5 ms·

Underrated even among physicists. Among the immediate post war generation his contributions are up there with Feynman and Schwinger. To quote Freeman Dyson: "P

Underrated even among physicists. Among the immediate post war generation his contributions are up there with Feynman and Schwinger. To quote Freeman Dyson: "Professor Yang is, after Einstein and Dirac, the preeminent stylist of the 20th century physics. From his early days as a student in China to his later years as the sage of Stony Brook, he has always been guided in his thinking by a love of exact analysis and formal mathematical beauty. This love led him to his most profound and original contribution to physics, the discovery with Robert Mills of non-Abelian gauge fields. With the passage of time, his discovery of non-Abelian gauge fields is gradually emerging as a greater and more important event than the spectacular discovery of parity non-conservation which earned him the Nobel Prize."

gsf_emergency_4 11mo ago
In order to explain his impact to people, someone could find a friendlier name for "gauge"? Some say that list of stylists would not be meaningful without von Neumann (although Dyson might say that frogs have no style*) https://youtu.be/OmaSAG4J6nw?t=24m19s https://youtu.be/OmaSAG4J6nw?t=24m19s Please see next slide for a minimal example of a "real(!) gauge field", even if you don't like philosophy of physics. *https://news.ycombinator.com/item?id=17457678 https://news.ycombinator.com/item?id=17457678
- MengerSponge 11mo ago
  > friendlier name for "gauge"? Do you suppose small-gauge railroads are too niche an interest? Or is "gauging" interest not friendly? It's abstractions all the way down, but the term was coined in its still generally used definition of "scale". To explain the concept to the general public, keep it simple and poetic. If they want to unpack your metaphor, they're going to need a few years of university physics education!
  - gsf_emergency_4 11mo ago
    Sorry: gauge-field. It's poetic and you can pardon the french but the combination is alien. Poetry is hard: a poetic way to say "co-ordinate transformation" or "tensors" could help students to calculate with them. I'd suggest "shear-squeezing-your-xray-lens" for everything but I fear the backlash from teachers because that would take a doctorate (or more) to unpack!
    - MengerSponge 11mo ago
      The problem you run into is that laypeople operate with modified Aristotelian physics. They might "know" that the speed of light is a speed limit, and they might "know" that quantum mechanics says you can't measure anything. They also believe that objects keep moving after you push them because they retain a memory of your push, and when that force runs out the objects come to rest* You are not, will not, cannot teach them how to do a meaningful modern calculation in a single conversation**. Hell, Feynman's lectures were a failure: they didn't serve the audience he was supposed to be teaching (first year students). So are you talking to students? Or is this a cocktail conversation? Because those are two very different settings. *&**) These points are extensively documented in the PER literature. SciComm is really important and really useful, but it's not the same as effective pedagogy.
      - gsf_emergency_4 11mo ago
