Einstein's Clocks and Poincare's Maps

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Einstein's Clocks and Poincare's Maps Page 24

by Peter Galison


  Einstein’s first important physics papers (1902–04) targeted thermodynamics and the underlying account of heat as the product of molecular motion (statistical mechanics). Somewhere among his explorations of philosophy, his immersion in thermodynamics at ETH, and his independent post-ETH research, Einstein began to forge an approach to physics that emphasized principles and eschewed detailed model building. Famously, thermodynamics could be formulated with two easily stated and yet grand claims about isolated systems: the amount of energy always remains the same, and entropy (the disorder of a system) never decreases. The simplicity and scope of this theory remained for Einstein an ideal of science throughout his career. In Poincaré’s Science and Hypothesis he would have found a powerful exposition of the view that physics was concerned with the analysis of such principles.

  And yet the terms “conventions” and “principles” did not resonate the same way for Einstein (and indeed for many German physicists at the time) as they did for Poincaré. In French, the triple meaning of the French word convention (legal accord, scientific agreement, Convention of Year II) was vividly present for Poincaré and his circle around the Convention du Mètre or the proposed convention for decimalized time. Moving the text into German meant breaking that particular chain of associations. Indeed, the German translators of Science and Hypothesis split their rendition of convention, sometimes offering a German noun that included a legal accord (Übereinkommen), sometimes a socially conventional agreement (konventionelle Festsetzung).42 More importantly, we would look in vain in Einstein’s works for a Poincaré-like insistence that principles were definitions, surviving purely because of their “convenience.” For Einstein principles supported physics and perhaps more than science, especially in later years. In a different context Einstein reflected:

  My interest in science was always essentially limited to the study of principles, which best explains my conduct in its entirety. That I have published so little is attributable to the same circumstance, for the burning desire to grasp principles has caused me to spend most of my time on fruitless endeavors.43

  Principled physics was important to Einstein. So was the critical philosophical reflection that pared physics concepts to their basic elements. But there was more. Throughout his Bern years, Einstein’s work and thought was saturated by the materialized principles of machines. From the outset, Einstein regarded the patent office not as a burden interfering with his “real” work, but instead as a productive pleasure. In mid-February 1902 he recounted how he had come upon a former ETH student who was now working at the patent office. “He finds that it’s very boring there—certain people find everything boring—I am sure that I will find it nice and that I will be grateful to Haller as long as I live.” Or as Einstein later testified, “Working on the final formulation of technological patents was a veritable blessing for me. It enforced many-sided thinking and also provided important stimuli to physical thought.”44

  What about time? By 1902 Lorentz had long since been experimenting with fictional mathematical variations in the way the time variable t would be defined for an object moving in the ether. With Poincaré’s and other physicists’ further articulation, the notion of a fixed ether had gained ground. As we know, Poincaré had (first ignoring the ether altogether and then for systems explicitly moving through it), interpreted simultaneity through light-signal-coordinated clocks. Though his use of the ether changed, Poincaré never wavered from his conviction that the ether was enormously valuable as a tool for thinking, a condition for the application of productive intuition. He never equated “apparent time” (time measured in a moving frame) with “true time” (time measured at rest in the ether).45

  Poincaré, Lorentz, and Abraham were determined to begin their theorizing with an analysis of dynamics, the forces that held together, flattened, and joined electrons as they ploughed through the ether. Forces contracted the arms of Michelson and Morley’s interferometer; forces kept all the negative charge in an electron from blowing that charged particle to smithereens. Out of such constructive, built-up theories of matter they wanted to deduce kinematics—the behavior of ordinary matter in the absence of external forces.

