The Man Who Stalked Einstein Read online

  Little did Einstein know that his marriage to Mileva would linger well past their separation. It would cost him five years and a great deal of misery. To overcome his wife’s reluctance to agree to a divorce, Einstein made a most unusual contract. Beginning in 1910, he had regularly been nominated for the Nobel Prize in physics. He promised to give Mileva the substantial monetary proceeds of the award should he ever actually receive it. By the terms of the divorce, the money was to be held in trust in a bank. While Mileva would be entitled to draw freely on the interest, she could only use the capital by agreement with Einstein. In the event of her remarriage or death, the money would go to their two sons.

  These plans were thrown into disarray by a turn of events. Their younger son, Eduard, was an excellent student. He had begun to study medicine with the goal of becoming a psychiatrist when he took ill at age twenty. He was diagnosed with schizophrenia and intermittently required hospitalization for the condition until he died at age fifty-five. The expense of treating his illness combined with the severe economic inflation that Einstein was experiencing living in Berlin put considerable financial stress on all parties. Mileva struggled with money, particularly during the periods when Eduard was out of the hospital and living at home.

  Despite the ongoing marital drama, Einstein’s work continued apace. He began to revise his view of Lenard around 1909–1910, influenced by his exchange of letters with Lenard’s assistant, Johann Jakob Laub. Laub originally wrote Einstein that he disagreed with the common view around the laboratory that Lenard was a tyrant. Nonetheless, from the very beginning of his employment, Laub’s correspondence with Einstein reveals a tension between Lenard’s scientific beliefs and his own. Laub’s May 1909 letter to Einstein includes the passage, “We have without Lenard a private colloquium in Pockel’s [another Heidelberg faculty member] home where we discuss the theory of relativity. In the coming days, we shall proceed to the light quantum theory. . . . I doubtless anticipate your visit. It is not so far to Heidelberg.”

  The conflict between Lenard and Laub would eventually engage Einstein on Laub’s behalf, but not for some time. A letter from Einstein to Laub extolling Lenard crossed Laub’s in the mail. “I took great pleasure in this news [of your working with Lenard],” he wrote. “However, I think that the opportunity to work together with Lenard is worth far more than the assistantship and income combined. . . . He is a great master, an inventive thinker!” Despite the compliments, Einstein may have had a premonition of disaster. He concluded with a veiled warning: “Perhaps he will be entirely affable in the face of a man he has learned to respect.”

  At this point, Einstein’s esteem for Lenard was reciprocated. Lenard went so far as to present a paper written by Laub on the theory of special relativity at the June 1909 meeting of the newly formed Heidelberg Academy of Science. The next year, with Lenard’s approval, Laub followed up this initial work by writing a paper entitled, “On the Experimental Fundamentals of the Relativity Principle.” The article was included in a volume edited by the man who was to become Lenard’s close colleague in his attacks on Einstein, Johannes Stark. Given the symbiotic relationship between Lenard and Stark, Lenard may well have prevailed on Stark to publish his assistant’s work. Regardless, the publication makes clear that Lenard was very familiar with what Einstein had been up to, as the work includes a complete listing of Einstein’s publications to that time.

  Despite the apparent bonhomie between the two men, important differences between Lenard’s and Einstein’s scientific philosophies were beginning to emerge. In particular, the two men disagreed over quantum theory, of which Einstein was a strong proponent. This was of special significance because Einstein had followed Lenard in investigating the photoelectric effect. Specifically, he employed the concept of energy quanta to develop a new law of physics that would, in time, earn him a Nobel Prize. Einstein’s position reflected his willingness to give up on the strictures of classical physics to explain the new phenomena associated with very small particles. In contrast, Lenard held tight to what he knew, preferring to adapt, modify, or expand upon the accepted fundamentals even if very complicated machinations were necessary to make the old ways work. In his 1910 publication, “On Ether and Matter,” Lenard was explicit in this regard: “I do not believe the difficulties should keep us from developing and protecting the existing view because otherwise we would discard each such view and even the mechanical comprehensibility of nature.”

