The Gravity Probe B experiment was conducted supposedly to detect the frame dragging effect "predicted" by general relativity aka by "gravitomagnetism".
However, if you take a look at the theory of gravitomagnetism carefully, you realize that it is "not" in fact general relativity. It is a theory derived from the modified Maxwell's equation to make it look like a gravitational effect. I couldn't believe that the official web pages of Gravity Probe B openly announces that they are testing general relativity.
But the general relativity community has already concluded that the magnet equivalent dipole gravity does not exist in general relativity long time ago. The mathematical term corresponding to dipole gravity exists but it was concluded that the term has no physical meaning. That conclusion is written in the text books of gravity including that of John Wheeler, Kip Thorne and Charles Misner.
Then what is this object called "Gravitomagnetism"? It has the DNA of the Maxwell's equation but it is not exactly the same as the Electromagnetism. In the early days of the development of general relativity, the gravitational physicists desperately needed to find the magnet like gravity from somewhere, but they could not find it inside the general relativity because they have already thrown out the mathematical term that was assigned the name "gravitational dipole moment". So, they created one from a piece here and another piece there by modifying the Maxwell's equation and made up this theory called gravitomagnetism. The assumption that the gravity will be topologically similar to the electromagnetism expressed by Maxwell's equation was a pure conjecture that was not tested at all. Even in the approximation, there was no guarantee that it will be the true depiction of the physical reality. It was obviously not the pure legitimate child of general relativity. It was born out of the Maxwell's equation and then adopted by the general relativity community and since then it went by as a child of general relativity without being contested. This is the birth history of the gravitomagnetism.
I can understand that they didn't know how the center of mass of an object can be shifted without any external force contrary to the Newtonian mechanics. But they know now. I showed it in my two papers listed in my scientific document list. It doesn't take an hour to show how the shift of the center of mass happens in the framework of relativity theory with 100 percent certainty, with the precise mathematical form for the model object.
The irony is that they do not seem to care of this revelation. Somehow it doesn't seem to matter to them. "We know now we have been wrong but who are you to tell us we all have been wrong?" is kind of their attitude.
What kind of arrogance is that?
What is the purpose of testing the atomic fine structure constant in such an accuracy in the first place? The physical science is after all about the accuracy and the precision, isn't it?
Whether it is in the matter of the fine structure constant or in the theoretical conceptual details in gravity, we strive to be accurate.
The dipole gravity effect that comes out of the dynamic shift of the center of mass from the rotating rigid body may look like a tiny, drop in a bucket, effect as it truly looks like one. But, still, that dipole term is the strongest gravity effect next to Newtonian in general relativity. It can not be ignored by any means.
On top of that, that's what science is all about, finding the details to reach the greatest accuracy. We spent close to a billion dollars to investigate the rotational gravity effect with GP-B. Yet they are comparing their data with the modified Maxwell's equation not with the genuine general relativity. It's like comparing an apple with an orange. They simply can not match. And the NASA announced that the GP-B experiment was a flop.
If your experimental result doesn't produce the predicted effect, isn't it time to investigate if the theory was correct in the first place at the same time investigating if there was any error in your experiment? Both activities should go hand in hand.
One may try to argue that, after all, general relativity might not have been correct at all. The so far known solution of general relativity has been wrong on the part of the gravitational dipole moment. However, that is a totally different issue compared to the question of if general relativity was correct at all. General relativity is such a gigantic yet simple framework of the theory of gravity that there is not much to go wrong except the detailed solutions that humans miss in the learning process of the theory. After all, Einstein himself missed it. He didn't know dipole gravity could be a meaningful solution of general relativity.
Someone asked me "Are you greater than Einstein?" to say Einstein missed the solution of dipole gravity that you found in his own theory? I'm a very modest and seclusive person. But if my discovery of dipole gravity can make me greater than Einstein, so be it. It's not my duty to assess my own achievement. It is up to the people in the coming generations in the field of science to decide.
These are the reasons that the GP-B experiment data is crucial to test the reality of dipole gravity as well as general relativity itself. That's why it is so important.
If I were one of them who have conducted the GP-B experiment, I would try to reproduce the so called "electrostatic patch effect" from the earth bound laboratory test to prove their own conjecture regarding the source of the error. If they can not reproduce the same error, the patch effect conjecture can not be right. And this will give their experimental data more credence.
However, if they knew the strength of the dipole gravity was so large, as predicted by dipole gravity, the level of the precision they achieved with their equipment would not have been necessary.
Even the GPS satellite could have been enough to test the dipole gravity effect. The oscillations of the GPS satellites along the equatorial plane of the rotating earth above the ground was already a direct proof of dipole gravity.
What baffled the GP-B experimental team initially was that they detected the unexpectedly large signal that they never expected to observe. Basically, they detected the new force that is topologically and quantitatively different from the one predicted by the theory of the gravitomagnetism which is a direct proof that the gravity has no resemblance to the electromagnetism, defying the widely spread conjecture that the rotational gravity will follow the Maxwellian paradigm.
When they announced that their results matched with the theory of gravitomagnetism within 10 percent or so was after the subtraction of this huge signal, which they regarded as error, from their data. This of course is a total nonsense. The systematic error can not be larger than the signal, which was the reason in the first place that NASA announced the GP-B experiment was a flop.
For a net dipole gravity effect to manifest, not only the rotation but also the longitudinal asymmetry of the rotating body is necessary, the fact of which could not be deduced from the analogy with the Maxwell's equation. In other words, the conventional gravitmagnetism was an unfortunate attempt of the theoretical experiment that did not turn out to be correct.
The fundamental premises of the conventional theory of gravitomagnetism was that like in the case of the Maxwell's equation where the movement of the charge creates the magnetic field, the motion of the mass should create the magnet like gravity, regardless of the geometrical shape of the rotating body, which was a totally failed assumption.
General relativity had its own way of creating the magnet like gravity.
Theory of Gravitation, Cosmology and a part of general relativity