It may surprise you to learn that I came late to the joys of Geology. Ten years ago, as I was preparing to start University, I had decided that life as a physicist was my scientific destiny, and I hadn’t given much thought to earth sciences since I dropped Geography at the age of 14; I had a fatal allergy to urban growth models and surveys of supermarket parking, which seemed to take up most of the syllabus.
However, my undergraduate degree was in Natural Sciences, which meant that it my first year, in addition to Physics and Maths, I had to take courses in two other experimental sciences, and in addition to Cell Biology, I opted to complete my set with Geology. I’d like to say that this was a decision made after long nights of serious deliberation, but I must confess that – not for the first or last time – what turned out to be one of the more important decisions in my life was pretty random and spur-of-the-moment. I thought that learning a bit more about earthquakes and volcanoes would be quite cool, and there was the additional attraction of field trips to satisfy my wanderlust.
So how did a random choice to fill my timetable become a consuming passion – so much so that I ended up specialising in it as an undergraduate, allowed 4 years of my life to be eaten by a PhD, and seem to spend most of my off-hours to be consumed by writing about it? The answer to that lies in the fact that the scientific enterprise is not a great monolith of uniformity. The underlying philosophy of seeing how your ideas about how the world works hold up against its reality remains the same, but the actual experience of practising science can differ greatly between fields. Physics is all about boiling the world down to its essence: taking a system and reducing it to an ideal case which can be more easily modelled, and then seeing how well the behaviour of that model describes the phenomenon you’re investigating. As it turned out, my somewhat practical* turn of mind, and my need to grapple with real-world examples** before I could get physical concepts straight in my head, was ill-suited to the very theoretical and maths-oriented physics courses at Cambridge, which meant that I struggled. This is clearly not a problem in Geology: you don’t struggle for real-world examples in a subject in which the world is the object of study! Flippancy aside, I’ve lost count of the number of times that equations which caused my brain to crash when I first encountered them in isolation in Physics lectures made a lot more sense when they cropped up accompanied by a demonstration of their application in Geophysics. I’m not sure how or why, but I can manipulate physical things in my head much more easily than I can manipulate equations, and in Geology that’s an asset rather than a problem.
Geology is also much more messy than Physics, because you can’t generally simplify things; it’s often all the little quirks and details that you’re interested in. A geological problem resembles a complicated jigsaw puzzle: you’re trying to reconstruct an accurate picture of the geological past from the clues left behind in the rock record. These clues are diverse in nature – you can find yourself using the tools of physics, chemistry or biology, or even all three in unison – and, because you almost never have all of the pieces, fitting the ones you do have together in a consistent way is very challenging, and very rewarding. Best of all, rather than an incomprehensible set of equations, the end result of your intellectual struggle is usually a story: how that mountain range was built, how that dinosaur lived, how that ice sheet has waxed and waned. I like teasing out those stories, and I like telling them.
The other appealing difference between Physics and Geology is that Geology has only really matured as a science in the last half century or so, as we finally got to grips with the concepts of plate tectonics and deep geological time (although, of course, the roots of both ideas stretch further back) and the framework they provide for understanding much of the history recorded in the rocks we study. There are therefore many more fundamental questions which remain unanswered, and many parts of geological history which are still poorly understood. Physicists are of course also pursuing answers to deep and important questions, but in geology it seems much easier to not only find yourself at the cutting edge, but also in a position to make an important contribution. I liked the fact that in my geology lectures we would often find ourselves hearing about modern questions to which there was no agreed answer – where, with a bit of reading and thinking, you could come to your own conclusions, which were just as valid as anyone else’s. Getting involved in a good argument makes you feel like you’re a scientist much more than learning about an argument which was done and dusted 150 years ago does.
Before I inadvertently start a flame war, I should point out that I am only arguing that Geology is better in Physics in personally subjective terms – in other words, it is better for me. The differences which I’ve highlighted above are things which fit my own temperament: I prefer messy reality to the purity of simple equations; I like puzzling together often contradictory evidence from a wide range of sources; I like spirited arguments. However, I can be quite stubborn at times, so it took me considerably longer than it should have for me to admit that the future I had set out for myself almost a decade previously was the wrong one for me, even after I started freaking out my friends by spending a scary amount of time looking down at the rocks rather than up at the scenery when out walking. It took a particularly incomprehensible lecture on thermodynamics in the spring of my second year to finally make me think the previously unthinkable thought: “why don’t I just specialise in Geology next year instead?”
So I did, and I’ve never looked back.
*Translation: I’m not great at maths.
**As above, just with a few reallys added.