  Einstein’s goal was altogether different: time would not begin with dynamics. In mid-1905, he advanced a new account of time and space that would start the physics of moving bodies with simple physical principles the way thermodynamics began with the conservation of energy and a forbidden decrease of entropy. Lorentz was willing to posit an artificial notion of time (tlocal) because of its utility in calculating solutions to his equations. Poincaré saw the physical consequences of “local time” for frames of reference in constant motion. Before Einstein, however, neither Poincaré nor Lorentz seized the coordination of clocks as the crucial step that would reconcile some of the great principles of physics. Neither expected that reconceiving time would up-end their conception of the ether, electrons, and moving bodies. Neither expected that the Lorentz contraction itself could be viewed as merely consequent to a redefinition of time. For his part, before May 1905 Einstein acknowledged only the basic features of Lorentz’s 1895 physics, and not a single piece of work on electrodynamics from Poincaré. Instead, Einstein was reading philosophical texts about the foundations of science (including Poincaré’s), publishing on the molecular-statistical theory of heat, and exploring the electrodynamics of moving bodies. Before stepping into the patent office, he left not the slightest clue that he had any interest in clocks, time, or simultaneity.

  Patent Truths

  So things stood for Einstein when he arrived at the Bern patent office in June 1902.46 This site represented (and not just for Einstein) not only a job but also a site of training—a rigorous school for thinking machines. Heading the patent office during Einstein’s tenure was Friedrich Haller, a stern taskmaster to his underlings, who directed the young inspector to be critical at every stage of his evaluation of proposals: “When you pick up an application, think that anything the inventor says is wrong.” Above all, he was warned, avoid easy credulity: the temptation will be to fall in with “the inventor’s way of thinking, and that will prejudice you. You have to remain critically vigilant.”47 To Einstein, already amply inclined to treat what he considered arbitrary authority as obsolete, thickheaded, and lazy, the injunction to indulge his skepticism to the full must have been gratifying. His inclination to test complacent assumptions in the use of gears and wires echoed a similarly iconoclastic attitude in less tangible realms of physics. For in the electrodynamics of moving bodies, Einstein had chosen a problem that had challenged him on and off for some seven years and was, with increasing force, preoccupying the leading physicists of the day.

  Einstein’s work in electrodynamics in 1902 did not include an inquiry into the nature of time. But he was literally surrounded by burgeoning fascination with electrocoordinated simultaneity. Every day Einstein stepped out of his house, turned left, and made his way to the patent office—a walk that brought him to a workplace which, he told one friend, “I enjoy . . . very much, because it is uncommonly diversified and there is much thinking to be done.”48 Every day he had to walk past the great clock towers presiding over Bern, their time coordinated. Every day he passed the myriad of electric street clocks recently, and proudly, branched to the central telegraph office. Strolling from his street, the Kramgasse, to the patent office, Einstein had to walk under one of the most famous clocks of the city. (See figures 5.3 and 5.4.)

  Friedrich Haller was in many ways as much Einstein’s teacher at the patent office as Weber or Kleiner had been at ETH. Under his aegis, the patent office truly was a school for novel technology, a site that aimed to train a quite specific and disciplined taking-apart of technological proposals. Early on Haller reproached Einstein: “As a physicist you understand nothing about drawings. You have got to learn to grasp technical drawings and specifications before I can make you permanent.”49 In September 1903 Einstein apparently had sufficiently conquered the visual language of the patent
world; he received notice that his appointment had been made permanent. Still, Haller was not yet ready to promote him, commenting in an evaluation that Einstein “should wait until he has fully mastered machine technology; judging by his course of studies, he is a physicist.” That mastery came as Einstein plunged himself into the critical evaluation of the parade of patents that came before him. Soon he could report to Mileva that he was “getting along with Haller better than ever before. . . . When a patent agent protested against my finding, even citing a German patent office decision in support of his complaint, [Haller] took my side on all points.”50 After three-and-a-half years at the patent bench, Einstein persuaded the authorities that, physics notwithstanding, he had learned a new way of looking through diagrams and specifications to the core of innovative technology. In April 1906, Haller promoted him to technical expert, second class, judging that Einstein “belongs among the most esteemed experts at the office”51 where, increasingly, patents on electric time swelled the number of applications.

  Figure 5.3 Coordinated Clock Tower: Kramgasse. As he stepped out of his Kramgasse apartment and turned left toward the Bern Patent Office, Einstein viewed one of the great (and by 1905, coordinated) clocks of the city. SOURCE: BÜRGERBIBLIOTHEK BERN, NEG. 10379.

