Introduction
Alfred Wegener is remembered above all for what he called the theory of continental displacements — the idea now familiar to everyone as 'continental drift' — and this book examines his life and scientific work. He first advanced the theory in 1912 and spent close to two decades elaborating it. On the Drift of the Continents, the volume in which he set it out, ran to three editions and became the centre of a controversy that crossed national borders both in his lifetime and for many years after his death.
At its core, his proposal held that a great many puzzles in the Earth's past would fall into place once the continents were treated as bodies that drifted sideways over time, instead of as landmasses locked permanently in one position. Drawing on findings from a wide array of disciplines — among them geology, geophysics, paleontology and climatology — he set out at length why such wandering was credible and how it might operate. That single notion, that the continents are in motion, now underpins the framework on which the modern Earth sciences depend, namely plate tectonics. The relationship is much like the one between present-day evolutionary theory and the account of biological evolution that Charles Darwin put forward in the 1850s: plate tectonics diverges from Wegener's original scheme in numerous ways, and yet it descends directly from his theory of continental drift, just as today's evolutionary thinking descends from Darwin's theory of natural selection.
What first drew me to Wegener, as I began writing about his life and work, was a striking contradiction: the man who conceived the theory of continental drift was no geologist at all. His training had been in astronomy, and the career he built afterwards lay in atmospheric physics. At the point when he introduced his theory of continental displacements in 1912, he held a lectureship in physics and astronomy at a university in central Germany. He was hardly an obscure figure, though. Back in 1906 he and his brother Emil had stayed aloft in a hot-air balloon for 48 hours, setting a world record; and between 1906 and 1908 he took part in a widely reported and exceptionally perilous expedition to the Spitsbergen coast. Among a small circle of German meteorologists and atmospheric physicists he had additionally made his name as the author of a clutch of notable scientific papers and of a textbook, The Physics of the Upper Air (1911).
However significant his continental-drift research has proved to be, for Wegener himself it remained something of a sideline to his real preoccupations — atmospheric physics, geophysics and paleoclimatology. For that reason I have taken considerable trouble to set that research within the wider frame of his remaining scientific output, and within the wider frame still of the atmospheric sciences of his day. Only in so far as the subject engaged him, and eventually made him famous, is this a book 'about continental drift'. I have treated the rest of his science in no less depth — although the reception of his continental-displacement ideas, being far more contentious than anything else he did, has admittedly drawn more of my attention.
Anyone who follows the particulars of his career closely will notice that Wegener repeatedly set aside a given line of enquiry — occasionally for years at a stretch — before returning to it. To help the reader through these abruptly changing interests, I have treated the successive phases of his life as though each were a career in a separate science, and the chapter headings reflect that choice. Readers after one specific facet of his life, rather than the whole of it, should therefore find the index guide enough. My own conviction, all the same, is that the individual pieces mean far less in isolation than the whole of his activity does when taken together, and on that account I would encourage readers to try to live through Wegener's life as he himself experienced it — interruptions, reversals of opinion, fresh starts and all.
Only a handful of published works came from Wegener's pen, and these, following the usual practice of his era, laid out what he had found rather than how he came to find it. Of the thousands upon thousands of letters he sent and received across a lifetime, barely a few hundred remain, for he kept no notebook or diary documenting his days. He rarely took part in scientific societies, a few exceptions aside, and made no attempt to win influence or promote his ideas through professional networking and intrigue; his hours went instead on reading and writing in his study, or gathering observations out in the field.
A biographer's task is easiest when the subject has left a great deal behind. Einstein, Darwin and Newton, for instance, each handed down an enormous archive — notebooks by the hundred and correspondence running to tens of thousands of items; Michael Faraday, for his part, filled lengthy journals with his musings and guesswork to sit beside his laboratory notebooks. The fuller the record a researcher bequeaths, in short, the more reliably a biographer can reconstruct how that person's thinking first emerged and later changed.
It is my settled view that hardly any of us — and Wegener is no exception — genuinely authors the life we lead. We make plans, we reflect, we act, often to all appearances freely; yet for the most part life simply 'befalls us', and only in hindsight do we shape that run of accidents into a tidy story of intentions carried through. What this book offers, then, is an account at once of the life and science Wegener meant and planned to have and of the life and science that in fact 'befell him' — and the two, as will quickly become apparent, do not always coincide.
