Supercontinent: Ten Billion Years in the Life of Our Planet (15 page)

Geologists in the USA, however, were facing other problems. First, there was the immensity of the continent – still largely unexplored – to be documented. Second, they remained deeply suspicious of European ‘authority’. They knew that evidence about the way the Earth worked that derived from
their
continent should carry no less weight than that from any other part of the globe. Moreover, they preserved a revolutionary dislike of pronouncements from on high. Somehow their science also had to declare independence. They had to find a new way of doing science, a democratic method that eschewed discredited Old World ways.

What they hit on, first of all, was induction. But realizing that this cure could end up being worse than the disease, and recognizing that the collection of data alone was not what science was about, America strove to develop a third way of its own, a method called multiple working hypotheses.

Under this method the scientist, like a good parent dividing his attention equally and impartially among his offspring, first presented his factual findings in as ‘theory-free’ a way as possible, and then
discussed
the observations in the light of as many different explanations as seemed reasonable. If in due course a leading theory or two emerged, these must be further refined by the subsequent collection of more data. From the end of the nineteenth century this approach quickly became the accepted, democratic, American way of science.

Into the middle of this new, republican method of doing science, expressly devised to counterbalance that outmoded, system-based theorizing of the Old World, dropped Wegener’s
On the Origin of Continents and Oceans.

Even today, with our modern obsession with ‘directed’ research, and when a scientist applying for research money won’t stand a chance of getting any unless he or she appears to be testing some grand
hypothesis
, Wegener’s book makes strange reading. But to Americans in the mid-1920s, which was when J. G. A. Skerl’s translation came out there, it read more like an affront to decent society.

We have already met Skerl, the man who should strictly be credited with introducing the English-speaking world to the word ‘Pangaea’. It is fair to say that his translation must share some of the blame for the revulsion that greeted Wegener’s book in the USA. From its
opening
paragraphs, everything that was upright, noble and distinctive
about American-style scientific method was, it seemed, being given a deliberate and blatant slap in the face.

The ideology behind American science was that it had no ideology. It built on the British model of facts first, interpretation later (if at all); but then went further. Science had to be democratic through and through. The multiple working hypothesis method enshrined these egalitarian motives in the way scientists did their everyday work. America prided itself on its pragmatic, no-nonsense approach, and on hard work.

Wegener’s book, by contrast, seemed to hark back to ‘the bad old days’, as they would have seemed, especially to American readers.

‘The first notion of the displacement of continents came to me in 1910 when, on studying a map of the world, I was impressed by the congruency of both sides of the Atlantic coasts,’ Wegener writes in his first chapter. He goes on: ‘This induced me to undertake a hasty analysis of the results of research … whereby such important
confirmations
were yielded that I was convinced of the fundamental correctness of my idea.’ In the English version of the fourth edition the words ‘hasty analysis’ are replaced by the less pejorative ‘cursory examination’ but the effect was the same.

Wegener in full flight often reads a little like the letter of a madman: an obsessive with no education in the field, who suddenly undergoes a Damascene conversion that sets him off on a selective spree looking for confirmations of his Big Idea and rejecting anything else. After this strident and frank opening, which could hardly have been better calculated to annoy Americans, there is the small matter of the over-use of the sensitive word ‘proof’. Skerl used ‘prove’ and ‘proof’ indiscriminately to translate gentler German originals, which might have been better rendered as ‘demonstrate’ or ‘evidence’. Wegener’s apparent dogmatism, enhanced by Skerl, gave the
impression
of an inexperienced, auto-intoxicated ‘armchair’ scientist with an
idée fixe.
Other ‘working hypotheses’ were not given a fair and equal chance.

Wegener’s book, in other words, was a polemic. He knew he was right. And what is more, when the criticisms began to rain down upon him, instead of meeting them halfway in an attempt to win his
opponents
over, Wegener merely became more and more adamant. In return, the trenchancy of his prose excused (and even encouraged) the brusquest of dismissals.

