et al.
FEUDING PARTIES
Alfred Lothar Wegener (1880–1930) – German meteorologist and astronomer, architect of continental drift theory
vs
Sir Harold Jeffreys (1891–1989) – geophysicist;
most of the rest of the geological world
DATE
1915–60s
CAUSE OF FEUD
The theory of continental drift
The story of Alfred Wegener and the theory of continental drift is often cited as a prime example of how theories that are beyond the pale can rapidly become accepted scientific dogma and of the way in which the real narrative of science (messy, contradictory and contentious) is quite different from the ‘classical’ picture of a serene progress from ignorance to enlightenment. In truth, the Wegener case is not a brilliant illustration of either of these, but it remains a popular and fascinating story.
The shrinking Earth
The most obvious evidence for the notion that the continents were once joined is the apparent fit between the coastlines of eastern South America and western Africa, which became apparent almost as soon as the first maps of the New World were produced. As early as 1596, Dutch map-maker Abraham Ortelius suggested that the Americas had once been joined to Europe and Africa, until they had been ‘torn away ... by earthquakes and floods’.
In 1881, pioneer geophysicist Osmond Fisher proposed a model of the Earth in which a crust of hard rock sat atop a fluid mantle, even suggesting that the ocean floor expanded through volcanic production of new rock, and that contraction of the continents gave rise to mountain ranges. This was a remarkably prescient prototype of modern plate tectonics theory, which went unheralded. Fisher was going against the grain of an Anglo–American tradition that emphasized the relative permanence of the oceans and continents. While in the German-speaking world the notion that the crust of the planet was mobile and the interior fluid had some currency, the mainstream hypothesis was that the Earth was cooling from an initial molten state (see page 17), and in the process contracting, so that its skin rumpled and creased, creating mountain ranges and oceanic basins.
Scientific adventurer
Onto this scene burst Alfred Wegener, an intrepid meteorologist and astronomer. Struck, like many, by the jigsaw-like fit of the South American and African coastlines, Wegener was intrigued when, in 1911, he came across a report outlining palaeontological connections between Brazil and Africa (such as fossils of the same species on both continents). Many other such connections between far-flung regions were known, but they were generally presumed to indicate the former existence of land bridges, now sunk beneath the oceans.
TIMELINE
Wegener claimed not to be aware of the ‘continental drift’ hypothesis of the American geographer F.B. Taylor, published in 1910, and in 1912 he came up with his own, similar theory. He fleshed out this theory in a 1915 book, Die Entstehung der Kontinente und Ozeane (The Origin of the Continents and Oceans), in which he laid out several strands of evidence for his theory of ‘Die Verschiebung der Kontinente’, properly translated as ‘continental displacement’.
Meteorological expedition in the Arctic. Wegener’s research background was in meteorology rather than geology. The vitriolic response to his geological theories was partly motivated by his outsider status.
Wegener, left, on one of his research trips in the Arctic.
Wegener’s theory
Wegener began by discussing flaws in the current contraction model: for instance, if the globe was uniformly contracting, why were the mountain ranges and ocean basins so unevenly distributed? He pointed to clear evidence that there were two distinct types of crustal rock – continental and oceanic – and tried to show how the strata underlying continental crust could deform under great pressure over long periods of time until it acted almost like a fluid (much as ice will). He collated evidence of similarities in rock types and strata on either side of the Atlantic, which suggested former contiguity, arguing: ‘It is just as if we were to refit the torn pieces of a newspaper by matching their edges and then check whether the lines of print run smoothly across.’
To this evidence he added the mounting evidence from the fossil record of species found on both sides of the Atlantic, such as Mesosaurus, a small reptile from the Permian era, and Glossopteris, a plant from the Permo-Carboniferous era. These distributions could not be explained by now-sunken land bridges, he pointed out, because such land bridges were an impossibility: continental granite was less dense than oceanic basalt, and therefore could not sink into the ocean floor. The prevailing belief in these land bridges was, he wrote, ‘a perfectly preposterous attitude’.
Wegener was particularly impressed by the presence at high latitudes of rock types and coal deposits that must have formed in the tropics. All this evidence suggested to him that the continents must once have been joined, and must, over time, have wandered across the face of the globe, like huge icebergs slowly forcing their way through thinner pack ice. He retraced their wanderings to a point where they were all joined together in a super-continent he termed Pangaea (from the Greek for ‘all land’). What force might conceivably drive such epic migrations he could not say for sure. Perhaps foolishly, however, he was willing to speculate that a Pohlfluct (‘flight from the Poles’) and some form of tidal friction might be jointly responsible.
‘If we are to believe Wegener’s hypothesis we must forget everything which has been learned in the last seventy years and start all over again.’
R.T. CHAMBERLAIN, 1926
The gathering storm
Right from the start, Wegener faced criticism for his bold attempt to cut across disciplines and forge a radical new theory. His father-in-law, who was a respected meteorologist, tried to dissuade him as early as 1911. Wegener defended himself: ‘I believe that you consider my primordial continent to be a figment of my imagination, but it is only a question of interpretation of observations ... Why should we delay in throwing the old concept overboard? Is this revolutionary? I don’t believe that the old ideas have more than a decade to live.’ His optimism was ill-founded.
Criticism began soon after publication and continued for decades. In 1922, Philip Lake dismissed him as ‘not seeking truth [but] advocating a cause ... blind to every fact and argument that tells against it.’ Lake savaged the attempt to reconstruct Pangaea by fitting together the coastlines of the continents: ‘It is easy to fit the pieces of a puzzle together if you distort their shape.’ In fact, the true fit is between the continental shelves, but these were not well mapped at this point. A year later, G.W. Lamplugh described Wegener’s theory as ‘vulnerable in almost every statement’, while R.D. Oldham wrote that ‘it was more than any man who valued his reputation for scientific sanity ought to venture on.’
Pangaea to present. A series of maps – showing equatorial and polar views – from Wegener’s book, The Origin of the Continents and Oceans,