Martin, Thank you. Nice response. I read your reply to the criticisms of North and Nieto a few years ago, in fact I think I still have a printed copy of it somewhere. Whilst I agree with your position regarding GR, I am not convinced by the Planck-particle liquid plenum aether idea, since this relies upon density and we have then gone full circle back to matter-matter interaction. Also, I see no reason why certain "fundamental" physical constants should be related to one another, this being an idea which, if carried far enough, would result in the conclusion that we should all be cooked to a crisp due to the temperature of the universe. I do accept that the mathematical foundations of this novelty are sound, as you rightly allude to by saying that it was reviewed by Stephen Hawking, but I feel that this approach is, frankly, absurd. Rather than saying that objects would pass freely through it, my position is that not even light would pass through it (all radiative energy would be absorbed immediately by this enormous energy sink). Furthermore, celestial objects do not exhibit uniform rectilinear motion, rather their velocities are constantly changing. My opinion, therefore, is that the plenum aether is a non-starter. Best wishes, Neville. "Martin G. Selbrede" <mselbrede@xxxxxxxxxxxxx> wrote: Neville, Viscosity conventionally considered is a measure of a frictional coefficient (so-and-so centistokes, for example) related to resistance to change in displacement, or, in other words, it is velocity-dependent in its effect. Operationally, a workable aether only resists change in velocity (its coefficient and higher order terms are arrayed not with the first derivative of displacement with respect to time, but with the second). It was calculation of these factors when analyzing a hypothetical liquid composed of maximon particles (maximon particles bear the Planck density) that led Markov to the proof that such a liquid comprises a "quasi-isotropic space" -- in other words, an aether composed of such ultra-dense particles functions like "empty space" as currently observed. Objects can travel through it freely without impediment, but the aether resists acceleration while conserving constant-velocity rectilinear motion. Newtonian macro observations are thus preserved in the classical limit, and his three laws of motion fall out of the properly normalized viscosity function. The key factor is the nature of the coupling at this scale -- THAT is what differs between matter-maximon interaction versus matter-matter interaction (from where we get our conventional notions of viscosity and its effects). Markov published this work in the compendium "The Very Early Universe," containing the Proceedings of the Nuffield Workshop held in 1983; this volume was edited by Hawking, Sykos, and Gibbons. In other words, these research results passed the scrutiny of Stephen Hawking: there's nothing fishy with the physics. I cited this material in a 1994 article which I believe is available at www.geocentricity.com (I think Dr. Bouw identifies it as "A Response to Drs. Nieto and North" by Martin Selbrede -- you have to drill down a bit to find it). In any event, we need to distinguish between conventional notions of viscosity, and viscosity related to Markov-compliant aethers. The terms are not equipollent, because different derivatives of the spatial displacement are affected, respectively, in the two cases. Martin --------------------------------- Yahoo! Answers - Got a question? Someone out there knows the answer. Tryit now.