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Helen Deutsch informed us ( The Psychology Of Women, Vol. 2,, 434 ) that in all cultures `` the term ' stepmother ' automatically evokes deprecatory implications '', a conclusion accepted by many.

A projectile shot up from earth returns rectlinearly to its ' natural ' place of rest.

But that one should superimpose all these charts, run a pin through the common point, and then scale each planetary deferent larger and smaller ( to keep the epicycles from ' bumping ' ), this is contrary to any intention Ptolemy ever expresses.

So when textbooks, like that of Baker set out drawings of the ' Ptolemaic System ', complete with earth in the center and the seven heavenly bodies epicyclically arranged on their several deferents, we have nothing but a misleading 20th-century idea of what never existed historically.

It is often stated that Copernican astronomy is ' simpler ' than Ptolemaic.

Historical records indicate that Copernicus was unaware of the fundamental aspects of his so-called ' revolution ', unaware perhaps of its historical importance, he rested content with having produced a simpler scheme for prediction.

This, of course, results from the non-systematic, ' cellular ' character of Ptolemaic theory.

Thus, in no ordinary sense of ' simplicity ' is the Ptolemaic theory simpler than the Copernican.

But ' simplicity ' here refers to systematic simplicity.

The strongest appeal of the Copernican formulation consisted in just this: ideally, the justification for dealing with special problems in particular ways is completely set out in the basic ' rules ' of the theory.

The lower-level hypotheses are never ' ad hoc ', never introduced ex post facto just to sweep up within the theory some recalcitrant datum.

The formal displacement of the geocentric principle far from being Copernicus' primary concern, was introduced only to resolve what seemed to him intolerable in orthodox astronomy, namely, the ' unphysical ' triplication of centric reference-points: one center from which the planet's distances were calculated, another around which planetary velocities were computed, and still a third center ( the earth ) from which the observations originated.

' I think you had better leave '!!