Martin S Welcome back -- I was beginning to think you were talking a sabatical! Unfortunately there are many things in this universe which I do not understand. No doubt there are even more of which I am wholly ignorant. The Lense-Thirring Effect belongs to the first group but not the second. Ignorance is still a factor though -- I haven't read up on it and I have no idea what it is about, I am simply aware of its existance. The same goes for rotational inertial dragging of frames. The truth is, I'm really a bit uncomfortable beyond Pluto's orbit and separated from Newton's company and that even within these confines, I have no particular skills. I'm an enthusiastic amateur. In my proposition, I also did not take into account the recession of the Moon due to tidal forces, the magnetic braking of a rotating Earth's magnetic field not being aligned with its axis of rotation, the torque of currents generated by interaction of that magnetic field with the solarwind, and so on. I did assume circular orbits, I did not state sources of error in measurement or define the precision of the units used. But within the context of this debate, it is a reasonable first order approximation as bourne out by your observation "... too tiny to detect." A bit like your suggestion that 0.37% equates to 1 part in 300. But again, for the purposes of this debate, it suffices. Considering all this, I suggest that I didn't really imply zero influence, but if it will ease anyone's misgivings, I here state that there are minor effects which I have not taken into consideration, without asserting that they are "... too tiny to detect..." but are in my opinion below the threshold of things we need to take into account in this debate. Concerning the acceleration/deceleration point. See the post -- From Robert Bennett Wed Mar 7 21:19:52 2007 re:Project Rosetta. "I see. For you the flyby is both accelerating and not accelerating." I'll let you decide what this statement means. Paul D Send instant messages to your online friends http://au.messenger.yahoo.com