NEW CONCEPTIONS IN SCIENCE 



other, can be perfectly explained on this theory. 

 If the number of stars was indefinitely great, the 

 combined pull they would exert would probably 

 be such that some of the stars would be flashing 

 through space at inconceivable speeds. If this 

 were true it could probably be observed. It has 

 not. The velocity of a number of stars has been 

 calculated, and, as this can be done by indepen- 

 dent methods, the results may be taken as fairly re- 

 liable. It is true that when the so-called "run- 

 away stars," like 1830 Groombridge, were first ob- 

 served, it was thought that the attractive force of 

 the whole stellar system was insufficient to hold 

 such stars in leash, and that they would dash into 

 the depths of space and be lost forever. Such a 

 view now appears untenable. The speed of these 

 stars merely indicates a stellar system vastly more 

 extensive than the one hundred million suns which 

 was the assumed figure when the runaway stars 

 got their name. There is no decisive reason to 

 believe, however, that the number is without end. 



The distance of most of the stars is so great, and 

 the angle which the earth's revolution subtends so 

 small, that it may take centuries of delicate ob- 

 servation before we shall have any definite idea 

 of the real size of the universe or of its shape or 

 contents. It is fairly certain we shall some day, for 



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