Alfred Wegener
Page 41
Following the New Year with his parents and Tony in Berlin, Wegener returned to Marburg, with a few days of rest before he resumed his grueling schedule of doing what he must do to make a living, and finding what time he could for his “own work.” He was, nevertheless, in a refreshed and relaxed frame of mind, with the satisfaction that he had submitted a book manuscript (well, most of it) to the publisher by the agreed-upon deadline. He was no stranger to the “afterlife” of a manuscript and the endless proof corrections, modifications, and numbering and renumbering of figures and diagrams, but the conceptual part of the book was indeed finished.
Stopping by the Physical Institute on his return to Marburg, he encountered his friend Emil Take (1879–1925), the other young physical assistant besides himself and Stuchtey. Take invited Wegener into his office (their offices were side by side) to show him his Christmas present. It was the Jubilee edition of Karl Andree’s Allgemeine Handatlas.1 Wegener wrote to Else Köppen a few days later:
My next-door neighbor Dr. Take received the large-format atlas by Andree for Christmas. For hours on end we stared admiringly at the stunning maps. While we were doing so, an idea occurred to me. Take a look (please) at a map of the world. Doesn’t the East Coast of South America fit exactly into the West Coast of Africa, as if they had formerly been continuous? It tallies even better if you look at the depth chart of the Atlantic Ocean and look, not at the current continental margins, but rather compare the margins of the continental shelves where they plunge into the abyssal ocean. I’m going to have to pursue this.2
This was the experience around which Wegener ordered his memories of the conceptual development that drew so much attention to him and to his career. It was a nearly solitary and qualitative moment of discovery in a time of relaxation and reflection, outside his own field of endeavor, and within a year of his return from a trip across the Atlantic from Europe to Argentina and back. This is the first part of the story he told when asked how the conception of continental drift had first occurred to him.
The point here is not how Wegener discovered continental displacements as much as how they discovered him—how he was fashioned by inclination, training, university education, and the contingent placement of his life in a certain stream of events to be the person through whom continental drift came to be. This entailed not just the raw intuition of similar coastlines but a robust and well-developed theory. If we are really to represent life as humans live it and not construct mythically comforting fables of the complete creative autonomy of individuals, we must attend to the fact that our biographical subjects’ lives happen to them, just as our own lives happen to us.
The obvious place to begin our discussion of this “eureka moment” is with an examination of the map that Wegener found so striking. In Andree’s Atlas, there is a world map toward the middle of the volume which takes up both pages, with two hemispheres conjoined in such a way that the Atlantic Ocean virtually disappears. The left-hand or American hemisphere has South America at its right-hand margin. The right-hand or Eurasian hemisphere has Africa at its left-hand margin.
Wegener was far from the first to notice this parallelism in the fit of the coastlines. It was known to Humboldt and figured in a variety of nineteenth-century theories of Earth, of which Wegener would become aware only much later. There are very few people in the world over the age of twelve who have had access to a globe or a decent school atlas and have not noticed this parallelism of the coastlines. So it was hardly this that was the kernel of his intuition.
What Alfred Wegener found striking here is contained in what he said in his letter to Else Köppen. To match continents at their sea level margins is trivial. The shape of a continental margin is an artifact of sea level, and sea level has varied by hundreds of meters over the past quarter-million years. This subject had been intensively studied since the middle of the nineteenth century in the context of the theory of ice ages, which required the periodic withdrawing of ocean water to produce ice caps and the rerelease of these melting ice caps back into the oceans.
