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 MS La Moreaux Oct9-09 07:40 PM

The version of Faraday's Law which purports to include both motional EMF and transformer EMF for circuits is false. There is no theoretical basis for it. Richard Feynman, in his "Lectures on Physics," pointed out the fact that this so-called law, what he called the "flux rule," does not always work and gave two examples. Every textbook and encyclopedia that I know of treats it as a true law. There is a lot of confusion and nonsense related to it. I believe that it is an indictment of the status quo and a scandal.

 CFDFEAGURU Oct9-09 07:57 PM

Could you post this version of Faraday's Law?

Thanks
Matt

 MS La Moreaux Oct10-09 04:35 PM

E=-d$$\Phi$$/dt

Mike

 cabraham Oct10-09 06:59 PM

Every law is "false" to an extent. As measuring equipment eveolves and we can see at a smaller level, FL will be modified. No one ever said that FL is 100% accurate from now until the end of time.

FL is based on observed data. I used it hundreds of times to design transformers, chokes, etc. I've had nothing but success with FL. It isn't perfect, but what is?

Your rant is much ado about nothing. Faraday's law stands tall today and those who wish to knock it down have to produce a better law. Until then, you have no case at all.

Claude

 MS La Moreaux Oct10-09 07:09 PM

FL is based on observed data. The problem with it has nothing to do with inability to measure small enough values. There are three problems that come to mind at the moment. 1. There are counter examples where it does not work at all. 2. There is no way to incorporated two independent principles into one term of an equation. 3. There is no principle upon which it is based. It is just an ad hoc formulation, like Bode's Law, which works for admittedly most cases, but is just an accident of geometry and math. It is an engineering convenience but is superfluous as a law. It adds nothing to our understanding as the principles of motional EMF and transformer EMF cover every possible case.

Mike

 Gear300 Oct10-09 07:38 PM

You might want to look into the quantum description of the phenomenon.

Quote:
 Quote by MS La Moreaux (Post 2387318) It adds nothing to our understanding as the principles of motional EMF and transformer EMF cover every possible case.
I wouldn't exactly say that.

Newton's laws weren't universal -- Relativity had to modify our outlook...but they still hold famous grounding. For that matter we can't really say any law is universal. It is part of what the institution of science is based on - the ability to build on old knowledge with new knowledge.

In the case of Faraday's law, it did indeed provide us with an understanding in the relation between electricity and magnetism. We were then able to continue on while using this law as a stepping-stone.

Quote:
 Quote by MS La Moreaux (Post 2387318) 1. There are counter examples where it does not work at all.
Same with Ohm's Law. That doesn't work for semiconductors. (And please provide an example where Faraday's doesn't work, so I better understand what you are talking about)

Quote:
 Quote by MS La Moreaux (Post 2387318) 2. There is no way to incorporated two independent principles into one term of an equation.
Same with Ohm's Law, which lumps together resistances caused by electrons and caused by phonons.

Quote:
 Quote by MS La Moreaux (Post 2387318) 3. There is no principle upon which it is based.
At the risk of sounding like a broken record, one can say the same about Ohm's Law.

 ZapperZ Oct11-09 05:36 AM

Quote:
 Quote by MS La Moreaux (Post 2387318) FL is based on observed data. The problem with it has nothing to do with inability to measure small enough values. There are three problems that come to mind at the moment. 1. There are counter examples where it does not work at all. 2. There is no way to incorporated two independent principles into one term of an equation. 3. There is no principle upon which it is based. It is just an ad hoc formulation, like Bode's Law, which works for admittedly most cases, but is just an accident of geometry and math. It is an engineering convenience but is superfluous as a law. It adds nothing to our understanding as the principles of motional EMF and transformer EMF cover every possible case. Mike
You have not shown any valid references to support your argument. And when I say valid sources, I mean published, peer-reviewed sources, which is the only type we will accept in this forum. Till you can do that, you are violating the speculative post rules from our PF Guidelines that you had agreed to.

Please post your required sources in the VERY NEXT post, or this discussion will end immediately.

Zz.

I wonder if this is referring to the Faraday paradox which, as I understand it, is only an apparent paradox.I tried a quick google and shall return there later since it looks quite interesting

 Peeter Oct11-09 08:31 AM

Quote:
 Quote by MS La Moreaux (Post 2385986) Every textbook and encyclopedia that I know of treats it as a true law. There is a lot of confusion and nonsense related to it. I believe that it is an indictment of the status quo and a scandal.
You have only to find a textbook that treats all of Maxwell's equations in their entirety (like Feynman's volume II). He's got a nice big table of "true in general" vs. "true only in restricted circumstances".

The objection to the falseness of this particular "law" is curious. So much of how physics is taught is this way. We start with Coulomb's law and find no, that's false (need maxwell's equations) ; pendulum as harmonic oscillator (false: only for small angles) ; Newton's laws ... (false: need relativity) ; classical mechanics (false: need QM) ; QM (need QFT?) ; ...

I view my physics studies as an attempt to learn progressively less false models of the world.

 CFDFEAGURU Oct11-09 08:34 AM

Peeter,

Quote:
 I view my physics studies as an attempt to learn progressively less false models of the world.
Very well put.

