As pointed out initially by Pierre-Simon Laplace and then later many others, if the force of gravity is purely central, i.e., points directly toward the source, the gravitational force carrier must propagate almost instantaneously, i.e., at a speed much greater than light, in order to account for the apparent lack of aberration. Hence any theory of gravity must either posit an effect that propagates much faster than light or else must not be purely central. General relativity is consistent with the lack of appreciable aberration because gravity is not a purely central effect, a characteristic which is required of any field theory in order to be consistent with relativity, as shown by Henri Poincaré [15] However, this attribute is considered inconsistent with purely non-interactive rectilinear trajectories, a fact which has led some modern proponents of Le Sage's theory to adopt the other alternative, i.e., to assert that the ultra-mundane particles do indeed move at extreme superluminal speeds. However, such a premise is in direct conflict with modern relativity, one of the most strongly validated theories in science.
