112 TWO NEW WORLDS 



a velocity closely approaching that of light, and 

 even within the system such velocities must be 

 very prevalent. That this is not the case tells 

 heavily against the possibility of a stellar aggrega- 

 tion isolated in space, and much larger than the 

 visible universe. 



The same argument is strengthened a million- 

 fold when we deal with a galactic system of the 

 density 10" 11 instead of 10~ 22 . This would give a 

 mass of 10 53 grammes to our galactic system, and 

 a velocity of over seven million miles per second, and 

 very much more in a larger system of equal density. 



These considerations effectively dispose of our 

 dark and comparatively dense supra-world, unless 

 that world is uniform and unlimited throughout 

 space. But as regards uniformity, one look at the 

 starry heavens will banish all hope of it. If any- 

 thing is certain, it is the infinite variety of the 

 universe. If uniformity had existed at any time, 

 the chances are overwhelming in favour of its 

 having rapidly disappeared. And this brings us to 

 a third line of argument. 



Stability. Those philosophers who start from 

 " creation," and date it a few hundred million 

 years ago a mere flash in the stellar scale of 

 tune have the great advantage of starting from 

 some point of uniformity, and ending in a final 

 cataclysm. But the purpose of these chapters is to 

 transcend, as far as possible, the barriers of space 



