66 FROM NEBULA TO NEBULA 



Were the planet ever to increase to a great size, 

 like that of Jupiter, for instance, the intense heat gen- 

 erated would quickly dissipate the present oceans, and 

 in time cause the earth to acquire the same general char- 

 acteristics as that giant orb. 



We thus see that the earth's economy provides what 

 it demands, a running supply of heat, and a uniform 

 one. The extreme variation implied by the Kinetic 

 theory, as currently understood, would have proved just 

 as inevitably fatal to earth-life as a variation in the 

 sun's temperature. Mature does not dole out treasured 

 heat, but evolves it as she goes along. 



In this process of gra vista tic heat production we 

 have the clue to why the universe did not long ago perish 

 by agglomeration into one mass, and why it never can 

 do so. Without some adequate dispersive force, constant 

 mutual attraction must tell in the long run. No matter 

 how long the climax might be deferred, the end would 

 have to como some day, and, when it did, there would 

 be nothing but a stupendous clinker to mark the tomb 

 of Nature. 



We have learned how our sun is a bubbling molten 

 mass by reason of his own exertions; thus it is with 

 the stars in general. At present he is able to get rid 

 of his heat as fast as it is generated, and there is no 

 doubt iu my mind that he has still many million years 

 of life. However, he is growing hotter and hotter by 

 infinitesimal degrees, in precise ratio with his increase 

 of mass due to bodies precipitating upon him. Since 

 he cannot lose any part of what he thus gains, matter 

 being assumed indestructible, the time must eventually 

 come when his radiating surface, which relatively de- 

 creases with the volume, will no longer suffice to dis- 

 charge the greater gravistatic heat of the bigger body, 



