Ideas aren’t getting harder to find and anyone who tells you otherwise is a coward and I will fight them

Photo cred: my dadI’ve worked with a lot of research assistants over the years, and at some point we inevitably have The Talk: should they get a PhD? I was recently having The Talk with one particularly distraught student, who was worried her ideas aren’t good enough. “Maybe I’m not cut out for it,” she told me, “or maybe all of the easy ideas have already been done.”Like her, I’ve worried that I was born too late and all the low-hanging fruit was picked before I got here. Fifty years ago, you could get a million citations just for showing that people like their own team the best, that kids will do something that they watch other people do, or that people think other people agree with them. Everything obvious has been done, and now it’s up to poor schmucks like me to figure out the hard stuff.Lots of people who think hard about the progress of science seem to come to the same conclusion:Scott Alexander:All the low-hanging fruit has already been picked […] it’s almost inconceivable that it could ever be otherwise.Holden Karnofsky: [I]deas naturally get harder to find over time, and we should expect art and science to keep slowing down by default.Dean Keith Simonton: The days when a doctoral student could be the sole author of four revolutionary papers while working full time as an assistant examiner at a patent office — as Einstein did in 1905 — are probably long gone. Natural sciences have become so big, and the knowledge base so complex and specialized, that much of the cutting-edge work these days tends to emerge from large, well-funded collaborative teams involving many contributors.Everyone agrees: we must resign ourselves either to tweaking what came before or spending our lives descending deeper and deeper into the idea mines, searching for the few nuggets of originality left.I once found this idea seductive. Now I find it outrageous. It’s not just because it’s wrong; it’s an affront to the human spirit. People only discover stuff when they think it’s worth trying, and there have been entire eras of human history where people didn’t think it was worth trying. A meme like “ideas are getting harder to find” could drive the desire to discover back into hiding again, fulfilling its own abominable prophecy. Somebody needs to defend the belief that mere mortals can still discover useful truths, and it’s me. I’m here to be that somebody.If we’re going to entertain, say, defunding theoretical physics on the grounds that there’s just no more useful physics to do, we should at least ask: could any cognitive biases be at play here?I can see two. First, all ideas seem obvious in retrospect. Heliocentrism, germ theory, and randomized controlled trials look like no-brainers once someone explains them to you, but they took people thousands of years to figure out. ("E = mc^2? That’s just three letters and a number!”)Second, it’s always going to feel hard to think of new ideas. What should we do next in physics, biology, music, or film? Gosh, I don’t know! I’d have to think pretty hard, just like everybody before me, and I might not come up with anything, just like almost everybody before me. So if past ideas seem obvious and future ideas seem obscure, it’s tempting to conclude we live at the inflection point where ideas suddenly get harder to find. And maybe we do. But we’d feel that way even if ideas weren’t getting harder to find, and that should make us a little skeptical.If our ancestors also thought they were running out of ideas and were wrong, then we should be wary about thinking the same thing. Our ancestors did think that, and they were wrong.For instance, physics was apparently about to end in the 1890s:Max Planck later remembered a professor telling him that during this period, “the system as a whole stood there fairly secured, and theoretical physics approached visibly that degree of perfection which, for example, geometry has had already for centuries.” The British scientist William Cecil Dampier recalled his apprenticeship at Cambridge in the 1890s: “It seemed as though the main framework had been put together once for all, and that little remained to be done but to measure physical constants to the increased accuracy represented by another decimal place.” British physicist J. J. Thomson: “All that was left was to alter a decimal or two in some physical constant.” American physicist Albert A. Michelson: “Our future discoveries must be looked for in the sixth place of decimals.”Surgery was nearing perfection in 1873:There cannot always be fresh fields for conquest by the knife. There must be portions of the human frame that will ever remain sacred from its intrusion – at least, in the surgeon’s hand. That we have nearly, if not quite, reached these final limits there can be little question.Psychology was on track to wrap up before 1920, according to the behaviorist John Watson:I believe we can write a psychology […] and never go back upon our