4 ms·

Since all theories trying to unite and reconcile quantum theory with general relativity kind of failed, I wonder if one of the two theories doesn't have some st

Since all theories trying to unite and reconcile quantum theory with general relativity kind of failed, I wonder if one of the two theories doesn't have some structural errors.

samus 3y ago
That far is known already: entropy and time have to be kind of bolted on to quantum theories. And there is a veritable zoo is "interpretations" of quantum theory. Meanwhile, general relativity struggles with singularities, dark energy, and dark matter.
- snarkconjecture 3y ago
  General relativity has no problem with dark energy or dark matter. Singularities, yes. And nonrenormalizability is an issue (with trying to make it quantum).
  - samus 3y ago
    That's right. The problem is more that it doesn't say anything useful about dark energy and dark matter. Apart from allowing us to infer their existence.
    - evanb 3y ago
      General relativity doesn't say anything useful about electromagnetism or baryonic matter either; I'm not sure you can lay an absence of an explanation of dark matter at its feet. For dark energy of course is much harder to say...
      - samus 3y ago
        It feels natural to expect it from General relativity as the dominant force at cosmic scales is gravity. The various MOND proposals are admittedly niche, and we might eventually be able to fully explain Dark matter without such modifications.
dragonwriter 3y ago
I thought the broad assumption is that both do, but they also bith kake a wide array of predictions which are useful; unification is about subsuming the demonstrated useful predictions of each within a common explanatory framework (ideally one which also adds additional predictive power, though parsimony is a win without that).
passion__desire 3y ago
M Theory ??https://youtu.be/plU31-qtZ78?si=G5nAmw5zp8kbaouL https://youtu.be/plU31-qtZ78?si=G5nAmw5zp8kbaouL
orwin 3y ago
And I wonder why we try to unit and reconcile them. Do we try to unite and reconcile different branch or mathematics? I get that we like to have metanarratives, but in my opinion, this might be a dead end.
- simiones 3y ago
  The framing of "uniting" or "reconciling" QM and GR is actually bad. The real problem is this: both QM and GR have been proven by experiments to be wrong. GR predicts entirely wrong results for the motion of electrons and other small particles. QM predicts wrong results at galactic scales. However, they both work very very well at certain scales. So we don't want to get rid of them. Instead, we want to find some rule that tells us when to use the math of GR, and when to use the math of QM, so that we don't need to guess and just pretend that they are right.
  - orwin 3y ago
    I agree with that, but I wasn't clear I think. You can find euclidian geometric proof of some standard arithmetic theorems, but geometry isn't the right tool to prove really complex arithmetic theorems. Try to make euclidian geometry complete enough to resolve all arithmetic, and you will probably find yourself in front of contradictions (I stopped doing math after my bachelor, so I clearly might be wrong about that). Why do we need to expand th9se theory? First correct the issues left within the defined context. Then find more contexts and see if you can define a new theory or use an old one?
- wruza 3y ago
  Langlands Program. To oversimplify, the fundamental lemma of the project posits a direct connection between the generalized fundamental representation of a finite field with its group extension to the automorphic forms under which it is invariant. This is accomplished through abstraction to higher dimensional integration, by an equivalence to a certain analytical group as an absolute extension of its algebra. Consequently, this allows an analytical functional construction of powerful invariance transformations for a number field to its own algebraic structure. https://en.wikipedia.org/wiki/Langlands_program https://en.wikipedia.org/wiki/Langlands_program
pa7x1 3y ago
This is not true, but I can see how one can lead to think this is the case given the poor journalistic reporting on the subject. At the time being we have no experimental access to the regime where quantum gravitational effects are relevant. So no theory of quantum gravity has been falsified experimentally. That is, none have failed because they didn't match the experiments. The experiments have not been carried out yet because we don't have the technological ability to do them or we haven't had the ingenuity to infer how to retrieve experimental data from available sourced.

Since all theories trying to unite and reconcile quantum theory with general relativity kind of failed, I wonder if one of the two theories doesn't have some structural errors.

samus 3y ago

That far is known already: entropy and time have to be kind of bolted on to quantum theories. And there is a veritable zoo is "interpretations" of quantum theory. Meanwhile, general relativity struggles with singularities, dark energy, and dark matter.

snarkconjecture 3y ago
General relativity has no problem with dark energy or dark matter. Singularities, yes. And nonrenormalizability is an issue (with trying to make it quantum).
- samus 3y ago
  That's right. The problem is more that it doesn't say anything useful about dark energy and dark matter. Apart from allowing us to infer their existence.
  - evanb 3y ago
    General relativity doesn't say anything useful about electromagnetism or baryonic matter either; I'm not sure you can lay an absence of an explanation of dark matter at its feet. For dark energy of course is much harder to say...
    - samus 3y ago
      It feels natural to expect it from General relativity as the dominant force at cosmic scales is gravity. The various MOND proposals are admittedly niche, and we might eventually be able to fully explain Dark matter without such modifications.

dragonwriter 3y ago

I thought the broad assumption is that both do, but they also bith kake a wide array of predictions which are useful; unification is about subsuming the demonstrated useful predictions of each within a common explanatory framework (ideally one which also adds additional predictive power, though parsimony is a win without that).

passion__desire 3y ago

M Theory ??https://youtu.be/plU31-qtZ78?si=G5nAmw5zp8kbaouL https://youtu.be/plU31-qtZ78?si=G5nAmw5zp8kbaouL

orwin 3y ago

And I wonder why we try to unit and reconcile them. Do we try to unite and reconcile different branch or mathematics? I get that we like to have metanarratives, but in my opinion, this might be a dead end.

simiones 3y ago
The framing of "uniting" or "reconciling" QM and GR is actually bad. The real problem is this: both QM and GR have been proven by experiments to be wrong. GR predicts entirely wrong results for the motion of electrons and other small particles. QM predicts wrong results at galactic scales. However, they both work very very well at certain scales. So we don't want to get rid of them. Instead, we want to find some rule that tells us when to use the math of GR, and when to use the math of QM, so that we don't need to guess and just pretend that they are right.
- orwin 3y ago
  I agree with that, but I wasn't clear I think. You can find euclidian geometric proof of some standard arithmetic theorems, but geometry isn't the right tool to prove really complex arithmetic theorems. Try to make euclidian geometry complete enough to resolve all arithmetic, and you will probably find yourself in front of contradictions (I stopped doing math after my bachelor, so I clearly might be wrong about that). Why do we need to expand th9se theory? First correct the issues left within the defined context. Then find more contexts and see if you can define a new theory or use an old one?
wruza 3y ago
Langlands Program. To oversimplify, the fundamental lemma of the project posits a direct connection between the generalized fundamental representation of a finite field with its group extension to the automorphic forms under which it is invariant. This is accomplished through abstraction to higher dimensional integration, by an equivalence to a certain analytical group as an absolute extension of its algebra. Consequently, this allows an analytical functional construction of powerful invariance transformations for a number field to its own algebraic structure. https://en.wikipedia.org/wiki/Langlands_program https://en.wikipedia.org/wiki/Langlands_program

pa7x1 3y ago

This is not true, but I can see how one can lead to think this is the case given the poor journalistic reporting on the subject. At the time being we have no experimental access to the regime where quantum gravitational effects are relevant. So no theory of quantum gravity has been falsified experimentally. That is, none have failed because they didn't match the experiments. The experiments have not been carried out yet because we don't have the technological ability to do them or we haven't had the ingenuity to infer how to retrieve experimental data from available sourced.