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## A SR experiment in which an entity exists in frame A but not frame B

 Quote by GregAshmore I'll work through the spacetime diagram some more. I see what I did wrong; now I'll see if I can do it right.
I think the diagrams that Mentz114 gave in post #22 are a good start:

http://www.physicsforums.com/showpos...6&postcount=22

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 Quote by GregAshmore The wave that is implied by what the paper calls "information" transmitted from negative to positive pole at the speed of light. This must mean some transfer of charge, I think.
My take on what this means is that it means the Lienard Wiechart potential
http://en.wikipedia.org/w/index.php?...ldid=518131167

Also known as the "retarded potential"

http://en.wikipedia.org/w/index.php?...ldid=530495062

To get the potential, you need to add up the contributing potentials for all charges. Initially, all the charges should be in the battery, so at the start the LW potetial is determined by the battery.

The electric part of it varioulsy called E or $\varphi$ is basically a voltage. You can measure it with a voltmeter except for an additive constant.

If you'll look at the definition, you'll see that because of the retarded time, the L.W. potential of a charge incorporates lightspeed propagation delays. So the position of a charge now doesn't add to the potential until "later", later being determined by the lightspeed delay in the frame you choose to do the analysis.

The magnetic part of it is usually called A. I'm not sure how much to say about A,perhaps it's best to read the wiki article and see if you have any questions about it. Failing that (i.e. if the wiki is so much goobley gook as far as you're concerned) you can tell us if you know what div, grad, and curl are. If you do, we might be able to say a bit more about A.

(E,A) forms a perfectly valid 4-vector (i.e. a tensor). If you regard tensors as "existing", then it "exists". But I'm not sure of your philosophy here.

Mentor
 Quote by GregAshmore Not if, at the event in question, the conditions stated for one frame are fundamentally different than the conditions stated for the other frame. In the present discussion, the paper referenced in the original post stated (in effect) that, at one and the same event: a) charge is transferred from terminal to plate in the rest frame of the plate; b) no charge is transferred from terminal to plate in the rest frame of the battery.
I certainly didn't read it that way, perhaps you can point out exactly where you drew that idea from.

However, if someone did propose such a scenario then the charges for a) and b) are not related by a boost so we wouldn't expect the resulting EM fields or any other aspect of the scenarios to be related by a boost. That doesn't contradict my assertion above, it is just not relevant to such a scenario.

 Quote by DaleSpam I certainly didn't read it that way, perhaps you can point out exactly where you drew that idea from.
I can't talk right now, I'm chewing...on the spacetime diagram. I expect that your original suggestion that the wave/signal is present in both frames will turn out to be correct.

 Quote by pervect My take on what this means is that it means the Lienard Wiechart potential. Also known as the "retarded potential" If you'll look at the definition, you'll see that because of the retarded time, the L.W. potential of a charge incorporates lightspeed propagation delays. So the position of a charge now doesn't add to the potential until "later", later being determined by the lightspeed delay in the frame you choose to do the analysis.
I get this part, conceptually. As to the rest, I'm afraid it is out of range for me mathematically at this point. How far I will pursue the math will be decided later. (If I keep making progress at the historical rate, not far.)

Honestly, I've never had an experience like this in my life. I've been working at understanding relativity for over five years--not full time, and not to the exclusion of other spare time interests, but five years just the same. I've been confused by other subjects, certainly. But in those cases, I never got it, I knew hadn't gotten it, and I moved on. With relativity, I read, I think I get it, I open my mouth, and I find that I am just plain wrong. That scenario has played out more times than I care to recall.

I have made genuine progress while actively working problems. I left off working problems for a while due to certain circumstances. I'm back at it, and, in spite of this most recent stumble, I believe that I will get this figured out.

I have not been able to form a mental picture of what happens in a relativistic episode that involves anything more than isolated particles. I can see the progression in either frame separately, but I cannot fuse the two into one process. It's the mix-up of time that gets me. I accept that the two seemingly contradictory narratives do not actually contradict each other, but until I can get a sense of the one reality that the two narratives express, I will continue to make dumb mistakes.

 Quote by pervect ...(E,A) forms a perfectly valid 4-vector (i.e. a tensor). If you regard tensors as "existing", then it "exists". But I'm not sure of your philosophy here.
This matter of the philosophy of reality is why I keep chipping away at the rock pile of relativity. I have a particular question I need to answer, a question at the junction of physics and metaphysics. I won't get into it here; I understand and agree to the rule that says we stick to physics on this forum.