Is the simple explanation of modern physics ever the case?

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Discussion Overview

The discussion revolves around the nature of explanations in modern physics, particularly in quantum mechanics (QM) and general relativity (GR). Participants explore the adequacy of simple explanations versus more complex mathematical formulations, the role of interpretations in QM, and the relationship between macroscopic phenomena and underlying microscopic theories.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that simple explanations in physics often fail to capture the complexities of underlying theories, particularly in QM and GR.
  • There is a view that while space-time curvature is a useful model for understanding gravity, it may not represent the fundamental reality of gravitational interactions.
  • Others argue that the predictive power of a theory is paramount, and the "picture" it provides may be secondary to its ability to make accurate predictions.
  • Some participants express skepticism about the necessity of multiple interpretations of QM, questioning their utility given that a predictive mathematical formulation suffices.
  • A contrasting perspective emphasizes the importance of understanding how macroscopic phenomena emerge from microscopic theories, suggesting that this connection is vital for scientific progress.
  • One participant asserts that Einstein's use of thought experiments should be taken seriously, as they provide valid insights into his theories despite their complexity.
  • Another participant highlights that the mathematics of physics is based on hypotheses, which are essential for explaining physical phenomena, rather than merely serving as tools for prediction.

Areas of Agreement / Disagreement

Participants express a range of views, with no clear consensus on the adequacy of simple explanations versus complex theories. Disagreement exists regarding the necessity and value of different interpretations in QM, as well as the fundamental nature of gravity as described by GR.

Contextual Notes

Some limitations in the discussion include the dependence on definitions of key concepts, the unresolved nature of certain mathematical steps, and the varying interpretations of quantum mechanics that remain open to debate.

jaydnul
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In QM for example, I realize it is pointless to try and picture what is happening because the is nothing macroscopic to base it on. In GR, we are told that something called space-time is curved which creates the phenomenon of gravitational force. The deeper you go into these subjects, however, it seems that the simple explanation is never the case. Am I right in saying that gravity really isn't the warping of something called space-time, but it is helpful to think of it in that way in order to predict certain outcomes in our macroscopic world? If that's what modern science is all about, being able to predict certain outcomes in our macroscopic world, then what is the point of ascribing these pictures when fundamentally, that is not what's going on (other than to help the general public who have no intentions of further study).

From what I've gathered, a modern working theoretical physicist tries to formulate mathematics to predict the macroscopic outcomes of experiments that could be performed. That's great, but it really doesn't tell us exactly what's physically going on, and our unaided human brains probably could never understand what's going on, unless it involved simple Newtonian dynamics. Is that somewhat accurate?
 
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Jd0g33 said:
From what I've gathered, a modern working theoretical physicist tries to formulate mathematics to predict the macroscopic outcomes of experiments that could be performed. That's great, but it really doesn't tell us exactly what's physically going on, and our unaided human brains probably could never understand what's going on, unless it involved simple Newtonian dynamics. Is that somewhat accurate?

It's always been that way. When Newton wrote ##F=Gm_1m_2/r^2## he was formulating mathematics to describe the outcomes of experiments involving falling bodies. That was great but it didn't tell us exactly what was physically going on - it just restated it in mathematical terms.
 
The space-time curvature is so far the best picture and best explanation we have for gravity (General Relativity). But any physical theory can only be judged on its predictions, and not on its "picture". What can you "really say is going on" in any theory? Even in classical mechanics we have the two different "pictures" - Newtonian and Lagrangian.
 
This might sound naive but why does that satisfy you?

Also, why do we have all these different interpretations of QM when at the end of the day, scientifically, we have what we need which is a predictive mathematical formulation.
 
Jd0g33 said:
Also, why do we have all these different interpretations of QM when at the end of the day, scientifically, we have what we need which is a predictive mathematical formulation.
That is a good question. Frankly, all of the worry and discussion about QM interpretations seems incredibly pointless to me.
 
Jd0g33 said:
In QM for example, I realize it is pointless to try and picture what is happening because the is nothing macroscopic to base it on.

Isn't that exactly the reason? ...to try to determine how the macro we know is built on the micro we don't know? Isn't finding that connection vital? We have grown used to rapid advancement and have no frame of reference for how long and arduous the crawl used to be in early work. In this frame, QM is but a baby, and babies get into trouble, make mistakes and messes, but in Science I'm betting everyone is aware of the retort "Of what use is a baby?" I think it applies here.
 
Jd0g33 said:
This might sound naive but why does that satisfy you?

Also, why do we have all these different interpretations of QM when at the end of the day, scientifically, we have what we need which is a predictive mathematical formulation.

That's an odd juxtaposition of questions. The only reason that the curved spacetime formulation of GR satisfies is that it makes predictions that match our observations... just as does QM without interpretation.
 
Jd0g33 said:
The deeper you go into these subjects, however, it seems that the simple explanation is never the case.
Einstein liked to use simple "thought experiments" to explain his theories. Take those seriously. They are correct, not just convenient.
Am I right in saying that gravity really isn't the warping of something called space-time, but it is helpful to think of it in that way in order to predict certain outcomes
No. The warping is completely correct as far as any experiments have been able to test it so far. Other, simpler, explanations have all failed. But those simpler explanations usually left some very serious questions unanswered (like, why is there a preferred inertial reference frame and who decides which reference frame is correct?). So they were not as complete an explanation as Einstein's is. The beauty of Einstein's theories is that, although the math is difficult, everything follows logically from a very small number of fundamental hypothesis.
From what I've gathered, a modern working theoretical physicist tries to formulate mathematics to predict the macroscopic outcomes of experiments that could be performed. That's great, but it really doesn't tell us exactly what's physically going on,
The mathematics is based on hypotheses. When the math works out to verify experimental results, that supports the hypotheses that started it all. The hypotheses are the explanation, not the math calculations. Einstein's special relativity hypothesized that the speed of light is constant. The math that followed from that gave better results than anything else. The hypothesis "the speed of light is constant." is the explanation of what is going on. The math is just necessary to see what follows from that hypothesis, to make predictions and to see if experiments support or disprove the hypothesis.
 
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