Four Revolutions in the Earth Sciences by James Lawrence Powell

four revolutions in the earth sciencesThe 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.

James Larence Powell
James Lawrence Powell

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.

Continental Drift
Continental Drift

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: 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.

Giant Impact Hypothesis for creation of the Moon Pciture credit: National Geographic
Giant Impact Hypothesis for creation of the Moon
Picture credit: National Geographic

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. (Oddly enough, I thought that one had been proved – Powell unconvinced me.)

Dinosaur extinction Credit: Mark Garlick, Science Photo Library Photo??? It must be true, then...
Dinosaur extinction
Credit: Mark Garlick, Science Photo Library
Photo??? It must be true, then…

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.

Amazon UK Link
Amazon US Link

TBR Thursday 44…

Episode 44


It’s that time of year when we all make fabulous resolutions so that by mid-January we can all feel like complete failures for having broken them all already. So, in the spirit of the season, here are the resolutions I plan to break over the coming months…

1) Cut back on taking freebies for review.

2) Make time for re-reads.

3) Reduce the TBR to no more than 70 by the end of the year.

4) Stop reading so many new-to-me authors (since the precious gold is hidden amongst a fair amount of dross) and catch up on the back catalogues of authors I know I enjoy.

5) Read more classics, including some Dickens and a book a month for the Great American Novel Quest.

6) Read more sci-fi/fantasy.

Hmm… I currently have 17 unread review copies, and have requested 6 more, so Resolution 1 is looking a bit shaky. I think we all know Resolution 3 isn’t going to work out. Resolution 4 is problematic since the TBR currently contains books by 54 new-to-me authors.

But I’m delighted to say that the TBR has increased dramatically to 133 – delighted since the increase is because I’ve added loads of things I want to re-read plus some sci-fi – AND I’ve wasted a happy few hours making up (yet) another lovely, lovely spreadsheet scheduling all my reading for the next few months so as to keep on top of Resolutions 2, 5 and 6. I won’t stick to it, of course, but the joy of lists is surely in the making of them… a beautifully over-complicated spreadsheet feels like an achievement in itself.

So here’s some of what’s coming up – judge for yourselves if they meet my intentions…



you zoran drvenkarI enjoyed Zoran Drvenkar’s Sorry a lot, despite it being darker than my normal fare, so I’ve been waiting impatiently for this one to be released for Kindle. Doesn’t sound my kind of thing at all really, but then neither did Sorry

The Blurb saysIt’s a late-summer night in Berlin and notorious criminal Ragnar Desche isn’t too happy. He’s just found his brother, Oskar, dead, frozen stiff and sitting in his home next to a swimming pool full of marijuana plants. Someone’s flooded the pool and stolen a Range Rover, but what’s worse is that Ragnar’s huge cache of drugs is missing—and he’s going to want it back. Meanwhile, nearby, a group of teenage girls are out at the movies. Thinking about boys and worrying about acne, they notice that the prettiest member of their clique is missing. She hasn’t been seen for days, and the trouble she’s found herself in is about to set all of the girls on a collision course with the Desche gang and drag them into a fight for their lives—a fight that might turn out to be more evenly matched than it first appears.

A gritty, pulsating, psychological thriller told through the eyes of an enormous cast of characters, You is an audacious and unpredictable combination of pulp, pluck, and revenge.

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four revolutions in the earth sciencesFour Revolutions in the Earth Sciences – just started reading this one and it looks as if it will be interesting, though I feel I might end up arguing with him as often as I agree with him. We shall see! Courtesy of NetGalley.

The Blurb saysOver 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. 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.

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station elevenIt seems everyone’s raving about how good this book is, so in the end I’ve given in, despite being a new-to-me author. Courtesy of NetGalley…again.

The Blurb saysAn audacious, darkly glittering novel set in the eerie days of civilization’s collapse, Station Eleven tells the spellbinding story of a Hollywood star, his would-be savior, and a nomadic group of actors roaming the scattered outposts of the Great Lakes region, risking everything for art and humanity.

Spanning decades, moving back and forth in time, and vividly depicting life before and after the pandemic, this suspenseful, elegiac novel is rife with beauty. A novel of art, memory, and ambition, “Station Eleven” tells a story about the relationships that sustain us, the ephemeral nature of fame, and the beauty of the world as we know it.

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the way things wereWhen I read Aatish Taseer’s earlier book Noon, I had a couple of reservations about it, but overall felt he was a compelling storyteller and one to watch. So I was delighted to be offered this via Amazon Vine.

The Blurb saysThe Way Things Were opens with the death of Toby, the Maharaja of Kalasuryaketu, a Sanskritist who has not set foot in India for two decades. Moving back and forth across three sections, between today’s Delhi and the 1970s, ’80s, and ’90s in turn, the novel tells the story of a family held at the mercy of the times.

A masterful interrogation of the relationships between past and present and among individual lives, events, and culture, Aatish Taseer’s The Way Things Were takes its title from the Sanskrit word for history, itihasa, whose literal translation is “the way things indeed were.” Told in prose that is at once intimate and panoramic, and threaded through with Sanskrit as central metaphor and chorus, this is a hugely ambitious and important book, alive to all the commotion of the last forty years but never losing its brilliant grasp on the current moment.

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NB All blurbs taken from Goodreads.

So…what do you think? Do any of these tempt you?