The mean principal orientations of these two sets make a 25° angle with each other, though a range of intermediate values exists. Surface measurements and 3D modelling (Figs. 3, 4a) indicate that the GBF plane dips steeply throughout (80°–90°). However, the master fault plane, as ...
was actually round. This came about after observing the shadow of the earth on the moon during an eclipse. The basic belief that there was a mathematical relationship between everything in the universe made the Pythagoreans postulate that the planets revolved following a particular cyclic pattern....