Hacker News new | past | comments | ask | show | jobs | submit login
When Feynman met Dirac (2020) (cantorsparadise.com)
204 points by jorgenveisdal 15 days ago | hide | past | favorite | 84 comments

Great article with a number of well-known references to biographies of Feynman. For those interested in Dirac, some excellent biographies have emerged over the years including: "The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom" and "Dirac: A Scientific Biography ". [0][1].

[0] https://www.amazon.com/gp/product/B002LDM8QS/ref=dbs_a_def_r...

[1] https://www.amazon.com/Dirac-Scientific-Biography-Helge-Krag...

one anecdote about Dirac. Dirac and Heisenberg discussed about religion. They involved Pauli in the discussion and Pauli summed up Dirac's point of view: "“Es gibt keinen Gott und Dirac ist sein Prophet. (There is no God and Dirac is his Prophet.)"

I really need to re-read Gleick's "Genius".

It might be more interesting to read a different Feynman biography. I read Genius first, then Mehra's The Beat of a Different Drum: The Life and Science of Richard Feynman, which I liked better.

Thanks for the tip!

It's my favorite work of nonfiction.

When I read those papers, I feel, How much relaxed (less stressed) one must be to create this. Current dopamine inducing attention grabbing world makes it really difficult for such deep studies.

There were many attention grabbing things (Cold War escalation, civil unrest, etc.) in the world when Feynman wrote those papers. I can't find the exact clip, but I remember seeing an interview where an older Feynman reflected on that time. He described a sense of hopelessness and impending doom hanging over him for years after his involvement with the Manhattan Project. Here's a similar quote to that effect[1]:

  ...I can't understand it anymore but I felt very strongly then. I'd sat in a restaurant in New York, for example and I looked at the buildings and how far away, I would think, you know, how much the radius of the Hiroshima bomb damage was and so forth. How far down there was down to 34th Street? All these buildings, all smashed, and so on. And I got a very strange feeling. I would go along and I would see people building a bridge. Or, they'd be making a new road, and I thought, they're crazy, they just don't understand, they don't understand. Why are they making new things, it's so useless?
Our times are certainly challenging, but I hope we can muster the strength and focus to keep building as others did in the past.

1. https://books.google.com/books?id=WO9D_BaDDhkC&pg=PA91&lpg=P...

I'm totally on board with this, and I've heard that quote too. But I think the OP was talking more about how our "distraction environment" today prevents us from having even 5 minutes of continued focus, unless we go through herculean efforts. Thus limiting our ability to do deep thinking, create deep work and make deep choices.

But for sure there were many EPIC distractions of a more general nature in that time.

In addition to all of the craziness going on in the world at the time his wife was hospitalized and dying of tuberculosis while he was working on the Manhattan project.

There's a certain category of people who cope with stress by becoming absorbed in work so that they can shut everything else out. Those people likely do their best work because of the tragedies surrounding them.

There definitely is. I'm not sure if that was the case with Feynman, but he sure did produce some great work during this era.

I used to be like that when I was in my 20s, but as I get older if I get depressed it significantly reduces my productivity.

Yeah but we're worse today. On top of all the impending doom we have vastly superior weapons of mass distraction in our hands and every computer/phone screen. Our attention spans have decreased.

You should read deep work. It's had a profound impact on how I consume social media.


Behaviors related to smartphones, email, social media etc should be evaluated by their holistic impact on our life In the same way we do with alcohol, drug use, and other addictive behaviors.

The effect it's had on my state of mind is profoundly positive. I don't even hear notifications anymore and I am far more productive.

Nitpick worth exploring on your valid point about our times: while stress can definitely be disruptive to deep cognitive work, it's a very different neuro/physiological processes than attention/focus (as you say: "attention grabbing world")

One can be quite relaxed but not at all focused and vice versa.

Look at Jørgen Veisdals other submissions on HN; 95% is articles he have written himself: https://news.ycombinator.com/submitted?id=jorgenveisdal

I think this is impressive compared to most users in here.

Yes, this article is both written and submitted by Jørgen.

It is impressive.

To add information, Jørgen's Cantor Paradise is a paid subscription (a very good one) with occasional free articles. So what you identify as a prolific submission history can also identified by others, as self-marketing.

It's fascinating reading about giants of academia, that I've personally never thought to link together, interacting and disagreeing with one another in such a relatable way.

I wonder if anyone's written about a younger Dirac and any interactions he got into with his heros, and so on and so forth back as far as possible? I'm sure there's an amazing story to be told through following this "thread of knowledge" through time...

are there similar books on lev landau ?

