Solo Adventure Through Firmament by Simon Clark

In this episode of Book Science, I dive into Firmament: The Hidden Science of Weather, Climate Change, and the Air That Surrounds Us by Simon Clark. It’s a beautifully written, surprisingly compact book that unpacks the atmosphere we live in—something so ever-present and invisible that we often forget it exists at all. Clark brings both expertise and charisma to the subject: he’s a UK-based science communicator with a PhD in atmospheric physics and a popular YouTube channel. His book explores foundational concepts in atmospheric science, from Boyle’s Law to global wind patterns, and weaves in the long arc of scientific discovery—from ancient meteo-astronomers to modern climatologists. It’s the kind of book that doesn’t just explain the science but tells the story of how we came to understand it, bringing in the people, experiments, and moments of insight that shaped our knowledge of the air.

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Tripp: This show was recorded in Narrm, Melbourne, Australia, where the traditional custodians include the Wurundjeri people of the Kulin Nation, and we pay our respects to elders past, present, and emerging. I'm Tripp Collins, and this is Book Science. The podcast explores how the best science books are written and why they matter. 

Today we are talking about Firmament: the hidden science of weather, climate change, and the air that surrounds us by Simon Clark. I read the paperback printing, which weighs in about 236 pages. It was published by Hodder & Stoughton, and it's a relatively slim volume. 

I also listened to the audio book, which was very nice. It was read by Simon Clark himself. Clark is from the UK, and whether it's fair or not, there is something about that UK accent that lends an extra level of credibility. His delivery was earned over many years as a YouTuber, where he runs a popular channel focused on science communication, especially around topics of climate change. He comes off like a young David Attenborough, which I believe he cites as an inspiration. 

Simon Clark has a PhD in atmospheric science from Oxford, and after graduate school, I believe Clark was able to fully transition into a career as a YouTuber. He also wrote this wonderful little book. I think I first became aware of the book through the Harvard Bookstore YouTube channel. They have a number of very interesting talks by authors of science books. 

So if you like what you're hearing here, you'll likely find content over there you'll enjoy as well. Let's begin with the title of the book, Firmament. Firmament, it's a cool title, but for the unfamiliar, the word may not convey exactly what the book is about, which is where the subtitle does the heavy lifting. So my initial associations with the word Firmament were related to the heavens or the sky, and here it's being used in a related vein. 

We're talking, of course, about the substance of the atmosphere, that thin film of gas that surrounds the surface of our planet. There's this wonderful quote from Alexander von Humboldt, who was around 1769 to 1859, and he was very fond of the word Firmament. He says, “it is the duty of philosophers to determine and adjust their various elements, according to the sublime model of the astronomical science, in order that some of those eternal walls may be made known by which the climatic changes of the Firmament are dependent on the liquid and aerial currents of our planet.” Here, Humboldt's Firmament is very much the substance of the atmosphere, and Google's word usage feature reveals that Firmament was in more frequent use back in Humboldt's day. And I wonder if there was some particular use or quote, maybe even from this time period, that inspired the book title. 

The subtitle starts with the hidden science, and the word hidden is apt. You know, the air that surrounds us reminds me of David Foster Wallace's famous commencement speech to Kenyon College, where he relates to the following story. There are these two young fish swimming along, and they happen to meet in order of fish swimming the other way. Who nods at them and says, morning boys, how's the water? And the two young fish swim on for a bit, and then eventually one of them looks over at the other and goes, what the hell is water? For David Foster Wallace, this is a didactic parable that underlines the theme of his speech, but here I invoke this little story way more literally. So every day we are the fish swimming in the air, and we almost never notice it. 

It is really quite incredible. Is there any other aspect of the Earth's planet system more crucial to life than the air we breathe? Or more important to our day-to-day lives than the weather? 

Or more important to our future and possibly the fate of humanity than climate? Yet we give it little to no thought to any of it in terms of what the heck is it, and how does it work? So Simon Clark wrote this book for this reason, and to give a history of the development of the ideas. Let's get into a bit of the book's contents. So the first chapter reintroduces the idea of Boyle's Law and the equation of state of a fluid. 

So if it's been a while since you've had your high school physics lesson, this is the classic relationship between temperature, volume, and pressure. And each chapter brings up a theme, and the first half of the book builds upon itself. So there's wind, fields, trade, distance, forecast, vortex, and change. Some of these terms may be a bit abstract before tackling the chapter. For example, fields refers to scalar fields, which is a number or value assigned to each position in space. 

