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{{In creation}}
Alfred Wegener proposed "continental drift" theory in 1912 and developed it extensively for nearly twenty years. His book on the subject, "The Origin of Continents and Oceans", went through four editions and was the focus of an international controversy in his lifetime and for some years after his death. Wegener's basic idea was that many problems and puzzles of the earth's history could be solved if one supposed that the continents moved laterally rather than supposing that they remained fixed in place. Wegener worked over many years to show how such continental movements were plausible and how they worked, using evidence and results from geology, geodesy, geophysics, paleontology, climatology and paleogeography.
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Now that he was no longer considering a career in astronomy, he decided against some astronomical courses : "The Three-Body Problem", "The Temperature of the Sun", and "Solar Physics". Since he was in Bezold's meteorology working group, he had no reason to attend the Astrophysical Colloquium. He retained an active interest in the history of science and elected to complete the full historical survey of astronomy with "History of Modern Astronomy since Newton". A practical course on measurement of celestial angles by theodolite with Forster looked useful, and he signed up for that as well. With Bauschinger, he took up "Potential Theory with Applications to the Figure and Rotation of Heavenly Bodies" and its practical counterpart "Introduction to the Art of Calculation".
=== Dissertation ===
{{Cquote| ''Find the true longitude of Mars for September 20, 1477 at 6:01:36 am Mean Time Toledo.'' <br><br>
Decimal 1477.0 + 263 days, 6 hours, 1.6 minutes (1477.72). We draw from the table the Mean Motions IV and V ... ||| Alfred Wegener (1905) ''Die Alfonsinischen Tafeln''}}
The usual dissertation for Berlin astronomy students at this time was an orbital determination for asteroid or comet. These were the sorts of problems on which Bauschinger was expert. The second most common was some study of the motion of the Moon and planets, or observations of the Sun. Forster supervised these. Alfred's assigned topic, supervised jointly by Bauschinger and Forster was quite different.
Alfred was directed to undertake a historical and critical study of a set of astronomical tables, the Alfonsine Tables. Commissioned by Alfonso X "The Wise" of Castile in the 13th century, they were used for navigation and time reckoning. They allowed one to find the position of the Sun, Moon, and planets at any hour and minute. They were the tables of reference throughout Europe from about 1330 until Erasmus Reinhold's Prutenic Tables appeared in 1551.
The creation of a modernized edition of these tables had applications to a problem in astronomy in which both Bauschinger and Forster were keenly interested. About thirty years before, in 1870, the American astronomer Simon Newcomb had discovered that the set of tables he was using to predict the position of the Moon showed increasing deviations from the Moon's actual position. This was disturbing to Newcomb because the tables in question had been prepared by the German astronomer Peter Hansen, probably one of the greatest master of celestial mechanics since Laplace. To figure out what had gone wrong, Newcomb traveled to Europe to study even older tables of the Moon's motion. He found that the farther he worked back before 1750, the greater the discrepancy became. He conceived the notion, based on his confidence in Hansen, that the reason for the discrepancy had to be a variation in Earth's rate of rotation. Newcomb worked steadily on this problem until the end of his life, assembling astronomical records back to preclassical antiquity to try to determine the pattern of rotational variation.
These Alfonsine Tables were now rare books available only in great university libraries. They were written in a difficult form of Medieval Latin and couched in terms of the of the Ptolemaic (Earth-centered) solar system. Moreover, the numerical values in the planetary tables employed base 60 sexagesimal system rather than the decimal system both for angular measurement and for date and time reckoning.
Alfred began his work in September 1904, comparing the six existing principal Latin editions to eliminate printer's error. He then translated the text from Latin to German. Then, he converted the tables from sexagesimal to decimal values, a task involving about 9,000 calculations. That was the heart of the task, but there was a good deal more.
Alfred provided a correction for the difference between Toledo, Spain -- the 0° of longitude in the tables -- and Greenwich, England -- the 0° of longitude for modern astronomy. He uncovered a systematic sixteen-minute offset in the tables resulting from a discrepancy between the Alfonsine way of calculating the mean time of a transit and the modern method of doing so. Finally, he devised a formal to eliminate a correction in the tables meant to account for the precession of the equinoxes which employed a (nonexistent) celestial motion called a "trepidation", which the modern user must discount. He also drew up a concise glossary of Latin technical terms for which there were no German counterparts, since the concepts in question had vanished from astronomy before German had become a scientific language.