  Figure 5.4 Bern’s Electrical Clock Network (circa 1905). Coordinated, electrical clocks were a matter of practical import and cultural pride. By 1905, they were a prominent piece of the modern urban landscape throughout the city of Bern. SOURCE: BERN CITY MAP FROM THE HARVARD MAP COLLECTION; CLOCK LOCATIONS SHOWN USING DATA FROM MESSERLI, GLEICHMÄSSIG (1995).

  Time technologies spun off patents in every sector of the network: patents on low-voltage generators, patents on electromagnetic receivers with their escapements and armatures, patents on contact interrupters. Fairly typical of the kind of electrochronometric work blossoming in the decade after 1900 was Colonel David Perret’s novel receiver that would detect and use a direct-current chronometric signal to drive an oscillating armature. It was issued Swiss patent number 30351 on 12 March 1904. Favarger’s own receiver did the opposite: it took an alternating current from the mother clock and turned it into the unidirectional motion of a toothed wheel. The request for this patent—later used widely—was stamped “received” on 25 November 1902 and was issued on 2 May 1905 after a long, but not entirely unusual, evaluation period. There were patents that specified systems for clocks to activate remotely placed alarms, while other submissions targeted the distant electromagnetic regulation of pendula. There were proposals for time to travel over telephone lines—even systems that sent time by wireless. Other patents advanced schemes to monitor railroad departures and arrivals or to display the time in different time zones. Yet others specified how remotely run electrical clocks could be protected from atmospheric electricity or how electromagnetic time signals could be silently received. A cascade of coordinated time.

  Some of these patents systemically addressed the problem of distributing simultaneity. Perret’s patent 27555 came in at 5:30 P.M. on 7 November 1902 (issued in 1903), offering “An Electric Installation for the Transmission of Time”; Perret floated a similar proposal in 1904. Mister L. Agostinelli, applying from Terni (patent 29073, issued 1904) proposed an “Installation with Central Clock for Indicating the Time Simultaneously in Several Places Separated from One Another, and with Bells for Calling Automatically at Predetermined Times.” There were patent applications by huge electrical combines like Siemens (“Motherclock Relay,” number 29980, issued 1904) and patents by smaller but still important Swiss firms like Magneta (patent 29325, submitted 11 November 1903, issued 1904), which manufactured the remotely set clocks gracing the Federal Parliament Building in Bern. A Bulgarian took out a patent in early 1904 for a mother clock and its electrical secondaries. Applications stacked up in Bern by the dozens.52 From New York, Stockholm, Sweden, London, and Paris, inventors launched their timing dreams toward the patent office, but it was the Swiss clockmaking industry that dominated the trade.

  Figure 5.5 Patenting Coordinated Time. Patents on the electromagnetic coordination of time surged around 1905. Here are but a few: Swiss Patent 33700 (upper left) shows a mechanism for the electric resetting of distant clocks (12 May 1905). Swiss Patent 29832 (from 1903) in the upper right illustrates a proposal for the electrical transmission of time. The distant clocks that were to be controlled are visible at the bottom of the wiring scheme. Swiss Patent 37912 (1906), depicted at the bottom of the figure, is one of the earliest approved applications devoted entirely to the radio transmission of time. Such schemes date almost to the first days of radio and were widely discussed in 1905. SOURCE: 33700 (JAMES BESANÇON AND JACOB STEIGER); 29832 (COLONEL DAVID PERRET); AND 37912 (MAX REITHOFFER AND FRANZ MORAWETZ).

  During the time that Einstein served as a patent inspector, interest in electrically controlled clock systems heightened. From 1890 to 1900 there were three or four electric time applications each year (with the exception of two in 1890 and six in 1891). As electric time transmission grew alongside the telegraph system, coordinated clocks began playing an ever-increasing role in both public and private sites. The numbers: 1901, eight patents; 1902, ten; 1903, six, and then in 1904 (the peak year from 1889 to 1910) fourteen patents on electric clocks overcame the hurdles of the patent office. Numerous others, lost to history, no doubt withered under Einstein’s and his colleagues’ critical gaze.53

  All these Swiss chronometric inventions—along with a great many others related to them—had to pass through the patent office in Bern and no doubt many of them crossed Einstein’s desk.54 When Einstein began work there as a technical expert, third class, he was chiefly charged with the evaluation of electromagnetic and electromechanical patents.55 At his wooden podium, alongside twelve or so other technical experts, Einstein dissected each submission to extract its underlying principles.56

