Dear Paul, Why did you find it necessary to patronise Regner in that way? Regarding the 'real thing' what in heavens name is Regner doing that no-one else is? Jack Well from my view, Regner is a professional Astronomer, I'm not even an amateur..But I got Wiki and a million web sites to help me follow his words. . And Allen cannot even tell us how many rotations the moon has. I dare not ask him the next question concerning the axes of the moons rotations. Philip.