Not a biography, but a collection of memorial articles and reminisces:


Also, I found the autobiography by Sagdeev (one of the <50 who finished the "Theoretical Minimum" of Landau) to have some nice anecdotes about Landau:

Roald Sagdeev, "The Making of a Soviet Scientist: My Adventures in Nuclear Fusion and Space"

thank you kindly!

As an ex-physicist, these were the golden years of physics. Studying and then doing your PhD at that time must have been fascinating.

Today's physics really bland. Either we look into some fantasy worlds we will never test (quantum foam & co), or extremely niche ones.

My sons are fascinated by science and I am lightly driving them towards biology (biophysics, bioinformatics, ...) because I feel this is where the revolutionary changes happen and will happen.

As a physicist, I would say that physics is still and will always be beautiful and fascinating, but I also believe that biology is where it is happening now.

Physics IS beautiful and fascinating. I am so glad that I studied that and went though a PhD.

It is especially fascinating during the first 3 years, when you slowly discover some unexpected links between the disciplines. When I discovered Noether's theorem I was in awe.

Then it gest more and more abstract, drifting away from the reality (I do not have QM here in mind but rather its evolution).

Thanks to the confinement we have in France due to COVID, I had the opportunity to take over a part of the duties of the National Education services :) Telling my children about mechanics and all basic topics was awesome. I got over excited several times and they had to cool me down.

Physics will always be my first love, but the future is elsewhere.

“When I discovered Noether's theorem I was in awe.”

The same thing happened to me. Many years later, I thought that it should be more popularly known, so I wrote this:


And now I am writing a book about it.

This is really an interesting article. I will be watching for the book as I also find that her works is really unappreciated despite blowing student's minds when learning about the theorem.

Why not computer science?

Computer science is not science, it is mathematics. Great stuff, but quite different stuff.

> Computer science is not science

Disagree profoundly.

And if perchance you got to that conclusion because you believe you can't apply the scientific method to CS (as in: formulate a theory about how the world "is", design an experiment to test the theory, run the experiment, rinse, repeat), you are mistaken: when dealing with systems of exploding complexity (which is, btw and imo, what physics is all about as well), this is a very fruitful attack strategy.

It seems in different countries (and universities) Computer Science mean different things.

In my country, Computer Science is exclusively theoretical study of some areas of mathematics. You don't go into CS to run experiments, just like in mathematics. You go to study theorems and complexity theory.

Anything related to the act of developing software is called Software Engineering/Informatic Engineering. Totally different things: as different as a mathematician and a bridge builder. In the real world there's an evident intersection between CS and SE, but in academia (in my country), CS _is_ math.

I think this is the "correct" approach. Much of what SWE do is analogous to Trade/Vocational/Polytechnic school training.

I think that the theoretical aspects of CS are interesting, this is lots of math (especially crypto) and lots of formal proofs (algorithms).

Being able to predict how complex and long simulations will be is great as well.

BTW I think that "Computer Science" is interpreted differently in different countries. In France for instance we have _informatique_ which means "things with computers" and usually is understood as "development" or "system/network administration". _

As a francophone, is informatique not supposed to be lexically close to other sciences in -ique to denote it being closer to Computer Science in meaning?

As the académie put it: "science du traitement de l'information"

Yes, this is true. But when you say "je travaille dans l'informatique" (I work in <informatique>), what comes to mind is a developer or a sysadmin. Not someone who does "computer science" (algorithms etc.).

"Je fais de la recherche en informatique" (I do research in <informatique>) would mean doing "computer science".

I am not sure what comes to mind to a native speaker of English when he heard "I work in computer science". Maye the same thing, actaully.

In which case "computer science" would be one "science" where you actually need to add "science" (as opposed to physics, biology, ...)

On the other hand, we have in French "Science de la Vie et de la Terre" - a school subject loosely grouping biology and geology.

I think you only think that you disagree. But I could be completely wrong.

The method that you describe is used in exploring mathematical landscapes, including CS. But, still, some people (like me) find it useful to distinguish between mathematics (including CS) and science, by which we mean empirical science. But I would agree strongly that the boundary is very fuzzy.

Computer science is a combination of fields, including mathematics (theory of computation, cryptography), empirical science (empirical software engineering, HCI, etc.), and engineering.

They are not sufficiently interested in the theory of computation for this to work out.

They are more into applied science (applied to everyday life). Theory of computation is certainly interesting, though.

Why computer science?

The best compliment to the two geniuses (from the article);

and Wigner said, "He is a second Dirac, only this time human."

