rich

question about fields

27 posts in this topic

The term "fundamental physical existents" was your own, and I take "fundamental" here to mean not explainable by, not composed of nor caused by anything more basic.

OK.

That the E field can produce the B field, and that one may be transformed into the other, is evidence that they are not fundamental, whether they are "physical entities" or not.

I admit I don't really understand the first part. It's possible for distinct, fundamental existents to have a causal effect on each other isn't it?

Yes, but if indeed they are all fundamental then none are reducible to the other.

You mentioned TEW in another post. Based on my somewhat shaky understanding of this, I think it's correct to say that elementary waves and particles are both considered to be fundamental and real. The particles are guided by their elementary wave and the elementary waves, in turn, are locally affected by the configuration of the detectors.

Granted the elementary waves are not actually _produced_ by the particles per se - they are merely affected and would exist anyway. They are omnipresent (again assuming my understanding is correct). However in a similar way one could say that the E,B fields in standard electromagnetism are not actually produced by induction but are merely affected in that way - they would exist anyway, possibly with value 0.

Leaving aside the problematic "exist ... with value 0," in the TEW you cannot transform a wave into a particle; each are fundamental and independent existents. But the E and B fields can be relativistically transformed such that there are different mixes of each depending on motion. One can therefore argue more strongly for the existence in physical reality of an electromagnetic field, with the E and B representing mathematical components that single out one part of the EM field rather than another. (Not that I want to actually make and defend such an argument.)

The point being: is it anymore dubious to say that E,B fields are real and fundamental and can affect each other (through induction) than it is to say that particles and elementary waves are both fundamental and real and can affect one another?

Yes, it is more dubious to make such a claim, given the reasons I outlined previously and above. And note it was precisely because Faraday's law with E and B fields is only approximate under Galilean transformations that a relativistically correct electrodynamics was developed using a single electromagnetic field. And further, holding onto the E and B field in this manner, much like the ether, leads to a dead end in terms of integrating with the rest of known physics.

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Yes, it is more dubious to make such a claim, given the reasons I outlined previously and above. And note it was precisely because Faraday's law with E and B fields is only approximate under Galilean transformations that a relativistically correct electrodynamics was developed using a single electromagnetic field.

Ok thanks. In that part I was only really referring to the induction issue (can E,B be fundamental if they can "produce" each other through induction) but regardless I agree that the fact they can be Lorentz transformed away means they shouldn't be considered real (and that was why I originally raised the possibility of regarding the F_uv field as real and fundamental instead).

And further, holding onto the E and B field in this manner, much like the ether, leads to a dead end in terms of integrating with the rest of known physics.

That's basically the reason I don't find ether theories very interesting - they have the feel of being a step in the wrong direction. It's not too surprising that one can start with some physical assumption like the ether and then adjust the model to agree precisely with SR, but that kind of approach is unlikely to lead to physical insight in the long run.

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