Alfred Wegener

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Alfred Wegener Page 18

by Mott T. Greene


  His hopes for a polar adventure dashed, he threw himself back into the scientific question he had begun to pursue in the fall, the cause of the temperature oscillations recorded on the kite thermographs. Throughout January and February 1906, he studied the daily records of the kite flights, looking for the pattern. While doing so, he began to reread and review the literature on the subject, most of it actually quite recent. The hunch he was following was that the temperature oscillations were the result of the kites riding on atmospheric waves of the kind predicted by Helmholtz. There was some solace here in a kind of work in which he excelled, as well as the chance to pursue a very interesting and potentially important problem.

  The problem Wegener pursued concerned a phenomenon that we are all familiar with from airplane travel: that of “clear-air” turbulence, when the plane suddenly begins to buck and shudder, and the pilot turns on the seat-belt sign and announces that he will ascend, or descend, to find smoother air. The knowledge that moving the plane up or down a few thousand feet will solve the problem is empirical, but the theory behind it is easy to understand. “Within the atmosphere,” Wegener explained, “just as on the surface of a body of water, when a warmer and therefore lighter layer of air moves across a colder, denser layer, waves must form.”53 The idea is that when one layer of a fluid slides over another, the difference in density suppresses mixing, but the difference in velocity encourages it. The mixing is the cause of waves, which draw their energy from the velocity difference between the two layers, and if the wavelength is right, the waves will continue to grow. If the velocity difference is great enough between the two layers, the waves can even break—creating severe “clear-air” turbulence.

  Within the atmosphere, the phenomenon is tied to inversion layers—warm layers above cold layers, in defiance of the normal lapse of temperature with altitude; the greater the temperature and velocity differences at the boundary surface (or discontinuity) between the two air layers, the greater the likelihood of mixing and the formation of waves. If conditions are just right, clouds will form at the wave peaks (though not the troughs), and these billow clouds can be seen from the ground in parallel lines at a common altitude—as if a number of cumulus clouds had been stretched enormously in the same direction.

  Helmholtz’s work on this problem was pathbreaking (in Wegener’s estimation) precisely because of the promise of generality: “using the principle of mechanical analogy … allowed one to calculate the wave-lengths of all the waves in a family sharing the same wave-form, for any air-density and any wind velocity, if one knew all the numerical values for one single case.”54 Actually, Helmholtz had achieved this result, Wegener knew quite well, by disregarding a number of problems, and the form in which he left his solution was very little use to meteorologists because of its lack of generality. Helmholtz had, however, put his student Wilhelm Wien (1864–1928) on the problem, and using analytical methods, Wien had been able to develop Helmholtz’s results into a much more useful form. This was where Wegener came in: “The theory [of Wien] is scarcely known in meteorological circles,” he wrote, “and because of its purely mathematical character, is accessible only to those well-versed in analytical methods.” Shorn of its formality, the plain language of this statement was, “Here’s a means for solving an interesting and important problem that has been around in the literature for a decade till a meteorologist came along who could understand enough of the mathematical physics involved to use it.”

  Wegener’s attempt to plot the wavelength of “Helmholtz air waves” as a function of the difference in temperature of two successive layers of the atmosphere (vertical axis) and the wind speed (horizontal axis). From Alfred Wegener, “Studien über Luftwogen,” Beiträge zur Physik der freien Atmosphäre 2 (1906): 55–72.

  Wegener actually had only some relatively light lifting to do to adapt the equations for meteorological use. Wien’s extension of Helmholtz’s work used the example of wind waves on the ocean, though his equations contained terms not readily available in meteorological observation. The real theoretical work for Wegener was the graphical representation of Wien’s theory in terms of “curves of equal wavelength.” To do this, he plotted the results of his (many) calculations with the vertical axis showing the temperature difference between the layers and the horizontal axis showing the wind-speed difference. The idea was to provide, for his analytically challenged meteorological colleagues, access to the predicted wavelength at the boundary surface, for any combination of air temperatures and wind speeds.