Anyone with a link that isn’t behind an auth-wall?

Site seems to be hugged to death. Backup link?

The site is hosted on medium. I doubt that it can be hugged to death?


"Eschew flamebait. Don't introduce flamewar topics unless you have something genuinely new to say. Avoid unrelated controversies and generic tangents."


Feyman has some post mortem heat on him under the lens of revisionism. Namely, as it pertains to his treatment of women.

In short, some people think he was sexist at best and an abuser of women at worst.

That is terrifying. I learned physics from his textbooks - ussr samizdat. I googled allegations against him and all I saw was a wall of vague text from a cardboard cut, predatory sensationalists, all cross referencing each other

> all I saw was a wall of vague text from a cardboard cut, predatory sensationalists, all cross referencing each other

I assure you his FBI file - https://www.muckrock.com/foi/united-states-of-america-10/fbi... - is not vague, predatory, sensationalist, and does not cross-reference any discussion you may find on the web today.

His ex-wife reportedly testified that on several occasions when she unwittingly disturbed either his calculus or his drums he flew into a violent rage, during which time he attacked her, threw pieces of bric-a-brac about and smashed the furniture.

Feynman's autobiographical writings about women are also disgusting enough by modern standards.

I don't understand why you would think having developed an excellent physics course is incompatible with that (or vice versa).

what do you think would be the worst, most shocking revelation in your own 300pages long FBI file? especially one that includes a deposition from a former spouse who was seeking divorce settlement at the time, plus depositions of everyone you broke up with? i can only speak for myself, but my hypothetical file would have made considerably more interesting read than feyman's

You could take issue with the accuracy or provenance of the file (which we can then discuss if you actually do rather than merely insinuate you could) but nonetheless it is none of "vague text from a cardboard cut, predatory sensationalists, all cross referencing each other" which is what you originally claimed.

This comment is not very popular, especially in America, but Feynman was by and large a showman. His most celebrated publication is path integral approach. Dirac had a paper earlier (known as Dirac’s little paper), so did Norbert Wiener in a different context, on this approach. They didn’t pursue path integrals, as they could not (and still people can’t) make sense of them rigorously. Feynman looked up that paper and expanded on it.

He also drew useful diagrams, but you know ... :)

Not American, but I would argue that his greatest contributions weren’t necessarily in exploring the fundamental laws of physics but in making physics more accessible, easier to understand, and more pleasant to study.

The fact he got his Nobel prize in part thanks to a way of representing interactions between particle is quite telling.

His books, and even more so his BBC interview (have yet to dive into the Physics lectures) completely changed my perspective on science.

I liked it, and wanted to love it, but watching him talk about fire and photosynthesis finally made it all click together.

Those weren’t abstract formulas, or curious and amusing concepts. All of it was deeply tied to everything around me, and somehow managed to make it all much more fascinating. I didn’t know the formulas, or the exact rules, but I got a general understanding of each of these processes and, feeling like a child once again, actually wanted to know more.

It was suddenly so obvious, and yet... why did it take all this time? And why couldn’t anyone else help me realise that earlier?

I certainly could blame the French education system, which isn’t really fond of making itself likeable or giving meaning to what it teaches, but still... it seems much more widespread than that.

So... I wouldn’t be surprised if he is both directly and indirectly responsible for many other physicists actually getting into research and developing this "intuition" that comes with truly understanding.

Edit: Also, his explanation is the first satisfying one I’ve ever gotten to "What is fire?" since I started asking the question over a decade ago.

I've found that my deepest understanding fire has come from building communal fires time and again over the course of the pandemic, seeing (and causing) the chain reaction grow from nothing into a continuous reaction.

If only. Dirac and Wiener did not understand the significance of the action appearing where it did. Feynman gave it meaning. An analogy for what you are saying is that Einstein just rederived Lorentz’s equations. That’s one of the most interesting characteristics of physics, it’s not just math and computation, meaning is hugely significant.

I’d also say the path integral is not what he is most known for among practicing physicists, but that’s another story (I recommend “QED and the Men Who Made It: Dyson, Feynman, Schwinger, and Tomonaga@).

Oppenheimer's opinion of Feynman seems to have vastly diminished after the Shelter Island and Pocono conferences. According to Dyson [1]:

“When after some weeks I had a chance to talk to Oppenheimer, I was astonished to discover that his reasons for being uninterested in my work were quite the opposite of what I had imagined. I had expected that he would disparage my program as merely unoriginal, a minor adumbration of Schwinger and Feynman. On the contrary, he considered it to be fundamentally on the wrong track. He thought adumbrating Schwinger and Feynman to be a wasted effort, because he did not believe that the ideas of Schwinger and Feynman had much to do with reality.