As the eminent scholar Mott Greene has pointed out, much is made today of the fact that Wegener was not a ‘proper’ geophysicist and was therefore shunned as an interloper. This ‘fact’ arises, I believe, because quite a lot of the mud that was slung at him by his near
contemporaries
still sticks. The same goes, as we shall see, for the assertion by the same opponents that there was ‘no plausible
mechanism
’ for drift. Wegener’s opponents were not just vehement: many were implacable.

Wegener was, in fact, no less a geophysicist than any of his
contemporaries
, he just happened to have written a book about the physics of the atmosphere and to hold a post in the only part of
geophysics
, meteorology, that had any money in it. Eventually he did move on to hold a chair in Graz, Austria, whose title had the word ‘geophysics’ in it. His writings, published in proper geophysical
journals
, show that he was fully conversant with all the relevant material, and his ideas were discussed, albeit rejected, by geophysicists
everywhere
. They could not ignore him. As Greene has written, if all this ‘does not identify Alfred Wegener as a geophysicist then nothing can and we can all retire to bedlam’.

Cultural differences also play their part here. If the meaning of the word ‘science’ can be so completely different between the Anglo-Saxon world and everywhere else (where it means ‘organized knowledge’ about anything, including literature, for example), there
is no hope of attaining worldwide agreement on the meaning of ‘
geophysics
’. In the 1920s the understanding in most languages of the term ‘geophysics’ as the physics of the ‘solid’ Earth had not yet come about, and it still hasn’t in Russian. Indeed, in that language the term ‘geophysics’ still is understood to embrace all Earth sciences.

Cultural incongruities dogged Wegener. His PR skills were not good. His method of doing science was out of favour. The Great War had ended almost a decade before, but the mid-1920s were still not a good time to be German. Wegener himself also came with
brandname
difficulties. As the eminent historian of science Naomi Oreskes has pointed out in her brilliant and comprehensive textbook
The Rejection of Continental Drift,
to his geological readers the name Wegener sounded ‘eerily similar’ to the name of his eighteenth-
century
compatriot Werner.

Abraham Gottlob Werner (1750–1817) was perhaps the archetypal grand theorist of an old school, and at that time one of the most blackened historical figures in the Anglo-Saxon panoply of scientific bad guys. He was a vivid example of European system-building folly: the proponent of a discredited
Weltall
theory who, being already slain, was only too readily re-slain by subsequent generations. He was, in fact, still as unfashionable as only the most recently fashionable can be. More subliminally yet, the name ‘Wegener’ even seemed to echo another megalomaniac, world-building German Romantic, Richard Wagner.

Perhaps the final straw was the fact that Wegener’s book had been written by a man who had gained the leisure to flesh out its ideas while recovering from wounds sustained during his country’s recent assault upon the free, democratic world. In 1914 Wegener was drafted, and was shot in the arm during the assault on Belgium. Two weeks after his return to active service, he was shot again, this time in the neck, and his days of active duty were over. The fact that this
objectionable theory had come to maturity in the mind of a man invalided from the hordes of the Boche was tactlessly given away in the author’s Introduction to the third and fourth editions. Drift seemed to pose as much a Teutonic threat as a tectonic one, with Wegener being described in print with such choice words as ‘
forgetful
’, ‘selective’, ‘unscientific’ and even ‘deranged’.

In Britain things were less heated. At the British Association
meeting
in Hull in 1923, British geologists had met to consider the drift idea. According to a report of the ‘lively but inconclusive’ meeting printed in
Nature
, the main common point of opposition occurred over Wegener’s idea that Pangaea could have broken up and the Atlantic opened during the Quaternary, the most recent geological period. Nobody was very sure at that time when, in years, the Quaternary had begun (actually about 1.6 million years ago) but, while they might have been prepared to concede that continents moved, they didn’t think it likely that they moved
that
much.

