Yeah, he was like that in person as well. When I was an undergraduate, he would "teach" a seminar on Tuesday afternoons called "PhysX" where you could go and ask any question you wanted. He'd go up to the blackboard and extemporaneously write things down and explain things in such a way that thought you really understood. But when you got back to your room and tried to replicate the chain of reasoning, there were always pieces missing or leaps that you now couldn't make. (It felt like the Star Trek Episode, "Spock's Brain".)

But we all took that as an indication of our own lack of knowledge and intuition and would just try harder.

I had a teacher in the University who took some courses taught by Feynman and had the same experience. He even tried to record some of the lectures, but the result was similar. While he was listening, he felt like everything was very clear. But as soon as he stopped the tape, nothing made sense anymore.

The funny thing is, if I remember his autobiographies correctly, he wouldn't let anyone else get away with that. I think he said that if he didn't understand something, he would always ask about it.

“That which I do not understand, I cannot create”

I also had a prof who took Feynman’s classes. He told us Feynman was a tough grader - he didn’t give partial credits, you either solved a problem or you didn’t.

Bob Ross -- the painter analogy comes to mind.

When Bob was drawing, it looked amazingly simple. That simplicity invited people into trying painting.

Probably very few could ever draw anything remotely similar in quality to him, though.

Physics is a bit like that anyway though, you can't learn it by reading or listening to anyone, you have to solve things yourself from scratch, usually multiple times.

Reading good books/having good lecturers certainly helps, but there is no way to replace the work.

> Reading good books/having good lecturers certainly helps, but there is no way to replace the work.

I watch with wry amusement how schools constantly try to take the work out of learning. It never works. It's like putting labor-saving machinery in the gym - you'll never get stronger. You gotta put in the sweat.

This is the real weakness of most MOOCs. Most people are not disciplined enough to do nearly enough of the real work themselves without some sort of outside incentive. At least not until they have several years of practice.

I think that's fair for trying to master physics or to become a physicist. But if you're looking for an intuitive understanding of the concepts or relearning it, which seems to be what the OP is looking for, Feynman-style seems like the optimal type of book.

I don't think Feynman's books are a replacement for a more traditional physics textbook as a student looking to pass a class, become a physicist, or a hobbyist trying to master it, but I do think they're pretty ideal for someone who wants to get much stronger grasp of the concepts than a layman without having to go through the struggle associated with solving problems they'll never actually apply.

Exactly, Feynman is a seductive writer, and it is a shock how little you can immediately apply after "understanding" a section. Long ago, they used Feynman's books for my introduction to physics, and it was only after struggling with a problem set that we "knew" the material.

http://www.feynmanlectures.caltech.edu/info/exercises.html

Some references to good collections of mathematics problems and solutions would be great for self-study.

Isn't that true for any physics or math texts? You need to do problems. That's why there were exercise books to accompany Feynman's lecture.

I didn't know about the companion exercises. That's great.

Sadly there are not that many availible AFAIK.

It seems as though there are approximately 300 pages' worth. https://www.amazon.com/Exercises-Feynman-Lectures-Physics-Ri...

Very much this. I'd recommend using these books as adjunct material. I found them indispensable as an undergrad when I was struggling to shift from a mathematician's rigor-and-proof perspective to a physicist's intuition-and-approximation perspective. However, I don't think I could have come close to passing my QM or E&M courses, even with a mathematical background that was stronger than most of my peers, if I'd only used Feynman to learn the physics.

It's a very good start. From there I think the most productive thing anyone could do is make a very thorough study of Classical Mechanics. People underestimate how much a thorough knowledge will help them. Start with an easy book and work your way up. Goldstein and Laundau are excellent intermediate level choices. For a beginner I think Jakob Schwichtenbergs "No Nonsense Classical Mechanics" could work or Leonard Susskind's "Theoretical Minimum Classical Mechanics" . Personally, I really liked Jakob's book. You'll need a friend or a study group online to help you when you get stuck. Classical mechanics is very serious physics and I regard a thorough foundation in say Hamiltonian Mechanics as a solid achievement. a sure sign someone could go on and learn E&M, Statistical mechanics, Quantum mechanics, Relativity and Gauge theories. For a semi advanced book if you know some advanced maths try Spivak's Classical Mechanics and anything by V. Arnold.

I daresay you would have the same experience with any other book.

If you just read a book and don't work through problems yourself, you simply don't learn enough to do it yourself.

I agree in general, but Feynman’s books are different. I usually read textbooks cover to cover; then go on to solve the hardest problems I can find at that level (sometimes they are from the book, sometimes from different sources).