I HAD KNOWN THAT HE HAD NEVER APPRECIATED FEYNMAN, but it came as a shock to hear him now violently opposing Schwinger, his own student, whose work he had acclaimed so enthusiastically six months earlier. He had somehow become convinced during his stay in Europe that physics was in need of radically new ideas, that this quantum electrodynamics of Schwinger and Feynman was just another misguided attempt to patch up old ideas with fancy mathematics.”

[1] Dyson F. Disturbing the Universe. Henry Holt and Co, 1979 ISBN 9780465016778.

This quote and an earlier one I made are from Oliver Consa's 2020 paper: "Something is rotten in the state of QED".

This all sounds an awful lot like a standard telenovela drama.

I have several friends who personally knew Feynman. He was a problematic individual in many ways. One of them remembers being in an elevator with his girlfriend, and Feynman getting on the elevator and immediately hitting on her. Another recalls being dragged along to crash parties at Caltech for free food. That same one commented that, yes, he was super careful about his legacy and all the stories published about him.

But they spent time around him in a working context, and they are all absolutely clear in their minds that, beyond the showmanship, he was a genius.

I've read Feynman's autobiography and at least half of the stuff in it reads like someone embellishing the story to make it more interesting.

There are parts where he goes totally /r/redpill that would get him in trouble today if he were still alive.

Okay, I'll rephrase what I said in the flagged reply.

Could you please rephrase what you wrote here, but without using the word "problematic" when describing a person? Thank you very much.

That's fair. I'm not sure what other word to use though. Admirable in some ways, socially unacceptable in others? Someone whose work was amazing but who really shouldn't be suggested as a role model? And who knows what parts of it are due to trauma and what parts are just being an asshole? I'm open to suggestions.


Please don't take HN threads into flamewar. Getting provoked by one word and making a flamewar reply out of it is definitely not in the set of response patterns we want here. We want the kind that lead to more interesting / less predictable discussion.

To do this requires resisting this sort of provocation in oneself—i.e. waiting until the activation dies down, and then either moving on to something else or finding a more interesting response to share. More on that here: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor....

Also, please don't use allcaps for emphasis and please don't go on about downvotes. These things are all in the site guidelines—would you please review them (https://news.ycombinator.com/newsguidelines.html) and stick to the rules when posting here? We'd appreciate it, because we're trying to avoid the internet hell in which everything becomes consumed by the never-ending flamewars.

Although I wasn't around during the 50s, this comment seems likely to be revisionist history to me. The article itself quotes Oppenheimer as writing (unsolicited): "He is by all odds the most brilliant young physicist here, and everyone knows this." and 'Wigner said, "He is a second Dirac, only this time human."'

I wonder if perhaps this opinion of Feynman as a showman has gotten more popular over the decades as Feynman and the physicists who knew him passed away, and more and more of us are exposed to him only through his lectures and books. (If you'll excuse an aside: a bit like Bill Simmon's thesis on the basketball greats Bill Russell vs. Chamberlain -- those of us looking back on history, with only artifacts, may draw conclusions that would be ridiculous at the time.) I don't know if this is the case, but it's a fun speculation.

Your assessment, while phrased provocatively, isn't all that controversial (except maybe in some pop-sci worship circles). Feynman shone in popularizing physics, and physicists.

Freeman Dyson, one of Feynman's closest friends (and a prodigious scientist in his own right; died last year) regularly described Feynman as a "fast calculator rather than a particularly deep thinker".

IIRC Dyson picked Fermi as the greatest physicist he'd ever met – much to the dismay of reporters, who of course expected Dyson to name his buddy Feynman :-)

The following is Serge's account of Dyson's account of Fermi's opinion of QED [1]:

''' “When Dyson met Fermi, he quickly put aside the graphs he was being shown indicating agreement between theory and experiment.

His verdict, as Dyson remembered, was “There are two ways of doing calculations in theoretical physics. One way, and this is the way I prefer, is to have a clear physical picture of the process you are calculating. The other way is to have a precise and self-consistent mathematical formalism. You have neither.”

When a stunned Dyson tried to counter by emphasizing the agreement between experiment and the calculations, Fermi asked him how many free parameters he had used to obtain the fit. Smiling after being told “Four,” Fermi remarked, “I remember my old friend Johnny von Neumann used to say, with four parameters I can fit an elephant, and with five I can make him wiggle his trunk.” There was little to add.” '''

[1] Segre G., Hoerlin B. The Pope of Physics: Enrico Fermi and the Birth of the Atomic Age. Henry Holt and Co, 2016 ISBN 9781627790055

This quote is from Oliver Consa's 2020 paper: "Something is rotten in the state of QED".

