I read Zen and the Art of Motorcycle Maintenance in high school. It’s got a reputation for being obnoxiously mystical, but one of its points seemed pretty reasonable: the claim that the hard part of science, and the part we understand the least, is coming up with hypotheses.
In some sense, theoretical physics is all about hypotheses. By this I don’t mean that we just say “what if?” all the time. I mean that in theoretical physics most of the work is figuring out the right way to ask a question. Phrase your question in the right way and the answer becomes obvious (or at least, obvious after a straightforward calculation). Because our questions are mathematical, the right question can logically imply its own solution.
From the point of view of “Zen and the Art”, as well as most non-scientists I’ve met, this part is utterly mysterious. The ideas you need here seem like they can’t come from hard work or careful observation. In order to ask the right questions, you just need to be “smart”.
In practice, I’ve noticed there’s more to it than that. We can’t just sit around and wait for an idea to show up. Instead, as physicists we develop a library of tricks, often unstated, that let us work towards the ideas we need.
Sometimes, this involves finding simpler cases, working with them until we understand the right questions to ask. Sometimes it involves doing numerics, or using crude guesses, not because either method will give the final answer but because it will show what the answer should look like. Sometimes we need to rephrase the problem many times, in many different contexts, before we happen on one that works. Most of this doesn’t end up in published papers, so in the end we usually have to pick it up from experience.
Along the way, we often find tricks to help us think better. Mostly this is straightforward stuff: reminders to keep us on-task, keeping our notes organized and our code commented so we have a good idea of what we were doing when we need to go back to it. Everyone has their own personal combination of these things in the background, and they’re rarely discussed.
The upshot is that coming up with ideas is hard work. We need to be smart, sure, but that’s not enough by itself: there are a lot of smart people who aren’t physicists after all.
With all that said, some geniuses really do seem to come up with ideas out of thin air. It’s not the majority of the field: we’re not the idiosyncratic Sheldon Coopers everyone seems to imagine. But for a few people, it really does feel like there’s something magical about where they get their ideas. I’ve had the privilege of working with a couple people like this, and the way they think sometimes seems qualitatively different from our usual way of building ideas. I can’t see any of the standard trappings, the legacy of partial results and tricks of thought, that would lead to where they end up. That doesn’t mean they don’t use tricks just like the rest of us, in the end. But I think genius, if it means anything at all, is thinking in a novel enough way that from the outside it looks like magic.
Most of the time, though, we just need to hone our craft. We build our methods and shape our minds as best we can, and we get better and better at the central mystery of science: asking the right questions.