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Regarding the "all models are wrong" maxim... Is that statement 100% true for the low-level models that physicists use and develop? In particular, I'm curious

Regarding the "all models are wrong" maxim... Is that statement 100% true for the low-level models that physicists use and develop? In particular, I'm curious if quantum-physics models are 100% right, just not 100% precise.

tomrod 7y ago
I keep this distinction in mind: - Models are deliberate simplifications of reality, in order to guide thinking and otherwise pull in only important information - Formulations (formalizations) are encapsulation of principles into a mathematical framework While there is significant overlap, the two categories do not overlap 100%. I see formalizations of physics as the latter, and we use the former to help keep our understanding of the latter clear.
- deleted 7y ago
  [deleted]
Jabbles 7y ago
Some predictions of Quantum Electrodynamics have been verified to within 1 part in 100,000,000. https://en.wikipedia.org/wiki/Precision_tests_of_QED https://en.wikipedia.org/wiki/Precision_tests_of_QED However, we know it cannot be completely accurate, as it has no way of explaining gravity.
deleted 7y ago
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carapace 7y ago
The Standard Model has no known contradictions in the real world. https://en.wikipedia.org/wiki/Standard_Model https://en.wikipedia.org/wiki/Standard_Model In "QED" Feynman states that the predictions are as precise as being able to measure the distance between (points in) New York and Los Angeles accurately to within the width of a human hair. https://en.wikipedia.org/wiki/QED:_The_Strange_Theory_of_Light_and_Matter https://en.wikipedia.org/wiki/QED:_The_Strange_Theory_of_Lig...
- magicalhippo 7y ago
  Neutrino oscillation[1] is a contradiction of the Standard model as-is, no? [1]: https://en.wikipedia.org/wiki/Neutrino_oscillation https://en.wikipedia.org/wiki/Neutrino_oscillation
  - carapace 7y ago
    Dunno. (IANAPhysicist) But that's hella cool. Cheers!
qchris 7y ago
At the level that you're talking about, you'll start running into the unresolved questions of modern physics. One of the best ways to look at this is through the Standard Model of particle physics, which essentially defines how the fundamental particles of the universe are related. Between the number of observations and large-scale experiments dealing with high-energy collision products, astrophysics, neutrino detectors, etc., some people consider the Standard Model to be the most thoroughly-tested and verified framework in all of science. That's a pretty grand claim, but hey. But it still falls short in some ways--for one, it starts breaking down past a certain scale. Classical field theory as defined by general relativity (another model that has had enormous success under test both theoretically and experimentally) and particle physics don't get along. Neither one fully explains reality, and the interface between those two models of reality hasn't been found. That's why people research things like string theory--they're attempting to find a mathematical framework that can resolve those two frameworks, among other things. So while each of them describes the universe extremely accurately in their own domain (check the sigma values and number of observations of experiments run on the LHC), they're not 100% right, since they can't be correctly extended to cover all scales and frames. The models remain just that--models which provide a useful framework to interpret reality, but don't fully describe the physical reality itself.
lidHanteyk 7y ago
Yes, it is completely true, and not in a probabilistic way, either. A model is a mathematical construction which relates observations to predictions. However, there is no epistemic basis by which predictions can be turned into observations; we can never ultimately draw conclusions just based on inferences. Perhaps you have heard of the idea that "the map is not the territory" [0]. Models can never be exactly descriptions of reality, not without some sort of special rationale and argument from the outside of reality. In particular, QM models aren't 100% right. Gravity is missing almost entirely from the model (!) and there are some glaring experimental discrepancies, particularly around the vacuum catastrophe [1]. We know that the combination of QM and relativity gives a hybridized model that cannot work at all scales but explains things like the color of gold [2], so we know that there ought to be a single unified model which does work at all scales and has the same explanatory power. [0] https://en.wikipedia.org/wiki/Map%E2%80%93territory_relation https://en.wikipedia.org/wiki/Map%E2%80%93territory_relation [1] https://en.wikipedia.org/wiki/Cosmological_constant_problem https://en.wikipedia.org/wiki/Cosmological_constant_problem [2] https://en.wikipedia.org/wiki/Relativistic_quantum_chemistry https://en.wikipedia.org/wiki/Relativistic_quantum_chemistry

tomrod 7y ago

I keep this distinction in mind: - Models are deliberate simplifications of reality, in order to guide thinking and otherwise pull in only important information - Formulations (formalizations) are encapsulation of principles into a mathematical framework While there is significant overlap, the two categories do not overlap 100%. I see formalizations of physics as the latter, and we use the former to help keep our understanding of the latter clear.