He had to provide extensive notes to give astronomical calculators the means to use them. The calculators in question were not machines, but observatory staff whose job it was to perform actual calculations. It required several explanations. The tables for the Sun are used differently than the tables for the Moon. Meanwhile, there are separate sets of tables for each of the planets. Latitudes are calculated in a way quite different from the calculation of longitude and distance. These require separate tables and figures showing the geometry of the relationships.
== Lindenberg Observatory ==
Royal Prussian Aeronautical Observatory conducted research on aerology, the investigation of the three-dimensional structure of the atmosphere by sending up (to altitudes of several kilometers) meteorological recording instruments via "captive balloons" and kites, tethered to the ground by steel cables. Aerologists also sent aloft to much greater altitudes "free balloons", designed to parachute back to earth with their instrument packages. Finally, the scientists went aloft themselves in manned balloons capable of carrying several investigators and a large and varied array of sensing and recording devices. The observatory studied several aspects of the atmosphere in the first few kilometers above the surface : atmospheric layering, winds, temperature, humidity, vertical atmospheric motions, cosmic radiation, polarization of light, atmospheric electricity, atmospheric particulates, cloud types, and photographic documentation of atmospheric phenomena of all kinds. The funding available for this new scientific station were a result of direct royal patronage. Kaiser Wilhelm II aspired to be a patron of science and technology, on the pattern of his friend Prince Albert of Monaco, a long patron of oceanography, meteorology, and marine biology.
On 1 January 1905, Alfred and his brother Kurt, joined the scientific staff as a technical assistant of the Royal Prussian Aeronautical Observatory at Lindenberg. As the technical assistants, they were to work directly with the observer, Arthur Berson, and with the director of the station, Aßmann, in conducting flights of these experimental aircraft and experimental instruments.
=== Ballooning ===
Berlin flattered itself a world center for aviation under the lavish patronage of the kaiser and the army. Kurt and Alfred had, many times in their childhood, looked up to see the great balloons soaring over the city. The opportunity to go ballooning had been from the beginning one of the main attractions that brought Alfred and Kurt to Lindenberg.
Berson and Alfred got an early start on 11 May 1905, lifting off just after 8.30 am, from the aerodrome at Reinickendorf in Berlin in a hydrogen-filled balloon. Berson was interested in measuring the electrical conductivity of the atmosphere and its change with altitude. Alfred's job was to be the navigator and determine their geographic position at regular intervals, as well as keeping the journal and handling the ballast.
On this flight, Alfred was able to find their position with an error of 10 - 15 kilometers. At the time of these first attempts by Alfred, an aeronaut could give only an intuitive guess at his position by observing the direction of flight, airspeed and by recognizing landmarks below. Moving laterally at several meters a second, changing altitude almost constantly, knowing one altitude by reference to atmospheric pressure alone, put much uncertainty into a measurement.
Alfred and Berson flew for ten hours, got up over 5,500 meters and made a controlled landing in Gleiwitz, East Prussia.
=== Ballooning (2) ===
Alfred's second balloon flight took place on 30 August 1905. The plan was to observe a partial eclipse of the Sun and, from the faintly visible stars, provide an opportunity for Alfred to practice astronomical position finding while aloft.
The balloon's pilot was Hans Gerdien, an expert on electrical phenomena in the atmosphere. The two aeronauts cast off at 10.30 am and rose rapidly to an altitude of 1,000 meters, where they encountered a cloud layer that drenched their balloon, causing it to descend precipitously to about 500 meters and forcing them to drop some ballast. They then rose again rapidly to between 1,300 and 1,400 meters.
{{Cquote | ''There we floated, between two cloud layers and we could again see the sun. So that at noon, we were able to measure its altitude and investigate the eclipse as it progressed. The truly remarkable reduction of the sun's brightness was just right for our mission, but it also made a strong emotional impression''||| Alfred Wegener in ''"Astronomische Ortsbestimmungen in Luftballon"''}}
When they finally dumped enough ballast to rise above the overcast layer, the vista was stunning : a sea of white clouds with dark plumes convecting rapidly upward. They could hear thunder from every direction. Eventually, a huge thunderhead, black as iron, built up near them.
Gerdien opened the valve on the gas cylinder to inflate the balloon further. A little after 3:00 pm, they reached an altitude of just over 6 kilometers. It was cold, almost -24°C. As soon as the gas in the cylinder was exhausted, the balloon began to sink.
