As someone who derives significant income from writing for money, I end up spending a fair bit of time reading writing advice. Not because I'm in need of tips, myself-- after many years of this, I've got a routine that mostly works for me. Rather, I'm looking for good advice to pass on to other people, because I get asked for advice on a regular basis, and I don't really have much of my own to offer.
That's how I came to read this advice post from Alyx Dellamonica, making an analogy between figuring out how fiction works and trying to learn about cars from a junkyard. I like the junkyard analogy quite a bit, but along the way she makes a couple of passing mentions to physics that I absolutely hate. Here's the first:
With the arts, you not a physics professor laying out a formula, some cut-and-dried procedure for which there is one satisfactory answer. You’re not showing someone how to paint the perfect yellow line down the middle of a strip of road, or fly an airplane without making it go kersplat, or performing open heart surgery. The arts are more fungible.
As a physics professor, this drives me nuts, because it's a terrible misconception about what physics is, one that sadly is shared not only by artists and writers but also by all too many of our students. (It's not even a good representation of modern physics education, but that's a side issue, here.)
Far too many of our students, particularly in the "service" courses that are required for engineering and pre-med majors, think that physics is as Dellamonica describes it: You just find the right magic formula, plug in numbers, and get the one correct answer that you check off against the key in the back of the book. Formula-hunting students are the bane of an intro physics professor's existence-- I see students on exams grabbing totally irrelevant formulae from the equation sheets we provide, just because some of the symbols used happen to be the same (the classic example is using an expression for the period of an oscillator as if it's a tension force, because in many books they both get the symbol T). This after I specifically warn them against looking for random magic formulae.
Even at the intro level, physics is not about finding magic formulae and plugging numbers into them. You can, alas, be somewhat successful in introductory classes by formula hunting and memorizing rote algorithms, but then you can be somewhat successful in introductory English classes by writing competent but formulaic essays.
The number of formulae you really need to know in physics, even at the intro level, is actually very small-- for about the first half of introductory Newtonian mechanics, it's pretty much just "F=ma". The hard part is conceptual, not mathematical-- looking at a complex physical situation and figuring out how to capture the essential physics of the situation, and apply a handful of simple rules. For all but the most basic and artificial examples, there are usually multiple paths to getting the same correct answer-- you can choose a different coordinate system, or work with energy instead of forces, and end up with the same answer for anything you might reasonably expect to measure. You can use symmetry arguments to eliminate big chunks of the calculation, or you can plunge right in and do a bunch of math to get to the same place in the end.
In fact, one of the things I try to drive home in intro classes is that it's often useful to use multiple approaches to a single problem as a way to check the answer. If a brute-force calculation shows that something is zero, you should look for a symmetry argument that shows it should be zero, to make sure you haven't made a mistake. If analyzing a circuit in terms of equivalent resistance gives you a particular current value, plug that into Kirchoff's Laws and make sure it checks out.
And, of course, once you're clear of the intro level, the situation is vastly more complicated. As a few seconds' thought would show it must be-- if physics were nothing but plugging numbers into well-known formulae, "physics research" wouldn't be a thing. In fact, the known formulae are only a tiny, not very interesting slice of physics.
We teach those well-worn formulae not because they're useful as is, but because they can be useful approximations to more complicated scenarios. The real business of physics at higher levels is figuring out creative ways to break complicated situations down and use those simple tools to describe pieces of the problem that you then recombine to get something complicated.
At the highest levels, physics is an intensely creative endeavor, involving finding unique approaches to problems that are impractical by other means. Einstein is admired not because he was great at chugging through rote algorithms, but because he had the startlingly original insight that gravity might be a property of spacetime, which led directly to general relativity. Feynman is revered not because he was a great mathematical calculator-- though he was exceptionally good-- but because he found a new way to look at the problems of QED, that made the calculations accessible to people who weren't brilliant. Julian Schwinger solved the same problems using a more standard mathematical approach, which was a gigantic accomplishment in its own right, but he's not held in the same esteem as Feynman because his techniques don't have the same creative flair.
Creativity is essential for physics in experiment as well as theory. In some ways, creativity is even more important in experiments, where you often don't know about the problems that will crop up until they actually happen. And sometimes what seems like a problem at one stage of an experiment turns into a useful tool down the road. To use a few examples from my home subfield of laser cooling, a set of internal sublevels of atoms that initially seemed pointless turned out to be useful for catching atoms in a Magneto-Optical Trap. A MOT coincidentally uses a set of laser polarizations that were essential to achieving ultra-low temperatures via the Sisyphus Cooling technique. Then a different set of internal levels that was a technical annoyance requiring an additional "repumping" laser turned out to be a key tool allowing the amassing of larger numbers of atoms by selectively removing that light from part of the sample. Putting all those elements together made laser cooling a tool that's still creating new opportunities in AMO physics, and allowed the creation of Bose-Einstein Condensation.
And that's just one small group of many examples of the value of creativity and ingenuity in experimental physics. I've read a ton of physics history over the last several years, and every time I dig into a great experiment of the past, I'm blown away by the creative ways they found to solve problems on the way to their final result.
This probably seems a bit harsh for a passing reference in Dellamonica's writing-advice post (which, again, is otherwise very good), but it pokes at a raw nerve for me and a lot of other physicists. We hear this kind of thing all the time and grapple with it in every class we teach. Real physics is very far from the undergrad misconception of a field full of plug-and-chug formula-hunting: it's a vital and creative field, which values original thinking just as much as the arts.
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