nebulajr
4 HN recommenders · recommended in 18 months, 2014–2026
7:33 · 1000K views · Apr 15, 2009
A short clip of Richard Feynman answering an interviewer's question about how magnets work, in which he explains why a why-question has no simple answer without a shared frame of reference.
HN returns to it constantly as a classic on the difficulty of explaining fundamentals and the limits of analogies.
20 comments from Hacker News
this video Richard Feynman explaining magnets is one of the best layman explainers I've seen (in between the ranting). I honestly didn't understand why magnets worked and found this on a late night youtube binge. (But don't search youtube for anything related to magnets, you end up amongst the perpetual motion nuts) Edit: Just to be clear with this video (it had been a while since I last watched it), he doesn't 'explain' magnets as much as he hints at the concepts involved. I already knew about the spins being lined up etc but it was the "you can't put your hand through the chair" comment that gave me the eureka moment.
I'm a physicist specifically working with magnetic systems, but I have very little pre-graduate teaching experience, so take this attempt to answer the question with a grain of salt. The reason some people regard Faraday's original explanation of the eponymous law (it is worth noting that at the time it was widely regarded as inadequate and handwavy) as illuminating is because Faraday visualized his "lines of force" as literal chains of polarized particles in a dielectric medium, thereby providing a seemingly mechanistic local explanation of the observed phenomena. Not much of this mindset survived Maxwell's theoretical program and it has very little to do with how we regard magnetism today. Instead, the unification of electricity and magnetism naturally arises from special relativity, whereas the microscopic basis of magnetism requires quantum mechanics. There isn't really any place for naive contact mechanics in the modern picture of physics, so in that sense I would regard Faraday's view as misleading. Finally, I can't end any "explanation" of magnetism without linking the famous Feynman interview snippet [1] where he's specifically asked about magnetism. It doesn't answer your question directly, but it's worth watching all the more because of it. [1] this video
I don't know if just going to nature is sufficient to get fascinated with biology. In my opinion it takes a fundamental reset in how you think about anything you see. Humans while smart have obviously had to learn to "ignore" thinking about how things work. You don't think too hard about how anything works really. I mean at a cursory level sure, but by vastly different interpretations of the word "cursory", you can change your thirst to know how things you see work at more and more fundamental levels. You don't need to go into nature to get this curiosity except for the possibility that it makes you more meditative. You can look at your arm and think what the hell happens in there at a molecular level to make you move the muscles. Or when someone says nerves conduct electricity what the hell does that mean? I revisit this feynman video of him explaining (or not) magnets every few months and I think it's relevant to this question. this video When I think like that I'm just curious why OP and others blame teachers or whoever else for not inducting the curiosity in them. Like it's someone else's job to make you curious? In my opinion you're either born that way or you're not. Some airport store book isn't gonna make you the next whatever scientist you adulate.
I appreciate it. You're absolutely right about how exciting it is to be able to share explanations with people. This is a video of Feynman's answer to an interviewer asking about what and why you feel something when you put two magnets together this video . It's a great description of the problems inherent to explaining this sort of thing to people. (Also, if anyone knows a video/essay/talk along these lines by a less sexist person, I'd love a link.)
Also there's the problem of context. When someone asks you a question you generally know what kind of answer they expect. In this classic example from Richard Feynman [1] the answer to "Why is Aunt Minnie in the hospital" can be "She broke her hip", "She slipped on the ice and broke her hip", "An ambulance took her there", "Because her husband is concerned for her well being". What's interesting about the Watson approach is that, by taking intelligently composed web pages as input (as opposed to randomly generated texts, or an arbitrary list of atomic facts) the context is already "baked in". Put another way, people make web pages with sentences like "Aunt Minnie is in the hospital because she fell and broke her hip", and don't make web pages with sentences like "Aunt Minnie is in the hospital because the ambulance was headed there and the friction between Aunt Minnie and the bed in the ambulance was high enough to keep them from becoming relatively displaced". [1] this video (Edit: I notice, of course, that I have now created a web page with that exact sentence.)