I have David Bressan to thank for learning that Alfred Wegener first spoke publicly about his radical theory of "continental displacement" on this day in 1912, in a talk presented in Frankfurt, Germany. Today students are taught that Wegener was the father of plate tectonics. He was both less than and more than that.
Wegener's theory claimed to solve a puzzle that geologists had long pondered: the clear ties between the New and Old World across the Atlantic Ocean, and the eerie parallel coastlines of the Atlantic. Certain mountain ranges and various ancient fossil species were distributed on both sides of that sea exactly as if it had not been there in the past. The consensus of the day was that the seabed must have once been high and then fallen to make that happen. This followed from the accepted view that Earth was a cooling, shrinking planet of rigid rock and that the forces resulting from that shrinkage made its surface buckle up and down over geologic history, turning continents to ocean basins and vice versa.
Wegener's bold contribution was to topple the two pillars of that worldview on the basis of new knowledge. First, Earth could not be cooling as previously thought because radioactivity (discovered barely a dozen years before) provided it with eternal heat. Thus there was no need for a shrinking, wrinkled planet. Second, continents and ocean floors were made of quite different rocks—light granite and heavy basalt, respectively—sitting permanently at their different elevations as recently established by the principles of isostasy. Thus there was no way they could ever exchange places (destroying James Hutton's long-standing vision of the geological cycle). What this meant for the Atlantic was that it must have formed by the splitting open of a former supercontinent, which he named Pangaea, and somehow spread apart from those times to today.
This notion was merely the seed of what would begin to emerge 50 years later as plate tectonics, and the result has only a superficial resemblance to Wegener's Pangaean vision. Indeed, the papers of the 1960s on plate tectonics are deeply different from today's understanding. From today's vantage point, the greatest thinkers of the 1960s can be seen fumbling through false starts and blind alleys, and we can only ponder the extent of ignorance that future readers will see in ourselves.
Wegener's core contribution was to push open a dialogue around the concept that Earth's face is not fixed, but mobile. Until his talk, only vertical motion was considered permissible in geology. Afterward, everything on the map could be rearranged if the evidence supported it. Many geologists regarded mobilism as chaos, and the popular name "continental drift" was their way of making light of Wegenerian tectonics. But he had the right idea, and Pangaea truly put his name on the map.
Further reading:
About Plate Tectonics
Five Myths of Plate Tectonics
James Hutton's Creationist Geology
More History of Geology
Great Geological Controversies by Anthony Hallam (Oxford, 1983)
Comments
Appropriate to note the 100 year anniversary of Wegener’s talk! Geological science certainly has come a long way in a mere 100 years.
Absent from the article here is a frank discussion of the sceintific establishment’s derision and furry which greeted Wegeners’s theory.
Biases based on “common understandings and consensus” oftens hampers research into potential hypothesis. Similar examples of this pernicious obstacle can be found in the work of Shoemaker (impact craters do form on earth!), Alvarez (K/T boundary as impact driven) and Marshall (ulcers are bacterially generated).
The NFS, recognizing this situation, recently funded a pool of research monies to be used for interdiciplinary research into “unorthodox” subjects. One wonders if they would have funded Wegener….
The fact that Wegener was a meteorologist, I’m sure, had much to do with some of the disdain showed when he presented his theory and the dismissal of his theory of continental drift.
Wegener’s theory got a warm reception in many places, notably in Germany and the southern hemisphere countries. Americans in particular turned against it, in my interpretation, because they were having a different conversation at the time. The situation was static for a long time because more data was necessary, and that arrived after World War II.
Wegener himself was dismayed at some of the opposition, but it didn’t destroy or even harm his career. Parts of his theory were easily dimissed because they were obviously wrong, but he was never a lone crank shunned by his peers. His meteorologist’s expertise in fluid dynamics served him well in making a novel argument that his fellow scientists always found stimulating.
I’d like to comment on the “Continental Drift” expression. As I understand, it was not Wegener”s.
Anyway, I believe it was not wrong nor sarcastic. It was only and very correctly translating the limited knowledge of that time. Indeed, what Wegener identified and postulated was the probable displacement of some continents. But he knew nothing of oceans and of the forces that could move those continents about !