KECENT COSMOGONIES 205 



as, in the order of size, we have the earth, Mars, and 

 moon, their order of roughness is, moon, the earth, Mars. 

 By deriving the moon from the earth, then, we may 

 theoretically endow the former with the same temper- 

 ature as our 80-times more massive planet. When, now, 

 we take into consideration the fact that the lunar gravity 

 is only about 1-6 of the terrestrial, it is easy to see why 

 the explosive effects on the satellite have been so much 

 more telling than upon either Mars or the earth. 



Inasmuch as the nebular earth did not give birth to 

 the moon as early in the process of condensation as did 

 the other planets to their satellites, but reserved its en- 

 ergies until it had attained a very compact stage and, 

 under the law of moments, a commensurately high veloc- 

 ity, it was only to be expected that the child should prove 

 the Titan it did. 



Criticism of the Tidal-Evolution Theory 



Any theory that breeds enigmas faster than it dispels 

 them is ipso facto false and worthless. Having ex- 

 plained, as he imagined, the moon's present posture by a 

 series of assumptions on assumptions, Darwin should 

 have gone further and proved all those assumptions. In 

 this long series, not one of his assumptions is universally 

 conceded by the astronomical profession the Laplacian 

 hypothesis is obsolescent, if not actually obsolete; the 

 lunar volcanic theory is contradicted by a large and grow- 

 ing faction who insist that the lunar asperities are due to 

 meteoric impacts ; the Planetesimalists assert that the in- 

 ternal heat of the planets is of later genesis than the 

 original ingathering of the nebulous matter; and so on. 

 In any event, it is quite as sensible and scientific to accept 

 the moon's fixed attitude as an ultimate fact of nature, 

 as to swallow a dozen other even greater uncertainties 

 and incomprehensibilities along with it in the effort to 

 appear wise. But let me show you the physical absurd- 

 ity of this tidal-evolution theory by a simple calculation 

 which anyone can follow and verify : 



