Hello. I’m new to this forum and I’m unsure of the best way to start out. Can I just jump in and begin a new thread? I was just wondering about something and am interested to see if anyone might think this is at least worth note and have something to say. Just how many different theories of gravity are there? And how many of them are actually accepted by the scientific community other than General Relativity (GR)? How many of them actually try to explain gravity in terms of simpler phenomena? In the same way that magnetism was explained as electricity plus special relativity creating electromagnetism, can gravity be explained in terms of other well understood phenomena? A theory such as GR provides a good mathematical description of gravity. It can be interpreted as describing gravity as a curvature of spacetime, but then, although it provides a good description, there’s something unsatisfying about considering spacetime as a physical object. Gravity can be described, like the other forces, as an exchange of bosons – gravitons in this case, but gravitons have not been detected yet. String theory, or M-theory, envisions strings that span higher multiple dimensions, but it sort of seems like this is borderline mysticism in that how can you observe these higher dimensions, or even the strings upon which everything else is supposed to be built? Has anyone heard of Stochastic Electrodynamics (SED) which tries to explain gravity in terms of an electromagnetic interaction of the zero-point field? At least that one has the advantage of describing gravity in terms of other fundamental phenomena of electromagnetism and zero-point energy. Is “Mach’s Principle”, where the inertia of a body is determined in relation to all other bodies in the universe, of any use at all as an explanation of gravity? It seems a little vague. How would you make an experiment to test this? Could gravity be explained using Relativity where an accelerating atom appears distorted due to its motion and that distortion makes the atom appear electrically polarized? The other accelerating atoms nearby “see” the electric field and an attractive force. Thus gravity is reduced to an electric force. Or if you think of the “cloud” that is the electron shell as extending far beyond each atom, there is a small probability of it extending near the nucleus of an atom of an adjacent object. The positively charged nucleus is concentrated over a very small space compared to the electron shell being smeared out over a larger volume, which intersects only a small part of the adjacent electron shell when they are far apart leaving a small net attractive force between the atoms. This would also reduce gravity to an electric force. When the atoms are close then the repulsion of the electron shells will overwhelm any other force between them, which is what accounts for the apparent “solidity” of an object that we observe. While the probability of this kind of interaction may be extremely low and the resulting net force low, it will add up when there are a large number of interacting atoms. When you consider the number of atoms in something the size of the Earth and a person you are still only left with a force of only a couple hundred pounds between them. What do you think? How many other theories about gravity are there out there? Thanks.