  Einstein’s expertise on electromechanical devices came in part from the family business. His father Hermann and uncle Jakob Einstein had built their enterprise out of Jakob’s patents on sensitive electrical clocklike devices for measuring electrical usage. One of Einstein and Co.’s electrical meters featured prominently in the 1891 Frankfurt Electrotechnical Exhibit, a few pages away from a mechanism (typical of the period) for mounting a backup mother clock to ensure the continued operation of a system of electrical clocks. So close were the electrical measuring systems and electric clockwork technologies that at least one of the Jakob Einstein-Sebastian Kornprobst patents explicitly signaled its applicability to clockwork mechanisms. Conversely, numerous patent applicants proffered devices that applied as much to electricity-measuring systems as to electric clocks.57

  During Einstein’s patent years (June 1902 until October 1909) machines of every sort surrounded him. Sadly, only a few of Einstein’s expert opinions survive, rescued from automatic bureaucratic destruction only because the patent process had driven negotiations into court. In one, from 1907, Einstein took aim at a proposal for a dynamo put forward by one of the most powerful electrical companies in the world, the Allgemeine Elektrizitäts Gesellschaft (AEG): “1. The patent claim is incorrectly, imprecisely, and unclearly prepared. 2. We can go into the specific deficiencies of the description only after the subject matter of the patent has been made clear by a properly prepared claim.”58 Description, depiction, claim: these were the building blocks of any patent; to demand their rigorous execution formed the curriculum of Einstein’s schooling under Haller.

  A second extant opinion by Einstein concerned a patent infringement suit between a German firm, Anschütz-Kaempfe, and an American company, Sperry. Competition to build workable gyroscopic compasses in the early 1910s was ferocious. Metal boats, newly electrified, were terrible sites for magnetic compasses. But in the race to outfit the world’s ships and airplanes, Anschütz-Kaempfe suspected the Americans of having stolen their invention. Hermann Anschütz-Kaempfe (the firm’s founder) called Einstein, who made short shrift of the Americans’ claim that an 1885 pate
nt actually lay behind all their “new inventions.” Noting that the 1885 patent described a gyroscope that could not move freely in all three dimensions, Einstein skewered the Americans’ claim by pointing out that the older machine could not possibly work accurately in the pitch and roll of a craft at sea. Anschütz-Kaempfe won. Einstein became such an expert on gyrocompasses that he was able to contribute decisively in 1926 to one of Anschütz-Kaempfe’s major patents, for which he received royalties until the distributing firm was liquidated in 1938. Significantly, in 1915 the gyrocompass served explicitly as a model for Einstein’s theory of the magnetic atom. This cross-talk between machines and theory so riveted his attention that Einstein temporarily put aside his work on general relativity to do a series of collaborative experiments—exceedingly delicate ones—showing that the iron atom indeed functioned like a submicroscopic gyroscope.59 Patent technology and theoretical understanding were closer than they might have appeared.

  Figure 5.6 Jakob Einstein & Co. Einstein’s uncle and father ran an electrotechnical company that produced, inter alia, precision electrical measuring equipment that shared much technology with that of electric clocks. SOURCE: OFFIZIELLE ZEITUNG DER INTERNATIONALEN ELEKTROTECHNISCHEN AUSSTELLUNG, FRANKFURT AM MAIN (1891), P. 949.

  A few years later, Einstein made it clear that he treated the very processes of writing and reading as if he were attacking a patent, even when he was treating matters far removed from dynamos or gyrocompasses. In July 1917 his long-time friend, the anatomist and physiologist Heinrich Zangger, wrote Einstein to solicit his judgment of a text Zangger was assembling on medicine, law, and causality. Einstein replied that he liked the “concrete cases,” “[b]ut I did not like some of the abstract parts; they often seem to me to be unnecessarily opaque (general) and in the process are not worded clearly and pointedly enough (not every word is placed clearly and consciously). Nevertheless, I understood everything; it may well be possible that my perpetual ride on my own hobbyhorse and the conventions at the Patent Office have driven my standards to exaggerated heights in this regard.”60

 

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