Hi PD, It is entirely irrelevant whether the Earth rotates or not, or revolves or not (except as discussed in my exchange with Martin S). The subject is satellite periods as predicted in the GS – geostatic – system. That means the Earth does not move. ‘Does not move’ includes ‘does not rotate’ and ‘does not revolve’. See Aristotle …. Again. New homework. Research the meaning of geostatic – geocentrism in the strict sense. ….In passing, I note that "In mathematics, probabilities always lie between zero and one." (Emphasis added). The probability of an event is generally represented as a real number between 0 and 1, inclusive. (Omission now included and underlined) http://en.wikipedia.org/wiki/Probability_theory A probability is a number from 0 to 1. If we assign a probability of 0 to an event, this indicates that this event never will occur. A probability of 1 attached to a particular event indicates that this event always will occur. http://www-math.bgsu.edu/~albert/m115/probability/interp.html A contradiction consists of a logical incompatibility between two or more propositions. It occurs when the propositions, taken together, yield two conclusions which form the logical inversions of each other. Aristotle’s law of noncontradiction states that "One cannot say of something that it is and that it is not in the same respect and at the same time." Robert and non-Robert