Trying to invent your own physics without studying real physics just makes you into a physics crank
This is demonstrably not (always) the case. Famously, Richard Feynman recommends that students always derive physics and math from scratch when learning. In fact his Nobel prize was for a technique (Feynman diagrams) which he developed on the fly in a lecture he was attending. What the speaker was saying didn’t make sense to him so he developed what he thought was the same theory using his own notation. Turns out what he made was more powerful for certain problems, but he only realized that much later when his colleagues questioned what he was doing on the whiteboard. (Pulled from memory from one of Feynman’s memoirs.)
One of the other comments here recommends against this unless you are a Feynman-level genius, but I think the causality is backwards on this. Feynman’s gift was traditional rationality, something which comes through very clearly in his writing. He tells these anecdotes in order to teach people how to think, and IMHO his thoughts on thinking are worth paying attention to.
Personally I always try to make sure I can derive again what I learn from first principles or the evidence. Only when I’m having particular trouble, or I have the extra time do I try to work it out from scratch in order to learn it. But when I do I come away with a far deeper understanding.
This is demonstrably not (always) the case. Famously, Richard Feynman recommends that students always derive physics and math from scratch when learning.
What Feynman recommended was to learn a topic, then put the book aside and see if you can rederive what you have supposedly learned on your own. This has little to do with the thesis you had quoted. I can take a bet 1000:1 that anything a person who has not studied “real physics” can propose as a their own physics will be at best a duplication of long-ago models and most likely just straight up nonsense. I suspect that there hasn’t been anyone since Faraday who made original useful contributions to physics without being up to date on the state of the art in the field. Not even Tesla made any foundational contributions, despite having a decent physics education.
I think we may be talking past each other. You say
What Feynman recommended was to learn a topic, then put the book aside and see if you can rederive what you have supposedly learned on your own.
That’s what I meant when I said “Feynman recommends that students always derive physics and math from scratch when learning.” You know the context. You know the evidence. You know, in the form of propositional statements, what the answer is. So make an attempt at deriving it yourself from the evidence, not the other way around.
In doing so, I often find that I didn’t really understand the original theory. What is built up in the from-scratch derivation is an intuitional understanding that is far more useful than the “book knowledge” you get from traditional learning. So, I would say, you never really learned it in the first place. But now we’re debating word definitions.
The other thing that you develop is experience deriving things “from scratch,” with just a couple of hints as necessary along the way, which sets you up for doing innovative research once you hit the frontier of knowledge. Otherwise you fall victim to hindsight bias in thinking that all those theorems you read in books seemed so obvious, but discovering something new seems so hard. In reality, there is a skill to research that you only pick up by doing, and not practicing that skill now when the answers could be looked up when you get stuck, is a lost opportunity.
I like this answer, but do question the point about Feynman’s gift being mainly traditional rationality.
One of the other comments here recommends against this unless you are a Feynman-level genius, but I think the causality is backwards on this. Feynman’s gift was traditional rationality, something which comes through very clearly in his writing. He tells these anecdotes in order to teach people how to think, and IMHO his thoughts on thinking are worth paying attention to.
I agree that Feynman portrays it that way in his memoirs, but accounts from other physicists and mathematicians paint a different picture. Here are a few example quotes as evidence that Feynman’s gifts also involved quite a bit of “magic” (i.e. skills he developed that one would struggle to learn from observation or even imitation).
First, we have Mark Kac, who worked with Feynman and was no schlub himself, describing two kinds of geniuses of which Feynman was his canonical example of the “magician” type (source):
In science, as well as in other fields of human endeavor, there are two kinds of geniuses: the “ordinary” and the “magicians.” An ordinary genius is a [person] that you and I would be just as good as, if we were only many times better. There is no mystery as to how his mind works. Once we understand what he has done, we feel certain that we, too, could have done it. It is different with the magicians. They are, to use mathematical jargon, in the orthogonal complement of where we are and the working of their minds is for all intents and purposes incomprehensible. Even after we understand what they have done, the process by which they have done it is completely dark. They seldom, if ever, have students because they cannot be emulated and it must be terribly frustrating for a brilliant young mind to cope with the mysterious ways in which the magician’s mind works… Feynman is a magician of the highest caliber.
(Note that, according to this source, Feynman did actually have 35 students, many of whom were quite accomplished themselves. so the point about seldom having students doesn’t totally hold for him.)
Sidney Coleman, also no slouch, shared similar sentiments (source):
The generation coming up behind him, with the advantage of hindsight, still found nothing predictable in the paths of his thinking. If anything he seemed perversely and dangerously bent on disregarding standard methods. “I think if he had not been so quick people would have treated him as a brilliant quasi crank, because he did spend a substantial amount of time going down what later turned out to be dead ends,” said Sidney Coleman, a theorist who first knew Feynman at Caltech in the 50′s.
“There are lots of people who are too original for their own good, and had Feynman not been as smart as he was, I think he would have been too original for his own good,” Coleman continued. “There was always an element of showboating in his character. He was like the guy that climbs Mont Blanc barefoot just to show that it can be done.”
Feynman continued to refuse to read the current literature, and he chided graduate students who would begin their work on a problem in the normal way, by checking what had already been done. That way, he told them, they would give up chances to find something original.
