Four Revolutions in the Earth Sciences: From Heresy to Truth

by James Lawrence Powell

Over the course of the twentieth century, scientists came to accept four counterintuitive yet fundamental facts about the Earth: deep time, continental drift, meteorite impact, and global warming. When first suggested, each proposition violated scientific orthodoxy and was quickly denounced as scientific -- and sometimes religious -- heresy. Nevertheless, after decades of rejection, scientists and many in the public grew to acknowledge the truth of each theory.

The stories behind these four discoveries reflect more than the fascinating push and pull of scientific work. They reveal the provocative nature of science, which raises profound and uncomfortable truths as it advances. For example, the Earth and the solar system are older than all of human existence; the interactions among the moving plates and the continents they carry account for nearly all of the Earth's surface features; and nearly every important feature of our solar system results from the chance collision of objects in space. Most surprising of all, we have altered the climate of an entire planet and threaten the future of human civilization. This absorbing scientific history is the only book to describe the evolution of these four ideas from heresy to truth, showing how science works in practice and how it inevitably corrects the mistakes of its practitioners. Scientists can be wrong, but science can be trusted. In the process, astonishing ideas are born and, over time, take root.

Genres: Science, History Of Science, Nonfiction, Earth

352 pages, Hardcover

First published January 6, 2014

About the author

Dr. James L. Powell graduated from Berea College with a degree in Geology. He holds a Ph.D. in Geochemistry from the Massachusetts Institute of Technology and taught Geology at Oberlin College for over 20 years.

He served as Acting President of Oberlin, President of Franklin and Marshall College, President of Reed College, President of the Franklin Institute Science Museum in Philadelphia, and President and Director of the Los Angeles County Museum of Natural History.

Powell currently serves as Executive Director of the National Physical Science Consortium. Asteroid 1987 SH7 is named for him.

Reviews

[Andy · Rating 5 out of 5]

Wow! I stumbled on this in a used-book store and it's been sitting on my shelf for years. (The title doesn't help.) This is maybe the closest thing I've found in terms of the anti-BS book I've been looking for. How do we get more people to "convert" to the acceptance of evidence that disconfirms their cherished beliefs? The old chestnut about just waiting for the old generation to die off is not very satisfactory.

I guess the take-home if you want to fight BS is to learn to discern between weak and strong evidence, know what the strong evidence shows, and then keep sharing that information. Generally being skeptical of authority is a good idea. A thing I hear a lot that bothers me is "extraordinary claims require extraordinary evidence." This sort of makes sense, but it has often been used to defend the flawed conventional wisdom with crummy evidence and that's not okay; all claims should be backed with rigorous evidence.
If you are a scientist, you can add in providing practical predictions, testing hypotheses and translating your findings into plain English. The evidence is what matters, but it does no one any good sitting on a shelf gathering dust.

This book confirms what I've been thinking: what matters is the overall weight of the best available evidence. You cannot rely on consensus/conventional wisdom/expert opinion. This is a crucial distinction. Over and over again the consensus of scientists or the opinion of Nobel Prize winners has been wrong. Looking back, the hard evidence was there and pointing in the right direction, but it was ignored--often for decades.

Science is not a religion. It does not provide perfect everlasting truths. It produces models of reality that are the best approximations of truth we can get. It is self-correcting and evolving in response to new empirical findings. Unfortunately, people don't look at the evidence, or they actively reject it. Even scientists of great stature will invent Ptolemaic epicycles of nonsense to support their flawed paradigms instead of fairly considering new ideas. And the rest of the herd will go along sheepishly with the pronouncements of their masters. (See The Structure of Scientific Revolutions.) The author doesn't explore cognitive biases and all that. What he does show convincingly with example after example (plate tectonics, demise of the dinosaurs, global warming, etc.) is that the conventional wisdom tends to rigidify into dogma, and challengers are viciously rejected as heretics. Science is not supposed to work that way, but scientists are people and apparently people are like that.

Since the author is a human being, he falls into this trap himself at times, just telling us that something is so without the proofs. I give him a pass on this because to me the book is not so much about what killed the dinosaurs or whatever as it is about "How do scientists try to figure out what killed the dinosaurs?" To the author, all the episodes of wrongness he describes are success stories in a way because eventually the evidence won.

