Tuesday, October 21, 2014

Martin J. S. Rudwick's "Earth’s Deep History"

Martin J. S. Rudwick is Professor Emeritus of History at the University of California San Diego, and an Affiliated Scholar in the Department of History and Philosophy of Science at the University of Cambridge. He had a first career as a paleontologist before turning to the history of science, which he taught in Cambridge, Amsterdam, Princeton and San Diego. He has published several books on the history of the Earth sciences, among them Bursting the Limits of Time and its sequel Worlds Before Adam.

Rudwick applied the “Page 99 Test” to his new book, Earth's Deep History: How It Was Discovered and Why It Matters, and reported the following:
Earth’s Deep History tells how our planet’s long and eventful pre-human history was first discovered. It’s written for people who may know little of either the scientific or the historical background, and it’s illustrated with lots of images reproduced from contemporary sources. It starts in the 17th century with the scholars who tried to piece together an accurate summary of human history, based on multicultural (including biblical) documentary evidence. James Ussher dated the original Big Bang at 4004 BCE, but he was expressing what seemed to them all to be common sense; they were not creationists in the modern mold. Also in the 17th century, naturalists complemented this kind of historical research, when they began to think of nature itself as having a history, which could be reconstructed by treating rocks and fossils, mountains and volcanoes, as nature’s own documents and archives.

Page 99 finds my story in the later 18th century, when several newer lines of evidence made it seem likely that the Earth’s timescale was far lengthier than earlier generations had imagined. But it was not until the 19th century, during the most creative period in the entire history of the Earth sciences, that this enlarged timescale was combined effectively with the idea of nature itself having a history. The Earth’s deep past then turned out to be not only unimaginably lengthy but also unexpectedly eventful; and there was an equally eventful history of life to match, with occasional mass extinctions and with the human species only appearing as it were at the last moment. And all this could be reconstructed reliably and in increasing detail, as the scope of geological exploration and debate expanded beyond Europe.

In the 20th century the newly discovered phenomena of radioactivity became the basis for a more precise timescale, which not only enlarged its magnitude still further but also showed, for example, that for most of the Earth’s history its life forms had all been microscopic in size. By the early 21st century the Earth’s deep history was being treated as just one among many diverse planetary histories, within the Solar System and probably beyond it, however unusual the particular history of our home planet seemed likely to have been.

One final point is worth emphasizing. Those who reconstructed the unexpectedly eventful deep history of the Earth and its life (at different times they called themselves “savants”, naturalists, scientists) have in each century included many who were devoutly religious people, as well as many who were not. In this book I dismiss the persistent myth – for such it is – of perennial conflict between “Science” and “Religion” on this issue. The modern creationists, who flatly deny the scientific reconstruction of the Earth’s deep history, are no more than a bizarre sideshow, and one largely confined to the US.

Page 99 [with bits from pages 98 and 100, to make it read coherently]:
The possibility of a hugely extended history of the Earth, almost all of it probably pre-human, was most convincing to those naturalists who had seen for themselves, in the field, the sheer scale of the piles of rock formations and the size of the great volcanoes. Their growing suspicion that vast spans of time must be involved generally remained both implicit and unquantified. This was not for fear of criticism from church authorities, but for the much stronger reasons that they had no reliable way to measure the time involved, and that they had no wish to be thought merely speculative. Yet their unpublished informal remarks (where any have survived in the historical record) show that by the later 18th century many of them were thinking – openly, routinely and almost casually – in terms of at least hundreds of thousands of years, or even millions, for the accumulation of the piles of strata and of the still more recent volcanoes. . . . Such an amount of time may seem pitifully inadequate to modern geologists, but it does show that their predecessors in the later 18th century had already taken the crucial imaginative step of thinking of the Earth’s own history in terms that vastly exceeded the traditional few millennia. At the time, imagining even hundreds of thousands of years had just as great an impact as imagining billions would have had. . . . Never in the subsequent history of this kind of science did those with the relevant field experience doubt that the Earth’s timescale must dwarf the totality of recorded human history; in contrast, the opinions of the general public, who lacked this first-hand knowledge, often remained quite different. . . . From now on, any savant who proposed or inferred a very long timescale, or just took an extremely ancient Earth for granted, was pushing at an open door (it is a modern misconception that this crucial change of perspective had to wait for the geology of the early 19th century, or even for Darwin’s evolutionary theory still later in that century).
Learn more about Earth's Deep History at the University of Chicago Press website.

--Marshal Zeringue