How do we know our laws of physics are correct?

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Discussion Overview

The discussion revolves around the validity and universality of the laws of physics. Participants explore how we can be confident in these laws, questioning whether they are universally correct or if they could be proven wrong in the future. The conversation touches on concepts of time, the second law of thermodynamics, and the evolution of physical theories.

Discussion Character

  • Debate/contested
  • Exploratory
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that the laws of physics make sufficiently accurate predictions to be treated as provisionally correct.
  • There is a call to define "correct," with some arguing that laws are accurate descriptions based on extensive measurements and observations.
  • Concerns are raised about whether laws like the second law of thermodynamics could be overruled or proven wrong in the future.
  • Participants discuss the idea that laws may not be universally correct and have specific domains where they are applicable.
  • Some express uncertainty about whether the laws of physics that are valid today will remain valid in the future, referencing historical shifts in understanding, such as Newtonian physics being refined by Einstein's theories.
  • There is a contention that Newtonian physics was not "proven wrong" but remains valid within its domain of applicability.
  • Participants note that while current laws are well-tested, there is an expectation that they will be improved upon in the future.
  • Some argue that all current laws are correct within their respective experimental domains, while others question the certainty of this assertion.

Areas of Agreement / Disagreement

Participants express a mix of agreement and disagreement regarding the universality and future validity of physical laws. While some assert confidence in the current laws, others highlight the potential for future revisions and the limitations of existing models.

Contextual Notes

Participants acknowledge that the laws of physics have domains of applicability and that there are circumstances, such as extreme conditions, where these laws may fail. The discussion reflects a recognition of the evolving nature of scientific understanding.

  • #31
Actually, we had a huge revolution recently, that concluded that the "Law of Conservation of Mass/Energy" is incorrect. The violation is that the universe seems to be expanding at an increasing rate. There is currently no way to reconcile this with the conservation law. An invisible source of mass/energy might work. But currently the understanding is that the expansion of the universe will increase its mass/energy by huge amounts--another few universes of mass wouldn't be enough to balance things. (The vacuum energy is more than enough.)

The second result is recent and much more subtle. https://physicsworld.com/a/dark-energy-emerges-when-energy-conservation-is-violated/ A QM model where energy is not conserved allows for the energy "lost" on a small scale to create the Cosmological Constant, even though the energy conservation violations are difficult or impossible to see on even a solar system scale.

Will a "Theory of Everything" eventually have a conservation law? Don't know. My guess is that just like adding mass as a result of nuclear physics, the true conservation law will have at least one more term.
 
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  • #32
eachus said:
Actually, we had a huge revolution recently, that concluded that the "Law of Conservation of Mass/Energy" is incorrect. The violation is that the universe seems to be expanding at an increasing rate. There is currently no way to reconcile this with the conservation law.

I'm not convinced. My understanding was that the issue simply wasn't settled yet and I haven't heard anything about a consensus on the subject.

eachus said:
The second result is recent and much more subtle. https://physicsworld.com/a/dark-energy-emerges-when-energy-conservation-is-violated/ A QM model where energy is not conserved allows for the energy "lost" on a small scale to create the Cosmological Constant, even though the energy conservation violations are difficult or impossible to see on even a solar system scale.

Note that this model is very speculative and currently has little to support it over other models.
 
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  • #33
eachus said:
Actually, we had a huge revolution recently, that concluded that the "Law of Conservation of Mass/Energy" is incorrect. The violation is that the universe seems to be expanding at an increasing rate.
Conservation of energy is valid at less than cosmological scales, as centuries of experimental evidence shows. None of the cosmological results change the non-cosmological evidence validating the conservation of energy.
 
  • #34
There's a famous syllogism by Bertrand Russell:

Bread is a stone
Stones are nourishing
Therefore bread is nourishing

The syllogism is supposed to illustrate that a theory can be valid even though the premises themselves are false. So, the postulates of a theory may lead to predictions that are borne out by experiment even if the postulates are not 'correct' (in the universal way the OP refers to). There is no way to tell whether a theory is universally correct.
 
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  • #35
Science evolves. That's what makes it interesting after all. If we knew all the laws from the start of written history (some around 10000BC) it would just be so boring, there would be no evolution.

The evolution of science involves (in my opinion) taking laws that are approximately correct in some domains (the error of approximation is so small in these domains that cannot be experimentally tested, for example Galileo transformations are correct for all domains with velocities <5% of speed of light) and extending them to new domains where the error of approximation is much bigger. So we have to evolve the previous known laws in order to make the error of approximation again small in the new domains. But we can't be sure whether the newly evolved laws are again a very good approximation or they are the absolute correct laws of the universe, the newly evolved laws maybe someday will have to evolve again to match new experimental data from new domains.
 
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  • #36
TheQuestionGuy14 said:
Sorry, I meant correct as in, are they just correct for now,
Of course they are. Our successful level of technology demonstrates that. What more could you want?
Recent developments in Physics have allowed more advanced technology.
 

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