Speed of Gravity
Subject: Speed of Gravity
On reading “Speed of Gravity Measured — or Maybe Not,” [Sky and Telescope April, 2003, p26] it is clear that when considering the bending of radio waves [or light] due to the gravity of Jupiter, that the bending occurs close to Jupiter. That is, the bending signal is imposed on the radio waves at Jupiter, and that deflection signal travels to detectors at Earth at the speed of light, as it is carried along by the radio waves. Thus it is clear that the signal speed is indeed the speed of light, regardless of the speed of gravity, and that signal speed says nothing about the speed of gravity. As your referred to experts noted, this experiment is just a rather difficult way to measure the speed of light.
Clearly the best and easiest way to see the speed of gravity is to note that Solar System bodies, particularly the Earth, are attracted to the true instantaneous position of the Sun, and not to the Sun’s light travel time delayed location. The momentum transfer signal in gravity is not traveling at light speed, it is superluminal. The gravity acceleration vector points exactly at the instantaneous Sun. This shows that the speed of gravity is dramatically greater than the speed of light. This fact noted by Newton and LaPlace and many others, and recently emphasized by VanFlandern [to the irritation of many] does indeed show that the conventional wisdom on gravity may be big time wrong.
Since the momentum signals of gravity clearly travel at near instantaneous speeds, then we may suppose it is likely that some form of energy signals go along with the momentum signals, and the energy signals are also transported at the same superluminal speed. Such universal superluminal energy transport, even if weakly coupled and inefficient, may mean that the entire universe is in energy exchange–thermal communication. If so, universal thermal communication would likely bring the universe into thermal equilibrium, and perhaps provide an alternative understanding of the cosmic microwave background radiation. Thus it is clear that the gravity signal question is of great potential consequence.