old fashioned science never stopped

[impossiblewizardry]

• Evolution by mutation and natural selection
• Quantum mechanics
• Relativity

When you picture the origins of these theories it's Darwin making sketches of birds or Einstein scribbling equations.

We've done a lot since then, like the human genome project and the standard model, and the character of the research seems to have changed. Big projects where each person plays a small part, expensive equipment like particle accelerators and space telescopes, and computers.

I want to argue though that the "one person with a notebook" type research never really stopped, not just because people had to do that to explain particle accelerator results, but because people kept making scientific advances that in principle could have been made in the early 20th century.

• Density functional theory, originating in the 1960s, nobel prize 1998. It's the basis of the computer programs used to get wavefunctions for large systems. But also it's just a convenient mathematical reformulation of quantum mechanics. For example you can derive a theoretical basis for something like Pauling's electronegativity scale. I imagine Pauling would have loved that, though idk of any comment from him.
• The coalescent process, originating in the 1980s. It's what's used in computer programs for data-based inference of stuff like how long ago a SNP originated or whether it was selected for. But it's also just an extremely convenient way to derive some of the basic evolution math stuff. Fisher would have loved it had he lived to see it.

These are mathematical reformulations of existing theories, which turned out to be very useful for computational work, but which are also of independent value. It seems to me they could have been thought of at any time during the 20th century, but in fact were thought of pretty late. Basically, when Fisher, Einstein, Heisenberg etc were working out the foundations of the new 20th century theories, they didn't go as far as they could have with their pencils and paper. There was still plenty of worthwhile pencil-and-paper work left to do through out the 20th century. And, maybe even up to today, I don't know.

Oh, I'd add a third bullet point related to general relativity, if I knew anything about it. But there must be something. There's been an explosion of GR practice to explain all the weird stuff we see with modern telescopes, and it's hard for me to believe it has much resemblance to Einstein's GR practice.

I do think that these mathematical reformulations are events of comparable insight and impact to the original discoveries of the theories. They're why we can actually do stuff with the theories. I don't think we would care nearly so much about quantum mechanics if it didn't turn out that it could be applied.