4 ms·

My understanding of the situation (which may be wrong, in which case please let me know) is that physics is stuck at a local optimum. There are two obvious way

My understanding of the situation (which may be wrong, in which case please let me know) is that physics is stuck at a local optimum. There are two obvious ways to get out (1) Surprising physical observations, or (2) Mathematical advances Way (1) is what kicked off quantum mechanics. Way (2) is what kicked off Newtonian mechanics. I see string theorists and loop quantum gravity people as working on (2). Their models are mathematically interesting and aren't totally understood from a mathematical perspective. But they're different enough that studying them may break the impasse. I see (1) as largely limited by the budgets and technology needed to build things like particle accelerators and spacecraft. For (2) you have to decide whether to only explore mathematics that defines physical reality, or whether to also allow exploration of non-physical systems. For example, you might explore a universe that is almost physical but has time machines. Restricting the search space to only physically realistic systems is a significant constraint, so there's a debate to be be had about how much weight to give it.

slashdave 2y ago
(1) is also limited by imagination
- tines 2y ago
  Isn't it (2) that's limited by imagination? Nobody imagined quantum theory, they observed it first.
Ma8ee 2y ago
Those mathematical advances weren't developed in a vacuum, but made to solve some very specific problems which came from better measurements. So even Newtonian mechanics originated in solving problems trying to explain measurements, not that someone sat in their chamber and dreamed up cool math that happened to be very useful.
- ants_everywhere 2y ago
  I agree. Generally, the scientific method has mutually recursive turns of theory and observation. And I don't mean to imply that exist independently. I'm just saying that if you get stuck, the two clearest ways out are to provide more observations or perturb the theory.
- killerstorm 2y ago
  Number theory and algebraic geometry were developed for their own sake (i.e. "it is cool"), but later people found practical applications in cryptography. So "useful math must be motivated by practice" is empirically false
  - Ma8ee 2y ago
    > So "useful math must be motivated by practice" is empirically false That was not the claim. The claim is that useful physics originates in measurements.
ordu 2y ago
> physics is stuck at a local optimum. I think I heard somewhere that the trouble with string theory is it can describe anything if you tune it just in a right way. It reminds me of epicycles, they also had this property, you can add more and more epicycles to describe literally any observation data. > Way (1) is what kicked off quantum mechanics. Way (2) is what kicked off Newtonian mechanics. Hmm... What was the way that kicked Copernicus to redraw epicycles with the Sun in the center? I mean, is there some notes on these? For example, Newton took as granted that celestial bodies move by elliptical orbits, and somehow he guessed that the gravitation law has r^2 in its denominator, and so he invented calculus to prove, that if you have r^2 in the denominator then you'll get elliptical orbits. The question where Newton got his guess it remains open for me, but back to Copernicus, what was his way? Maybe he thought how movements of planets will look if seen from the Sun, and so he had redrawn epicycles to take a look, and he got circles? (I'm not sure that it could work this way, I propose this answer to my question just to give an example of the kind of an answer I'd like to have). I ask this question for two reasons. 1. I believe that Copernicus advanced the science not with surpising physical observation and not with mathematical advances, to me it seems more like surprising mathematical observation. I'm not sure what was that observation exactly. 2. Can one apply techniques of Copernicus to the modern physics? I suspect that it will not. I'm sure physicist already tried everything and there were (is) a lot of them and they are pretty smart people, so it is highly unlikely that Copernicus can help them in any way. But I'm still curious, what Copernicus would do? Would he tried to imagine how electron flying through a double-slit might observe scientists-observers? Or maybe it would try to feel the pain of a black that may believe that the whole universe is falling on it? I bet that the true Copernicus idea would require to use some pretty hard mind-altering substances, and I like such ideas.
- WillAdams 2y ago
  My understanding as a layman: 1. Copernicus figured out that if you put the sun at the center, then epicycles weren't necessary, and the math got easier --- because epicycles were based on a mis-understanding of the actual state of the universe --- I don't believe that anyone has identified such a non-alignment of fact and reasoning and observation for contemporary physics. 2. The problem is, modern physics is arguably getting boxed into a corner by approaching an end game state where the fundamental particles are getting identified, but are so small and difficult to separate out, that measurements are challenging to the point that while one can speculate and do math, actually proving out the speculations experimentally and taking actual measurements is expensive or so difficult to reason about that there doesn't seem an obvious path to an experiment, e.g., it looks as if the electron may be a fundamental particle, which is a sufficiently difficult concept to parse that it led to "The one-electron universe"/"The single electron hypothesis" and if that is the case, it walls off a not insignificant portion of particle physics at a size/state which can't be gotten smaller than.
throwawaymaths 2y ago
Name a single physics phenomenon that was discovered purely with way 2. I can only think of one, the positron. Newtonian physics was not kicked off by math "advances". Approximately speaking it was the other way, Newton created the math to explain p^2 ~ r^3, which was a surprising observation. Even theory of relativity wasn't really a math advance, the math was already mostly worked out by mach, lorenz, and minkowski. Einstein put it together into a coherent story (v. Important)
- zburatorul 2y ago
  The Higgs.
  - cb321 2y ago
    Also, the W's and the Z.. neutrino oscillations. There is actually a long list. Physics is the poster child science of theory-experiment interplay and this shows up constantly in the philosophy of science and other things resulting in expressions like "physics envy" ( https://en.wikipedia.org/wiki/Physics_envy https://en.wikipedia.org/wiki/Physics_envy ).
  - throwawaymaths 2y ago
    No the higgs mechanism was directly proposed from how particles masses were not explainable from the existing model -- so it's clearly in the "surprising observation" category. The positron was, "oh what if we had this thing that is mathematically possible". Very different. IIRC the discovery was kind of independent. It was in the data the whole time so if the physicists didn't just ignore those "impossible" bubble tracks they might have found it before the math. If we discovered superluminal tachyons that would definitely count. But we haven't found those.
- versteegen 2y ago
  Bose-Einstein statistics, which originated purely from finding a derivation of an equation, without immediately understanding of the true physical meaning of the derivation. And then Bose-Einstein condensates; a thought-experiment consequence of Bose-Einstein statistics. Radio waves etc., from formulating Maxwell's equations.

slashdave 2y ago

(1) is also limited by imagination

tines 2y ago
Isn't it (2) that's limited by imagination? Nobody imagined quantum theory, they observed it first.

