The Copernican Geological Revolution
The Copernican Revolution did not just affect astronomy and physics: it revolutionized geology. So argued Walter Alvarez in Geology this month.1 Geologists usually talk rocks in their rags, but Alvarez (the one who brought impacts into extinction theories) decided to play historian. With Henrique Leitao, he announced, “we argue that the Copernican Revolution represented not only a revolution in astronomy and physics, but also a radical change in understanding the Earth.”
Part of their motivation seems to be to extend the history of their discipline. “Many geologists think of geology as a young science that originated about 1800,” they said. Apparently it would be more prestigious for geologists to sink their roots deeper into intellectual history. To do that, though, Alvarez and Leitao have to navigate geology through multiple upheavals: the plate tectonics revolution of the late 1900s, the Darwinian revolution of the late 1800s, the Hutton revolution of the late 1700s – and now, the Copernican revolution of the late 1500s. (Not much happened in the 1600s geologically except for the foundational work in stratigraphy by Nicholas Steno around 1669.)
The authors acknowledged the revolutions in philosophy and history of science of the 20th century; they mentioned Kuhn, Laudan, Lakatos, Rudwick, and others. They had to justify the word “revolution” to make their case that geology has foundations in Copernicus. This was made somewhat more difficult by the fact that the word geology was not invented till after Copernicus (1603) and was not widely used till about 1800. Nevertheless, they felt that the Copernican system led to a new view of the earth: “there has never been any serious reason since then to think that Earth is not a planet.” This contrasts sharply with the earth view of Aristotle and Ptolemy, they argued. The “recognition that Earth is not compositionally different from celestial bodies” was important for the founding of geology as a science: it was the Copernican revolution “that gave Earth its personality and its independence and finally made it a worthy object of study.”
Alvarez and Leitao tried to recreate the world view of the medieval mind. Planets were wandering stars, points of light that moved in complicated patterns against the stars, which were perfect celestial objects embedded in crystalline spheres. The Earth meant different things to different people. “In Medieval Christianity, Earth was a temporary abode for human beings prior to the Day of Judgment,” they said; “For philosophers, earth was one of four elements, along with air, fire, and water, which made up the terrestrial globe.” Whatever one thought, nobody believed till Copernicus that the Earth was a planet. “It is difficult today to recapture that alien worldview, but we may imagine that ‘Earth’ and ‘planet’ had as little to do with each other then as, for example, ‘Pangea’ and ‘B-flat minor’ do today,” they quipped. Then Copernicus comes, and now Earth is a planet! “It was as if we were to learn that Pangea was written in B-flat minor.” (Wasn’t that a march by John Phillip Sousa?)
Seeing the earth as a planet orbiting under physical laws of motion opened the way for using it as a natural laboratory, Alvarez and Leitao said; “It is difficult to imagine a more profound change in the understanding of the Earth, or to envision a serious science of the Earth that does not recognize that Earth is a planet.” They spent most of their conclusion clearing up confusion about the Copernican clich�:
In addition, contrary to what is commonly believed, we now know that in the eyes of its contemporaries, the Copernican Revolution glorified the Earth, making it an object worthy of study, in contrast to the preceding view, which demeaned the Earth. Ironically, the Copernican Revolution is almost invariably portrayed today as having demoted the Earth from a position at the center of the universe, the main concern of God, to being merely one of the planets. Danielson2 (2001) made a compelling case that this portrayal is the opposite of what really happened, i.e., that before the Copernican Revolution, Earth was seen not as being at the center, but rather at the bottom, the cesspool where all filth and corruption fell and accumulated. The revolution changed that view, as can be seen in a quote from Galileo, speaking as his alter ego Salviati, in Dialogue of the Two World Systems: “As for the earth, we seek…to ennoble and perfect it when we strive to make it like the celestial bodies, and, as it were, place it in heaven, from whence your philosophers have banished it” (see Danielson, 2001, p. 1032).
Danielson (2001) showed how historians came to misinterpret this glorification of the Earth as a demotion, an erroneous change of interpretation embodied in the now almost universal viewpoint that he called the “Copernican clich�.” It is difficult to imagine a science of geology developing when Earth was considered an accumulation of filth and corruption. The post-Copernican Earth, ennobled and perfected, became an object worthy of study by the emerging science of geology.
In the acknowledgements, Alvarez credited a “2007 visit of three Portuguese historians of science to Berkeley that triggered this study”. His thesis can be summed up thus, “With the advantage of hindsight, we realize that recognizing Earth as a planet was a precondition for understanding the universe. When that recognition destroyed the Aristotelian view that Earth is fundamentally different from celestial bodies, the Earth could become a laboratory for studying the universe.” The science of geology, therefore, can extend its origins to the Copernican revolution.
1. Walter Alvarez and Henrique Leitao, “The neglected early history of geology: The Copernican Revolution as a major advance in understanding the Earth,” Geology, v. 38 no. 3, p. 231-234, doi: 10.1130/G30602.1.
