According to one of the articles I wrote, “Gravity is the Aether Wind,” Michelson and Morley oriented their interferometer directly perpendicular to the "flow" of the medium. Naturally, they obtained the famous null result. Here are some of the articles that go into more details:
Gravity can be described by Onsager’s equations that quantify coupled heat and mass flow. These relationships show how mass, analogous to thermal diffusion, "diffuses” to a heat source thus illustrating how mass is sucked towards blackbody radiation coming from a large mass. The grinding action from friction within the large mass creates blackbody radiation that emanates outward according to Planck’s law. Mass accelerates inward creating blackbody radiation outward resulting in a circular process. One creates the other and Vis versa. Only so much mass can converge on the heat source at once thereby creating a vortex holding pattern that forms moons, planets and stars. The spherical shape is a consequence of that holding pattern.