What excited Wegener’s interest and imagination was not the margins of the continents at sea level but the oceanic depth contours circumscribing the continental maps of South America and Africa. Andree’s Atlas was the first atlas in Germany (in fact, the first atlas anywhere) to incorporate the full bathymetry of the Challenger Expedition into a map and to make this information widely available. The Challenger Expedition, under the command of the Arctic explorer George Nares (1831–1915) and the scientific supervision of Wyville Thompson (1830–1882), had spent the years from 1873 to 1876 dredging, sampling, and measuring the floor of the Atlantic Ocean. As often happens with such expeditions, the publication of results takes not years but decades. The scientists aboard Challenger were, above all, zoologists and most interested in their biological specimens; they worked this material up first. The depth data, collected by ship’s officers as additional duties superimposed on their regular duties of running the ship, therefore languished. The thousands of depth measurements compiled over several years sat uninterpreted and unmapped as raw data throughout the 1890s. Systematic English-language publication of this material did not appear until 1912, and much of the working up, cartographic and otherwise, was done by German scientists in the interim and made available to the publishers of Andree’s Atlas.
Plate from Andree’s Handatlas which first brought to Wegener’s attention the congruence of the coasts of South America and Africa. The projection is an “equal-area” map with two hemispheres, with the Atlantic cut out on the inner margins, bringing South America and Africa closer together. From Richard Andree and Albert Scobel, Andrees Allgemeiner Handatlas in 139 Haupt- und 161 Nebenkarten; nebst vollständigem alphabetischen Namensverzeichnis, 5th revised and expanded; Jubilee ed. (Bielefeld: Velhagen & Klassing, 1907). Photo courtesy of Botany Libraries, Harvard University.
These depth contours of the Atlantic continental margins of South America and Africa appear in the Atlas at depths of 200 meters (656 feet), 2,000 meters (6,562 feet), and 4,000 meters (13,123 feet), the last being contiguous with the floor of the abyssal ocean. Their outlines, as you may see in the map in the adjacent figure, are parallel and nearly identical in shape to the sea level margin of the continents: Africa has the same shape 200 meters, 2 kilometers (1.2 miles), and 4 kilometers (2.5 miles) below the surface of the ocean. This continuity of shape below the temporary position of current mean sea level meant to Wegener that these continental forms were not variable artifacts but structural features of Earth. It was this that he was determined to look into.
As determined as Wegener might have been to look into this matter of the parallelism of the coast of Africa and South America, his experience of the first week of January was, instead, the more or less customary tsunami of correspondence, proof correction, and composition which was his normal routine. The insight was not forgotten; Wegener did not forget plans for research. But he was an expert at postponing them in favor of still other plans and still other research.
Close-up of the Atlantic margins of South America and Africa in Andree’s Atlas, showing the depth contours at sea level, 200 meters, 2,000 meters, and 4,000 meters. The parallelism of these contours indicated to Wegener that the close match of the coastlines was not an artifact of sea level but a structural feature of the continents. He was especially struck by the fit of Cape Sao Roque (K.S. Roque) in Brazil and the Gulf of Guineas (Busen von Guinea) in Africa. From Andree, Allgemeine Handatlas. Photo courtesy of Botany Libraries, Harvard University.
It is thus with many supposed “eureka moments” recorded in the history of science. The intuition was there, the seed was planted, and Wegener’s mind was certainly ready for it. However, as a detailed examination of most such “eureka moments” reveals, there was a much longer process to follow in making something of this intuition. It is good to have the idea, but scientific success comes not just from having an idea but also from working out its detailed consequences in a convincing
manner.
So Wegener turned away from what would later make him famous, and for which he had yet accomplished nothing, to face the work at hand. On 6 January 1911 he wrote to Köppen with a variety of news. There was always the need to thank Köppen, for every letter from him arrived with a parcel of papers, books, references, and photographs. In this case Wegener found some heavy volumes and tornado photographs that he hoped to use in his thermodynamics book, and he was delighted. He could also report to Köppen, in response to a query, that he indeed had compared stellar spectra with the spectrum of the northern lights and had found no overlap. The question here was whether the light of the northern lights was actually a chemical consequence of the altitude and the gaseous composition of the atmosphere at that altitude or starlight refracted through Earth’s magnetic field.
