[deleted]
James,
Abraham did correctly clarify my earlier statements.
"Personally, I do not find it satisfying that the law of universal gravitation presumes some gravitational force that can be instantaneously imparted at great distances."
You are correct, nothing is stated in the "law of universal gravitation" that the gravity influence is instantaneously imparted. You will not find any traditional text that teaches Newtonian mechanics mentioning, "Oh, by the way, there has to be an instantaneous influence at a distance for solar system objects to not have spiral forms."
Unfortunately, some assume the gravitation influence is instantaneous regardless of distance. That type of assumption is based upon "incomplete information". I cite a reference in my paper, The Helical Structure of the Electromagnetic Gravity Field that gives estimates of the influence velocity. It is not infinite, but much faster than the speed of electromagnetic propagation.
Experimental physicists should be able to approximate the influence velocity, if they look. Measurement instruments will have to be improved to obtain a value that has good precision.
Supporters of Einstein's gravity theory state that the gravity influence propagates at the speed of light. They are half correct. The electromagnetic (EM) field that establishes the gravity influence does propagate at the speed of light, but the influence, once established, is not limited by the original propagation velocity. The EM gravity field of objects with mass has been propagating for a long, long time.
The one attachment Abraham provided, Fig. 71.07 "Galaxy Rotations", has the two force equations F, one based upon gravity and the other on charge. For a century now, it is essentially heresy to even suggest that gravity might have an electromagnetic cause. Two simultaneously published papers can shed some light on the issue. The first by Ross McPherson titled, Electrifying Gravity and the second by James Gilson Newton's Gravitation Constant G as a Quantum Coupling Constant
Einstein's generation never considered the existence of longitudinal EM fields. Unless researchers specifically look for them, using the proper antenna configurations, they will not be able to identify them.
"I prefer to reduce requirements for imaginary elements whenever possible." You are diplomatic when you use the term "imaginary elements," I use the term "physics fiction."