58 FROM NEBULA TO NEBULA 



he attains the theoretical maximum I have indicated. 

 What I mean to say is that even in the case of the most 

 favorable and regular evolution of a star that may be 

 imagined, its ultimate passage by disruption into a 

 nebula is inevitable. Nor does this mean that the staiv 

 as such, necessarily vanishes. On the contrary, our sun, 

 for example, has shattered himself thousands of times by 

 virtue of deep-seated explosions, but with the exception 

 of a very small fraction of his mass he has as often pulled 

 himself together again, within perhaps a year's time, 

 leaving the missing fraction in the shape of a nebulous 

 cloud to be swept up by his planets as they leisurely con- 

 tinue their rounds under the steadying guidance of the 

 Prime Resultant. Thus does Nature utilize gravity as 

 her detonating agent for the dispersal of her overgrown 

 stars and to keep the path of descent clear of obstruc- 

 tions. 



If it were possible to step out of our system and 

 view it from a great distance, which of its myriad bodies 

 would appear to travel most slowly? Undoubtedly, the 

 sun. For the sun has only the one translational move- 

 ment, while his planets not only possess that in common 

 with him, but, besides, revolve rapidly around him at 

 the same time. Which, again, travels the faster, the 

 earth or the moon? The latter, because in addition to 

 partaking of the former's movement around the sun it 

 has, superadded, its rotation around our planet. In 

 general, then, it can be stated that the larger the star the 

 slower it travels. Moreover, it follows mathematically 

 from the law of gravitation that where two bodies ap- 

 proach each other, under their mutual attraction, their 

 velocities vary inversely as the square roots of their re- 

 spective masses. 



Some of my readers, remembering that Jupiter and 

 Saturn are recorded as being less dense than the sun, 

 may suppose me to be in error in asserting that the 

 density in bodies of stellar size is inversely a function 

 of the mass. These particular discrepancies, however, 

 are easily reconciled when w T e take into consideration the 