  With the graph in hand, the next part of the investigation was to compare temperature observations on kite flights with the theory as embedded in the chart, thus creating a role for kite and captive balloon aerology in the study of these air waves. There were a variety of methods already in use for finding and studying the waves, all requiring relatively unusual conditions. If one were on a mountaintop or in a balloon above a cloud layer, one could see them directly from above; if there was sufficient condensation at the wave crests, one could see them from Earth as clouds. For invisible (clear-air) waves, manned balloon flights could provide a record of the waves via recorded temperature oscillations, or, when there was no vertical convective motion (“vertical wind”), one could discover waves in the up-and-down motion of the balloon, registered on a barograph as oscillations in atmospheric pressure. Finally, one could, in clear air, look for oscillations in a record of atmospheric refraction, since the air on one side of the discontinuity was less dense than that on the other. Compared to any of these, kites and captive balloons seemed to offer a less expensive and exacting path for study.

  The observational difficulties were formidable, however. The contrast between the grand sweep of theory and the niggling minutiae of observation stands in sharp relief in the accompanying figure, showing Wegener’s calculated curves of equal wavelength and the raw data off the meteorograph from the kite flight he superintended on 6 December 1905. From the latter, after numerous corrections, Wegener had tried to extract a wavelength by comparison of near-invisible oscillations of temperature between 0.1° and 0.7° and then to compare it to the predicted value on his chart. The results were not encouraging here or in succeeding months. By the end of February, he had only been able to find three useful records out of nearly fifty flights, each of them punctuated by their own maddening peculiarities and vagaries. Moreover, the agreement between theory and observation was terrible—an error of 25–30 percent. At least it was consistent—the observed wavelengths were all shorter than the values predicted from the table and persisted across an order of magnitude (the error for a 200-meter [656-foot] wave was nearly the same as the error for a 2,000-meter [6,562-foot] wave). The best possible construction he could put on the outcome was that “there seems to be a systematic discrepancy between observation and theory, insofar as the very small number of observations permit a conclusion.”55 It appeared that this required a long series of observations and some intricate correcting—it would last perhaps the rest of the year, and certainly the rest of his time at Lindenberg. He could see the implications if he had any success: some further understanding of global atmospheric circulation, and some marginal advantage in weather forecasting—but that seemed a long way off.

  The days began to blend into one another—there was heavy overcast most of the time, cold rain, and a round of increasingly demanding work: not only did Alfred and Kurt do most of the kite and balloon flying, but it was up to them to extract the observations and interpret the meteorograph records—sometimes two or three a day. In the evenings, as time permitted, they had many discussions with Coym, who had a number of practical hints for Alfred about tricks for squeezing more data out of his flight records. Kurt and Alfred also talked privately about what they were going to do after Lindenberg—Kurt was negotiating (quietly) for a job as assistant at the Physikalischer Verein in Frankfurt beginning in the fall, where he would be involved in an intensive program of flying, soon to include airplanes as well as balloons. Alfred was ser
iously considering making a move at the same time.

  On 23 March 1906, Alfred was in the smoking room of the headquarters building at Lindenberg reading the Tägliche Rundschau, a major daily newspaper from Berlin, when his eye fell on a telegraphic notice about the Mylius-Erichsen expedition. It announced that the Danish government had indeed decided to match the funds raised by Mylius-Erichsen: Christensen had made good on his promise, and Mylius-Erichsen had collected sufficient sponsors. The article also contained the following astonishing paragraph: “Outside of the Danish members of the expedition it is likely that Dr. phil. A. Wegener of Germany will take part as physicist and meteorologist, and Dr. phil. Baron von Firicks from Russia as geologist: the negotiations with these two scholars, have not been concluded, however.”56

  Alfred dashed upstairs and sat down to compose a letter. He knew better than to try to get an answer from the ever-elusive Mylius-Erichsen directly, so he wrote to Paulsen, describing what he had read “just this minute” in the paper. When he had read his name and that of a Russian along with the news of the award of funds by the Danish parliament, he “could not help thinking that this meant that Herr Erichsen now found himself in the position of putting his undertaking on a broader basis, and eventually of relinquishing the principle that only Danes should be allowed to take part.” Alfred indicated to Paulsen that he badly needed an immediate response, adding, “I’m in the middle of negotiating the terms of a new position, negotiations that I’ll have to break off [if I am being considered for the expedition], so I’d be very obliged if you could tell me as soon as possible what you know about this.”57 He apologized to Paulsen for bothering him again, begging him to take it as an expression of his deep interest in the expedition.