  Even allowing for their differences over quantum theory, their relationship at this time remained cordial. It wasn’t long, though, before Lenard’s tolerance for the new physics reached its limits. Lenard’s regard for Einstein began to deteriorate around the issue of the ether—the mysterious medium that Lenard believed supported the passage of electromagnetic radiation through space and was responsible for gravitational effects. Lenard was very attached to the idea of ether, which had held sway for nearly two hundred years. Einstein’s theory of special relativity obviated the need for ether, but for Lenard, the abolition of ether from the mainstream construct of how the universe worked was unimaginable. He was prepared to defend ether “even if, in order to make clear the mechanics of the ether, he would have to establish after the ether and its assembly still another ether.”

  The postulates of theoretical physics had put the believers in ether under the gun to demonstrate its presence. During 1910 and 1911, Lenard designed new experiments based on equations developed by his collaborator, the Norwegian Vilhelm Bjerknes, and set Laub to work. Lenard pushed the disbelieving Laub hard to uncover some expression of ether’s presence. It was to no avail. If ether actually existed, it was proving itself a worthy quarry for even as dedicated a hunter as Philipp Lenard. Einstein witnessed the growing tension between Lenard and Laub from afar, his correspondence with the young scientist a window onto the dark side of a man he had admired.

  Lenard’s disappointment with Laub’s failure to prove the existence of ether was palpable. Unwilling to consider the possibility that he might be wrong, Lenard instead blamed the poor outcome of the experiments on Laub. He wrote a letter to Bjerknes in February 1911, which cited Laub’s disagreement with the principles of the research he’d been assigned to conduct. “I have arranged these things for Herr Laub with great zeal. He is, however, forever so captivated with the principle of relativity that I always dread that he cannot be correct.”

  As they had with Einstein, the events of Lenard’s personal life intruded upon his absorption with his work. His son, Werner, had been a sickly child and continued to incur health problems into adolescence. His illness excluded Werner from participating in military service during the Great War, a crushing blow for an arch-nationalist like Lenard. Lenard’s view of the pathophysiology affecting his son was that he “suffers from the narrow-minded school teaching that ignores the individual and from the bad nutrition during the war.” At the same time, his daughter, Ruth, was maturing and had an academic bent. Against the fierce resistance of her father, she secretly qualified for university admittance to study history and languages with the goal of becoming a teacher.

  Ultimately, Lenard and Einstein’s relationship was doomed not only by their scientific differences but also by their personal ones. Lenard’s initial pleasure at Einstein crediting him as an inspiration for his work on the photoelectric effect morphed into a much more negative assessment. Beginning in 1915, with Einstein’s first publications related to what would become his theory of general relativity, Einstein broadened his concepts to apply to not only bodies in a steady state, as in his theory of special relativity, but all physical circumstances. He chose as an experimentally provable example of the power of his theory an explanation of the perihelion of the planet Mercury, wherein, contrary to Kepler’s law, the point in the orbit of Mercury closest to the sun changes from orbit to orbit.

  Einstein’s critics went on the attack. In 1917, Ernst Gehrcke, an ardent anti-relativity scientist—and someone who would be linked to Lenard’s future effor
ts to discredit Einstein—republished in the Annalen der Physik a 1902 work by a physicist named Paul Gerber. Gerber had devised a formula for explaining the perihelion phenomenon that did not require reference to relativity. Bringing to light the Gerber publication gave Gehrcke the chance to raise the possibility that Einstein had plagiarized Gerber’s ideas. He attacked both Einstein’s primacy and his integrity in a single blow. It would be the first of a stream of accusations by Einstein’s critics—including Lenard’s claim that Einstein had cribbed the work of the obscure Austrian physicist, Friedrich Hasenoehrl—that Einstein was fundamentally a plagiarist.

