In 1911, physicist Ernest Rutherford did his famous "gold foil" experiment, where he determined that at the center of every atom is a small, dense, and positively charged mass. In 1912, he named this the nucleus. However, he wasn't the first person to use that word in reference to tiny particles; Michael Faraday actually coined the term in 1844, but only to refer a hypothetical central point of an atom, so Rutherford really gets the credit there. However, it goes deeper: the word has really been around in English since 1704 as a synoynm for "kernel of a nut", and Faraday just borrowed that because it seemed like a good analogy. However, this had the side effect of making the atomic definition become so popular that it largely drove out the more nutty meaning. Before then, the word was a diminutive of Latin nux, meaning "nut", and that in turn is from Proto-Indo-European kneu, with the same definition.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.