This book is somewhat academic, so it's not a great page-turner, but it is outstanding serious non-fiction. The Conclusion is very short and doesn't really develop the themes of Truth and Heresy from the previous chapters. That makes sense because it's like the conclusion of a scientific paper, but then we could have used a Discussion chapter before that, not about the earth science topics but about how scientists (fail to) change their minds.

I learned a lot about geology and astronomy and whanot.

[Leah · Rating 4 out of 5]

The weight of evidence...

In the introduction, Powell tell us he was inspired to write this book when a friend, discussing the fact that the vast majority of scientists accept that the activities of man are contributing to global warming, remarked that scientists have been wrong before. Accepting the undeniable truth of that, Powell decided to look at the recent history of four important theories in earth sciences, showing that though scientists may have been wrong at first, they "eventually came to be right".

"The history of the four discoveries confirms the cardinal virtue of science: it is self-correcting. Scientists pushing the boundaries of knowledge are often wrong, but they do not stay wrong."

Considering the fair amount of depth Powell goes into on each of his subjects, the book is surprisingly accessible to the non-scientists among us. I found I only got lost occasionally and, when reading books like this, I accept that there are things that are too complex to simplify down to my level! In each section Powell starts at a point before the theory he is discussing was developed, explaining the existing state of knowledge and supposition. He then introduces us to the scientists who contributed to the development of the new theory, along with those who opposed it, and finally to those who 'proved' it. He provides little anecdotes of their lives, or their friendships or quarrels with each other, which prevent the book from becoming too dry a read.

There are two types of enjoyable popular science books as far as I'm concerned - those that clearly explain something and convince me of it, and those that clearly explain something and provoke me to argue with the author's conclusions. This one falls firmly into the latter category. Oddly, I started out a fairly firm believer in all four (five really, or six if you include the extinction of the dinosaurs) of the theories in the book, and ended up only fully convinced of two - or two and a half at a push. Throughout, Powell is critical of scientists who accepted theories and held onto them despite lack of proof or even once discoveries had been made that clearly invalidated them. But I felt Powell fell into that same trap himself too often, claiming a thing as being so when in fact the proof isn't yet there. The very subtitle of the book - From Heresy to Truth - is a prime example of this. His basic position seems contradictory - that scientists of old were stubborn and foolhardy to stand by their theories without adequate proof but that we should accept the theories of current science, also often without final evidence of their validity. And he makes generalized statements that are clearly an expression of his opinion rather than of 'fact'...

"The discoveries from astronomy and earth science expose the infinitesimal standing of the human race in time and space. They force us to admit that we are the products of, and the potential victims of, random events."

Do they really? I would imagine that the billions of people who believe in some form of God might not feel forced to admit that. Indeed, Powell himself points out in the course of the book that even many scientists are willing to admit that science and religion can co-exist. But this is just one example - there were several occasions when I felt he expressed himself more forcefully than the evidence justified, or substituted opinion for fact.

However, despite finding I was treating his conclusions with some caution, I found the book interesting and informative, and felt that overall he more or less made his case. Perhaps had he been a little less ambitious to prove the rightness of so many current theories, he might have been more convincing overall. Here is a brief summary of the theories he discusses...

Deep Time

Powell shows how the assumed age of the Earth has changed over the last century or so, as scientists made discoveries - such as evolution - that negated the previous assumptions. As he does in each section, he highlights the scientists involved, including those who fought strongly to retain their existing position even when the evidence became overwhelming. He also points out that, in the end, it was physicists rather than geologists who made the most important discovery - how to determine the age of rocks through developing ways to measure radioactive decay.

My verdict (based on the info in the book): Not proven - an old Scottish verdict which means basically 'I believe it, but I don't think you've really proved it'. I admit the main reason for this verdict is that the stuff about radioactive decay went largely over my head - but it seemed to me that, as Powell described it, there were still too many assumptions involved for this to be a theory incapable of being overturned by further future discoveries.

Continental Drift and Plate Tectonics

In 1911, Alfred Wegener noticed that the east coast of South America was a great fit for the west coast of Africa, and speculated that they had once been joined. The then greats of the scientific world largely dismissed this idea, even when the fossil records between the two coasts showed a remarkable similarity. Powell takes us through all the experimentation that gradually proved the truth of the theory, as geologists speculated that continental drift and plate tectonics were the likely cause of mountain formation and of the mid-Atlantic ridge.

