Re: High-level question about the relationship relativity and quantum mechanics

"Juan R." González-Álvarez wrote on Thu, 24 Sep 2009 11:51:56 +0000:

Tom Roberts wrote on Tue, 22 Sep 2009 20:41:12 -0500:

Juan R. González-Álvarez wrote:
Tom Roberts wrote on Sun, 20 Sep 2009 19:05:14 -0500:
squarooticus wrote:
One thing that has always bugged me is the notion that the major
goal of theoretical high-energy physics is to unify quantum
mechanics and relativity
This is not true. All theories of high energy physics are Lorentz
invariant. That is, they conform to relativity. The need for Lorentz
invariance in theories was solidly established long before the advent
of high energy physics (aka elementary particle physics).

This is all plain wrong. There exists no unification of quantum
mechanics with relativity.

Read what I wrote. The type of quantum mechanics that is unified with
relativity is called quantum field theory. OF COURSE it is not the same
as the eponymous non-relativistic quantum mechanics.

And since it is *not* a relativistic quantum mechanics this is why is
not named "relativistic quantum mechanics" (RQM) but "relativistic
quantum field theory" (RQFT).

Moreover, being strict, there is not real unification even at RQFT
level!

For instance in SR or in RQM the Lorentz transformations relate
positions and times measured in different intertial frames. The *formal*
analog of the transformations in RQFT has not relation to measurements
of positions or times.

As remarked by H. Bacry in 1989 Nucl. Phys. Proc. Suppl. 6, 222:

Every physicist would easily convince himself that all quantum cal-
culations are made in the energy-momentum space and that the Minkowski
xμ are just dummy variables without physical mean- ing (although
almost all textbooks insist on the fact that these variables are not
related with position, they use them to express locality of
interactions!)

As is well-known (read a textbook), any attempt to develop a
relativistic quantum mechanics failed and particle physicists
abandoned the problem and developed a relativistic quantum field
theory.

Right. So what I wrote is not "all plain wrong" as you claimed above;
indeed, what I wrote and what you wrote say the same thing using
different words.

This is plain wrong, I did not say "the same thing".

(...)

Note that this is Special Relativity, not General Relativity. But
that's OK, as the processes studied in HEP are all so localized that
the curvature of spacetime is utterly negligible (factors of
~10^-42).

For HEP, all one needs in relativistic quantum field theory. Because
HEP are simple experiments.

<giggle> There's nothing "simple" about HEP experiments -- the LHC and
associated experiments are the largest and most complicated scientific
instrument in the world. And no knowledgeable theorist would consider
these experimental situations, or the standard model used to describe
them, "simple".

Deleting the links and sniping the extra information do not hide your
utter ignorance of modern state of research in physics Tom.

REINTRODUCING SNIPED PART:

A discussion of several approximations used in HEP are given in

http://www.canonicalscience.org/en/publicationzone/canonicalsciencereports/20083.html";

http://www.canonicalscience.org/en/publicationzone/canonicalsciencereports/20083.html

If you had followed the link, read, and understood it, you would know
the existence of the modern scientific field of complexity (Gell-Mann
calls it plectics).

If we draw a linear scale from simple scientific problems to complex
problems we find to HEP in the simplest side of the scale.

By being unable to accept this fact, you are showing the same "arrogance
of the particle physicists" denunciated by the nobel Prize for Physics
P.W. Anderson in his /Science/ paper about Complexity. See page 12 in
above canonical science report.

In the page 13, I quote the standard text from Goldberger and Watson,
explaining why the HEP theoretical analysis "can be done in a general
and straightforward manner". They add "The description of the
interaction of the system (i.e. during the collision) involves the most
important and difficult problems in physics".

I explain in the report some of the simplifications involved in HEP :-D

The standard model is *trivially simple* when compared with the advanced
formalism are being developed in other fields of science you unknow.

In my reference 32 you may find one of those advanced theoretical
frameworks, developed by Prigogine's group and recently published in
Phys. Rev. A.

In the reference 13 you may find to one of the most cited
particle-string physicists in the world

http://en.wikipedia.org/wiki/Dimitri_Nanopoulos

adapting an *old* version of Prigogine theory to a generalization of
superstring theory, which (I at least wait you to know this) is more
complex and advanced than the standard model of HEP.