What may have also diverted him from his plan to look into this matter of the continents was some unexpectedly depressing news from Professor Wiechert in Gottingen. He had written to inform Wegener that the planned polar station at Spitzbergen, to be occupied in parallel with the Filchner expedition to Antarctica, and of which Wegener and Stuchtey had planned to be part, was now not to happen. “Why, he doesn’t want to say in print.”3 This probably indicates that expedition and funding politics had killed it off. So he would not be able to go to Spitzbergen at the end of 1911, and he would not get a chance to measure the northern lights spectra to determine further the chemical composition of the atmosphere; he had urged that this research be undertaken in his papers on the chemical differentiation of the atmosphere, and he was more than willing to do it himself if he had the opportunity. Wiechert also told him that he had not yet decided whether to publish Wegener’s submission of his investigations into the outermost layers of the atmosphere. The problem was not, as before, that he could not find the manuscript among his papers; he had located it. But the submission was so long that it might be necessary to publish it as a “separate.”
The correspondence between Wegener and Köppen, with the turn of the year, began to take on a less formal tone. Köppen had become a trusted older friend and adviser, as well as an intellectual guide through the labyrinthine meteorological literature bearing on the thermodynamics of the atmosphere. Wegener was increasingly at ease with Köppen and felt free to unburden himself to the older man: “Have you seen [Arthur] Wagner’s note criticizing my work [on the vertical partition of the atmosphere]? You would think he would have a better use for his time, and he has shown that he can make better use of it. Unfortunately, I don’t have time to answer him, as I’m so busy with the details of my manuscript … my residence is now a post office and I am constantly overwhelmed with correspondence.”4
Part of this new informality, and the attendant increase in Köppen’s solicitude for Wegener, had to do not only with his admiration for the work of the young man but with something decidedly more personal. Since the Christmas holidays, Alfred and Else Köppen had been in frequent correspondence. She had written to thank him for Friis’s book containing his adventures in Greenland; he had replied. In early February she wrote to him to tell him that she had passed her teacher’s examination and was scheduled after 1 April to begin as a teacher at her old school. Köppen was at this time revising his climate map of the world, and Else, who had considerable skill in drafting, was helping him by drawing it. She wrote to Wegener about this. He replied to her on 4 March:
I am so happy that you’re helping your father with this necessarily tiring work. For me there is little agreeable to report. I think I’m going to drop dead. Wednesday I had to give a lecture on cloud formation and had no manuscript so I had to dictate on that day to a typist. But the heavy lifting is still to come: on the 13th I give a lecture here in Marburg on “piloting airships,” and one the 17th in Cologne on the “Danmark Expedition” with color photographs and special attention to the kite flying, on the 18th once more without the “special attention,” on the 20th in Kassel on “travels in a free balloon.” Will I live through this? It feels like that everything that could possibly happen has descended upon me all at once: the proofs of my articles for MZ and PZ, from Ambrosius Barth [the Thermodynamics] and from Copenhagen, then streaming sunshine, so we have to be outside a lot measuring with the albedo meter, and on Monday I hope “if there’s good weather” to make a short little flight … soon my brother will return, he should probably have already left Samoa. Where he is stuck only the gods know … my parents wrote me if I would please come home to them for Easter but I don’t think I’m going to be able after all to do that. With my own work I haven’t moved an inch but I shouldn’t complain to you so much … my thermodynamics is going well, the first 100 pages are at the printer and I hope to have those proofs soon. Now it’s happily already two o’clock in the morning so you will get this letter at the earliest on Monday. Thus, good night. With my heartiest greeting your Alfred Wegener.5
