Extra Dimension Evidence
Greg Egan
One thing that baffles me here is why, if geomagnetic field variation is sufficient to produce observable changes in G, the vastly greater range of field strengths that can be produced with artificial magnetic fields can't be used to create proportionately greater changes in G.
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General Relativity and Quantum Cosmology, abstract
gr-qc/0204064
From: Jean-Paul MBELEK <mbe...@discovery.saclay.cea.fr>
Date: Fri, 19 Apr 2002 16:51:18 GMT (344kb)
Possible evidence from laboratory measurements for a latitude and longitude dependence of G
Authors: J.P. Mbelek (Service d'Astrophysique, CEA, Saclay, France), M. Lachièze-Rey (Service d'Astrophysique, CEA, Saclay, France)
Comments: Latex, 20 pages with 2 Postscript figures
Stability arguments suggest that the Kaluza-Klein (KK) internal scalar field, $\Phi$, should be coupled to some external fields. An external bulk real scalar field, $\psi$, minimally coupled to gravity is proved to be satisfactory. At low temperature, the coupling of $\psi$ to the electromagnetic (EM) field allows $\Phi$ to be much stronger coupled to the EM field than in the genuine five dimensional KK theory. It is shown that the coupling of $\Phi$ to the geomagnetic field may explain the observed dispersion in laboratory measurements of the (effective) gravitational constant. The analysis takes into account the spatial variations of the geomagnetic field. Except the high PTB value, the predictions are found in good agreement with all of the experimental data.
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General Relativity and Quantum Cosmology, abstract
gr-qc/0205089
From: Jean-Paul MBELEK <mbe...@discovery.saclay.cea.fr>
Date: Tue, 21 May 2002 08:59:06 GMT (283kb)
A five dimensional model of varying effective gravitational and fine structure constants
Authors: J.P. Mbelek (Service d'Astrophysique, CEA, Saclay, France), M. Lachièze-Rey (Service d'Astrophysique, CEA, Saclay, France)
Comments: Latex, 6 pages with 1 Postscript figure
We explore the possibility that the reported time variation of the fine structure constant $\alpha$ is due to a coupling between electromagnetism and gravitation. We consider the coupling predicted by a very simple {\sl effective} theory of physical interactions, under the form of an improved version of the Kaluza-Klein theory. We show that it is precisely expressed by a variation of the effective fine structure constant with cosmic conditions, and thus with cosmic time. We compare the predicted variation with the recent data from distant quasars absorption line spectra: we find a good agreement, which moreover reconcile the claimed results on $\alpha$ with the upper limit from the Oklo naturel Uranium fission reactor.
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Uncle Al
>
> Two relevant papers by the researchers discussed in the New Scientist article are cited below.
>
> One thing that baffles me here is why, if geomagnetic field variation is sufficient to produce observable changes in G, the vastly greater range of field strengths that can be produced with artificial magnetic fields can't be used to create proportionately greater changes in G.
> --------------------------------------------------
> gr-qc/0204064
> gr-qc/020508e dimensional model of varying effective gravitational and fine structure constants
The *very first* thing to note is that the two cited locations
purportedly evidencing gravitational constant coupling to varying
geomagnetic field... have the *same* geomagnetic field,
http://picasso.ngdc.noaa.gov/cgi-bin/seg/util/gifrmt?map_24207.gif
(units are nanoteslas)
The second thing to note is that the researchers haven't the foggiest
notion of where the most and least intense geomagnetic fields are
located. The two extrema are both in the Southern Hemisphere - Sao
Paulo, Brazil to the eastern border of Paraguay at the same latitude
(minimum) and somewhat north of south magnetic pole (maximum). The
nearest solid stuff is Adelie Land to the Banzare Coast.
--
Uncle Al
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)
"Quis custodiet ipsos custodes?" The Net!
John Baez
In article <amu5gn$4d9$1...@inky.its.caltech.edu>,
Greg Egan <greg...@netspace.zebra.net.au> wrote:
>Two relevant papers by the researchers discussed in the New Scientist
>article are cited below.
>
>One thing that baffles me here is why, if geomagnetic field variation is
>sufficient to produce observable changes in G, the vastly greater range
>of field strengths that can be produced with artificial magnetic fields
>can't be used to create proportionately greater changes in G.
I can't really answer that question. I haven't read these
papers. However, my attitude is that any wild claims about
physics in New Scientist can safely be ignored, because this
magazine is really sinking into the depths of sensationalism -
more and more, it seems to prefer eye-catching flakey physics
to solid stuff. If I see something about this in a more reputable
source, I may think it's worth bothering with.
A couple of years ago I got email from a reporter there asking me
about the revolutionary by now utterly forgotten work of
Cahill and Klinger on "self-referential noise and the synthesis
of three-dimensional space". I told them they should instead
write about something neglected but really substantial, like
algebraic quantum field theory. They expressed some interest, but
as far as I know they never wrote anything about that. It's far
from shocking, but still too bad: I'm sure with proper packaging
this could be made even more mind-blowing than the stuff they *do*
talk about! Of course you'd need to find someone who could explain
it well.
Ralph E. Frost
Greg Egan <greg...@netspace.zebra.net.au> wrote in message
news:amu5gn$4d9$1...@inky.its.caltech.edu...
> Two relevant papers by the researchers discussed in the New Scientist
article are cited below.
>
> One thing that baffles me here is why, if geomagnetic field variation is
sufficient to produce observable changes in G, the vastly greater range of
field strengths that can be produced with artificial magnetic fields can't
be used to create proportionately greater changes in G.
A couple odd thoughts, which may not be so odd in light of J.P. Mbelek ,
et. al...
1. When one imposes artificial magnetic fields, both poles are usually in
essentially the same local region and they have some orientation wrt to the
encapsulating field. The (supposed??) lack of influence (Has any one
tested?) may be related to that difference with the natural system, a
cacneling effect. I guess this notion is testable or may be observed
should variations in G turn out to be, say, generally more positive or
larger nearer the north pole and negative or smaller nearer the south pole.
2. Besides, the dramatic change in attraction that you think is missing IS
routinely observed on certain types of materials ...those which folks call
"magnetic". ;-) [i.e., that's not a bug, that's a feature.]
--
Ralph Frost
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