The balloon descended into the cloud layer. Soaked with water once again, they began to fall rapidly. Gerdien jettisoned two sacks of ballast, but this did not entirely control the descent. The winds near the surface were brisk, about 15 meters per second. The ballon was moving very fast across the plain below. They knew they were in for a rough landing, as the means of stopping the balloon consisted entirely in tossing the anchor overboard and waiting for it to catch something and jerk the balloon basket to a halt.
Seconds after tossing the anchor, Alfred felt the basket tip and realized that the anchor must have caught.
Suddenly, there was a tearing sound. The anchor rope had torn completely away and the balloon picked up speed again. Gerdien, in this critical moment, pulled the ripcord and deflated the balloon. Then came the impact.
{{Cquote|''I saw, in a flash, everything go topsy-turvy. I realized that I was being dragged along the ground, then I felt sharp pull on my body, and that my left foot was tangled. Then my left boot pulled off and I was free. My stiff collar dug itself into the earth like a plow and my head was covered with dirt ''}}
Alfred got unsteadily to his feet and went looking for his boot. He was delighted to find both it and Gerdien, who had a worse landing. Gerdien had hit his knee very hard and wrenched his left shoulder. Searching the area around, Alfred managed to find his house keys and eventually his hat as well.
Limping to a nearby farmstead, they learned that they had crashed near the village of Novy Miastov, almost 500 kilometers to the east of their home base, inside the borders of Russian Poland. They spent the night quartered in the village school.
It took three days to get out of Poland. They packed up the balloon after their sleepless night in the school building and it was dark before they set out under escort for the nearest Russian military outpost. The road was terrible. Their cart driver, unable to see anything in the gloom, hit a deep rut and pitched them into a roadside pond. Drenched, muddy and sore, they eventually found their instruments and their day packs in the deepest part of the pond.
At the Russian fort they were finally conducted to a room and allowed to sleep. On the next day, they were examined by the post surgeon. The surgeon took them to lunch and that night the colonel threw a full Russian banquet in their honor. On the following day, transit visas arrived from Warsaw. They were allowed to return to Germany.
=== Polar expedition ===
Toward the end of October 1905, shortly before his 25th day, Alfred read a newspaper feature story about a Danish polar explorer, Ludwig Mylius-Erichsen, who was preparing to mount a two year expedition to the far northeast of Greenland, to map the last uncharted section of Greenland's coast and carry out an extensive scientific program.
The account given was of a great public meeting in the Copenhagen Concert Hall on 17 October 1905. On the podium, in addition to famous naval officers who had explored Greenland, were representatives from parliament, the university, scientific societies, the press, as well as even Crown Prince Frederick -- soon to be King Frederick VIII. Mylius-Erichsen, just back from a two-year expedition to the west coast of Greenland, spoke feelingly about the importance of the opportunity -- almost the last chance offered to any man or nation to fill in the final blanks on the map of Earth.
A part of Mylius-Erichsen expedition plan, as described in the press, included the possibility of a four-man team crossing the ice cap well north of Nansen's route, from east coast to the west. On his birthday, 1 November 1905, Alfred sat down to compose a letter of application. Not knowing how to contact Mylius-Erichsen, he wrote instead to Professor Adam Paulsen, Danish meteorologist and director of the Danish Meteorological Institute, who had considerable experience in Greenland, dating back to the International Polar Year of 1882 - 1883.
Paulsen did not respond to Wegener, but on 3 November he forwarded the letter to Mylius-Erichsen with a brief note, saying that he had received a letter from Dr. Alfred Wegener who hoped to take part in the expedition to Greenland. Mylius-Erichsen was, at the time of Alfred's letter, in a white heat of fund-raising, following his public appeal. Jens Christensen, a leading officer in the Danish government, had promised that if Mylius-Erichsen could raise half the money necessary to fund the expedition, Christensen would see that parliament provided the other half. Mylius-Erichsen had to come up with 130,000 kroner in a very short space of time. It is hardly surprising that Alfred's first letter got no response.
Alfred waited two weeks. When no response was forthcoming, he wrote again, this time to Mylius-Erichsen directly. This time he assured Mylius-Erichsen that he would certainly provide a full scientific kit for atmospheric research, but again emphasizing that he would come on the expedition whether or not there was any need for such research. He wanted to go, and he was willing to suspend his career to do so. This letter apparently brought no response either.
He was not to be deterred. He wrote to Mylius-Erichsen again around 26 November. Alfred explained to Mylius-Erichsen that he was in a bind. If he were to go on the expedition, he would have to give up his place at Lindenberg on 15 April 1906, which entailed giving notice by 1 January 1906. Without such notice, he ran the risk of not being released to join the expedition, even if chosen. "Under these circumstances," he wrote, "even a provisional and non-binding response would be of great value to me."