Thanks
Matt

 MS La Moreaux Oct11-09 02:26 PM

I am not speculating. I am repeating what has already been published by a distinguished source. Ironically, Faraday's disk dynamo, or homopolar generator, is a counter example, as pointed out by Richard Feynman in his "Lectures on Physics." I would think that someone of his status would be the equivalent of a peer-reviewed source. By the way, is there a published peer-reviewed source that states or proves that Faraday's Law is based upon an established physical principle?

Mike

 cabraham Oct11-09 05:18 PM

Quote:
 Quote by MS La Moreaux (Post 2388398) I am not speculating. I am repeating what has already been published by a distinguished source. Ironically, Faraday's disk dynamo, or homopolar generator, is a counter example, as pointed out by Richard Feynman in his "Lectures on Physics." I would think that someone of his status would be the equivalent of a peer-reviewed source. By the way, is there a published peer-reviewed source that states or proves that Faraday's Law is based upon an established physical principle? Mike
Would you please quote exactly what Feynman said about FL? You suggest that Feynman questions the validity of FL. but you must elaborate in detail. FL is pretty simple. v = -N*d(phi)/dt, or in vector form, curl E = -dB/dt. What part is non-valid? Is there another term needed, or factor, or both? If that equation is wrong, please illuminate us with the right one. If you can do that, and have said equation verified through independent testing, then you have something. Otherwise, you're just "talking the talk". I don't think you're as clever as you think you are. You bluff and bluster as if you hold 4 aces, when all you have is a mere pair of deuces, or less.

Claude

 ZapperZ Oct11-09 05:26 PM

Quote:
 Quote by MS La Moreaux (Post 2388398) I am not speculating. I am repeating what has already been published by a distinguished source. Ironically, Faraday's disk dynamo, or homopolar generator, is a counter example, as pointed out by Richard Feynman in his "Lectures on Physics." I would think that someone of his status would be the equivalent of a peer-reviewed source. By the way, is there a published peer-reviewed source that states or proves that Faraday's Law is based upon an established physical principle? Mike
What "established physical principle" is Coulomb's law is based on? What established physical principle is the symmetry of our universe based on? What established physical principle is the Schrodinger equation based on?

You still haven't given any valid references. What "published by distinguished source" are you talking about? Give exact references the way they do in peer-reviewed sources.

Zz.

 cesiumfrog Oct11-09 07:07 PM

Quote:
 Quote by ZapperZ (Post 2388662) [..]any valid references to support your argument.
I think Feynman's lectures are acknowledged as a valid source in the expert literature, wouldn't you agree?

Quote:
 Quote by MS La Moreaux (Post 2385986) his "Lectures on Physics," pointed out the fact [but nonetheless, other sources] that I know of treats it as a true law. [..] I believe that it is an indictment of the status quo and a scandal.
I think you will find Feynman also points out that Newton's laws are false. (And that Schroedinger's equation is also false.)

And yet, modern textbooks still teach Newton's laws (and Schroedinger's equation). Is that a scandal? An indictment? For example, are all of these authors completely unaware of relativity theory? Or are you just getting unnecessarily over-dramatic about the fact that it is practical to first teach the parts that are simple and widely applicable (and only afterwards to build upon it by teaching the superseding knowledge, which is more abstract, difficult, and not directly relevant to daily experience). Perhaps you're also mistaken about what scientists mean when they use the term "law"? (And as for implying Feynman's course is separate from the status quo...)

Quote:
 Quote by cabraham (Post 2388650) v = -N*d(phi)/dt, or in vector form, curl E = -dB/dt. What part is non-valid?
Apparently (linking to a direct quote) the former, not the latter. (In this particular context.)

 russ_watters Oct11-09 07:18 PM

Quote:
 Quote by cesiumfrog (Post 2388781) I think Feynman's lectures are acknowledged as a valid source in the expert literature, wouldn't you agree? [emphasis added]
Yes, but the OP has not provided a valid reference, which means a direct quote and a link to where it may be read/heard in context. That's the only way for other users to judge the quote for themselves. 'Take my word for it' isn't a reference.

Unless the reference is posted so the others here can know what the heck the OP is talking about, this thread will have to be locked.

 cesiumfrog Oct11-09 07:35 PM

Quote:
 Quote by russ_watters (Post 2388789) Yes [that source is valid], but the OP has not provided a valid reference, which means a direct quote and a link to where it may be read/heard in context. That's the only way for other users to judge the quote for themselves. 'Take my word for it' isn't a reference. Unless the reference is posted so the others here can know what the heck the OP is talking about, this thread will have to be locked.
I've put a link in above, but seriously, how will an exact page citation help? Anyone who has the volumes need only look up the homopolar generator in their index anyway, anyone else is still stuck either way.

 ZapperZ Oct11-09 07:37 PM

Quote:
 Quote by cesiumfrog (Post 2388781) I think Feynman's lectures are acknowledged as a valid source in the expert literature, wouldn't you agree?
What the OP did was similar to saying that he found it PRL. PRL is a respectable journal, but the WAY it is cited is not a VALID reference. Besides, is this what the OP meant as one of the "distinguished source"? If you read the post, it doesn't sound like it.

Zz.

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