One of the more interesting aspects of the fringe is the aether-flow models of gravity. There are various versions and they differ mainly in the nature of the aether and the specifics of how it interfaces with ordinary matter.
The basic idea behind the aether-flow model, is that some substance, which is the aether, flows everywhere in all directions at all times. However, the aether can be blocked by ordinary matter to a degree. The idea then is that if you have to objects, object A and object B, object A blocks a portion of the aether flux from reaching object B, such that the net pressure of aether flux on object B is towards object A and pushes object B towards object A. Likewise, object B blocks a portion of the aether flux from reaching object A, and thus the net pressure of aether flux exerted on object A is towards object B, object A is pushed towards object B.
Part of what appeals to me about the aether flow model of gravity is that it proposes an actual physical mechanism for gravity as opposed to the bending of a geometric coordinate system. Another aspect that I find interesting is that aether flow models of gravity accurately predict a small but existing non-linear component of gravity and this does appear as a deviation in the swing vector of a Foucault Pendulum
during a solar eclipse.
An aspect of the aether flow model that is problematic is that aether flow models that I am aware of do not addresses the issue of how gravity affects electromagnetic energy. Since we know gravity does in fact affect light, we have measured the displacement of a star near the Sun and also near Jupiter, as predicted by general relativity. There are also numerous examples of gravitational lensing that are known and have been photographed by Hubble. A successful aether flow model must also account for that observed bending of light.
Another area of concern is one of thermodynamics. If aether interacts with matter, if it has particles which collide, it should, it is argued, transfer some energy to that matter and thereby heat it. This of coarse makes assumption about the interaction of aether with matter that may not be valid.