THE PROBLEMS OF ASTRONOMY. 



By Prof. Simon Newcomb. 



Assembled, as we are, to dedicate a new institution to the promotion 

 of our knowledge of the heavens, it appeared to me that an appropriate 

 and interesting subject might be the present and future problems of 

 astronomy. Yet it seemed, on further reflection, that, apart from the 

 difficulty of making an adequate statement of these problems on such 

 an occasion as the present, such a wording of the theme would not fully 

 express the idea which I wish to convey. The so-called problems of 

 astronomy are not separate and independent, but are rather the parts 

 of one great problem, that of increasing our knowledge of the universe 

 in its widest extent. Nor is it easy to contemplate the edifice of astro- 

 nomical science as it now stands, without thinking of the past as well 

 as of the present and future. The fact is that our knowledge of the 

 universe has been in the nature of a slow and gradual evolution, com- 

 mencing at a very early period in human history, and destined to go 

 forward without stop, as we hope, so long as civilization shall endure. 

 The astronomer of every age has built on the foundations laid by his 

 predecessors, and his work has always formed, and must ever form, the 

 base on which his successors shall build. The astronomer of to-day 

 may look back upon Hipparchus and Ptolemy as the earliest ancestors 

 of whom he has positive knowledge. He can trace his scientific descent 

 from generation to generation, through the periods of Arabian and 

 mediaeval science, through Copernicus, Kepler, Newton, La Place, and 

 Herschel, down to the present time. The evolution of astronomical 

 knowledge, generally slow and gradual, offering little to excite the 

 attention of the public, has yet been marked by two cataclysms. One 

 of these is seen in the grand conception of Copernicus that this earth on 

 which we dwell is not a globe fixed in the center of the universe, but is 

 simply one of a number of bodies, turning on their own axes and at the 

 same time moving around the sun as a center. It has always seemed 

 to me that the real significance of the heliocentric system lies in the 

 greatness of this conception rather than in the fact of the discovery 

 itself. There is no figure in astronomical history which may more 



*An address given by Prof. Simon Newcomb at the dedication of the Flower 

 Observatory, University of Pennsylvania, May 12, 1897. Eeprinted from Science, 



May 21, 1897. 



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