Quote:
Originally Posted by Jerry
One expects the polhode moment of an egg to vary over eighteen months, but not a set of spheres made from materials chosen because of their known (presumed?) stability. It would seem to be a worthwhile test of the varacity of this 300,000,000+dollar assumption to construct a duplicate set of spheres and see if the polhode properties on earth are the same as they are in the heavens.
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I can understand your logic, Jerry, but...
doing that would obviate the whole reason for using a zero g environment in the first place....at least for gyroscopes.
Do you think the exact polhode precession could be duplicated precisely.?
Even if the spheres could be duplicated exactly, duplicating the space environment on earth would not be possible, neither would it be possible to duplicate the precise patch effect....and its response in a zero g environ.
Most are unaware that the original conception was to do earth-based gyros, but it was easily shown that the suspension and unbalanced mass torques on earth-based gyros were far more problematic than that of their (greatly improved) performance in zero g.
Furthermore, working out the equations for constrained motion for gyroscopes (earth-based) is far more complex, and even though they were eventually obtained for the geodetic precession (only ~0.4 arcsec/yr. on earth), I am not sure the frame dragging portion of the precession was ever obtained precisely for constrained gyro motion, especially since there were some ambiguous assumptions in doing so.
So 'modeling' the polhode from the orbital data is appropriate.
. Here's a video simulation of the modeled Polhode effect over time....from the orbital data:
http://einstein.stanford.edu/Media/P...animation.html
Now, having said all that...I want you to realize there actually was pre-launch testing of possible Polhode effects; its just that, in part, because of the above mentioned complications in constrained moton, that modeling did not match the orbital data....at least that's the assumption.
Do I think the polhode theory provides the definitive answer for the anomalous precession? Not necessarily; and I think that other 'causes' should be suspected and modeled....especially since the introduction of Tajmar/ deMatos's unusual experimetal results ...which indicate much larger Gravitomagnetic response of superconductors than would otherwise be expected by GR. (More on that in the bold print below).
G^2
Quote:
Originally Posted by Jerry
OK, that is a legitimate premise: If a torsion gravity theory is correct, One would expect this hypothetical angular momentum coupling to be time variable; that is, to effect the rotational moments of the Gravity B probe.
We know the rotational moments of the Gravity B probes did change over time, and this unexpected change is thought to be due to electrostatic coupling and a time-dependent Polhode moment. If this unexpected momentum is due to torsion coupling;.....
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Excellent ; Jerry; you are thinking outside the box now....the GR box.
We should follow GR as far as it can take us; but it is important to realize it does have its limits and when we get to its limitations, it is appropriate to take the next step by considering possibilities beyond its scope.
I believe it was Hehl who admitted that Gen Rel. was not at all adept in handling correlated spins. If I remember his comment was along the lines that GR has an axiom that all motion can be transformed away by an appropriate choice of reference frame, but with correlated spins that is not possible. Thus he, like others, have recognized the limitations of GR.
Your recognition of that point is noted.
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**The other modeling I would like to see (in GP-B) is that which would take into account the Tajmar / deMatos effect. As I mentioned to Publius some time back, the greatly enhanced gravitomagnetic field of the gyros should not influence the frame dragging precession portion of the experiment.....BUT that was ONLY considering its interaction (or lack of interaction) of a
SINGLE gyroscope with the earth's gravitomagnetic field.
The problem developes when we realize there are
FOUR gyros in GB-P, two spinning one direction and 2 spinning the other direction....(which was done for redundancy to cross check and make for greater accuracy in the data).
If we consider the multiple effects of 4 greatly increased GM fields of the 4 SC gyroscopes, then we have to deal with their INTERACTION WITH EACH OTHER. Surely if the gravitomagnetic field of a superconducting Gyro is enhanced as great as Tajmar experiments suggest, then the interaction of the dipole GM field of each gyro with the others must be taken into account.
Even though each gyro is magnetically isolated, it is impossible to gravitomagnetically isolate them....Gravitomagnetism is an angular momentum transferring field, the interaction between gyros of which can very possibly mimic unbalanced torque (or at least confound any modeling) of polhode / electrostatic coupling of the gyro to the frame.
Hope that all made sense.
All comments welcome.
.
G^2