CHAPTER II 



INFINITY OF THE UNIVERSE 



IN 1786 William Herschel remarked that he had 

 discovered fifteen hundred universes. He referred, 

 of course, to as many nebulae, which he believed to 

 be galaxies external to our own. But, in any case, it 

 is risky to use the word universe in the plural 

 number without some special definition. If by 

 " universe " we mean the totality of things, there 

 can, of course, be only one totality. But if we 

 mean by "universe" the sum total of things 

 accessible to our senses, or, in other words, the 

 aggregate of those things of which we can now or 

 at any time have cognisance, then that very human 

 " universe" may be imagined to exist side by side 

 or interwoven with other universes, accessible to 

 different sets of senses, whether of beings lower or 

 higher than ourselves. In that sense, the infra- 

 world is a distinct universe interpenetrating our 

 own, just as our human or " visible" universe, the 

 world we live in, interpenetrates the supra- world. 

 As already pointed out, our faculties are in touch 

 with the confines of both the other worlds. The 

 smallest perceptible length and the greatest measur- 