2. D. R. Danielson, 2001, “The great Copernican clich�,” American Journal of Physics, v. 69, p. 1029�1035, doi: 10.1119/1.1379734.
To his credit, Alvarez helped clear up the misinterpretation of the Copernican revolution being a demotion; this was a point emphasized in The Privileged Planet, in which Danielson himself appeared to clarify the historical record. It would have been nice to chastise Carl Sagan a little bit for misconstruing the medieval world view in Cosmos so badly for his millions of viewers, but at least this article agreed with Danielson. And Alvarez did not use his article to bash Christians and creationists. Still, there are a number of problems.
For one, he used fairly broad brushes to portray historical views. Any period was likely to have many dissenting opinions. It’s doubtful that nobody ever thought of studying the earth before Copernicus. Could any traveler climb the mountains or cross the deserts without wondering about them? Many people may have studied the earth without leaving written records. A good historian of science would probably find many examples in ancient writings through to the middle ages displaying early “geological” thinking. Are we to believe, too, that every Christian before Copernicus held their nose at the Earth as a pit of wretched filth? Read Psalm 96, Psalm 104 and Psalm 148. See if those hymns of praise to the Creator of the earth are so dismissive. Notice that these were all written long after Genesis, even though the Hebrew authors knew about the curse and the judgment of God. They still saw the creation of the natural order as a beautiful, wonderful, source of awe and joy. Psalm 111:2 said, “Great are the works of the LORD, studied by all who delight in them.” That verse alone should have liberated science many centuries before geology was born. It is wrong, therefore for Alvarez to allege that the Earth was “ennobled and perfected” by Copernicus. It was ennobled long ago by the Bible.
A central hold-up to serious study of the earth was that the medieval church became wedded to Aristotelian and Ptolemaic concepts that were not Biblical. There is nothing in the Bible about crystalline spheres. There is nothing that rules out the Earth as a planet. There is nothing that says that all the filth and corruption finds its place at the center, where Earth is located. Those all came out of pagan Greek philosophy. Jeremiah taught that the stars were innumerable. There are indications in Job and elsewhere that creation follows natural laws. Jesus referred to the beauty of birds and wildflowers, and used them as examples of God’s care for his creation. To the extent “Medieval Christianity” was anti-scientific (a dubious proposition to those who know their history), their mistakes cannot be traced to the Bible. (Note: three statements in the Psalms that “the earth shall not be moved” are not talking about geology or physics, but about God’s sovereign rule over the earth; they have nothing to do with the question of earth’s physical motion.)
There are also some non-sequiturs in the proposition that nothing serious could be done in geology before Copernicus. It’s not clear that one has to see the earth as a planet to study it. Any medieval person, or Roman or Egyptian for that matter, could have picked up rocks, wondered about fossils, and examined other real-life geological phenomena. Maybe more of them did than we know. Maybe they didn’t write down their ideas. Whatever we think about the stars, we humans all walk on the ground, and curiosity is a normal human trait. Seeing the connection of the Earth to other celestial bodies might enhance understanding of the Earth, but not seeing it does not preclude investigation. Consider that comparative planetary geology in our own day did not really begin in earnest till Mariner 4’s flyby of Mars in 1964, long after geology was established as a science. Geology was not held up till Copernicus arrived.
Two of the most serious flaws in this article are the myth of progress and the assumption of deep time. “During the geological revolution” of the late 18th and early 19th centuries],” he said, “geologists recognized that Earth has a long, complicated history that is recorded in rocks, and learned to read that history and to date those rocks using fossils.” That’s an overly simplistic characterization. Actually, the assumption of deep time was a choice, not a discovery. Geologists did not recognize millions of years. They needed them to back up anti-Scriptural interpretations. This is clear from the writings of Buffon, Hutton and Lyell, who wished to liberate science from Moses. Steno was a creationist, but the 18th-century founders of geology determined a priori that nothing in Scripture could be used in the interpretation of the rocks. Thus the only potential eyewitness accounts of earth history were ruled out of court. That’s objective science for you.
Early geologists jumped on that bandwagon and scorned the “scriptural geologists” as old fuddy-duddies out of touch with the new fad. They set to work fabricating an artificial framework for interpreting strata, assigning them the millions of years needed to fulfill Hutton’s vision of an ancient planet with no Creator and no Flood. There is nothing written on the Cambrian layers Sedgwick and Darwin found at Wales that shouts out “550 million years old!” (On the contrary, there is a lot to suggest otherwise.) Darwin became the leader of the band, and now we have this ossified bandwagon called the Geologic Column that has become the cart pulling the horse in university geology departments today. What are the chances it corresponds with reality? To answer that, one only need consider the other major flaw in Alvarez’s article, the myth of progress.