And here trade refers to trade winds, and that chapter is more broadly about persistent or reoccurring wind patterns on Earth. The size of this book is remarkable. For such a slim volume, I'm really impressed with how much Clark packs in it without it feeling dense. As we go through each chapter, he explains maybe a phenomenon or a feature or an aspect of the atmosphere or atmospheric science. In some cases, as in stratospheric winds, the phenomenon itself may feel a bit distant to those of us who live on the surface of Earth, and its existence and its importance needs some explaining. He also explains the physics behind why the atmosphere is the way that it is. Clark includes loads of relevant history. He introduces us to the relevant scientists throughout history. There's also stories that build and are returned to throughout the book. There's a bit of fun where the opening anecdote in the forward connects to the closing chapter. 

There were some clever uses of structure, and I wonder how much of it was planned out from the beginning, and how much of it was constructed during revision. The opening chapter covers the history of human scientific interest in the weather from Meteo-astronomers, which were sort of priests of ancient times that used observations of the stars to divine the weather. We fast forward to the beginnings of reasoning with Aristotle to the scientific thoughts of Galileo. However, a working theory of the atmosphere wouldn't come until much, much later. This is because scientific theories require measurement to prove or disprove, and we were awaiting the development of technology. And just what would one measure? Well, temperature and pressure to start and wind speed at some point as well. And Clark traces the history of the development of technologies that could make such measurements. 

The accumulation of measurements inspire the first theories of atmospheric physics. This first chapter also starts with a thrilling balloon journey which nearly killed the men involved. This faithful balloon ride is a story that's returned to you throughout the first half of the book. Why were they in a balloon? Well, a balloon was a reasonable way to access the atmosphere, and one of the vehicles that facilitated the discovery of how temperature and pressure vary as a function of altitude, or meaning height in the atmosphere. 

Later, with the invention of weather balloons and then rockets, we discovered more layers and structure to the atmosphere. In a later chapter, we discussed the discovery of cyclonic winds, which was described after someone noticed a spiral pattern in wind-fallen trees after a storm. Later, a theory was developed by William Ferrell that could explain the cyclonic winds. 

Still later, a mathematical generalization, again by Ferrell, which described the fluid motion of the surface of a rotating sphere, kick-started the field of geophysical fluid dynamics. Clark loves to use an analogy or metaphor. For the atmosphere itself, Clark uses a giant. For the wind and weather we feel at Earth's surface, this is the footprint of the planet. 

Next, Clark discusses fields, which for those of you not intimate with a math and physics might be a bit of an abstract topic. The analogy here is a room full of cats and dogs and birds. If you broke up the room into a grid and you assigned a number to each grid cell and that number was based on how many dogs were in the cell, this would be the dog field and so on for the cat and bird field. 

Because cats and dogs and birds react to each other and behave in certain ways, there may be a relationship between the different fields which you might come to after a long time of observation and tinkering around. This is the case for the atmosphere where temperature, pressure, and density fields are related. Be specific, pressure equals temperature times air density. Now we have an equation relating fields and since when there is a function of pressure, we nearly have everything we need for the math underlying weather prediction. Weather being mainly the wind at the surface driven by pressure fields. Wind goes from areas of high pressure to low pressure. 

Areas of high and low pressure exist because the temperature differences around earth and the temperature differences in turn are caused by uneven heating from the sun. There are a couple of interesting features about solar heating. First is that the incoming solar radiation has relatively short wavelengths and the shorter the wave, the higher the energy. The atmosphere is more or less crystal clear for short wave radiation. This means the atmosphere is not directly heated by the sun because the sunlight passes straight through it. Instead, the earth's surface, the land and the ocean absorbs that short wave solar radiation and is heated up. 

Then the earth and the oceans having a temperature, they emit their own radiation but it's much less energetic than the incoming solar radiation. So the earth glow is long wave radiation. The atmosphere, while clear to sunlight, is opaque to earth glow. So the atmosphere is heated from below. The consequence of this is that when heated from below, the atmosphere is unstable and it tends to turn over. Air from the bottom of the atmosphere heats up, the density falls due to the rising temperature. Then that hot low density air is buoyant. It rises up into the atmosphere and is replaced by cool dense air that sinks to the bottom. This is called convection and convection drives a lot of the air movement and therefore wind and weather around earth. If instead it happened that the atmosphere was heated from above, then it would be a stable setup. 