But while British geologists were arguing over the speed of the process, the basic concept did not seem to give those present much trouble. It helped that many of them had seen the African and South American rocks, but there was neither philosophical outrage nor any feeling at all that public decency had been affronted.

But there was another problem facing Wegener in the USA that did not affect his Hull audience. British geologists thought of isostasy in terms of the Airy model, with its mountain roots, that presupposed that rocks not only could flow but did. This was not the prevailing view in America. There a different model held sway.

After a seventy-three-second flight, at 11.39am on 28 January 1986, Mission 51L, the Shuttle programme’s oldest vehicle,
Challenger
, and
its seven-strong crew, were blown to oblivion in the Florida sky. The brilliant physicist Richard Feynman quickly and intuitively hit on the immediate cause. Standing on the launch pad in freezing weather had reduced the springiness of rubber O-ring seals between the sections of
Challenger’s
solid rocket boosters, causing them to fail under pressure during lift-off. In a press conference Feynman demonstrated this simple idea using a section of O-ring, a beaker of iced water and a simple clamp.

But that engineering failure was only the immediate cause. Subsequent investigations exposed many quality-control
shortcomings
at NASA, notably a tendency to tweak the safety envelope rather than the engineering, so that systems could be certified ‘safe’ more quickly and so allow NASA to meet its tight launch schedule, dictated largely by the need to put secret defence-related satellites in orbit. In his appendix to the Rogers Commission report, Feynman reserved his most withering criticism for this. NASA, he said, had made the
fundamental
scientific mistake of confusing their models with reality. ‘Nature,’ Feynman wrote, ‘cannot be fooled.’

Models encapsulate our view of the world according to scientific principles and hypotheses, though, like supercontinents, even those that really did once exist, they are no more than imaginary
constructs
. Models are maps of reality, and like all maps, they have errors and it’s never too long before someone finds something that was missed.

Nevertheless, it is all too easy for scientists to forget this and start thinking that model and reality are the same. As we have seen, in Britain the accepted model of isostasy – the theory that explains why mountains stand high and oceans stand low – was based primarily on the Airy model. This envisaged mountains as the tops of great rocky icebergs with deep ‘roots’, ‘floating’ in the Earth’s mantle. But the other explanation, put forward by Archdeacon Pratt, supposed
instead that mountains stood high because they were less dense and had no ‘roots’ reaching deep into the Earth. This idea, though not entirely mistaken, is less in accord with the true internal geometry of the planet than Airy’s. However, Pratt’s model does have one big advantage to mapmakers: it makes the sums easier.

If you belonged to a hard-pressed survey department in the early twentieth century, desperately churning out accurately triangulated maps of an emerging nation with a booming economy, you also had to correct thousands upon thousands of survey measurements for the effects of local gravity variations. And because nobody had yet invented the computer, this was all done manually, by armies of
careful
ladies with pencils. The big advantage of the Pratt model is that it makes these laborious calculations much easier. Easier means quicker, and time is money.

But it appears that the sober and practical US Coast and Geodetic Survey had become so attached to their convenient
calculating
strategy that some of them actually came to believe it was true, and none more so than the chief geodesist, William Bowie (1872–1940).

It is often said that the Airy model, with its implicit presumption that rock must flow over long periods of time, actually demands that continents can move. The Pratt model, on the other hand, carries the reverse implication. If you choose to believe it, then the idea of
laterally
sliding continents becomes worse than unnecessary: it becomes inconceivable.

In Pratt’s model the base of the ‘crust’ is envisaged as a smooth, uniform surface sitting at the same depth everywhere. Mountains stick up above the general surface level to the extent that their rocks are less dense; the higher the mountains, the less dense the
underlying
rocks. But lateral motions of the crust would even out these density differences in time, and although the Earth is very old, we still
have mountains. To a Pratt believer, therefore, drift seemed to be impossible. The influential Bowie had glimpsed an elegant model and taken her for Mother Nature: just because the maths was simpler.