MODERN VIEWS ON MATTER. 303 



Whether the total amount of matter in the universe is constant 

 likewise, as much disappearing at one end by resolution into electrons 

 as is formed at the other end by their aggregating together, is at 

 present quite unknown ; and indeed it is clear that we have now become 

 far immersed in the region of speculation. Nevertheless, it is specula- 

 tion not of an illegitimate character, for it is very consistent with all 

 that we know about the rest of the material universe. 



Astronomy tells us that the cosmic scheme, though it looks perma- 

 nent, is subject to constant flux. In the sky we see solar systems and 

 suns in process of formation by aggregation out of nebulae ; we see them 

 rise in brilliancy, maintaining a number of planets in health and 

 activity for a time, and then slowly become subject to decay and death. 

 What happens after that is not certainly known ; it may be that by col- 

 lision a nebula may be reconstituted and the process started again; 

 though so long as there is only a force of one sign at work (gravitation 

 only) it would seem that ultimately the regenerative process must 

 come to an end. The repellent force exerted by light upon small 

 particles, however, must not be forgotten; it can overcome gravitation 

 when it acts on small enough bodies; and there are other possibilities. 

 Among the parts of an atom certainly the forces are conspicuously not 

 of one sign; inside an atom there exist both attractive and repulsive 

 forces; the resolution of an atom into its electron constituents, and 

 the aggregation of these constituents into fresh atoms, are both per- 

 fectly thinkable. All we have to do is to ascertain by careful and 

 patient investigation what really happens; and my experience has led 

 me to feel sure of this, that whatever hypotheses and speculations we 

 may frame, we can not exceed the reality in genuine wonder; and I 

 believe that the simplicity and beauty of the truth concerning even 

 the material universe, when we know it, will be such as to elicit feel- 

 ings of reverent awe and adoration. 



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