  Paulsen received Wegener’s letter the next day, and he wrote immediately to Mylius-Erichsen, telling him that he had yet another letter from Wegener and urging him to make up his mind about the matter immediately and to write to Wegener and tell him whether he was to be a part of the expedition. Mylius-Erichsen very much wanted to make this a Danish expedition, and he had been able to put together an all-Danish cartographic and scientific staff from those who had applied (though no contracts had yet been signed). With the money in the bank, the pressure for an all-Danish expedition had lessened at least enough for him to send up the “trial-balloon” in the newspaper about Wegener and Firicks, and it is clear that he had to.

  In March of 1906 the expedition still lacked a geologist and someone to do physics and meteorology—glaring lacunae for an enterprise billing itself as a major scientific expedition. It had been easy to find a hydrographer and a marine biologist—chosen from a large number of eager suppliants—and there were plenty of eager ornithologists. The expedition’s successful candidates for physician and botanist had even spent several years in Greenland. Yet they were all young men, many still in school. Even the older candidates mostly lacked degrees or academic affiliations; only a few came with expedition experience. Mylius-Erichsen was an unknown quantity, and the planned expedition, in spite of its towering ambitions, was also a shoestring operation with low salaries. It was therefore difficult for him to hire credentialed scientists, and in the end he still lacked the scientists needed to study most of what they would see: rock, ice, and weather.

  Time to prepare for an expedition was running desperately short by any measure. The funds had been voted on by parliament on 22 March and announced on the next day. On the twenty-fourth, the expedition’s governing committee officially took up its duties, setting a departure date of 24 June 1906, a scant ninety days away—and the expedition did not yet even have a ship! Mylius-Erichsen decided that he could get along with a geology student and settled on young Hakon Jarner (1882–1964), a Danish student at the Polytechnic Institut—thus no need to bring the Russian baron (Firicks) along. Wegener, however, was the only expedition candidate with a PhD and the only professionally employed scientist who had applied for any of the jobs. He was a German, true, but had a Danish-sounding name, and Prof. Paulsen, who had been unfailingly helpful to Mylius-Erichsen with advice and support, really wanted a meteorologist on the expedition. Wegener had been remarkably persistent and had expressed unfailing interest for five months.

  Alfred, once again unable to stand the suspense, took a train the next day (Saturday) to Copenhagen, arriving on Mylius-Erichsen’s doorstep within hours of Paulsen’s letter. With money in hand and little time to waste, Mylius-Erichsen was now prepared to take Alfred’s participation seriously, and when they finally met face to face, Mylius-Erichsen must have liked what he saw, because he made a decision on the spot and formally offered Alfred the job of physicist and meteorologist on the expedition, with the provision that he would also be expected to make geological observations and to take part in the cartographic and position-finding work. They signed a preliminary agreement and discussed salary. Mylius-Erichsen told Alfred that he should prepare his personal and scientific kit immediately: the expedition would leave in less than three months.

  Wegener was too happy with the outcome to be very analytical about it on the train ride back to Lindenberg, but it was a wonderful object lesson, seen from outside, in how dogged persistence can aid chance in producing an event. His odds for getting on the expedition, objectively, had always been slim—if any Danish meteorology student with ten fingers and ten toes had shown up, he’d have been out of luck. He had not made success a precondition for effort, and he had remained aggressively in pursuit of his goal from November until March. It had “happened to him,” yes—but he had made it happen to him, forcing all visible contingencies in his direction, and in some real sense he had the experience of bending the world to his will. Here was that philosophy of “vital freedom” made real. He had obtained the results of such vital striving—and they felt very good indeed.

