We discussed the flyby anomaly
here. It was noted that the ‘anomaly’ consists of an error of 0.000094628% in explaining the craft’s velocity.
But here we come to an impasse in trying to compare the plausibility of two competing theories.
RE sends up a spacecraft so that it uses the gravity slingshot once, or twice, to assists its flight. Doing this
at all requires everything we currently know about planetary masses, the theory of gravitation, which predicts varying gravitational attraction between the planet and the spacecraft depending on the distance, not forgetting the difficulty of that attraction changing continuously as they change relative positions, etc. It does this to within an error of 0.000094628%.
FE by contrast postulates that we can do away with gravitational theory altogether, on an assumption that includes abolishing the conservation of energy.
Which is more plausible? The impasse is that there are no varying degrees of ‘completeness’. Both theories are incomplete. RE cannot explain the error above. FE cannot explain where the energy source for the acceleration comes from. So are both equally plausible? Difficult.
Note I can ‘complete’ the FE theory by postulating giant flying turtles which accelerate the earth and the whole universe through space. Is that more plausible than either of the incomplete theories? It’s a well-known problem in the philosophy of science.