“I suspect that Einstein had some of the same character,” Coleman said. “I’m sure Dick thought of that as a virtue, as noble. I don’t think it’s so. I think it’s kidding yourself. Those other guys are not all a collection of yo-yos. Sometimes it would be better to take the recent machinery they have built and not try to rebuild it, like reinventing the wheel. Dick could get away with a lot because he was so goddamn smart. He really could climb Mont Blanc barefoot.”
Coleman chose not to study with Feynman directly. Watching Feynman work, he said, was like going to the Chinese opera. “When he was doing work he was doing it in a way that was just—absolutely out of the grasp of understanding. You didn’t know where it was going, where it had gone so far, where to push it, what was the next step. With Dick the next step would somehow come out of—divine revelation.”
In particular, note the last point about “divine revelation”.
Admittedly, these are frustratingly mystical. Stephen Wolfram describes it less mystically and also sheds light on why his descriptions of his discoveries always made them seem so obvious after the fact even though they weren’t (source:
I always found it incredible. He would start with some problem, and fill up pages with calculations. And at the end of it, he would actually get the right answer! But he usually wasn’t satisfied with that. Once he’d gotten the answer, he’d go back and try to figure out why it was obvious. And often he’d come up with one of those classic Feynman straightforward-sounding explanations. And he’d never tell people about all the calculations behind it. Sometimes it was kind of a game for him: having people be flabbergasted by his seemingly instant physical intuition, not knowing that really it was based on some long, hard calculation he’d done.
He always had a fantastic formal intuition about the innards of his calculations. Knowing what kind of result some integral should have, whether some special case should matter, and so on. And he was always trying to sharpen his intuition.
Now, it’s possible that all this was really typical rationality, but I’m skeptical given that even other all star physicists and mathematicians found it so hard to understand / replicate.
All that said, I think Feynman’s great as is deriving stuff from scratch. I just think people often overestimate how much of Feynman’s Feynman-ness came from good old fashioned rationality.
This is demonstrably not (always) the case. Famously, Richard Feynman recommends that students always derive physics and math from scratch when learning. In fact his Nobel prize was for a technique (Feynman diagrams) which he developed on the fly in a lecture he was attending. What the speaker was saying didn’t make sense to him so he developed what he thought was the same theory using his own notation. Turns out what he made was more powerful for certain problems, but he only realized that much later when his colleagues questioned what he was doing on the whiteboard. (Pulled from memory from one of Feynman’s memoirs.)
One of the other comments here recommends against this unless you are a Feynman-level genius, but I think the causality is backwards on this. Feynman’s gift was traditional rationality, something which comes through very clearly in his writing. He tells these anecdotes in order to teach people how to think, and IMHO his thoughts on thinking are worth paying attention to.
Personally I always try to make sure I can derive again what I learn from first principles or the evidence. Only when I’m having particular trouble, or I have the extra time do I try to work it out from scratch in order to learn it. But when I do I come away with a far deeper understanding.
What Feynman recommended was to learn a topic, then put the book aside and see if you can rederive what you have supposedly learned on your own. This has little to do with the thesis you had quoted. I can take a bet 1000:1 that anything a person who has not studied “real physics” can propose as a their own physics will be at best a duplication of long-ago models and most likely just straight up nonsense. I suspect that there hasn’t been anyone since Faraday who made original useful contributions to physics without being up to date on the state of the art in the field. Not even Tesla made any foundational contributions, despite having a decent physics education.
I think we may be talking past each other. You say
That’s what I meant when I said “Feynman recommends that students always derive physics and math from scratch when learning.” You know the context. You know the evidence. You know, in the form of propositional statements, what the answer is. So make an attempt at deriving it yourself from the evidence, not the other way around.
In doing so, I often find that I didn’t really understand the original theory. What is built up in the from-scratch derivation is an intuitional understanding that is far more useful than the “book knowledge” you get from traditional learning. So, I would say, you never really learned it in the first place. But now we’re debating word definitions.
The other thing that you develop is experience deriving things “from scratch,” with just a couple of hints as necessary along the way, which sets you up for doing innovative research once you hit the frontier of knowledge. Otherwise you fall victim to hindsight bias in thinking that all those theorems you read in books seemed so obvious, but discovering something new seems so hard. In reality, there is a skill to research that you only pick up by doing, and not practicing that skill now when the answers could be looked up when you get stuck, is a lost opportunity.
I like this answer, but do question the point about Feynman’s gift being mainly traditional rationality.
I agree that Feynman portrays it that way in his memoirs, but accounts from other physicists and mathematicians paint a different picture. Here are a few example quotes as evidence that Feynman’s gifts also involved quite a bit of “magic” (i.e. skills he developed that one would struggle to learn from observation or even imitation).
First, we have Mark Kac, who worked with Feynman and was no schlub himself, describing two kinds of geniuses of which Feynman was his canonical example of the “magician” type (source):
(Note that, according to this source, Feynman did actually have 35 students, many of whom were quite accomplished themselves. so the point about seldom having students doesn’t totally hold for him.)
Sidney Coleman, also no slouch, shared similar sentiments (source):
In particular, note the last point about “divine revelation”.
Admittedly, these are frustratingly mystical. Stephen Wolfram describes it less mystically and also sheds light on why his descriptions of his discoveries always made them seem so obvious after the fact even though they weren’t (source:
Now, it’s possible that all this was really typical rationality, but I’m skeptical given that even other all star physicists and mathematicians found it so hard to understand / replicate.
All that said, I think Feynman’s great as is deriving stuff from scratch. I just think people often overestimate how much of Feynman’s Feynman-ness came from good old fashioned rationality.