Christopher Sykes
3 HN recommenders · recommended in 15 months, 2010–2017
7:33 · 1.6M views · Dec 28, 2008
A clip from the BBC Fun to Imagine series in which Richard Feynman is asked how magnets work and explains why 'why' questions depend on a shared framework of understanding and cannot always be answered in layman's terms.
Cited constantly when discussing explaining to non-experts, the limits of explanation and what a 'why' question really asks.
16 comments from Hacker News
Of anyone I've read or seen (in person or from videos), Feynman has the best fundamental grasp of meta-knowledge. By meta-knowledge, for lack of a better term, I mean understanding what it means to know something. mhartl has already posted this excellent video: this video , where he explains what the word "why" means in scientific inquiry. When we answer a "why" question, we don't really explain a concept in its entirety. At best, we're able to remove a layer of skin off the onion, but no one has ever really reached the center. I suppose science at it's heart is really just the elucidation of intermediate cause and effect scenarios. For the question "why did the ball fall?", "Jimmy dropped it" is a perfectly valid answer. So is "Jimmy's motor neurons passed an action potential threshold, causing the muscles in his wrist to contract". So is "the ball moved along the curvature of space caused by the earth". How far do we go?
Sometimes it's not always possible to explain something in sufficient detail to someone who has no concept of what you are trying to explain. Feynman explains this really well when trying to answer a question about magnets: "Of course, it's an excellent question. But the problem, you see, when you ask why something happens, how does a person answer why something happens? For example, Aunt Minnie is in the hospital. Why? Because she went out, slipped on the ice, and broke her hip. That satisfies people. It satisfies, but it wouldn't satisfy someone who came from another planet and who knew nothing about why when you break your hip do you go to the hospital... when you explain a why, you have to be in some framework that you allow something to be true. Otherwise, you're perpetually asking why." "I can't explain that attraction in terms of anything else that's familiar to you. For example, if we said the magnets attract like if rubber bands, I would be cheating you. Because they're not connected by rubber bands. I'd soon be in trouble. And secondly, if you were curious enough, you'd ask me why rubber bands tend to pull back together again, and I would end up explaining that in terms of electrical forces, which are the very things that I'm trying to use the rubber bands to explain. So I have cheated very badly, you see." The key quote being: "I really can't do a good job, any job, of explaining magnetic force in terms of something else you're more familiar with, because I don't u
For those who think this doesn't sound at least a little bit like Feynman, I highly recommend this video: this video
This Feynman quote from the article is put in the wrong context: > I really can’t do a good job, any job, of explaining magnetic force in terms of something else you’re more familiar with, because I don’t understand it in terms of anything else you’re more familiar with. The article implies this is a case of the scientist expressing that he didn't understand a thing. But watching the video in full[1], one realizes he is saying something different: "It's a force which is present all the time and very common and is a basic force. [...] I can't explain that attraction in terms of anything else that's familiar to you. For example if we say that magnets attract like as if they are connected by rubber bands I would be cheating you because they're not connected by rubber bands-- I should be in trouble if you soon ask me about the nature of the band. And secondly, if you were curious enough you would ask me why rubber bands tend to pull back together again, and I would end up explaining that in terms of electrical forces which are the very things that I'm trying to use the rubber bands to explain. So I have cheated very badly, you see." In other words, for some phenomena the only simple examples are themselves instances of that same phenomena. So the only possible analogies are themselves merely tautologies. I've noticed something less sweeping though similarly absurd with the internet. As more and more of people's daily lives depend on internet technologies, it becomes more difficul
I would argue that it (unlike all the other things that did not evolve) did evolve for the reason that it was useful. It's not like all of a sudden there was someone that had wrinkly fingers and that "stuck around because it was useful". In all likelihood, there were many incremental changes that were progressively selected for and the "reason" for that selection is that it was useful. It seems to me that it's perfectly acceptable language to say that a cause is the "reason" for an effect, even if it's not possible to assign intent. Your comment reminds me of Feynman responding to the question of why magnets attract each other ( this video ) which, while inscrutable from a physical point of view, seems not to be a fruitful way of approaching questions. There are always levels of deeper understanding, but you have to take it one level at a time.