Since we're trading Dyson anecdotes, here's a similarly awkward one, about how Dyson met Wolfgang Pauli for the first time [0]:

> I remember the very first time I met [Pauli] at a conference in Zurich. He was talking with a whole group of people about Julian Schwinger, who had just come to Switzerland. Schwinger was a brilliant young American who had done some very fine work. He was a rival of Feynman; they were the two geniuses then. Pauli was saying that Schwinger told us all this stuff that actually made sense, not like that nonsense Dyson has been writing. At that point I came walking up with a friend of mine, Markus Fierz, who was also a Swiss scientist. With a twinkle in his eye, Fierz came up to Pauli and said, “Please allow me to introduce you to my friend, Freeman Dyson.” Pauli said, “Oh that doesn’t matter. He doesn’t understand German.” Which of course I did. That was a good beginning and we were friends right from the very first day.

[0] https://nautil.us/issue/43/heroes/my-life-with-the-physics-d...

I recall that fitting example from undergrad physics. Nowadays, with deep learning going on with billions of parameters being fit, it probably makes somewhat more sense to recall that bit of humor.

> Your assessment, while phrased provocatively, isn't all that controversial (except maybe in some pop-sci worship circles)

HN is therefore likely a good place to remind people of such...

I would say its not a very popular comment because its deliberately contrarian and not the full story. Yes, Feynman was a showman (amongst many other things) but he was also a truly gifted physicist. You can be both those things at the same time. And he was.

"Feynman looked up that paper and expanded on it", yes, science doesn't happen in a vacuum? Standing on the shoulders of giants etc

I agree that his original contributions might not be so important as believed by those who actually do not know them in detail.

On the other hand, as a child I have enjoyed very much the Feynman Lectures on Physics, much more than most other similar books.

I am certainly very grateful to him, because his work had a very positive influence on me, when I was young.

He was definitely a showman, but Schwinger and Tomonaga were definitely not. Being a larger-than-life character type does not detract from his contributions.

Murray Gell-Mann talks about Richard Feynman


This comment may be unpopular because it's not tremendously useful.

Feynman was a showman but he was also a good physicist. Not among top 10 or 20 in the 20th century as many popular polls put him, but still really good physicist.

He had great teaching ability. That justifies his fame. Just like Gilbert Strang deserves his fame.

So he was awarded the Nobel Prize for being a "showman"?

For contributions I noted in my comment. I wouldn’t say he didn’t deserve it (he was a good popular expositor).

You should not neglect the role of politics and presentation in academia.

As science became increasingly a valuable commodity, it attracted a lot of people with perverse incentives: politicians, administrators, research managers, status-hungry individuals etc. I see what’s happening and it’s not pretty.

Frankly, I think it’s not a healthy environment and this academic system would not last too long. Smart people will leave, as they realize this has become an industry not different from banking or any other, except the currency is fame and reputation, and stakes are so low. It’s no longer like 1930s, and people like Feynman helped set the stage for a new eta.

And it’s not surprising at all, once you learn that politics and showmanship actually pay off.

There are a lot of politicians, administrators and managers in academia. To say that Feynman is responsible for them, is pretty ridiculous. And to say that Feynman wasn't a great physicist makes words basically meaningless.

Without looking it up, can you name the other two people who won the Nobel with him? Were they lesser physicists than Feynman? If not, why so much focus on his life but not theirs?

S. and T., didn't take half a second's thought.

Being a showman doesn't mean that Feynman was only a showman. Indeed, one can hardly be an effective educator without a strong touch of showmanship in presenting ideas.

You don't normally win a Nobel for being an effective educator or communicator either - and nominally he didn't.

Do you believe that all Nobel prizes are equivalent ?

Wouldn’t be the first. Bob Dylan, Winston Churchill, Barack Obama etc

It seems reasonable to hold Nobel Prizes in advancing science to a different level than Nobel Prizes in influencing people. Though both are valuable for society, the latter essentially must include elements of showmanship.

Henry Kissinger

There is a tendency for such awards to go to those in the top 10% of both the field in question and the top 10% of ability to sell themselves, rather than those in the top 1% of the field in question.

That can be true for Literacy or Peace Nobel's but not for physics.

The amount of cynical consipratory thinking in HN horrifies me.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact