Jack Sarfatti
2 minutes ago via Twitter
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    http://t.co/wYnvApwlL2 updated 12-20-13
    Jack Sarfatti - Academia.edu
    lnkd.in
    More on the physical meaning of gauge transformations in both gravity and the electromagnetic-weak-strong interactions 12-18-13 The subject of gauge transformations is almost always presented in an obscure way as a purely formal mathematical exercise without direct physical meaning. This is all clas...
     
     
     
  • Jack Sarfatti On Dec 20, 2013, at 8:58 AM, JACK SARFATTI wrote:

    On Dec 20, 2013, at 6:02 AM, Paul Murad wrote:

    So you are calling electric forces which I would call as real forces...

    Paul Murad
    Morningstar Applied Physics, LLC
    www.morningstarap.com
    This email address is being protected from spambots. You need JavaScript enabled to view it.

    Electric force is real because it pushes charges off timelike geodesics of Einstein's geometrodynamical field, i.e. the Ruvwl curvature tensor field, which can be zero of course - zero is a good real number.
    http://en.wikipedia.org/wiki/Riemann_curvature_tensor

    My point is perhaps a bit surprising.

    The canonical 3-momentum of a charge e of mass m is

    P = mV + (e/c)A

    Total local momentum of the charge + EM field = Kinetic momentum of the charge + EM field momentum

    A gauge transformation is

    mV -> mV' = mV + hgradf

    (e/c)A -> (e/c)A' = (e/c)A - hgradf

    P -> P' -> P + hgradf - hgradf = P

    http://www.ippp.dur.ac.uk/.../QED/GaugeInvariance_2.html

    Therefore the canonical 3-momentum P is gauge invariant.

    h is Planck's constant, so this is a quantum effect in what first appears to be a purely classical problem.

    First surprise!

    From the point of view of local field theory if we suppose that the charge and the field at the charge are a closed system so that

    dP/dt = 0

    then what we have is simply a Newton third law 

    ACTION + REACTION = 0

    where

    mV -> mV' = mV + hgradf 

    is the ACTION of the electromagnetic field A on the charge e of mass m.

    (e/c)A -> (e/c)A' = (e/c)A - hgradf

    Is the equal and opposite REACTION of the charge e on the field A

    This is a LOCAL exchange of a virtual photon of momentum hgradf between COINCIDENT charge and field.

    The classical equation of motion in an inertial frame follows trivially

    dP/dt = mdV/dt + (e/c)dA/dt = 0

    E = - (1/c)dA/dt

    Therefore

    mdV/dt = eE

    Now I can do the same thing for Einstein's GR using the Levi-Civita connection, where now, instead of virtual momentum transfers between particle and field, we have real proper acceleration changes between locally coincident LNIFs measuring the motion of test particles that keep the proper forces on the observed test particles a tensor. This gives direct physical meaning to the inhomogeneous terms in the non-tensor Levi-Civita connection transformation induced by the formal general coordinate transformations. In other words it is a heuristic physical picture of gravity gauge symmetry on the Levi-Civita connection, which is not a tensor. 

    http://en.wikipedia.org/wiki/Gauge_theory
    http://www.ippp.dur.ac.uk/.../QED/GaugeInvariance_1.html

    On Thursday, December 19, 2013 8:58 PM, JACK SARFATTI wrote:
    it's real
    On Dec 18, 2013, at 6:13 PM, Paul Murad <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:

    What electric force or is that fictitious?

    Paul Murad
    Morningstar Applied Physics, LLC
    http://www.morningstarap.com/
    This email address is being protected from spambots. You need JavaScript enabled to view it.

    On Wednesday, December 18, 2013 6:36 PM, Jack Sarfatti wrote:
    Imagine two bricks taped together with a dynamite stick and timer released from an airplane 

    The dynamite explodes

    There are transient real electric forces on the shattered brick pieces momentarily pushing them off their geodesics
    After a while these forces vanish and all the pieces relax to geodesics 
    Where is the beef?

    The fact is that Jim uses an undefined primitive he calls "inertial reaction force" that has no relation to anything in textbooks on the subject unless he means

    F = DP/ds

    Jim has never given me a straight answer and I cannot find a clear definition in his book either.

    Any suggestions?

    Sent from my iPad

    On Dec 18, 2013, at 3:20 PM, Jack Sarfatti wrote:

    Sent from my iPad

    On Dec 18, 2013, at 10:41 AM, Ruth Kastner wrote:

    But I should add that Jack can give a 'substantivalist' account of what you describe by appealing to the constraining effect of spacetime to keep the remaining block on its geodesic. What you describe as an inertial force, Jack describes as geodesically-constrained motion. Different, irreconcilable, metaphysical pictures. (I happen to question the substantivalist idea that spacetime has these sorts of causal powers. But that's the mainstream view.)

    RK