Still hearing nothing from Mylius-Erichsen, Alfred could stand it no longer. He obtained a brief leave to travel to Copenhagen, arrived on Sunday, 17 December, and checked into the Hotel Victoria. He called at Mylius-Erichsen's home the next day, only to be told that Mylius-Erichsen was in Norway until the following Friday.
Not sure how to proceed, he then called on Paulsen at the Meteorological Institute. Paulsen's news was bitter. Mylius-Erichsen was billing the expedition as an all-Danish affair, in order to assure a good response to the public appeal for funds and in the hope of arousing patriotic sentiment and royal patronage. No non-Danes could currently be considered.
That was that. Alfred returned to Lindenberg and went back to work.
=== Clear air turbulence ===
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.
The problem Alfred pursued concerned a phenomenon that we are all familiar from airplane travel : the clear air turbulence. "Within the atmosphere," Alfred explained, "when a warmer and therefore lighter layer of air moves across a colder denser layer, waves must form." 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. 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 the [[Stratosphere|tropopause]], the boundary between warm layers above and cold layers below. The greater the temperature and velocity differences between the two air layers, the greater the likelihood of mixing and the formation of waves.
Alfred plotted the results of his 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 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.
However, the observational difficulties were formidable. By the end of February, he had only been able to find three useful records out of nearly fifty flights. Moreover, the agreement between theory and observation was terrible, and error of 25 - 30 percent. 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.
They days began to blend into one another. Kurt and Alfred already 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. Meanwhile, Alfred was seriously considering making a move at the same time.
=== Polar expedition (2) ===
On 23 March 1906, Alfred was in the headquarters building at Lindenberg, reading the Tägliche Rundschau, a major daily newspaper from Berlin. His eye fell on a telegraphic notice about the Mylius-Erichsen expedition. Christensen had made good on his promise. It announced that Mylius-Erichsen had collected sufficient sponsor and the Danish government had indeed decided to match the funds. 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. However, the negotiations with these two scholars have not been concluded."
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. He indicated that he badly needed an immediate response, adding, "I'm in the middle of negotiating the terms of a new positions, negotiations that I'll have to break off. So I'd be very obliged if you could tell me as soon as possible what you know about this." He apologized to Paulsen for bothering him again, begging him to take it as an expression of his deep interest in the expedition.
The funds had been vetoed on by parliament on 22 March and announced on the next day. On the 24th, the expedition's governing committee officially took up its duties, setting a departure date of 24 June 1906, a scant ninety days away. Mylius-Erichsen decided that he could get along with a geology student and settled on young Hakon Jarner, a Danish student at the Polytechnic Institut. Thus no need to bring the Russian geologist (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. Alfred 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 to Copenhagen, arriving on Mylius-Erichsen's doorstep. With money in hand and little time to waste, Mylius-Erichsen was now prepared to take Alfred's participation seriously. When they finally met face to face, he made a decision on the spot and formally offered Alfred the job of physicist and meteorlogist 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, since the expedition would leave in less than three months.
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 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.
On 28 March 1906, he wrote a letter to Wladimir Köppen, head of the Meteorological Department of the German Marine Observatory at Hamburg, asking to buy meteorological kites. Aßmann immediately gave his blessing and promised twenty kites and three varnished-cotton captive balloons, at all cost. In a response to a letter sent with Berson's endorsement, de Bort not only agreed to sell Wegener two of his meteorographs at cost, but also made him a present of two additional meteorographs. Hans Gerdien agreed to loan him instruments for measuring atmospheric electricity, with instructions for their use.
=== Ballooning (3) ===
Alfred was exhilarated to put together his part of the expedition, but he still had a burden of work at Lindenberg. He and Kurt had been selected by Aßmann and Berson to represent Lindenberg and the German Empire in the Gordon Bennett International Balloon Competition, scheduled for 4 April 1906. Teams of aeronauts all over Europe were to compete for time, altitude and distance. For the Lindenberg team, they were to exploit their night flight to practice navigation by star sightings. Kurt Wegener, with five previous flight, would direct the flight. Alfred would serve as navigator, instrument monitor and ballast heaver.
On 3 April, Alfred and Kurt traveled to Berlin to prepare for the balloon flight. They carried in their luggage the balloon's meteorological instrument package and Alfred's own balloon theodolite for night navigation, as well as camera and glass plates.
