Masterpieces of Science 



every event that history records, not merely our 

 earth, but the sun and the whole solar system 

 with it, have been speeding their way toward the 

 star of which I speak on a journey of which we 

 know neither the beginning nor the end. During 

 every clock-beat through which humanity has 

 existed it has moved on this journey by an 

 amount which we cannot specify more exactly 

 than to say that it is probably between five and 

 nine miles per second. We are at this moment 

 thousands of miles nearer to a Lyrae than we were 

 a few minutes ago when I began this discourse, 

 and through every future moment, for untold 

 thousands of years to come, the earth and all 

 there is on it will be nearer to a Lyrae, or nearer 

 to the place where that star now is, by hundreds 

 of miles for every minute of time come and gone. 

 When shall we get there ? Probably in less than 

 a million years, perhaps in half a million. We 

 cannot tell exactly, but get there we must if the 

 laws of nature and the laws of motion continue 

 as they are. To attain to the stars was the 

 seemingly vain wish of the philosopher, but the 

 whole human race is, in a certain sense, realizing 

 this wish as rapidly as a speed of six or eight 

 miles a second can bring it about. 



I have called attention to this motion because 

 it may, in the not distant future, afford the 

 means of approximating to a solution of the 

 problem already mentioned, that of the extent 

 of the universe. Notwithstanding the success of 

 astronomers during the present century in meas- 

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