        I was disabused of such pretty quick when I realized I had to repeat the same exercise over multiple sessions to replace in the students' heads Aristotelian physics with Newton's 3rd law XD. At the same time, I learnt to design a better force diagram than displayed in the assigned textbooks (many of which I suspect were influenced by Feynman).. Which is kinda my point. That the status quo kinda suck doesn't mean the notation or examples can't be improved upon. It's heartening that we're entering a post-textbook age.. I wasnt so interested in scicomm up there because I suspect that the "slow" uptake of Yang's ideas had more to do with bad pedagogy
        MengerSponge 11mo ago
        Better force diagrams, you say? Any literature (or textbook) references for that? How about some notes?
- scotty79 11mo ago
  The word gauge is completely opaque to me, invokes no reasonable connotation. I always wished they gave this thing a better name but I have no idea what.
  - cvoss 11mo ago
    It's named that for a reason. It has to do with invariance under an arbitrary selection of parameters like scale, hence, choice of railroad gauge. At least they tried to give a descriptive name! Most ideas are named after the people who are most closely associated with them. Yang-Mills. Newtonian. Euclidean. Planck. Many of those names invoke very specific ideas, even though eponyms are about as opaque as they come.
    - scotty79 11mo ago
      > It has to do with invariance under an arbitrary selection of parameters like scale, hence, choice of railroad gauge. Could you elaborate on that?
      - dannymi 11mo ago
        Just as you can select whatever railroad gauge as a country (if you also build compatible trains, obviously) and have it work just fine no matter what you select--until you try to connect it to another country and then you need to have converters--, some physical theories have gauges like this that you can choose however you want and it will work fine (and be equivalent to a theory in any other gauge)--but if you want the theory to work with the next guy's theory you have to have converters.
MengerSponge 11mo ago
The Yang in Yang-Mills is the same Yang as Lee-Yang! Somehow I had those filed as a different generation, where Lee-Yang is "old", and Yang-Mills is "young". I'm an idiot
- gsf_emergency_4 11mo ago
  The path from Lee-Yang to Yang-Mills is short (~months) but the shortness is instructive (It's more than just a lesson in style, imho. Lee-Yang could become more famous than Yang-Mills, in time! Like you're implying there-- that was a honest mistake on your part; your claim to "idiocy" teaches less than it might seem :). See this comment which might seem completely throwaway https://news.ycombinator.com/item?id=45632370 https://news.ycombinator.com/item?id=45632370) In the same vein, here is a short-note of Yang, readable to nonscientists, here: https://doi.org/10.1142/S0217751X03017142 https://doi.org/10.1142/S0217751X03017142 (He rebuts Dyson) Necessary Subtlety and Unnecessary Subtlety
  - MengerSponge 11mo ago
    It's also an artifact of my subfield (nEDM): A common "history of nEDM" goes Lee-Yang then skip forward to Cronin and Fitch, then sketch a picture of how nEDM violates T (and P, but that's not groundbreaking), then talk about how the French used a decommissioned naval gun turret for one of their experiments. Bless 'em. Have you ever seen The Timetables of History? It re-syncs world events that you learned about from disparate sources. I kind of need that here!
    - gsf_emergency_4 11mo ago
      Thanks! I've squirreled your perspectives here as they are likely to be useful at some point.. (Esp. the "reification" of TRI-breaking)
kurtis_reed 11mo ago
How do you know he's underrated?
- tasuki 11mo ago
  I think it's so obviously a personal opinion it didn't need explicit mentioning.

