itself surmounted by the gendered symbolism of angels and victory. The bronze groups offer an allegorical retelling of Czech history in a nationalistically tendentious variant: they are designated with titles like “Oppression,” “History Tells the Story,” and “The Awakener.” The whole ensemble took six years to design and months to erect.5 It must have been noisy. Einstein could not have failed to notice it as he passed along the north edge of the structure down a side street on his way to the Physics Institute on Weinberggasse, a few blocks away.
FIGURE 3. The Palacký monument, unveiled in 1912, facing the Palacký Bridge across the Vltava/Moldau toward Einstein’s neighborhood of Smíchov. Source: Rémi Diligent, 2006, https://commons.wikimedia.org/wiki/File:Frantisek_Palacky_monument_(global).jpg.
Public officials, both Habsburg and Czech nationalist, freighted public monuments with enormous significance in the decades surrounding the turn of the century, and the Palacký memorial was no different.6 During Einstein’s time in Prague, memorials meant to convey the growing political strength of Czech activists popped up in the most visible surroundings. A plaster cast of the giant memorial to Bohemian religious reformer Jan Hus was presented in the Old Town Square in March 1911, there for Einstein to see when he took in the obligatory sights upon his arrival. On 11 April, a few days after his first entry to the city, the Prague Cit
y Council affirmed the original 1899 ordinance that had approved the memorial—a rebuke to the Catholic Habsburg symbol that graced the square, the Marian Column (which would be torn down in November 1918 a week after the declaration of Czechoslovak independence by a nationalist mob returning from a gathering at White Mountain). Palacký himself had been instrumental in elevating the image of Hus as a touchstone of Czech nationalism, despite the overwhelming Catholicism of the Bohemian population.7 In 1912, Myslbek’s bronze Wenceslas statue was unveiled, replacing a stone monument, removed in 1879, that had been there since 1680 and had been damaged in the 1848 uprisings.8 So salient were these recent additions to the public image of the city that the 1913 edition of the Baedeker guide made sure to insert a reference to the new Palacký tableau.9
It would have been hard for Einstein not to notice any of this, given how central each was to the landscape of his own path through the city. Even the unveiling must have caused a ruckus, disrupting his path to work in his final months at the university. The Palacký monument was ceremonially unveiled in late June 1912, timed to coincide with a huge gathering (Slet) of the Czech nationalist gymnastics league, the Sokol. Athletics in this period were central to Czech nationalists, who participated in the 1912 Olympics as a separate grouping from Austria named “Bohemia”—though not, as in 1908, under an entirely separate flag and anthem.10 Crowds for the Slet began to flood into the city in May for public demonstrations of physical prowess and the touting of symbols of ethnic autonomy; the events continued into the first week of July. As many as 300,000 people converged on the city, with one day alone garnering a high of 120,000.11 It must have been quite a crowd at the base of the Palacký Bridge.
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