Hot air, which is less dense, would remain at the top and cool dense air would remain at the bottom. The other interesting fact about solar heating is that the equator is much more exposed to sunlight than the poles. You probably knew this. The equator is much hotter than the poles. 

Hopefully you knew this as well. So air moves in response to these pressure gradients, which are primarily a function of the uneven heating around the earth. Clark has a great chapter on trade winds. Here he relays an interesting story where Edmond Halley, the same Halley of Halley's Comet, the same Halley that personally funded the publication of Newton's Principia. Before all that, he traveled to the island of St. Helena aboard a ship owned by the British East India Company. There he collected wind observations from all of the British colonies and was able to not only compile the data into an intelligible graph, clearly showing the location of the trade winds, he also attempted a mathematical explanation that was very close to the right answer. 

The correct answer would have to wait until someone worked out how the conservation of angular momentum worked on a rotating sphere, which was done much later by a Frenchman with a name you might recognize, Coriolis. Next, Clark gets into the connection between weather, which is the day-to-day expression of the atmosphere at a particular location, and climate, which is the longer term average of the state of the weather. He also describes in details the workings of some weather patterns that are longer scale than weather, but shorter than climate. The most important being El Niño, Southern Oscillation, otherwise known as ENSO. 

So ENSO connects the ocean and the atmosphere with effects that are felt globally, including devastating possibility of Indian monsoons not arriving during strong-on El Niños. Clark is able to weave in the historical portions so perfectly. He gives each scientist just enough description and time in the spotlight so they don't feel flat without getting bogged down into the details of their biography. 

In my opinion, this is very difficult to do, and I think Clark handled it with skill. A point that Clark emphasizes is that the development of atmospheric science, and science in general, especially during the 19th and 20th centuries, these were times driven by expansionism and colonialism by the United Kingdom and by other European countries, and any endeavor, including scientific endeavors, relied heavily on colonial institutions and other systematic forms of injustice in order to fund the collection of data and the societies that published the scientific articles. As I've mentioned in connection to other books, science is fundamentally a human thing, and scientists are humans. I think it's an interesting context to bring up these issues, not just for the people who might be harboring ideas about science being above human folly, but very specifically because the data that Edmond Halley and others were able to get was data from around the world and collected in the centralized way. This was only possible because the British had colonies around the globe, and the British East India Company was a global company, and these institutions collected data for their benefit. 

So it could have only been someone like Halley, in the circumstance of where he was born, that he was able to access this data and produce the type of science he was able to produce. The final chapter is called Change, as in Climate Change. This is a great explainer on global warming and the resulting changes in our climate. 

I got the feeling that somehow all the previous chapters in the book were leading up to this. He takes on the history of the development of the topic, including the realization that climate of the past was significantly different to the climate of the present, how and why gases like CO2 increased the heating of the Earth's atmosphere, and the incontrovertible and controversial evidence of global warming and its connection to CO2, which has been increasing steadily since the invention of coal burning engine. He is unequivocal about the scientific consequences around climate change and its causal relationship to human activity, which was made intentionally cloudy by bad faith actors and politicians. He is also pessimistic about the future of humanity if we continue on our current path. 

But as he reminds us, we are in a position to curb our emissions by replacing fossil fuel with renewable energy. The epilogue to the book is a bit of a diversion on the diversity of atmospheres on other planets, which is an interesting topic in and of itself. Then it turns to the thought of humans occupying other worlds, perhaps getting to know other atmospheres. Perhaps we will, and maybe we won't. 

The fact is that humans are a product of Earth, and we would do well to try to keep it as possible to human life and to all life forms by protecting the environment. So, firmament, I really enjoyed this book. Since it's small, it's a quick read, and I went through it a few times. Each time it was a joy to read, and each time I got something new out of it. 

Thanks to Simon Clark for writing this brilliant little book, which is giving me a fresh way to appreciate, like a fish in water, what surrounds us all the time. Alright, thanks for listening. See you all next time. Thanks for listening. 

I am Tripp Collin, and this has been Book Science. Your invitation to thank people, stay curious, get off the scroll, and get out to the world. Take care. Thank you.