deleted 7y ago
[deleted]

Jabbles 7y ago

Some predictions of Quantum Electrodynamics have been verified to within 1 part in 100,000,000. https://en.wikipedia.org/wiki/Precision_tests_of_QED https://en.wikipedia.org/wiki/Precision_tests_of_QED However, we know it cannot be completely accurate, as it has no way of explaining gravity.

deleted 7y ago

[deleted]

carapace 7y ago

The Standard Model has no known contradictions in the real world. https://en.wikipedia.org/wiki/Standard_Model https://en.wikipedia.org/wiki/Standard_Model In "QED" Feynman states that the predictions are as precise as being able to measure the distance between (points in) New York and Los Angeles accurately to within the width of a human hair. https://en.wikipedia.org/wiki/QED:_The_Strange_Theory_of_Light_and_Matter https://en.wikipedia.org/wiki/QED:_The_Strange_Theory_of_Lig...

magicalhippo 7y ago
Neutrino oscillation[1] is a contradiction of the Standard model as-is, no? [1]: https://en.wikipedia.org/wiki/Neutrino_oscillation https://en.wikipedia.org/wiki/Neutrino_oscillation
- carapace 7y ago
  Dunno. (IANAPhysicist) But that's hella cool. Cheers!

qchris 7y ago

At the level that you're talking about, you'll start running into the unresolved questions of modern physics. One of the best ways to look at this is through the Standard Model of particle physics, which essentially defines how the fundamental particles of the universe are related. Between the number of observations and large-scale experiments dealing with high-energy collision products, astrophysics, neutrino detectors, etc., some people consider the Standard Model to be the most thoroughly-tested and verified framework in all of science. That's a pretty grand claim, but hey. But it still falls short in some ways--for one, it starts breaking down past a certain scale. Classical field theory as defined by general relativity (another model that has had enormous success under test both theoretically and experimentally) and particle physics don't get along. Neither one fully explains reality, and the interface between those two models of reality hasn't been found. That's why people research things like string theory--they're attempting to find a mathematical framework that can resolve those two frameworks, among other things. So while each of them describes the universe extremely accurately in their own domain (check the sigma values and number of observations of experiments run on the LHC), they're not 100% right, since they can't be correctly extended to cover all scales and frames. The models remain just that--models which provide a useful framework to interpret reality, but don't fully describe the physical reality itself.

lidHanteyk 7y ago

Yes, it is completely true, and not in a probabilistic way, either. A model is a mathematical construction which relates observations to predictions. However, there is no epistemic basis by which predictions can be turned into observations; we can never ultimately draw conclusions just based on inferences. Perhaps you have heard of the idea that "the map is not the territory" [0]. Models can never be exactly descriptions of reality, not without some sort of special rationale and argument from the outside of reality. In particular, QM models aren't 100% right. Gravity is missing almost entirely from the model (!) and there are some glaring experimental discrepancies, particularly around the vacuum catastrophe [1]. We know that the combination of QM and relativity gives a hybridized model that cannot work at all scales but explains things like the color of gold [2], so we know that there ought to be a single unified model which does work at all scales and has the same explanatory power. [0] https://en.wikipedia.org/wiki/Map%E2%80%93territory_relation https://en.wikipedia.org/wiki/Map%E2%80%93territory_relation [1] https://en.wikipedia.org/wiki/Cosmological_constant_problem https://en.wikipedia.org/wiki/Cosmological_constant_problem [2] https://en.wikipedia.org/wiki/Relativistic_quantum_chemistry https://en.wikipedia.org/wiki/Relativistic_quantum_chemistry