My verdict: Proven. With GPS, scientists have now been able to measure the rate of drift - that's the kind of proof I like!

Meteorite Impact

While discussing the theory that meteorites have impacted the Earth, on occasion with catastrophic results, I felt Powell got himself a bit side-tracked into both the extinction of the dinosaurs and the impact theory for the creation of the Moon.

My verdict - the jury is still debating. I don't think any of us who watched Shoemaker-Levy 9 crash into Jupiter some years back could doubt that major meteor strikes happen, nor be unconvinced of their catastrophic potential; and I was convinced of the evidence that they have happened here on Earth. However I felt Powell's certainty that this was the cause of the extinction of the dinosaurs was too strongly expressed - again, I tend to believe it, but don't think it has been 'proved'. And as for the Moon creation theory, even Powell had to admit that this one needs much more evidence before it moves from theory to fact.

Global Warming

So this is the crucial one - Powell's starting and finishing point. Although he refers to it as Global Warming, in fact the crux of his argument is proving that it's caused in large part by man's actions. Again this one got a bit 'sciency' for me, but for the most part I was able to follow the arguments.

My verdict: Proven. It seems to me the weight of measurable evidence - such as from atmospheric measurements over time showing the rapid rise in concentration of carbon dioxide to be almost exactly parallel with the increase in emissions - makes this one as close to proven as it's likely to be. And given the potential impact, I'd rather err on the side of caution anyway. But, although Powell's position is that this one is beyond doubt, he also makes it clear that estimates of the likely impact are still subject to debate. Personally, I feel we're probably safest to assume a worst-case scenario and act accordingly...and on that final note, I think Powell and I finally reached agreement.

An interesting book, despite Powell's occasional forays beyond the evidence, and one I would recommend to anyone who is still in doubt as to the reality of man's impact on the environment.

NB This book was provided for review by the publisher, Columbia University Press.

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[David · Rating 4 out of 5]

Very good account of the historical development of four theories in the Earth sciences over the last ~200 years or so: 1) Deep Time--"our planet is billions of years old", 2) Continental Drift and Plate Tectonics--"continents and ocean floors move", 3) Meteorite Impact--"rocks as big as mountains fall from the sky", and 4) Global Warming--"humans are changing the climate" (Introduction, p. xv). Each "revolution" serves as a case study in how science works--how accepted ideas become the "consensus" view and how sometimes those ideas are overthrown by further research and newer and better explanations of how the world works.

Here are some thoughts I had about this book.

I was surprised that one of these "revolutions" was the idea of meteorite impacts on the Earth and the Moon. Without knowing the historical development of this idea, I just assumed that it was "always" known that the craters on the Moon were caused by past meteorite impacts. But Powell shows that as late as the 1960s, when we were planning the Apollo missions to the Moon, most scientists thought the craters were volcanic in origin. The same was true for the rare meteorite craters on Earth, which have survived eons of erosion. Geologists called these features "cryptovolcanic" because they didn't quite make sense as purely "volcanic" features. But detailed mapping of the Moon and the flood of new evidence gathered by the Apollo astronauts showed the meteoric origin of the Moon's cratered face.

In the section on Continental Drift, I learned of the importance of a single map of the Atlantic Ocean floor ( http://blogs.agu.org/georneys/2010/12... ). The Heezen-Tharp map gave geologists their first view of what lay hidden beneath the ocean waves:

The raft of new information from the ocean basins, but especially the Heezen-Tharp map, deeply impressed geologists. Those of a certain age may never forget the first time they saw the map. It was impossible not to recognize that something horrific had happened to the Atlantic Ocean floor, something beyond the ken of continent-bound geologists. The permanent, immobile continents had begun to teeter on their supposedly rock-solid foundations. (p. 112.)

Powell's first "revolution" (the billion-year age of the Earth) and the fourth (Global Warming) are linked in an interesting way...

