Lesser known but possibly more relevant to most HN readers are Feynman's lectures on computation - https://theswissbay.ch/pdf/Gentoomen%20Library/Extra/Richard... . There's some really great explanations in there of computability, information theory, entropy, thermodynamics, and more. Very little of it is now out-dated.
“For our first seminar he invited John Hopfield, a friend of his from CalTech, to give us a talk on his scheme for building neural networks. In 1983, studying neural networks was about as fashionable as studying ESP, so some people considered John Hopfield a little bit crazy. Richard was certain he would fit right in at Thinking Machines Corporation.”
Interesting, he also talks about quantum computing (a first?): p. 191, "We now go on to consider how such a computer can also be built using the laws of quantum mechanics. We are going to write a Hamiltonian, for a system of interacting parts, which will behave in the same way as a large system in serving as a universal computer."
p. 196: "In general, in quantum mechanics, the outgoing state at time t is
eⁱᴴᵗ Ψᵢₙ where Ψᵢₙ is the input state, for a system with Hamiltonian H. To try to find, for a given special time t, the Hamiltonian which will produce M = eⁱᴴᵗ when M is such a product of non-commuting matrices, from some simple property of the matrices themselves, appears to be very difficult.
We realize, however, that at any particular time, if we expand eⁱᴴᵗ out (as 1 + iHt − H²t²⁄2 + …) we'll find the operator H operating an innumerable arbitrary number of times — once, twice, three times, and so forth — and the total state is generated by a superposition of these possibilities. This suggests that we can solve this problem of the composition of these A’s in the following way..."
Feynman is indeed often quoted among the first people to propose the idea of a quantum computer! This talk he gave in ‘81 is among the earliest discussion of why a quantum universe requires a quantum computer to be simulated [1]:
> Can a quantum system be probabilisticaUy simulated by a classical (probabilistic, I'd assume) universal computer? In other words, a computer which will give the same probabilities as the quantum system
does. If you take the computer to be the classical kind I've described so far, (not the quantum kind described in the last section) and there're no changes in any laws, and there's no hocus-pocus, the answer is certainly, No! This is called the hidden-variable problem: it is impossible to represent the results of quantum mechanics with a classical universal device.
Another unique lecture is a 1959 one [2] about the potential of nanotechnology (not even a real thing back then). He speaks of directly manipulating atoms and building angstrom-scale engines and microscope with a highly unusual perspective, extremely fascinating for anyone curious about these things and the historical perspective. Even for Feynman’s standards, this was a unique mix of topics and terminology. For context, the structure of DNA has been discovered about 5 years prior, and the first instruments capable of atomic imaging and manipulation are from at least the 80’s.
If you’re captivated by this last one as I was, I can also recommend Greg Bear’s novel “Blood Music”. It doesn’t explore the nanotechnology side much, but the main hook is biological cells as computers. Gets very crazy from there on.
Poets say science takes away from the beauty of the stars—mere globs of gas atoms. Nothing is 'mere.' I too can see the stars on a desert night, and feel them. But do I see less or more? The vastness of the heavens stretches my imagination—stuck on this carousel my little eye can catch one-million-year-old light. A vast pattern—of which I am a part—perhaps my stuff was belched from some forgotten star, as one is belching there. Or see them with the greater eye of Palomar, rushing all apart from some common starting point when they were perhaps all together. What is the pattern, or the meaning, or the why? It does not do harm to the mystery to know a little about it. For far more marvelous is the truth than any artists of the past imagined! Why do the poets of the present not speak of it? What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?
A footnote for those of the millenial or more recent persuasion: we take the full “vastness of the heavens” as given, as we’ve seen it described pretty confidently all the way back to the science books of our childhood. But cosmology, and frankly the entire field of astrophysics, is strikingly young. The idea that nebulae are in fact whole independent collections of stars, and that the observable universe is large enough to accomodate all of that, is younger than quantum mechanics and relativity both, and only got acceptance after a huge fight. The name “Big Bang” was originally a pejorative used in a similar, later fight. And so on. When Feynman said this, the idea of nebulae as galaxies was younger (~40 years) than the key idea of quarks (confinement/asymptotic freedom) is today (~50 years), and I’m guessing the latter still counts as new and arcane in your mind.
