The last part of today’s discussion about the application of conceptual knowledge to solving real-world problems reminded me of a college friend of mine in the 1970s who was studying Materials Science. He had a book of equations, organized strictly along the lines of mathematical logic. A part of his work process was to look at experimental results, and then look through the book of equations to try to find one that fit the results. He could then use the equations both descriptively and predictively for future experiments, to characterize the behavior of material and to invent new materials. I thought this was a really interesting process. It baffled me at the time, because my mathematical knowledge was limited to simple calculus and this was very advanced differential equations, etc. But it seemed like a logical approach for someone who could wrap their head around the math. I imagine that today much of this would be done using computers, but this was in the days of punch cards and batch processing.