In the late 1800s, the "consensus" view on the Earth's age, supported by the authority of the physicist Lord Kelvin, settled on an estimate of about 100 million years old. This estimate was the best that geology and physics could offer at the time, but the estimates were built on many assumptions about the Earth, which were inaccurate or unfounded. Kelvin assumed that the Earth originated as a molten mass and he calculated the Earth's age based on how long it would take such a planet to cool to its present state. What he didn't know about, what he couldn't have known about, was that certain elements are radioactive and as these elements decay they give off enormous amounts of heat within the Earth. Hence, any calculation of the Earth's cooling over the eons that doesn't include this source of radioactive heat is hopelessly inaccurate. But this new-found force of nature offered a much more accurate way of measuring the Earth's age. Radioactive elements (such as uranium) decay at very precise rates into other elements (such as lead). The age of rocks can be estimated by measuring the ratios of radioactive to non-radioactive elements within them. With this much more accurate "atomic clock" discovery, the age of the Earth relies on simply finding the oldest rocks on the planet. These measurements point to an age of about 4.6 billion years old.

What does this have to do with Powell's fourth "revolution"--Global Warming? I won't go through the many details which Powell gives of the historical development of the CO2 theory of global warming. I'll just cut to the chase: by the 1990s the CO2 theory had become the "consensus" view of climate scientists. But how do we know that this view won't be overturned as Powell shows of the other "consensus" views in this book?

In a very good section called "How We Know We Are Right" Powell briefly goes through the many lines of evidence that support the CO2 theory. Yet, some claim that this evidence isn't enough, that the climate has always changed naturally and that the current change is natural as well. Powell states that deniers of the CO2 theory are betting on two unknowns: "First, some invisible process must have offset the greenhouse effect. Second, with the greenhouse effect diminished or absent, some other invisible process must have caused the observed temperature rise." (p. 286.)

In effect, they are betting on some kind of "climate change radioactivity", some unknown force or process similar to the radioactivity that was discovered in the 1890s, and which played a pivotal role in overthrowing Kelvin's consensus view on the age of the Earth.

Is such a monumental discovery possible? Perhaps, but it would need to re-write all of our understanding of basic physics and chemistry. And that is highly unlikely.

[Neil R. Coulter · Rating 4 out of 5]

I don't have enough of a science background to read much "real" science, but I love reading science books that are geared to the general reader (me). James Lawrence Powell's Four Revolutions in the Earth Sciences is just the kind of book I like. It's a quick history of four major issues in geology, astronomy, physics, and other fields related to earth science: the age of the earth; plate tectonics; meteorite impacts; and climate change. Setting these four discussions side by side in this way really brings out the similarities in how science has worked and progressed from the late 19th century through the present. Really fascinating! Of course, the big payoff in the final quarter of the book is to show how the current debate about climate change is simply following a standard progression (except that the climate change "debate" is being supported and continuously manufactured beyond the point at which it should have ceased to be any debate at all).

Powell's narrative moves extremely fast, and for me, with relatively limited science knowledge, it was sometimes a little too quick. I had a tough time keeping track of all the names he dropped along the way. Scientists who are already familiar with the names and general trends won't have this problem--though I can imagine that they might be annoyed at the surface-skimming nature of the storytelling. However, even having to keep up with the speed, I still enjoyed this book a lot. I wish the public discourse on current science issues could be more informed about the history of science, even just the relatively recent history of the past century. This helps to set everything I learned in high school science into its fuller context.

[Baal Of · Rating 4 out of 5]

This is yet another book that should be read by a lot of people, but I suspect those to whom it would be most useful will never know it exists, and even if they did, they wouldn't bother reading it since they've already made up their minds. What makes this book so important, is that it examines in great detail how and why scientific theories become accepted, revealing the difficult struggles that occur for an idea to become mainstream. The common belief that science is a set of facts, that the progress follows a linear progression from hypothesis to proof to acceptance, is shown to be much more complicated in the details.
This book does require some patience, since it goes into a lot of depth on each of the four major scientific theories it examines. I found that I had to slow down my usual reading speed, to better absorb the information and arguments.

[Teemu Öhman · Rating 5 out of 5]

During the past few years, geologists James Lawrence Powell has been involved with some rather dubious activities related to impact cratering research, namely the Younger Dryas nonsense and its various incarnations. However, this should not scare away the potential readers of at least the two great books of his that I’ve read. Night Comes to the Cretaceous was an excellent account of the K/T exctinction and the scientific debate about it. A couple of chapters from that are actually reused in his later book, Four Revolutions in the Earth Sciences – From Heresy to Truth.

The revolutions are the discovery of the age of the Earth, continental drift, asteroid impacts and global warming. Powell provides clear, thorough and highly readable summaries about the development of these ideas that the scientific establishment considered heretical for a long time. He knows the topics, so factual mistakes are largely absent.