As explained in page 8 of the above canonical science report the
excursion of Nanopoulos and coworkers, in their own words, "beyond
string theory or even high-energy physics" is at best *outdated* now.

About the complexity of the experimental instruments used in HEP. I
could say much also. But I will merely add they are not sophisticated
and complex enough for resolving the time-dependent dynamics. Luckily
this is why quantum field theory is all that is needed to study the
outcome of *those* HEP experiments.

But those simple formalisms are not enough in the rest of fields of
science where the HEP approximations do not hold.

The S-matrix used in HEP experiments is an approximation to the U_QFT,
wich is a local approximation to the propagator U=exp(Ht), which is an
pure state approximation to the exp(Lt) evolutor (see equation 4 in page
7 of the canonical science report), which is an approximation to a more
general dynamical equation as eq. 3.

(...)

Hmmmm. Neither electric nor magnetic "fields" are really fields in
the modern sense (the names are archaic). The actual field is the
Maxwell 2-form, which combines E and B in a way that is independent
of frame.

No. Of course E and B are fields in the usual physical sense (this is
why we call them fields in modern literature).

No. Speaking loosely they can be considered "fields on space",

No, we do not mean "fields on space" when say that E and B are fields.

(...)

In fact your 'modern' Maxwell 2-form is an old covariant concept only
valid in the local limit.

It is valid wherever Maxwell's equations are valid. This is not "old"
(but it's not new, either), and is not any sort of approximation. Using
the language of differential forms, Maxwell's equations can be written
in terms of the Maxwell 2-form; they are IDENTICAL to the usual
Maxwell's equations when projected onto inertial coordinates of a flat
manifold, and have the advantage that they are also valid when
projected onto any coordinates, inertial or non-inertial, of a flat or
curved manifold.

As said before, the Maxwell 2-form is valid only in a local
approximation (again you show your ignorance of modern state of
research).

Moreover, there adittional approximations involved in the description of
EM over curved spacetimes since the Riemanian metric g_ab is only valid
in the geometric limit of a physical theory of gravity.

One lesson of modern physics is to not attempt to describe things
that cannot be measured. That includes "fluxes of force-carrying
particles". Instead, describe things that can be measured like the
trajectories objects, etc. Modern quantum field theories have no
definite flux for their force carriers, but the trajectories of
objects are independent of frame.

As explained in virtually any textbook on quantum field theories,
position is not observable in those theories.

And yet all particle experiments are based on measuring particles'
TRAJECTORIES. You attempt to make a theoretical objection that has no
practical consequences, and you need to learn how theories are actually
used.

And as explained in any good treatise of RQFT those trajectories have no
physical correspondence to the (x,t) in RQFT, which is not a mechanics.
This is why the final S-matrix used in the laboratory does not depend on
time or position of any particle.

You show once again a complete ignorance of what is measured and what
part of measurements are compared (and how) to the predictions of RQFT.





--
http://www.canonicalscience.org/

BLOG:
http://www.canonicalscience.org/en/publicationzone/canonicalsciencetoday/canonicalsciencetoday.html
.

Relevant Pages

  • Please give us your opinion about this debate on quantum mechanics
    ... I have been arguing with another poster about physics, quantum ... mechanics, whether a broken glass tumbler can spontaneously put itself ...
    (sci.physics)
  • Re: High-level question about the relationship relativity and quantum mechanics
    ... of theoretical high-energy physics is to unify quantum mechanics and ... All theories of high energy physics are Lorentz ... That is, they conform to relativity. ... There exists no unification of quantum ...
    (sci.physics.relativity)
  • Re: RAH and Light speed
    ... examined and found wanting if classical principles had been reinstated. ... (Relativity would not have disappeared as ... it combined with the old quantum mechanics, ... but times were busy and physics was confused. ...
    (rec.arts.sf.written)
  • Re: Sci Am proposes SR wrong and Aether exists
    ... Dispersion of short wavelength light by a black hole doesn't seem to be ... > this frame necessarily violate relativity? ... the article was about quantum gravity - a theory that does not yet ... "I consider it quite possible that physics cannot be based on ...
    (sci.physics)
  • Re: The Fifth Dimension
    ... >physics, where meanings are relative. ... This is to cover your complete and utter ignorance of the ENGLISH ... imagination, with nothing to do with relativity, or any other physical ... Wave-particle duality is a part of Quantum Mechanics. ...
    (sci.physics)
Loading