JustinLevy
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Thank you for your responses.
However, since we will be working with Lagrangians and Hamiltonians in CED, where it is the potentials that are given higher status (as coordinates, where as the E and B fields are not coordinates and are just defined in terms of the potentials), in the context that Maxwell's equations and the Lorentz force law are derived from the Lagrangian or Hamiltonian, I hope we can agree that my wording there are least makes sense.
As you say though, quibbling about such wording is pointless. The mathematical definition relating the fields to potentials is a definition either way.
So for now, we can agree to disagree, but here is my stance on these:
Said an even more concretely way:
The Lagrangian has time translation symmetry and space translation symmetry. Via Noether's theorem, this very clearly has energy-momentum conservation in any situation. Nothing needs to be added.
To then complain that a different set of equations containing the Abraham-Lorentz force can cause problems is immaterial.
Because the Lagrangian has energy-momentum conservation, there CANNOT be any run-off solutions. Any such solutions must be due to mathematical error.
Okay. That is my stance on CED pathologies.
We can agree to disagree. I don't want to argue about those; I just want you to understand where I am coming from. I also don't want to argue about these because the motivations of your theory are not important for this discussion, just the details of what your theory is.
So... moving on.
Anyway, if you could just answer the last two bolded requests, then the content of your theory will be clear enough to me so that I can start playing with it myself. It is not even necessary to make any comments beyond those, for once I have that it will allow me to work through everything myself so that the results in the paper will hopefully make much more sense to me.
So yes, let's please move on to the meat of the discussion.
Thank you.
Yes, that is the historical order.Bob_for_short said:Historically the Maxwell equations were written in terms of field tensions. Very soon the vector-potential was introduced for some conveniences. So it is the properties of the vector potential that follow from the Maxwell equations, not on the contrary.
However, since we will be working with Lagrangians and Hamiltonians in CED, where it is the potentials that are given higher status (as coordinates, where as the E and B fields are not coordinates and are just defined in terms of the potentials), in the context that Maxwell's equations and the Lorentz force law are derived from the Lagrangian or Hamiltonian, I hope we can agree that my wording there are least makes sense.
As you say though, quibbling about such wording is pointless. The mathematical definition relating the fields to potentials is a definition either way.
I am really hesitant here. I do not want to derail this discussion by arguing over pathologies in CED. But I do want you to at least understand where I am coming from.Bob_for_short said:Thus, in order to answer properly your questions I have to note the following: The Maxwell (field) equations together with particle equations work fine in two limiting cases:
I. The fields in the particle equation are known functions of space-time, so the Lorentz force is known (case of external fileds). Then we look for trajectories.
II. The charge-current distribution is known function of space-time, i.e., the source terms for fields are known (external sources). Then we look for the field solution.
In temrs of Lagrangian of interaction it corresponds to two cases: jA = jAext and jextA, where j and A are four-vectors. This covers practically all CED applications.
So for now, we can agree to disagree, but here is my stance on these:
This comment makes no sense. The equations do NOT "only" contain an external field. The equations very clearly contain source equations for the fields (or in the Lagrangian context, j.A not only provides a term in the force equation, but also for the evolution of the fields).Bob_for_short said:The theoretical question raised by H. Lorentz was to make ends meet with the energy-momentum conservation for a radiated particle. As long as its equations contained only an external filed (magnetic, for example), no particle energy losses were taken into account.
Said an even more concretely way:
The Lagrangian has time translation symmetry and space translation symmetry. Via Noether's theorem, this very clearly has energy-momentum conservation in any situation. Nothing needs to be added.
We just agreed on what the equations of CED are.Bob_for_short said:So he decided to develop further the particle equations and introduced new terms.
To then complain that a different set of equations containing the Abraham-Lorentz force can cause problems is immaterial.
Because the Lagrangian has energy-momentum conservation, there CANNOT be any run-off solutions. Any such solutions must be due to mathematical error.
No, it is the other way around. Non-physical solutions were the result of modification of CED as listed above. CED expressly forbids run-away solutions as shown by Noether's theorem.Bob_for_short said:Anyway, any attempts to get rid of non-physical solutions were reduced to modification of CED.
Okay. That is my stance on CED pathologies.
We can agree to disagree. I don't want to argue about those; I just want you to understand where I am coming from. I also don't want to argue about these because the motivations of your theory are not important for this discussion, just the details of what your theory is.
So... moving on.
Yes, let us move onto your approach now.Bob_for_short said:You and me will speak of another way of preserving the conservation laws, OK?
I'm sorry, but the article really wasn't clear enough for me to extract the answer to those bolded requests myself. I was hoping someone else would jump in and help since your paper is online for everyone, but despite the "read counts" for the thread going up, no such luck. Maybe no one is willing to answer for fear of stepping on your toes if they misunderstood the paper as well.Bob_for_short said:If you are agree, I will continue answering tonight. By the way, "skimming" my article is not sufficient. I tried to explain everything in details including canonical coordinates and momenta.
Anyway, if you could just answer the last two bolded requests, then the content of your theory will be clear enough to me so that I can start playing with it myself. It is not even necessary to make any comments beyond those, for once I have that it will allow me to work through everything myself so that the results in the paper will hopefully make much more sense to me.
So yes, let's please move on to the meat of the discussion.
Thank you.