The part about impacts deals also with the origin of Moon (about which he’s also written a book, which I probably should read), so lunar enthusiasts also benefit from reading Powell’s excellent book. At the end of the impact part he does discuss the Younger Dryas stuff, so he was already clearly intrigued, but in this book his tone is still pretty neutral.

In my experience, Powell is one of the best writers of the history of Earth sciences. Thus, both Night Comes to the Cretacous (which I read before joining Goodreads, hence no proper review) and Four Revolutions in the Earth Sciences are highly recommended to anyone with an interest in geology and/or the history of science.

4.5/5

[Elaine Aldred · Rating 4 out of 5]

‘Four Revolutions in Earth Sciences’ concerns four key scientific concepts involving the earth; deep time (the geological age of the earth), continental drift (the action of tectonic plates), meteorite impact (associated with the mass extinction of the dinosaurs) and global warming. Although interesting science subjects in their own right, it is the scientific wrangling and politics associated with these concepts that form the core of the book’s narrative. It is also interesting that each is connected to the other either by proposed mechanisms or the scientists involved in the sometimes Machiavellian scheming that went on during their development.
At times the book reads like a corporate takeover, with numerous examples of children perpetuating their father’s work and pursuing it to the end, regardless of whether that end result is valid or not, while other scientists persist in refusing to change their perspective (usually because it invalidates their life’s work). Viewpoints that we now regard as ludicrous are discussed in a way that makes it possible to understand why they were once considered viable and how, often through the dogged determination of one person or verification from more than once source, they were overturned.
There are examples of scientific heroism such as Alfred Wegner’s initial presentation of continental drift (often likened to Galileo’s assertion that the Earth rotated around the sun for the institutional wrath that descended on him). The history of earth sciences would also appear to be populated by characters straight out of a ‘Boy’s Own’ comic (Wegner again, who died on an expedition in Greenland, as well as several scientists serving in the Second World War).
James Powell Lawrence is not always completely successful in creating an engaging narrative (the first chapter on deep time, does at times feel like a list of events), but when he does the reader feels as if they are in the thick of a novel retelling a dynamic power struggle while really getting to getting to grips with the science of the particular topic. The book has also been written in a way that makes it highly accessible to someone with little or no science background and provides some interesting material for any writer wanting to consider the nature of scientific thought.
It is the discussion of the progression of the development of each theory and its subsequent verification that brings about a realisation in the reader that science is not set in stone and that what we currently accept as received wisdom might be overturned in the future.

[The Inquisitive Biologist · Rating 5 out of 5]

A riveting story of the progress of science, looking at four theories in the geosciences that went from heretical suggestions to accepted ideas. See my full review at https://inquisitivebiologist.com/2018...

[Yeah · Rating 4 out of 5]

Very very well-written and well-researched; but, I could not shrug the feeling that I was expending time on reading what was essentially very detailed trivia. Mainly, this is because past advancements are no longer relevant except to those who seek to get inspired. Secondarily, the underlying idea of the provisional nature of scientific knowledge is something I have already learned about, thus it was not exciting. I contend that the subtitle of this book bastardizes the author's entire project; because, you see, "from heresy to truth" asserts unjustifiably a completeness and indefatigable truth to the four areas of science he talked about. Indeed, I think he misses the point he brought up. He himself described how geologists made spurious assertions and ad verecundiams to support their ideas that the Earth was somewhere around 200 million years old back in the 1900s. None of them, especially Lord Kelvin, expected the atomic model, or that we might one day use such roundabout ways to determine the age of the Earth. I think thus that because of how roundabout these methods are, even though they provide seemingly certain answers, even more roundabout ways in yet to be discovered science could one day unravel new shocking truths. Perhaps this sociological aspect to the conduct of science warranted a concise treatment within the novel. It did not get that right, that is why I do not think this book very compelling. It is facts and not arguments.

[Steve · Rating 4 out of 5]

Rating of 4.5. Excellent History of Four key ideas in geology. Covers the history, the science and current thinking. Very good notes and bibliography for those interested in pursuing any of the topics.

[Anne · Rating 2 out of 5]

A little too strident in the global warming section. Interesting stuff but not fascinating. Glad I read it but not sure I would recommend it to others. Kind of slow at times.