  As evidenced by a letter that Lenard wrote to Johannes Stark, then the editor of the omnibus publication Almanac of Radioactivity and Electronics, Lenard was in league with Gehrcke: “I would like to ask whether a short original post by me . . . on ether and gravitation . . . could be quickly published in the Almanac,” Lenard wrote following Gehrcke’s republication of Gerber’s article.

  Stark responded, “I will gladly include your study on ether and gravitation in my edited almanac. . . . I find it meritorious that you have co-contributed to the acceptance of Gerber’s work.” In what was certainly a direct reference to Einstein’s theory of general relativity, Stark continued, “The work is physically well thought and is, for me, more likable than so many of the theoretical works, which, with a sort of dialectical sorcery, pretend to solve the difficult physical problems.”

  Lenard immediately thanked him for agreeing to publish his commentary, which was intended to accomplish several goals: reinforce the rationale for belief in ether; set to right the infringement by Einstein on Gerber’s ideas; establish the failings of the theory of general relativity; and, in Lenard’s words, make clear that “the ether explanation of gravitation [believed at the time to act as a radiomagnetic wave] . . . appears good to me because it is so simple that by it alone, everything works.”

  Unfortunately for Lenard, events conspired to put him on the defensive. The very next issue of the Annalen der Physik contained scathing reviews of the Gerber article by well-respected astronomers Hugo von Seeliger and a close friend of Einstein’s, Max von Laue. Lenard had to choose to either dispute their arguments or withdraw the most serious of his concerns about Einstein. Because, at the time, he was otherwise occupied with scientific and administrative issues related to the Institute, he chose the latter approach and provided Stark with a replacement commentary for the Almanac. Interestingly, this revised version was accepting of Einstein’s theory of special relativity and even of much of his theory of general relativity. However, Lenard believed that “[t]he principle must give up its universality and no longer claim relativity of all movements but restrict itself to those movements which proceed under the influence of mass proportional forces, as is gravitation.”

  Given their history of mutual encouragement, Einstein must have wondered about Lenard’s assault. He retaliated by publishing in Naturwissenschaften “Dialog on the Objections against the Theory of Relativity,” a courtly and creative exchange of views pitting the arguments of a hypothetical “Critic” against the defense of a “Relativist.” The fictional debate is stylized and civil, beginning with the apologetic tone of the Critic, and directly references Gehrcke’s charges of plagiarism:

  Critic: So as not to upset you too much, and possibly even make you undertake this business (which you can’t avoid anyway) with a certain pleasure, I will say this in comfort. Unlike many of my colleagues, I am not so full with the status of my guild so as to make me act as a superior being with superhuman insight and certainty (like newspaper journalists about scientific literature, or playwright-critics). . . . Also I have no wish to—as was lately done by one of my colleagues—jump on you like a district-attorney and accuse you of theft of intellectual property, or accuse you of equally dishonorable acts.

  There follows an extended interchange between the Critic and the Relativist on such issues as the relationship between very high speeds and the slowing of the passage of time; the different possible perspectives for considering the effects of rapid deceleration; and the perihelion of Mercury. These vignettes afforded Einstein the opportunity to explain certain misconceptions about relativity. In the special world that Einstein creates, the Critic concedes the logic of relativity but with some reservations.

  Critic: After your last statements it does seem to me that no self-contradiction of the theory of relativity can be deduced. . . . Indeed, it now seems not unlikely to me that the theory is free from self-contradiction altogether, but it does not in itself mean that the theory should be considered in earnest.

  Particularly with regard to the perihelion of Mercury, Einstein argues for the plausibility of his theory rather than its correctness and calls out Lenard’s objections:

  Relativist: The secular perihelion motion of the planet Mercury had to be clarified. This perihelion motion was certainly noticed by astronomers, and they were unsuccessful in finding an explanation on the basis of the Newtonian theory. . . . In asserting the equality of coordinate systems as a matter of principle it is not said that every coordinate system is equally convenient for examining a certain physical system. . . . However as a matter of principle such a theory of relativity is equally valid as any other.

