None of those things you keep appealing to (gravity inertia)define how or the why they (gravity inertia) work the way they do..... but those things(gravity inertia) keep getting explained and justified by the HC/AC construct Allen Absolutely not! You are failing to see my point, and what you say here, is a misconstruction of my point. If you believe the above then your case completely fails. "those things(gravity inertia) keep getting explained and justified by the HC/AC" This is not true.. Gravity and inertia have nothing to do with and are not influenced by cosmology. We may use them to explain cosmology, but they existed and had to be explained and justified long before cosmology was thought of . We had the horse before the cart. Gravity: the attraction between two masses. Demonstrated in the laboratory by having two masses suspended in a vacuum jar. Later experiment taken outside and showing the deviation of a plumb bob hanging down the face of a cliff towards the cliff. Nothing to do with planetary motions... Inertia..flywheels , and merrygorounds likewise.... When as a child beside the camp fire, I swung the billy full of boiling tea over my head with out spilling a drop, I would have known, had I been enclined to think about it, just how a satellite would stay in orbit. And later as a space enthusiast I supported and accepted the theory of orbitting space stations, knowing they would work, and withstood the ridicule of the world who treated it as nonsense dreams. This would have been the case, even if the world was the centre, and the cosmos rotated around it. The principles did not need heliocentrism to be true. Heliocentrism was a natural deduction from the principles already demonstrated. I did NOT imagine the sun was stationary. I KNEW it was holding on to a lot of billys full of tea, as they swung around it, just as old billy moon was held to the earth. I knew the calculations would have to show that the sun was a very heavy Mass to do that.. No imagination here, seeing as you prefer deduction. Knowing what I knew as "reasonable deductive facts", this IS a reasonable deduction. In fact it would take a lot of imagination, more like fantasy, to consider geocentrism as an option. This is the reson we have to search for and prove supranormal possibilities, like the aether. Philip PS We don't need to talk about frames of reference. Lets just keep the discussion on basic mechanics.. There is only one reference point.. Its here. Your methodology is damaging to the cause, because it lacks credible thought processing and smacks of flat earther reasoning. plm