history of 19th century physics is fascinating; big questions that took a really long time to resolve, often because the right answer defied common sense the g

history of 19th century physics is fascinating; big questions that took a really long time to resolve, often because the right answer defied common sense the guy who in 1901 developed the double-slit experiment, actually a single paper card back then, created a mystery that lasted at least a century, if not until today. (it was the same guy who decoded the rosetta stone, weirdly). In a large way the project of the century was understanding the elements, separating them and measuring their weights. I think constantly about this 1870s essay by an important geochemist asking 'are the elements elementary'[1]. It is nearly poetry (to me at least). the key observations coevolved with the math, so sometimes experiment led (someone put a wire near a compass and the compass moved), other times the math led. (As in the 20th century, when lasers were a numeric phenomenon before anyone thought to build one). Maxwell's math feels to me like it's at the center of it all. A 20th century physicist, Wigner, has an essay about the 'unreasonable effectiveness of math in science'. maxwell's equations predict a speed limit for light, and were largely intact in einstein. (the speed of light was known experimentally way before this from eclipse observations, I think). you could say that maxwell + electron research + planck led naturally to einstein, and there's no reason someone's annus mirabilis couldn't have been 50 years earlier other than that it took this long to think of these ideas. if there's any takeaway from this history it's that big questions, if you sink your teeth into them, lead to big answers 1. https://books.google.com/books?id=CSIDAAAAMBAJ&pg=PA463 https://books.google.com/books?id=CSIDAAAAMBAJ&pg=PA463