definition: never use the terms consciousness, mental states, mind, content, introspectively verifiable, imagery, and the like. I believe that we can do it in a few years…It was only going to take a couple of dudes and a summer to solve some of the fundamental problems in artificial intelligence:We propose that a 2-month, 10-man study of artificial intelligence be carried out during the summer of 1956 at Dartmouth College in Hanover, New Hampshire. The study is to proceed on the basis of the conjecture that every aspect of learning or any other feature of intelligence can in principle be so precisely described that a machine can be made to simulate it. An attempt will be made to find how to make machines use language, form abstractions and concepts, solve kinds of problems now reserved for humans, and improve themselves. We think that a significant advance can be made in one or more of these problems if a carefully selected group of scientists work on it together for a summer.(They didn’t solve everything but they did start the field of artificial intelligence, so it was still a pretty productive summer, all things considered.)When I wrote recently about how all popular stuff now comes from just a few franchises and superstars, one of the responses on Twitter was:Glyn Hughes@SquashedBoxI suppose the day has to come sooner or later when we've used up all the new ideas. Adam Mastroianni @a_m_mastroianniChart-topping original movies have gone extinct. People have a lot of explanations for this, but they're all incomplete because they don't realize the same thing is happening everywhere. An oligopoly has conquered all of popular culture. https://t.co/9oVoSIlNdj7:29 PM · May 4, 20221 LikeBut there’s more original content than ever; it’s only popular content that's been dominated by reruns. Clearly, it’s easy to rush to the conclusion that we’re close to the end of ideas, and easy to be wrong.Pessimists seem to think that the universe was born with a long list of discoveries, ordered from easy to hard, like this:As time goes on, the thinking goes, more and more of the easy discoveries get crossed off the list, leaving only the hard ones. But knowledge doesn’t work like this at all. Every discovery opens up additional discoveries to make:Which in turn lead to more discoveries: And so on.You might worry that this means discovery gets harder over time because you have to follow a chain to its end before you can add a new link. Fortunately:We can all agree that discovering fire was pretty rad. The first humans to do it probably spent a lot of time learning which kind of kindling was best, how to nurse a spark into a flame, and what sorts of fires were best for cooking vs. heating. They must have painstakingly passed this knowledge from generation to generation, and youngsters had to practice making lots of fires before they got it right.But in 2022, I don’t have to do any of that. When I need to cook, I turn on the stove and it makes fire for me. Or I tap a button on my phone and a human makes food for me using their own fire, then they bring it to me. When it gets cold, a fire in the basement turns on, heats up some water, and then the water flows up into the room where I live and makes me warm, too. I don’t really know how any of this works. All the fire-knowledge I’ll ever need is encoded into the innovations that surround me.This is how science works, too. To do science, you don’t need to start with the dawn of all human knowledge and then work forward. You start with the current state of knowledge and go from there. Learning the history of science is helpful for shaping your intuitions and giving you perspective, but you don’t actually have to read Darwin, for example, to do evolutionary biology.That’s why I’m puzzled by the claim that scientists must labor under an ever-increasing burden of knowledge. The author of that paper writes: “If one is to stand on the shoulders of giants, one must first climb up their backs, and the greater the body of knowledge, the harder this climb becomes.” This suggests that if you peek into PhD programs, you’ll see lots of students bent over their books, desperately trying to learn everything that’s come before so they can start their own projects. “I can’t do any physics yet,” you might hear them lament. "I’m only up to Huygens!” Instead, you’ll see PhD students doing original research from Day 1—and often long before. Indeed, many students start doing more interesting work once they stop looking at lots of previous work, as it finally frees them from imitating other people and searching for “gaps in the literature,” two strategies that are unlikely to yield anything interesting.The world heats up. Stars explode. Species invade. Tectonic plates shift around. The internet upends society. Wars break out, diseases spread, and an ambiguously colored dress turns brother against brother. All of this demands explanation, and we’re the ones who get to explain it, because all the scientists of yore are dead. We probably won’t get far before a