Ma8ee 2y ago

Those mathematical advances weren't developed in a vacuum, but made to solve some very specific problems which came from better measurements. So even Newtonian mechanics originated in solving problems trying to explain measurements, not that someone sat in their chamber and dreamed up cool math that happened to be very useful.

ants_everywhere 2y ago
I agree. Generally, the scientific method has mutually recursive turns of theory and observation. And I don't mean to imply that exist independently. I'm just saying that if you get stuck, the two clearest ways out are to provide more observations or perturb the theory.
killerstorm 2y ago
Number theory and algebraic geometry were developed for their own sake (i.e. "it is cool"), but later people found practical applications in cryptography. So "useful math must be motivated by practice" is empirically false
- Ma8ee 2y ago
  > So "useful math must be motivated by practice" is empirically false That was not the claim. The claim is that useful physics originates in measurements.

ordu 2y ago

> physics is stuck at a local optimum. I think I heard somewhere that the trouble with string theory is it can describe anything if you tune it just in a right way. It reminds me of epicycles, they also had this property, you can add more and more epicycles to describe literally any observation data. > Way (1) is what kicked off quantum mechanics. Way (2) is what kicked off Newtonian mechanics. Hmm... What was the way that kicked Copernicus to redraw epicycles with the Sun in the center? I mean, is there some notes on these? For example, Newton took as granted that celestial bodies move by elliptical orbits, and somehow he guessed that the gravitation law has r^2 in its denominator, and so he invented calculus to prove, that if you have r^2 in the denominator then you'll get elliptical orbits. The question where Newton got his guess it remains open for me, but back to Copernicus, what was his way? Maybe he thought how movements of planets will look if seen from the Sun, and so he had redrawn epicycles to take a look, and he got circles? (I'm not sure that it could work this way, I propose this answer to my question just to give an example of the kind of an answer I'd like to have). I ask this question for two reasons. 1. I believe that Copernicus advanced the science not with surpising physical observation and not with mathematical advances, to me it seems more like surprising mathematical observation. I'm not sure what was that observation exactly. 2. Can one apply techniques of Copernicus to the modern physics? I suspect that it will not. I'm sure physicist already tried everything and there were (is) a lot of them and they are pretty smart people, so it is highly unlikely that Copernicus can help them in any way. But I'm still curious, what Copernicus would do? Would he tried to imagine how electron flying through a double-slit might observe scientists-observers? Or maybe it would try to feel the pain of a black that may believe that the whole universe is falling on it? I bet that the true Copernicus idea would require to use some pretty hard mind-altering substances, and I like such ideas.

WillAdams 2y ago
My understanding as a layman: 1. Copernicus figured out that if you put the sun at the center, then epicycles weren't necessary, and the math got easier --- because epicycles were based on a mis-understanding of the actual state of the universe --- I don't believe that anyone has identified such a non-alignment of fact and reasoning and observation for contemporary physics. 2. The problem is, modern physics is arguably getting boxed into a corner by approaching an end game state where the fundamental particles are getting identified, but are so small and difficult to separate out, that measurements are challenging to the point that while one can speculate and do math, actually proving out the speculations experimentally and taking actual measurements is expensive or so difficult to reason about that there doesn't seem an obvious path to an experiment, e.g., it looks as if the electron may be a fundamental particle, which is a sufficiently difficult concept to parse that it led to "The one-electron universe"/"The single electron hypothesis" and if that is the case, it walls off a not insignificant portion of particle physics at a size/state which can't be gotten smaller than.

throwawaymaths 2y ago

Name a single physics phenomenon that was discovered purely with way 2. I can only think of one, the positron. Newtonian physics was not kicked off by math "advances". Approximately speaking it was the other way, Newton created the math to explain p^2 ~ r^3, which was a surprising observation. Even theory of relativity wasn't really a math advance, the math was already mostly worked out by mach, lorenz, and minkowski. Einstein put it together into a coherent story (v. Important)

zburatorul 2y ago
The Higgs.
- cb321 2y ago
  Also, the W's and the Z.. neutrino oscillations. There is actually a long list. Physics is the poster child science of theory-experiment interplay and this shows up constantly in the philosophy of science and other things resulting in expressions like "physics envy" ( https://en.wikipedia.org/wiki/Physics_envy https://en.wikipedia.org/wiki/Physics_envy ).
- throwawaymaths 2y ago
  No the higgs mechanism was directly proposed from how particles masses were not explainable from the existing model -- so it's clearly in the "surprising observation" category. The positron was, "oh what if we had this thing that is mathematically possible". Very different. IIRC the discovery was kind of independent. It was in the data the whole time so if the physicists didn't just ignore those "impossible" bubble tracks they might have found it before the math. If we discovered superluminal tachyons that would definitely count. But we haven't found those.
versteegen 2y ago
Bose-Einstein statistics, which originated purely from finding a derivation of an equation, without immediately understanding of the true physical meaning of the derivation. And then Bose-Einstein condensates; a thought-experiment consequence of Bose-Einstein statistics. Radio waves etc., from formulating Maxwell's equations.