gsf_emergency_4 11mo ago

In order to explain his impact to people, someone could find a friendlier name for "gauge"? Some say that list of stylists would not be meaningful without von Neumann (although Dyson might say that frogs have no style*) https://youtu.be/OmaSAG4J6nw?t=24m19s https://youtu.be/OmaSAG4J6nw?t=24m19s Please see next slide for a minimal example of a "real(!) gauge field", even if you don't like philosophy of physics. *https://news.ycombinator.com/item?id=17457678 https://news.ycombinator.com/item?id=17457678

MengerSponge 11mo ago
> friendlier name for "gauge"? Do you suppose small-gauge railroads are too niche an interest? Or is "gauging" interest not friendly? It's abstractions all the way down, but the term was coined in its still generally used definition of "scale". To explain the concept to the general public, keep it simple and poetic. If they want to unpack your metaphor, they're going to need a few years of university physics education!
- gsf_emergency_4 11mo ago
  Sorry: gauge-field. It's poetic and you can pardon the french but the combination is alien. Poetry is hard: a poetic way to say "co-ordinate transformation" or "tensors" could help students to calculate with them. I'd suggest "shear-squeezing-your-xray-lens" for everything but I fear the backlash from teachers because that would take a doctorate (or more) to unpack!
  - MengerSponge 11mo ago
    The problem you run into is that laypeople operate with modified Aristotelian physics. They might "know" that the speed of light is a speed limit, and they might "know" that quantum mechanics says you can't measure anything. They also believe that objects keep moving after you push them because they retain a memory of your push, and when that force runs out the objects come to rest* You are not, will not, cannot teach them how to do a meaningful modern calculation in a single conversation**. Hell, Feynman's lectures were a failure: they didn't serve the audience he was supposed to be teaching (first year students). So are you talking to students? Or is this a cocktail conversation? Because those are two very different settings. *&**) These points are extensively documented in the PER literature. SciComm is really important and really useful, but it's not the same as effective pedagogy.
    - gsf_emergency_4 11mo ago
      I was disabused of such pretty quick when I realized I had to repeat the same exercise over multiple sessions to replace in the students' heads Aristotelian physics with Newton's 3rd law XD. At the same time, I learnt to design a better force diagram than displayed in the assigned textbooks (many of which I suspect were influenced by Feynman).. Which is kinda my point. That the status quo kinda suck doesn't mean the notation or examples can't be improved upon. It's heartening that we're entering a post-textbook age.. I wasnt so interested in scicomm up there because I suspect that the "slow" uptake of Yang's ideas had more to do with bad pedagogy
      - MengerSponge 11mo ago
        Better force diagrams, you say? Any literature (or textbook) references for that? How about some notes?
scotty79 11mo ago
The word gauge is completely opaque to me, invokes no reasonable connotation. I always wished they gave this thing a better name but I have no idea what.
- cvoss 11mo ago
  It's named that for a reason. It has to do with invariance under an arbitrary selection of parameters like scale, hence, choice of railroad gauge. At least they tried to give a descriptive name! Most ideas are named after the people who are most closely associated with them. Yang-Mills. Newtonian. Euclidean. Planck. Many of those names invoke very specific ideas, even though eponyms are about as opaque as they come.
  - scotty79 11mo ago
    > It has to do with invariance under an arbitrary selection of parameters like scale, hence, choice of railroad gauge. Could you elaborate on that?
    - dannymi 11mo ago
      Just as you can select whatever railroad gauge as a country (if you also build compatible trains, obviously) and have it work just fine no matter what you select--until you try to connect it to another country and then you need to have converters--, some physical theories have gauges like this that you can choose however you want and it will work fine (and be equivalent to a theory in any other gauge)--but if you want the theory to work with the next guy's theory you have to have converters.

MengerSponge 11mo ago

The Yang in Yang-Mills is the same Yang as Lee-Yang! Somehow I had those filed as a different generation, where Lee-Yang is "old", and Yang-Mills is "young". I'm an idiot

gsf_emergency_4 11mo ago
The path from Lee-Yang to Yang-Mills is short (~months) but the shortness is instructive (It's more than just a lesson in style, imho. Lee-Yang could become more famous than Yang-Mills, in time! Like you're implying there-- that was a honest mistake on your part; your claim to "idiocy" teaches less than it might seem :). See this comment which might seem completely throwaway https://news.ycombinator.com/item?id=45632370 https://news.ycombinator.com/item?id=45632370) In the same vein, here is a short-note of Yang, readable to nonscientists, here: https://doi.org/10.1142/S0217751X03017142 https://doi.org/10.1142/S0217751X03017142 (He rebuts Dyson) Necessary Subtlety and Unnecessary Subtlety
- MengerSponge 11mo ago
  It's also an artifact of my subfield (nEDM): A common "history of nEDM" goes Lee-Yang then skip forward to Cronin and Fitch, then sketch a picture of how nEDM violates T (and P, but that's not groundbreaking), then talk about how the French used a decommissioned naval gun turret for one of their experiments. Bless 'em. Have you ever seen The Timetables of History? It re-syncs world events that you learned about from disparate sources. I kind of need that here!
  - gsf_emergency_4 11mo ago
    Thanks! I've squirreled your perspectives here as they are likely to be useful at some point.. (Esp. the "reification" of TRI-breaking)

kurtis_reed 11mo ago

How do you know he's underrated?

tasuki 11mo ago
I think it's so obviously a personal opinion it didn't need explicit mentioning.