I feel uncomfortable labelling nebulae as collection of stars. The more appropriate term is stellar nursery if you want to allude to their role in star formation.
They themselves are just clouds of gas and dust where protostars have begun to form.
Stellar clusters are what you would call a collection of stars.
Also on the note of cosmology and astrophysics being strikingly young fields, I think that's fair statement if we consider their modern definitions. Although their core ideas have already been discussed in a lot of ancient civilizations. It was a lot more philosophical and less rooted in science though (except for the observational astronomy, which remains perhaps one of the oldest scientific discipline).
I have the print version and have been working through them slowly. Funnily enough I didn’t find it very useful when I had physics classes in school/uni since most of those classes were just memorizing equations and solving problems. But now that there is no exams pressure, it makes for such wonderful reading! I think its not just an introduction to physics but to the scientific method itself. Its first principles approach is so different than most physics textbooks.
It just wears thin after a while. Nobody studies Feynman to learn social skills or sexual ethics. If they did, these types of complaints would certainly be relevant... but they don't, and they aren't.
The guy invented the path integral in his PhD thesis. He invented Feynman diagrams and figured out how to do finite calculations in quantum electrodynamics. Unless you're a perfect human being, please, cut him just a tiny bit of slack.
I understand not watching a 3 hour video before leaving a comment, but this is a disrespectful reaction to a very well thought out video by a professional physicist giving a nuanced opinion about Feynman's legacy. She acknowledges many times in the video that Feynman was a great physicist who deserved his Nobel prize. The central topic of the video is dissecting his public image and the many books published under his name that he did not in fact write, including Surely You're Joking and indeed the Feynman Lectures, as well as criticizing misogynistic behaviors celebrated in those books that has left a negative impact on the culture of physics.
(And also, "cutting him a tiny bit of slack" is pretty lax language considering the behavior being criticized includes beating his wife.)
misogynistic behaviors were cultural at the time, I agree they're abhorrent but people are embedded in their culture. The same is said of Hitchcock, (as an example) and his behaviour was unacceptable by todays standards. We've come some way from that but still a way to go.
From the about the authors in the OP's link "Feynman was a remarkably effective educator. Of all his numerous awards, he was especially proud of the Oersted Medal for Teaching, which he won in 1972.". He probably didn't do a lot of the stuff he popularised, but that was what he did, it is a skill taking abstract stuff and making it coherent. I know when I did physics (in the 90's) many swore by his books, particularly for quantum, it was a bit of a secret we'd have these incomprehensible books on quantum, and someone would say - have you seen "The Feynman lectures", they are good, I wish we had the videos available at the time.
> misogynistic behaviors were cultural at the time, I agree they're abhorrent but people are embedded in their culture. The same is said of Hitchcock, (as an example) and his behaviour was unacceptable by todays standards. We've come some way from that but still a way to go.
The video actually addresses this very point in the first few minutes:
> the second component of the Feynman lifestyle that the Feynman bro has to follow, you know as told in this book, is that women are inherently inferior to you and if you want to be the smartest big boy physicist in the room you need to make sure they know that I think people are sometimes shocked to hear this like that that exists in this book especially because as I said if you were a precocious teenager interested in physics people shoved this book at you they just put it into your hands like oh you want to be a physicist here's the coolest physicist ever
> I feel like it's at this point in the video when like Mr. Cultural Relativism is going to show up in the comments and be like how dare you judge people from the past on their actions that's not fair things were different back then women liked when men lied to them and pretended to be an undergrad so that-- it was fine back then it was fine and I just, no, actually this book was published 40 years ago which is just not that long ago Richard Feynman should have known that women were people 40 years ago like absolutely not it's not "how things were back then" what's wrong with you people, no, it's inappropriate then it's inappropriate now
Later the actual author, Ralph Leighton, of "Surely You're Joking, Mr. Feynman!" is mentioned so perhaps the responsibility for what was included is his more than Feynman's. I think the criticism stands that the degree of sexism effectively celebrated by inclusion was certainly less culturally accepted in 1985 when the book was published than when the events occurred, and that's the point of raising the issue of why was it judged as good and proper to include this marginalizing anecdotes when his actual contributions to physics and teaching were worthy of celebration.
I do not think Feynman was celebrating his activity in the book. From memory, he learnt the behaviour from other bar flies at the bars he hung out. And he expressed his surprise at how some women reacted. This was far from his upbringing and his experience with his fiancee.
The behaviour is hardly laudable, but "celebrated" it is not.
This should be mandatory. It's like yt folks force introducing their kids to Monty Python, we've got better stuff now, let it go. Feynman is massively over venerated and a lot of us getting tired of hearing about a man who made up most of his aura.
One gem if you're interested in semiconductors is the Feynman lecture "There's plenty of room at the bottom." He basically laid out the case for the modern nanotechnology age in 1959
I'm using these to teach an intermediate mechanics class, and my only regret is that there are no problems. The flip side is that sometimes Feynman skips over the derivations of certain things, and that makes good assignments ("Fill in the steps between [these assumptions] and [this result]").
Feynman's writing of course is stellar. The order is a bit unusual and not really designed for a "standard" university-level course. I can pick and choose, but I wish I could easily reorder the material.
There is a book of exercises, which I've heard of but not looked at myself, titled "Exercises for the Feynman Lectures on Physics". I don't know if that will help you but it might be worth a look.
Finally, asking Google something like "what is new in physics since feynman lectures", Gemini gave me a helpful summary in its "AI Overview" which you can try out.
Lesser known but possibly more relevant to most HN readers are Feynman's lectures on computation - https://theswissbay.ch/pdf/Gentoomen%20Library/Extra/Richard... . There's some really great explanations in there of computability, information theory, entropy, thermodynamics, and more. Very little of it is now out-dated.
Apropos of Feynman on computing, the story of his time working at Thinking Machines Corp https://longnow.org/ideas/richard-feynman-and-the-connection...
“For our first seminar he invited John Hopfield, a friend of his from CalTech, to give us a talk on his scheme for building neural networks. In 1983, studying neural networks was about as fashionable as studying ESP, so some people considered John Hopfield a little bit crazy. Richard was certain he would fit right in at Thinking Machines Corporation.”
Interesting, he also talks about quantum computing (a first?): p. 191, "We now go on to consider how such a computer can also be built using the laws of quantum mechanics. We are going to write a Hamiltonian, for a system of interacting parts, which will behave in the same way as a large system in serving as a universal computer."
p. 196: "In general, in quantum mechanics, the outgoing state at time t is eⁱᴴᵗ Ψᵢₙ where Ψᵢₙ is the input state, for a system with Hamiltonian H. To try to find, for a given special time t, the Hamiltonian which will produce M = eⁱᴴᵗ when M is such a product of non-commuting matrices, from some simple property of the matrices themselves, appears to be very difficult.
We realize, however, that at any particular time, if we expand eⁱᴴᵗ out (as 1 + iHt − H²t²⁄2 + …) we'll find the operator H operating an innumerable arbitrary number of times — once, twice, three times, and so forth — and the total state is generated by a superposition of these possibilities. This suggests that we can solve this problem of the composition of these A’s in the following way..."
Feynman is indeed often quoted among the first people to propose the idea of a quantum computer! This talk he gave in ‘81 is among the earliest discussion of why a quantum universe requires a quantum computer to be simulated [1]:
> Can a quantum system be probabilisticaUy simulated by a classical (probabilistic, I'd assume) universal computer? In other words, a computer which will give the same probabilities as the quantum system does. If you take the computer to be the classical kind I've described so far, (not the quantum kind described in the last section) and there're no changes in any laws, and there's no hocus-pocus, the answer is certainly, No! This is called the hidden-variable problem: it is impossible to represent the results of quantum mechanics with a classical universal device.
Another unique lecture is a 1959 one [2] about the potential of nanotechnology (not even a real thing back then). He speaks of directly manipulating atoms and building angstrom-scale engines and microscope with a highly unusual perspective, extremely fascinating for anyone curious about these things and the historical perspective. Even for Feynman’s standards, this was a unique mix of topics and terminology. For context, the structure of DNA has been discovered about 5 years prior, and the first instruments capable of atomic imaging and manipulation are from at least the 80’s.
If you’re captivated by this last one as I was, I can also recommend Greg Bear’s novel “Blood Music”. It doesn’t explore the nanotechnology side much, but the main hook is biological cells as computers. Gets very crazy from there on.
1. https://s2.smu.edu/~mitch/class/5395/papers/feynman-quantum-... 2. https://www.zyvex.com/nanotech/feynman.html
A footnote for those of the millenial or more recent persuasion: we take the full “vastness of the heavens” as given, as we’ve seen it described pretty confidently all the way back to the science books of our childhood. But cosmology, and frankly the entire field of astrophysics, is strikingly young. The idea that nebulae are in fact whole independent collections of stars, and that the observable universe is large enough to accomodate all of that, is younger than quantum mechanics and relativity both, and only got acceptance after a huge fight. The name “Big Bang” was originally a pejorative used in a similar, later fight. And so on. When Feynman said this, the idea of nebulae as galaxies was younger (~40 years) than the key idea of quarks (confinement/asymptotic freedom) is today (~50 years), and I’m guessing the latter still counts as new and arcane in your mind.
I feel uncomfortable labelling nebulae as collection of stars. The more appropriate term is stellar nursery if you want to allude to their role in star formation.
They themselves are just clouds of gas and dust where protostars have begun to form.
Stellar clusters are what you would call a collection of stars.
Also on the note of cosmology and astrophysics being strikingly young fields, I think that's fair statement if we consider their modern definitions. Although their core ideas have already been discussed in a lot of ancient civilizations. It was a lot more philosophical and less rooted in science though (except for the observational astronomy, which remains perhaps one of the oldest scientific discipline).
Unlike the commercial audio CDs of the lectures the recordings here have the chat before and after the lecture which is fun.
My favourite lecture is the standalone "The Principle of Least Action" at
https://www.feynmanlectures.caltech.edu/II_19.html
Audio: https://www.feynmanlectures.caltech.edu/II_19.html#Ch19-audi...
I have the print version and have been working through them slowly. Funnily enough I didn’t find it very useful when I had physics classes in school/uni since most of those classes were just memorizing equations and solving problems. But now that there is no exams pressure, it makes for such wonderful reading! I think its not just an introduction to physics but to the scientific method itself. Its first principles approach is so different than most physics textbooks.
"the sham legacy of Richard Feynman" https://www.youtube.com/watch?v=TwKpj2ISQAc
Brave to link to that here.
It just wears thin after a while. Nobody studies Feynman to learn social skills or sexual ethics. If they did, these types of complaints would certainly be relevant... but they don't, and they aren't.
People also don’t think he’s one of the greatest physicists ever.
As he said, he was just an ordinary person who worked very hard.
The guy invented the path integral in his PhD thesis. He invented Feynman diagrams and figured out how to do finite calculations in quantum electrodynamics. Unless you're a perfect human being, please, cut him just a tiny bit of slack.
I understand not watching a 3 hour video before leaving a comment, but this is a disrespectful reaction to a very well thought out video by a professional physicist giving a nuanced opinion about Feynman's legacy. She acknowledges many times in the video that Feynman was a great physicist who deserved his Nobel prize. The central topic of the video is dissecting his public image and the many books published under his name that he did not in fact write, including Surely You're Joking and indeed the Feynman Lectures, as well as criticizing misogynistic behaviors celebrated in those books that has left a negative impact on the culture of physics.
(And also, "cutting him a tiny bit of slack" is pretty lax language considering the behavior being criticized includes beating his wife.)
misogynistic behaviors were cultural at the time, I agree they're abhorrent but people are embedded in their culture. The same is said of Hitchcock, (as an example) and his behaviour was unacceptable by todays standards. We've come some way from that but still a way to go.
From the about the authors in the OP's link "Feynman was a remarkably effective educator. Of all his numerous awards, he was especially proud of the Oersted Medal for Teaching, which he won in 1972.". He probably didn't do a lot of the stuff he popularised, but that was what he did, it is a skill taking abstract stuff and making it coherent. I know when I did physics (in the 90's) many swore by his books, particularly for quantum, it was a bit of a secret we'd have these incomprehensible books on quantum, and someone would say - have you seen "The Feynman lectures", they are good, I wish we had the videos available at the time.
> misogynistic behaviors were cultural at the time, I agree they're abhorrent but people are embedded in their culture. The same is said of Hitchcock, (as an example) and his behaviour was unacceptable by todays standards. We've come some way from that but still a way to go.
The video actually addresses this very point in the first few minutes:
> the second component of the Feynman lifestyle that the Feynman bro has to follow, you know as told in this book, is that women are inherently inferior to you and if you want to be the smartest big boy physicist in the room you need to make sure they know that I think people are sometimes shocked to hear this like that that exists in this book especially because as I said if you were a precocious teenager interested in physics people shoved this book at you they just put it into your hands like oh you want to be a physicist here's the coolest physicist ever
> I feel like it's at this point in the video when like Mr. Cultural Relativism is going to show up in the comments and be like how dare you judge people from the past on their actions that's not fair things were different back then women liked when men lied to them and pretended to be an undergrad so that-- it was fine back then it was fine and I just, no, actually this book was published 40 years ago which is just not that long ago Richard Feynman should have known that women were people 40 years ago like absolutely not it's not "how things were back then" what's wrong with you people, no, it's inappropriate then it's inappropriate now
Later the actual author, Ralph Leighton, of "Surely You're Joking, Mr. Feynman!" is mentioned so perhaps the responsibility for what was included is his more than Feynman's. I think the criticism stands that the degree of sexism effectively celebrated by inclusion was certainly less culturally accepted in 1985 when the book was published than when the events occurred, and that's the point of raising the issue of why was it judged as good and proper to include this marginalizing anecdotes when his actual contributions to physics and teaching were worthy of celebration.
I do not think Feynman was celebrating his activity in the book. From memory, he learnt the behaviour from other bar flies at the bars he hung out. And he expressed his surprise at how some women reacted. This was far from his upbringing and his experience with his fiancee.
The behaviour is hardly laudable, but "celebrated" it is not.
If you listen to the taped Feynman lectures, yes Feynman did write them. The published versions were edited from transcripts.
https://www.feynmanlectures.caltech.edu/recordings.html
Be forewarned. There's a new YouTube channel with an AI Feynman delivering slop.
I saw this and what makes this particularly pernicious that you assume it was a fan applying ai voice to his authentic words, but you don't know.
There is also an ai slop channel featuring Leonard Susskind.
He was accused, in divorce papers. And it wasn't beating, FWIW.
path integrals existed since the 19th century
This should be mandatory. It's like yt folks force introducing their kids to Monty Python, we've got better stuff now, let it go. Feynman is massively over venerated and a lot of us getting tired of hearing about a man who made up most of his aura.
What's this better stuff?
Shrek for example.
One gem if you're interested in semiconductors is the Feynman lecture "There's plenty of room at the bottom." He basically laid out the case for the modern nanotechnology age in 1959
https://web.pa.msu.edu/people/yang/RFeynman_plentySpace.pdf
My copy of volume 1 is signed!
I'm using these to teach an intermediate mechanics class, and my only regret is that there are no problems. The flip side is that sometimes Feynman skips over the derivations of certain things, and that makes good assignments ("Fill in the steps between [these assumptions] and [this result]").
Feynman's writing of course is stellar. The order is a bit unusual and not really designed for a "standard" university-level course. I can pick and choose, but I wish I could easily reorder the material.
There is a book of exercises, which I've heard of but not looked at myself, titled "Exercises for the Feynman Lectures on Physics". I don't know if that will help you but it might be worth a look.
I'll try to find it; thanks!
What has changed in 60 years, I wonder? If you are teaching this material, what do you have to update and/or contextualize?
This is a good question and my initial thought would be Atomic Physics and Cosmology.
A book like Modern Atomic Physics by Vasant Natarajan (2015) - would be a good place to look - https://www.routledge.com/Modern-Atomic-Physics/Natarajan/p/...
Also Wikipedia has a helpful Timeline of fundamental physics discoveries page to browse - https://en.wikipedia.org/wiki/Timeline_of_fundamental_physic...
Finally, asking Google something like "what is new in physics since feynman lectures", Gemini gave me a helpful summary in its "AI Overview" which you can try out.