  5

  The Polar Meteorologist

  GREENLAND, 1906

  There is no such thing as friendship on an arctic trip. Not friendship of the right kind, where worth is equal and individual partners really mean something to each other. The arctic air, which is said to be free from bacteria, certainly contains one contagious germ: personal ambition.

  LUDWIG MYLIUS-ERICHSEN, Journal (13 July 1903)

  The Danmark Expedition

  The Danmark Expedition to East Greenland, for which Alfred Wegener was to be meteorologist and physicist, aimed to be the largest polar-scientific endeavor ever mounted. Its immediate predecessor, Drygalski’s “Gauss” Expedition of 1901–1903 to the Antarctic, had employed a scientific staff and ship’s crew of twenty-two, though this number included everyone on board, including stokers and deckhands; there were actually only seven scientists.1 Ludwig Mylius-Erichsen’s Danmark party was to be twenty-eight, of whom sixteen would perform real scientific work; all of the latter had agreed to work as deckhands and even as stokers if need be, in order to keep the ratio of scientists to support staff as favorable as possible.

  Of the forty or so major polar expeditions mounted between 1890 and 1914, Mylius-Erichsen’s exceeded all others in size and scientific ambition. Even so, most readers outside Denmark will never have heard of it, perhaps because the reputation of polar expeditions and their scientific worth are generally in inverse proportion. The only two expeditions that came close (in size) to Mylius-Erichsen’s were the Australasian Expedition to Antarctica in 1912, led by Douglas Mawson (1882–1958), which had planned to land twenty-six men, and the celebrated Endurance Expedition in 1914–1915 of Ernest Shackleton (1874–1922), which got to twenty-eight only by counting Perce Blackboro, a deckhand who stowed away. Of these twenty-eight, only four were scientists, and the crushing of the Endurance by the Antarctic sea ice effectively destroyed their scientific program almost before it began.2

  Wegener, with no polar experience, was hired for the Danmark Expedition with a late and brief interview. He felt fortunate to be included in such an undertaking, but he was better prepared than most polar novices. He had mountaineering and glacier-climbi
ng experience, he could sail, and he had meteorological skills the expedition needed. In any case, men with scientific credentials and serious polar experience were quite rare, even in Denmark, where national sovereignty extended to all of Iceland and most of Greenland. Mylius-Erichsen, choosing among novices, picked more carefully than many better-known expedition leaders. Shackleton appointed Leonard Hussey meteorologist for the Endurance Expedition, even though Hussey knew nothing about meteorology, on the grounds that he “looked funny,” and it appealed to Shackleton’s sense of whimsy that Hussey had applied for the expedition while working as an ethnologist in the Sudan. Shackleton hired Reginald James as physicist for the same expedition because he had good teeth, had a sense of humor, and could sing.3

  Part of the secret of Alfred’s successful candidacy was that while the expedition airily aspired to be “scientific,” it had no specific scientific aims beyond the most obvious and essential—geographical discovery and making maps of the newly discovered terrain. Mylius-Erichsen was an adventure traveler and literary intellectual; if science was to be done on his expedition, it would be up to his subordinates to do it. The expedition contracts specified that the Committee of the Danmark Expedition would pay for all the scientific equipment, but declined to specify what that equipment might be. Each scientist had to plan his own program and then build, buy, or borrow the instruments to carry it out. “The Committee” (i.e., Mylius-Erichsen) would have to approve the purchases, but the scientists were responsible for acquiring their equipment and getting it to Copenhagen by the middle of June. Each man had a budget: the more ingenuity he showed in stretching that amount, the more instrumentation he could take and the more science he could do. Alfred had come forward not just with expertise but, as evident in his first letter to Mylius-Erichsen in November 1905, a specific scientific program in mind. Mylius-Erichsen’s reluctance to allow a German scientist a role in a Danish undertaking gave way to his desire to claim abundant scientific results for the expedition and, in this way, to secure his own place in the history of scientific exploration.

 

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