This review appeared in the Sunday Times on 22 February 2004
Richard Fortey, The Earth: An Intimate History, HarperCollins, £25, pp. 501
When the great 18th-century painter Joseph Wright of Derby climbed Mount Vesuvius during a visit to Naples in 1774, he said afterwards that he wished he could have made the ascent in the company of a geologist, since “his thoughts would have center’d in the bowels of the mountain; mine skimmed over the surface only.” Should anyone be struck by a similar wish today, then I could recommend no better climbing companion than the palaeontologist Richard Fortey, whose latest book casts him in the role of an enthusiastic field guide, leading us around — and into — some of the world’s most exhilarating geological sites. The field-trip begins (and ends), naturally enough, on the dark slopes of Vesuvius, the crucible of early earth science, and continues via the Swiss Alps, the Grand Canyon, Hawaii, Dartmoor, India and Newfoundland, in a dazzling voyage of telluric discovery.
As one might expect from the only science writer ever to have published a book with an exclamation mark in its title (Trilobite! Eyewitness to Evolution), we are in for a spirited excursion. “Onwards — to Africa!” he exclaims at one point, in mock-heroic emulation of his scientific heroes, the great 19th-century geologist-explorers who “trekked across remote areas with little more than a hammer and a notebook”, but whose efforts laid the foundations for all today’s knowledge of the earth. The scope of that knowledge is considerable, although increasingly fragmented within academic departments, so it is greatly to Fortey’s credit — as both a scientist and a writer — that he has been able to piece together such a readable and coherent survey of such a vast and disparate subject.
At the heart of the book is an explication of plate tectonics, the global mechanism through which our 4.5 billion-year-old planet endlessly recycles its own dark materials. A cross-section of the earth reveals how the mechanism works: a solid metal core is surrounded by vast molten layers of metal and rock, the outer skin of which, the solid lithosphere, has cooled and cracked into variously sized sections which are known as tectonic plates. Powered by thermal convection currents rising from the molten regions below, the plates migrate slowly across the surface of the earth, interacting with each other in various and complex ways. Some rub alongside their neighbours, one ragged edge slowly grinding past another, while others collide head on, one slipping beneath the other to melt back into the depths below like the disappearing end of a conveyor belt; the lost plate material is replaced at the other, originating ends, where the sea floor spreads at the mid-ocean rifts, and new molten matter rises up from below to cool and solidify into rock.
According to geologists, our ancient, battered earth has always been on the move: mountains have risen, rocks have ground down, oceans have widened and continents realigned, all as a result of these slow tectonic migrations across the face of the molten globe. It seems that there may have been as many as four or five supercontinents that broke up, coalesced, and broke up in turn over the past four billion years, “like one of those eighteenth-century dances in which the participants move apart at one stage, only to repeatedly find one another again in the centre of the ballroom on an appropriate prompt from the music”. Fortey’s great skill lies in transforming these mind-numbingly distant geological episodes into real historical events, while encouraging us to recognise that the same slow processes remain hard at work today: his field-trip takes us to some of the places where the evidence for these ancient and ongoing processes can clearly be seen on the ground, from “the badly-made lasagne” of folded Alpine strata to the 800-mile-long San Andreas Fault, “one of the great fractures on our planet”, along which the Pacific and North American plates are grinding past each other at a rate of an inch a year, their seizures serving to brew up trouble for cities such as San Francisco that lie along the join.
These geodynamic processes have occupied hundreds of millions of years of our home planet’s past, and anyone who writes about them is faced with the recurring problem of how to convey the vastness of deep geological time. There are plenty of analogies available, of course, from outspread arms to 24-hour clocks, but being essentially domestic in scale, none of them is equal to the task. As Fortey points out, “to collapse time by whatever analogy is to misunderstand it,” and he urges us instead to “think hard”, which is an unusual prescription for a populariser of science, but it is nonetheless an effective one, and when I stared at the time-line on the end-pages of the book, which takes us right back into the Hadean era, 4 billion years before the present, I was rewarded with a slightly giddy feeling as the immensity of time, or at least an impression of it, flashed a momentary glimmer in my mind.
“A kind of anti-textbook”, as Fortey describes it, The Earth is a true delight: full of awe-inspiring details and groan-inducing puns (“it is the fault’s fault”, he says at one point), it blends travel, history, reportage and science to create an unforgettable picture of our ancient earth as it spins through eternity, slowly unravelling beneath our feet.