sci.physics.electromag

On Aug 7, 6:53 pm, Igor wrote:
> On Aug 7, 8:03 am, "Juan R."
> wrote:
>
>
>
> > In the current micro-thought,
>
> > /
>
> > I present some relativistic Lagrangians and discuss several
> > limitations of the field-theoretic approach.
>
> > This is motivated by the generalized belief on field theory as being
> > 'fundamental' or 'complete' for modelling interactions.
>
> > First, I introduce some popular choices for field relativistic
> > Lagrangians.
>
> > Next, I list several fundamental limitations of the field theoretic
> > approach related to the relativistic equations of motion. This shows
> > the field theoretic formulation is not fundamental.
>
> > Those limitations are often unknown and still some authors try to get
> > some kind of "unified field theory" or believe that general relativity
> > (a metric formulation) is our last word about macroscopic gravity.
>
> > Authors who considered the field-theoretic description to be limited
> > and worked in alternatives includes celebrated Fokker, Dirac, Wheeler,
> > or Feynman between others.
>
> > S. Weinberg has not provided us an alternative to the field paradigm
> > but at least he warns his readers in the page 1 of his textbook on
> > quantum field theory (vol. 1):
>
> > {BLOCKQUOTE
> > If it turned out that some physical system could not be described
> > by a quantum field theory, it would be a sensation; if it turned out
> > that the system did not obey the rules of quantum mechanics and
> > relativity, it would be a cataclysm.
>
> > In fact, lately there has been a reaction against looking at
> > quantum field theory as fundamental.
>
> > }
>
> > But field theory is not fundamental already at the classical level. We
> > need alternatives. What one?
>
> > This Micro-thought addresses next misunderstandings in
> > :
>
> > "Relativistic theories compatible with special relativity may use
> > fields"
> > --Bilge--
>
> > "There is not relativistic potential energy"
> > --Bilge, Karandash2, Eric, Bill--
>
> > "L = T - V is not valid for relativistic systems"
> > --Eric--
>
> > Note for readers: due to inability of some 'experts' to learn i will
> > not reply their further misunderstandings. Almost anyone here knows
> > who they are.
>
> > Note for readers: Because some past episodes of flamming in
> > , both comments in the blog and my newsgroup e-
> > mail are disabled.
>
> Sounds to me that you just might be confusing the field Lagrangian
> with the mechanical Lagrangian.

It would be good for readers if you explain exactly where I am (you
claims so) confusing the "field lagrangian" with the "mechanical
Lagrangian". And if you explain how this invalidates the limitations
cited.

In the blog i write stuff like "field-theoretic Lagrangian" and if it
is not clear to you by the context, i am writing about the _field
description of interactions_. It may be clear because i am deriving
the equation of motion for _particles_.

Of course, i am not writting about the Lagrangian of a free field
(which appears to be your confusion).

Let me know and if more people misunderstand in that way I will
eliminate that 'ambiguity' from the blog in an update.

> By the way, if you can actually come
> up with a model that can explain how things work without invoking
> either fields or action-at-a-distance, you're welcome to it.

It sound strange that after knowing that fields give incorrect or
limited answers one were to work a fundamental theory invoking fields,
no?

The tendency in research is to go beyond fields and metrics.