By the end of March Wegener was, in spite of his fears, still alive. It had been a wonderfully productive month. He and Stuchtey had collected enough measurements to finish their paper on the albedo of clouds and of Earth using their novel albedometer, and they had sent it off to publication.6 He had received a commission, with a sizable honorarium, to write a summary of recent advances in atmospheric physics for a new journal edited by the chemist Emil Abderhalden (1877–1950), Fortschritte der Naturwissenschaftlichen Forschung (Progress in natural scientific research). Abderhalden was one of the first to see the need for the kind of review-article journal that is quite common today, something like “Annual Review of Geophysics” or “Progress in Microbiology,” containing review articles by active researchers sketching out the main line of development of a field. Most of the readers of Abderhalden’s journal were medical doctors, and most of the topics were medical and chemical, but the editor was branching out. The new journal was, from its inception, very well received and widely read, and Nature reviewed the first annual volume (1910) with the following comment: “The plan of this new publication is to furnish summaries of recent results and select the departments of knowledge in which some degree of settlement and certainty has already been reached. This policy will avoid any risk of wasting time on raw speculations, and, under the able guidance of a man of Dr. Abderhalden’s experience and prodigious industry, the series promises to be useful and judiciously chosen.”7
This commission to write a long article (the finished version was seventy pages) on his area of research was very auspicious. He wrote to Köppen on 3 April about being unable to decide whether he should call it “Physik der Atmosphäre” or “Neue Forschungen auf dem Gebiete der atmosphärischen Physik,” but he knew what he would talk about: the new results in aerology in which he played a role, and the new results in the investigation of the outer reaches of the atmosphere, with which he was also vitally concerned. It would end up being, in many respects, a reduced version of his thermodynamics of the atmosphere, with the purely physical chapters left out, and without mathematical apparatus, but with all the conclusions of which he was so proud. It was an excellent opportunity to get his ideas before the public and to proclaim that a very large number of new researches in the area of atmospheric physics, at least the most important ones, were the work of Alfred Wegener.8 It would also be very nice to have his own particular and original view of the structure of the atmosphere characterized, in Nature’s terms, as one in which “certainty has already been reached.”9
The article for Abderhalden was due on 1 May, but there was more work to come. Wegener’s broad responsibilities for the scientific work of the Danmark Expedition included the aerology, the station meteorological observations, the magnetism, the atmospheric electricity, and the marine observations during the voyages to and from Greenland. These also included, as coauthor with his friend and comrade Johan Peter Koch, the glaciological observations of the expedition. There were not a lot of data to be processed for this last publication: photographs of the margins of the Inland Ice, the Randzone, with its discolored ice, laminar s
tructure, and complex folding and flow banding. Most of these results were from the ten-day reconnaissance in the spring of 1908 to Dronning Louise Land, that remarkable area of ice-free mountains, Inselbergen, surrounded by outwash gravels and glacial till, which Koch, Wegener, and the others had discovered some tens of kilometers into the Inland Ice cap. Wegener had loved the place and recorded in his diary how frustrated he had been that Koch had kept him constantly on the move and would not allow time for study, poking around, and rumination.
Wegener would never be free of the Danmark Expedition until all the material had been published, and he was pushing ahead as fast and as hard as he could in every way to make this happen; he pushed Lüdeling, he pushed Brand. Koch was determined, apparently, to help him out, by volunteering to come to Marburg for a few days, so that they might talk over the remaining problems with their scant (seventy-seven pages when published) manuscript on the glaciology of the expedition.10 Wegener was delighted. Other than his conversations with Richarz, or with Stuchtey and Take, he had no social network in Marburg, and it would be good to see his old friend.
In Nansen’s Footsteps
Koch arrived on 29 March and stayed until 2 April. He could not afford much travel time out of the country; only a captain in the Danish army, he was one of Denmark’s leading cartographers and was also poised to play a leading role in the construction of Denmark’s air force. Since time was short, it was fortunate that there was not much that the two men needed to do other than provide a bare description of where they had been and what they had seen. They had not really been prepared to carry out a systematic program of glaciological research. They had taken a few ice borings, but these were contextless and essentially meaningless. Yet the two men had much to talk about. How could they not? Those who share the experiences of the sort that they shared find a unique solace in the company of others who knew exactly where they had been, what it had cost, and how close to death they had been on many occasions.