Notice the first major subheading: “Major Advances in Understanding the Earth.” How much do we understand the earth? That’s a loaded question. We tend to see science as progressive because of the very clear evidence of technological progress: we have cell phones; our great grandparents didn’t. Nobody questions that kind of progress. But when you ask whether we really understand a scientific phenomenon, the assumption of progress is na�ve. One of the ideas Dr. Stephen Goldman emphasizes in his Teaching Company lecture series “Science Wars” (see Resource of the Week for 12/19/2009) is that science has a historical character. This is not the same as progress; it means that scientific ideas and concepts are relevant to the time periods in which they are expressed. The “earth” means something very different today than it did 100 years ago – and 100 years before that. In 1900, he says, Earth was a basically static globe with occasional volcanoes and earthquakes. Now, geologists believe tectonic plates are moving all over the place and colliding, and catastrophism is back with a vengeance. You need to ask the follow-up question: how confident can we be that 100 years from now, geologists would have anywhere near the same theories and concepts of the earth as we do today, considering the fact that at each time in history, the intelligentsia were confident their concepts were correct? Our concepts of the universe have changed even more dramatically from what they were in 1900 – more so, arguably, than after the Copernican Revolution. We didn’t even know about external galaxies before 1923. Each branch of science has a similar story to tell. Physics was pretty much locked up in the late 1800s except for refining a few decimal places, then boom! relativity and quantum mechanics changed everything.
The basic question is whether our scientific theories provide a view of nature that is True with a “capital T” – or is at least progressing toward that truth. Notice that truth is not the same thing as explanation, prediction, or control. Our theories can provide those things, but so did ancient Greek and Egyptian theories that are now known to be incorrect. Regarding control, the Egyptians built the pyramids with false views of nature. And prediction can be misleading; the fallacy of “assuming the consequent” dogs scientific reasoning (theory predicts A, A happens, therefore theory is correct – ignores other successful theories). Explanation can be little more than storytelling. Geologists today should not be na�ve to think that their ability to explain, predict and control nature with current theories means that their theories are true.
Much of geology deals with phenomena that are not observable (e.g., the core of the earth, earth origins and history). Even the phenomena accessible to observation produce theories subject to major revisions. The same issue of Geology this month has a paper about alluvial fan formation that overturns a previous theory that had overturned one before that, and supports the earlier theory. Is that progress, or rather a swinging pendulum? Some liken scientific progress to the path of a hunting dog. A bloodhound may wander from left to right, but the resultant vector shows progress as he hones in on the scent. Even so, how do you know you are on the right trail? Maybe when the dog catches up with the suspect, it will be the wrong culprit, and the forensic team would have to start over.
The point is that even if you see progress in explanation, prediction or control, it does not mean your scientific efforts are converging on the Truth. Neither does it mean so if you have thousands of PhDs pursuing the consensus paradigm, munching croissants at huge AGU conventions, and teaching textbook science to undergrads using calculus. Geological theories of the earth go far, far beyond what can be verified through observation. In the years between Buffon and Lyell, a priori decisions were made to disregard Scripture as having any relevance to geology. Suppose historians decided to build a theory of Rome by deciding in advance to disregard all texts and inscriptions, and only studying monuments and ruins. Suppose they won over all the universities and journals with this approach. Imagine them celebrating their Enlightenment, their independence from the slavery to texts. Would they be likely to make much progress toward the true history of Rome? Consider that none of the following accoutrements to a paradigm have any necessary connection to its truth:
- The number of experts promoting a view (10,000 Frenchman can be wrong)
- The tightness of the camaraderie binding supporters of a view together
- The prestige of the institutions supporting the view
- The reputation of the journals doing the publishing
- The number of journal articles published (10,000 lies don’t add up to a truth)
- The length of time a view has been believed (Ptolemaic astronomy lasted 1500 years)
- The dazzle of the charts, graphics and textbooks available
- The quality of animations in TV documentaries produced to illustrate the view
- The denseness of the jargon used in discussing the view
- The cleverness of the classification schemes employed
- The chutzpah of its supporters
- The political power of its supporters
- The ability of its leaders to demonize and marginalize opposition
- The incompetence of some of the view’s detractors (they could still be right)
- The ability of its proponents to win court cases
- The dignity of the conferences held in support of the view
- The view’s success at explanation, prediction and control
What matters is evidence. Eyewitness testimony is evidence. Rather than ruling out that class of evidence for geology, the question 18th-19th century geologists should have considered was the reliability of the only Eyewitness available. Sedgwick and Lyell and others tried to hang on to their Christian God, but they abandoned his Word, leaning on their own understanding (Prov 3:5-6). They also dismissed the greatest witness of all – Jesus Christ – who taught creation and the Flood (Matthew 24:38-29). By cutting off their authority at the knees, they have been hobbling around on stumps in shifting sand, thinking it was progress. Not all motion is progress. Some is just commotion.