Most books, I make some progress on some problems, get stuck on others, and generally have a good grasp of the overall landscape and where I am lacking; then I go back and reread (and practice) the missing pieces.

But Feynman’s lectures are different in that they make you feel you understand a lot, without really giving you any tools to address things he did not address (and basically only address those things he did address in the same way).

I am not saying they are bad - 25 years later, I still remember (and occasionally use) some of them; most recently insights from the chapter on minimum principles. I am just saying that it only became useful after I already had a good (but not great) grasp of the material from other sources — despite giving that impression when read as introductory.

Came here to say this. The professors I've learned the most from were the ones who weren't awesome at explaining things. I didn't understand them and had to struggle through the material. That struggle made the material stick more. I think ideally you want a professor who's 80% good at explaining things, but leaves enough gaps and says things just confusingly enough that you have to engage your brain. Feynman was too clear, which allowed my brain to coast.

At a meta level, I think this means we'll never (as a society) be great at teaching, because teachers who make us work make us feel like we're learning less. We prefer (and rate more highly) the professors, like Feynman, who make us feel smart.

disagree here. you're judging society on the most naive ranking a student would give. in an ideal world you can optimize for the perfect amount of understanding and imperfect leaps for each student to best address long term understanding and success.

You're right that in principle it's possible. But say you were a great teacher, and knew that clear teaching was worse than imperfect teaching. Could you actually make your lectures less clear on purpose?

Personally I thought the Feynman lectures were ok but with room for improvement.

Vol 1 was good. Vol 2 was good though overly repetitive, iirc it's 90 percent Maxwell's equations. Vol 3 was unintuitive to me. Still I learned qm from it and made this http://tropic.org.uk/~crispin/quantum/

I'm fairly confident I get qm now, but most of that understanding came from trying to code it in simulation. Which suggests there are better ways to learn than Feynman 3.

My understanding is that you can't learn without going through mistakes first.

If you find it intuitive, you find it correct and the brain doesn't change your neural structure; because why would it? No neural structure change -> you didn't learn anything.

If you find it difficult, do mistakes, can't get the correct answer -> your brain start to change its neural structure to be able to resolve these problems -> you learn.

People want intuitive explanations because it seems the easiest. It is, that's the problem. Learning is supposed to be painful. You have to get your hands dirty.

It's easier to feel that you know something than to actually know it.

Learning requires a lots of false starts, traps, etc. Once one has mastered, he/she can provide an intuitive explanation (a path through the wild forest that learning is).

After doing the hard learning, you can lecture your intuitive mental model you have. But it's difficult to install that mental model into a beginner's mind. Often the intuitions are illusory mnemonics for the deeper understanding, which if you never learned in the first place would just point to nothing. You have to do the hard learning to arrive at the "intuitive" mental model.

While i see where you are coming from; i feel that you are putting the cart before the horse. While Intuition by itself is not enough, it should absolutely be the first thing you should focus on before doing the hard work through rigor and formalisms. The former can be "grasped" while the latter needs "practice and applications". This is how Science itself developed (a good example is Faraday vs. Maxwell's approaches). Intuition/Rigor are analogous (in a certain sense) to Theory/Practice. You need both, each amplifying the other's effects at various stages.

Here is a neat communication from Faraday to Maxwell on receiving one of Maxwell's paper;

“Maxwell sent this paper to Faraday, who replied: "I was at first almost frightened when I saw so much mathematical force made to bear upon the subject, and then wondered to see that the subject stood it so well." Faraday to Maxwell, March 25, 1857. Campbell, Life, p. 200.

In a later letter, Faraday elaborated:

I hang on to your words because they are to me weighty.... There is one thing I would be glad to ask you. When a mathematician engaged in investigating physical actions and results has arrived at his conclusions, may they not be expressed in common language as fully, clearly, and definitely as in mathematical formulae? If so, would it not be a great boon to such as I to express them so? translating them out of their hieroglyphics ... I have always found that you could convey to me a perfectly clear idea of your conclusions ... neither above nor below the truth, and so clear in character that I can think and work from them. [Faraday to Maxwell, November 13, 1857. Life, p. 206]”

"Hard work" is not just rigor and formalism. Hard work is going through a lot of intuitive models that turn out to be false. If seen this way, the comment you respond to, makes sense.

> It's easier to feel that you know something than to actually know it.

Well said! All students need to keep this in mind.

At Caltech (home of Feynman) in the 1970s, his books were not used as the main texts in physics classes, but as supplements.