Faraday's Law and magnetic flux

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Discussion Overview

The discussion revolves around the phenomenon of electromagnetic induction as described by Faraday's Law, specifically questioning why a changing magnetic flux through a surface induces an electromotive force (emf). Participants explore theoretical explanations, the nature of scientific understanding, and the role of experimental evidence in validating scientific laws.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Meta-discussion

Main Points Raised

  • Some participants inquire about the origin of the non-conservative electric field that induces emf, questioning the underlying mechanisms of Faraday's Law.
  • Others argue that the validity of scientific paradigms should be based on their predictive power rather than the existence of more fundamental explanations.
  • A participant suggests that the appearance of emf can be explained through the transformation of the magnetic field according to Lorentz transformations, proposing this as a more fundamental understanding.
  • There is a sentiment expressed that many people mistakenly believe physicists accept theories on faith, while participants assert that serious scientists critically engage with theories.
  • Some participants reflect on the importance of questioning and seeking deeper understanding in the advancement of scientific knowledge.

Areas of Agreement / Disagreement

Participants express differing views on the nature of scientific understanding and the reasons behind the induction of emf. There is no consensus on a definitive explanation for why changing magnetic flux induces emf, and the discussion remains unresolved.

Contextual Notes

Participants acknowledge that the explanations for electromagnetic induction may rely on postulates that are not derivable from other principles, highlighting the limitations in fully understanding the phenomenon.

Gza
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Why is it that a changing magnetic flux through a surface should induce an emf? I know that the emf is from a non-conservative electric field, but how exactly was this field generated? (if that is the correct expression for it)
 
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When someone gives you an answer as to why this happens, won't you just want to know why whatever answer they gave happens? What will this explanation tell you, exactly?

In my humble opinion whether you accept a paradigm a famous scientist offers you shouldn't depend on whether there is a more fundamental explanation proposed later, but instead depend on wether you can verify it to be a good predictor - which with Faraday's Law is easy to do.
 
THe apearance of the emf is due to the transformation of the B field to the reference frame of the wire. The transformation laws are governed by the Lorenz equations. I guess this explanation ( given in more detail) is a more fundamental and satisfactory one. Dont forget Faraday was an experimental guy. It's an experimental law
 
Gza said:
I know that most people are all too willing to take whatever some famous scientist says on faith ...
I've never met a physicist who took anything on faith. To be honest, I don't recall anyone who seriously studies science taking anything on faith.
..and simply learn their theories without thinking what they mean, ..
I've also never met anyone who seriously studies science who didn't think when learning a theory.
Why is it that a changing magnetic flux through a surface should induce an emf?
You've never learned it because nobody knows the answer to that question. I.e. it's one of Maxwell's equations and those equations are postulates, i.e. not derivable from from other postulates.

For details please see - http://rustam.uwp.edu/202/lec18_19.html

Pete
 
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When someone gives you an answer as to why this happens, won't you just want to know why whatever answer they gave happens? What will this explanation tell you, exactly?


This is the nature of an inquisitive mind. If it weren't for people asking why, we would still be in the realm of classical physics, with no motivation to advance.

And I apologize if my original post seemed to be confrontational to anyone; the people on this board are obviously the last people one would expect to take things on faith. It just seemed like a sensible question to ask.
 
Gza said:
And I apologize if my original post seemed to be confrontational to anyone; the people on this board are obviously the last people one would expect to take things on faith. It just seemed like a sensible question to ask.

No problemo! I all the years I've been posting in physics boards on the internet I've seen many people think that physicists are just gulible people who believe anything a prof tells them too. I don't know why people make that assumption so much but it does seem to be a common theme to those people who are not scientists.

Pete
 

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