They arrived at Reinickendorf early on the next morning to discover that their balloon had sprung a leak while filling. The other available balloon owned by the observatory was too small to carry the load, so hurried arrangements were made to borrow one of the army's 1,200 cubic-meter military balloons.
The substitute military balloon, a mass-produced, tested, completely unexceptional design, was unpacked overnight. In the early dawn hours of 5 April, filled rapidly with 1,200 cubic meters of hydrogen. The instruments were lifted on board and secured to the basket rim and to the trailing cable. The meteorograph had to be suspended away from the balloon basket if it was to be read properly. The ballast sacks, 38 in all, were slip-knotted to the inside of the ballon basket, with their pull toggles at the level of the basket rail. The provision sack for the flight, containing 0.9 kilograms of chocolate, four smoked pork chops, 2 liters of seltzer in rechargeable siphon bottles and two oranges, was gently stowed in a corner. Setting their watches by the station chronometer and checking the engagement of the catch on the meteorograph recording drum, they jumped aboard, attired in summer suits and their fedoras, waited for their scheduled liftoff.
At 9.00 am, the balloon took off rapidly and flew northwest. It headed directly for Brandenburg and flew right over the Ruppiner See, just a few kilometers from die Hütte. From there it proceeded on to Wittstock, Richard Wegener's birthplace and the destination of many childhood visits. Kurt and Alfred were able to photograph it from the air at an altitude of 500 meters. From there, still heading northwest, the balloon passed over the Plauer See (scene of many boyhood sailing adventures) then on to the Baltic, and then headed straight for Denmark, crossing into Jylland at about dark.
As the wind dropped, it began to drift east, over the Kattegat (between Denmark and Sweden) and to gain altitude, passing 1,000 meters. With the coming of night and the increase of altitude, the air turned sharply colder. It was only then that Kurt and Alfred realized that they had left their overcoats in Berlin. The air temperature fell below freezing and soon shivering made sleep impossible. They moved about to keep warm as much as they could.
By morning they were both nearly frozen. In the dry air they had risen to 2,500 meters and were drifting slowly back south in slack wind. Not until noon on 6 July did the wind pick up again. Then the balloon began to rise and fall in the convecting air. Down to 300 m, up to 1,000 m, down again. They began to drift away to the west. At about 8.00 pm, they passed back over the Danish coast. They had now been in the air for 35 hours and they had been up most of the night previous to the flight, while the balloon was being filled. They were dehydrated, very cold and very tired. It looked that evening as if the balloon was going to head directly west across Jylland to the North Sea. They knew that once past that coast, it was 500 kilometers of open ocean to England. Consequently, they began to pack the instruments and prepared to set down.
Just then, however, the balloon changed course and began to gain altitude and fly south toward Hamburg. In continued on this course through the night, traveling at very low altitudes, sometimes sinking to 100 m. This was hair-raising, as it put them repeatedly within a few seconds of crashing to the ground. At least, it was warmer at the lower altitude, for they were weakening badly and beginning to cramp in their arms and legs from dehydration and almost 40 hours of bracing against the swaying of the basket.
As dawn broke, they passed over Kassel (between Hannover and Frankfurt). They were by then shivering uncontrollably, having been at −16°C for three hours or more. They were out of food and water.
They decided to make a final push for altitude before ending the flight. Their target altitude was above 5,000 meters. However, this time cold and hunger were stronger than will. They were so weakened that when they tried to drop ballast, neither of them could push a sack over the rim of the balloon basket. They were done. They drifted to a landing near Aschaffenburg, east of Frankfurt.
They sent the following telegram to Aßmann : "Today at 1-30 landed very smoothly at Laufach near Aschaffenburg after 52 hour flight over Aalborg on Jylland around 3000 m minus 16 degrees". They had stayed aloft for fifty two and a half hours, having broken the world record for time aloft by seventeen hours.
Their flight was a major event in the early history of aeronautics. It was treated as such by newspapers around the world. Everyone involved got a share of the rewards. Aßmann was delighted, as was his principal patron, Kaiser Wilhelm. The German army was pleased that their balloon had accomplished the feat. It gave Kurt a remendous boost in landing the job he desired at Frankfurt. It gave Alfred something priceless at the moment : widespread name recognition while he was writing to numerous officials who had never heard of him, asking them for large and expensive favors. It gave him a distinctive achievement as an explorer before he had even gone anywhere.
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