PS Paul

Your use of "gravitational field" is ambiguous.
You must clearly specify in each instance, do you mean
at local point event P. In the sense of "passive diff invariance" e.g.
Note 6 of Carlo Rovelli's "Quantum Space-Time: What do we know?" in
"Physics Meets Philosophy at the Planck Scale", which may be ~ 20 powers
of ten larger than 10^-33 cm IMHO:

I. guv(P) a LOCAL tensor under general coordinate transformation group

II. G-Force, i.e. connection field from partial derivatives of guv(P)
not a tensor

III. 4th rank curvature tensor Ruvwl(P) from first and second partial
derivatives of guv(P)

guv(P) - Minkowski flat metric LOCALLY at P only on "preferred"
timelike geodesic tangent vector free float (weightless) LIFs (3
space-like directions orthogonal to the timelike tangent vector of the
geodesic -- Cartan mobile frame). G-Force vanishes in the LIF. Like
Duchamp's Nude Descending a Stair Case, each point on the geodesic is a
different LIF. Curvature tensor of 4th rank does not vanish in the LIF.
Local map between LIF and LNIF at SAME P is the tetrad special case of
general coordinate transformation. One needs non-gravity EM near field
of virtual photons to make a timelike non-geodesic world line with
non-vanishing G-Force (weight). One needs non-gravity EM far field of
real photons to have a causal light cone structure in the first place.
Therefore, gravity must be "More is different" (PW Anderson) emergent
from quantum electrodynamics in Andrei Sakharov's sense. I have a toy
model of this in
http://qedcorp.com/APS/EmergentGravity.doc

PPS on Susskind's "Landscape". The landscape of possible physical vacua
must generally depend upon the "moduli" of Calabi-Yau extra space
dimensions beyond space-time because supersymmetry is badly broken in
our universe and 96 % of the large-scale stuff of our universe is exotic
vacuum repulsive "dark energy" and attractive "dark matter" from zero
point vacuum fluctuations of all quantum fields combined. What is the
vibrating string projected down to 3+1 uncompactified space-time? It is
like a vortex in a superfluid dominated by attractive zero point
energetic "dark matter" exotic vacuum cores of vanishing "vacuum
coherence" where /\zpf ~ - (1fermi)^-2 at least in the present Ho
spacelike FRW foliation where CMB temperature fluctuations are isotropic
to ~ 10^-5.

On Sun, 21 Dec 2003 00:32:02 +0000, Jack Sarfatti wrote:

PS Paul

Your use of "gravitational field" is ambiguous.
You must clearly specify in each instance, do you mean
at local point event P. In the sense of "passive diff invariance" e.g.
Note 6 of Carlo Rovelli's "Quantum Space-Time: What do we know?" in
"Physics Meets Philosophy at the Planck Scale", which may be ~ 20 powers
of ten larger than 10^-33 cm IMHO:

I. guv(P) a LOCAL tensor under general coordinate transformation group

II. G-Force, i.e. connection field from partial derivatives of guv(P)
not a tensor

III. 4th rank curvature tensor Ruvwl(P) from first and second partial
derivatives of guv(P)

guv(P) - Minkowski flat metric LOCALLY at P only on "preferred"
timelike geodesic tangent vector free float (weightless) LIFs (3
space-like directions orthogonal to the timelike tangent vector of the
geodesic -- Cartan mobile frame). G-Force vanishes in the LIF. Like
Duchamp's Nude Descending a Stair Case, each point on the geodesic is a
different LIF. Curvature tensor of 4th rank does not vanish in the LIF.
Local map between LIF and LNIF at SAME P is the tetrad special case of
general coordinate transformation. One needs non-gravity EM near field
of virtual photons to make a timelike non-geodesic world line with
non-vanishing G-Force (weight). One needs non-gravity EM far field of
real photons to have a causal light cone structure in the first place.
Therefore, gravity must be "More is different" (PW Anderson) emergent
from quantum electrodynamics in Andrei Sakharov's sense. I have a toy
model of this in
http://qedcorp.com/APS/EmergentGravity.doc

PPS on Susskind's "Landscape". The landscape of possible physical vacua
must generally depend upon the "moduli" of Calabi-Yau extra space
dimensions beyond space-time because supersymmetry is badly broken in
our universe and 96 % of the large-scale stuff of our universe is exotic
vacuum repulsive "dark energy" and attractive "dark matter" from zero
point vacuum fluctuations of all quantum fields combined. What is the
vibrating string projected down to 3+1 uncompactified space-time? It is
like a vortex in a superfluid dominated by attractive zero point
energetic "dark matter" exotic vacuum cores of vanishing "vacuum
coherence" where /\zpf ~ - (1fermi)^-2 at least in the present Ho
spacelike FRW foliation where CMB temperature fluctuations are isotropic
to ~ 10^-5.

Its the distance between your ears, Jack,