  The Critic is convinced to the extent of the specific examples that Einstein has discussed. However, he cannot help himself. He must ask one more question. At this point, it appears that Einstein is speaking for Lenard as he wishes Lenard might speak:

  Critic: After this conversation I have to admit that the refutation of your point of view is not as easy as it seemed to me earlier. I do have more objections up my sleeve. But before pestering you with that I want to think over our present conversation thoroughly. . . . I ask out of pure curiosity: how does the diseased man of theoretical physics fare, the ether, that many of you have declared to be definitely dead?

  Relativist: If there would be an ether, then in each space-time point there would have to be a particular state of motion, that would have to play a part in optics. There is no such privileged state of motion, as has been taught to us by the special theory of relativity, and that is why there is no ether in the old sense . . . space without matter and without electromagnetic field seems to be characterized as absolutely empty. . . . One can quite well construe this circumstance in such a way that one speaks of an ether, whose state of being is different from point to point. Only one must take care not to attribute to this ether properties similar to properties of matter.

  Lenard fought back in 1918, writing a new version of an earlier article, On the Principle of Relativity, Ether, and Gravitation, as a free-standing publication. Unlike the compliant hypothetical critic in Einstein’s article, Lenard is anything but agreeable. There is a hard edge to his writing. “What Mr. Einstein carried out as ‘a relativist’ . . . was and is not convincing to me. He touches on certain principal points too little or not at all.”

  The fundamental difference between the two men is that Einstein made the claim for all reference systems being equally plausible (e.g., his example where the train or the station could serve equally well as the reference point), while Lenard favored using “simple, sound common sense” to favor one reference system over another. This complaint—that the application of Einstein’s theory of relativity lacked common sense—would become a long-lasting theme for Lenard and other Einstein critics.

  This exchange marked the end of Lenard’s and Einstein’s discourse until their very public confrontations in Berlin and Bad Nauheim of 1920. Secular events took precedence. World War I concluded hostilities in November 1918. The Kaiser abdicated, ending centuries of monarchic rule. The weak republic that filled the ensuing vacuum in governance was marked from the start. The Allies’ demand for reparations led to rampant unemployment and poverty across Germany. A deadly struggle developed between nationalist right-wing extremists and worker-backed, socialist, and communist interests. The days were filled with angst, anger, and violence, while th
e nights were devoted to hedonistic gaiety that signaled a sense of there being no tomorrow.

  Meanwhile, Einstein persevered. He cemented growing support among natural scientists for his theory of relativity. Measurements made during a 1919 solar eclipse confirmed the accuracy of a prediction of the theory of general relativity, giving new credence to Einstein’s theory and making him an unlikely international celebrity. In the same year, soon after his divorce from Mileva was final, he married Elsa. It was to become a marriage of convenience in which both Elsa and Einstein accepted their shares of a tacit bargain.

  Elsa lived the life of a spouse of a famous man, reveling in the travel, social status, and comfort her marriage afforded her. Einstein could focus on his work, secure in the knowledge that Elsa would handle the details of his daily life while allowing him the freedom to seek romance in sleeker, more ardent arms. His letters reveal that he took several lovers during his marriage and that, at least on some occasions, he discussed his relationships with Elsa. Writing to Elsa of one paramour, socialite Ethel Michanowski, he noted,

  Mrs. M definitely acted according to the best Christian-Jewish ethics: 1) one should do what one enjoys and what won’t harm anyone else; and 2) one should refrain from doing things one does not take delight in and which annoy another person. Because of 1) she came with me, and because of 2) she didn’t tell you a word. Isn’t that irreproachable?

  Soon after the end of the war, Lenard further tightened his grip on every aspect of his institute, becoming more remote in his dealings with the students and his subordinates. He mourned the death of his only son. “He was not given the privilege to take part in the war. . . . With him, the last bearer of my name left the earth.” Lenard grew more radical. He became a believer in the widespread but outrageous notion that the German army had not been defeated in battle but had been “stabbed in the back” by the pacifists, republicans, and Jews who had sued for peace. Passages from his autobiography detailing this period provide early evidence of his developing anti-Semitism.