534 SCIENCE OF HOME AND COMMUNITY 



years since then, all the time at the tremendous rate of 

 186,000 miles a second. And yet this beam of light has 

 just reached us. 



Other stars are even farther away than this. It is be- 

 lieved that from the very farthest stars it takes light thou- 

 sands of years to reach us, so that possibly the light that 

 now reaches our eye from some stars started even before 

 Jesus was born. 



What the spectroscope shows about the stars. Since these 

 stars are situated so far away, it would seem almost impos- 

 sible to find out anything about them. But the light that 

 comes from the stars tells certain facts about them, and by 

 allowing this light to pass through a spectroscope, astron- 

 omers have learned two facts about stars, their composition 

 and their motions. Spectra of starlight can be obtained 

 the same as spectra of sunlight and these are so much alike 

 that it shows that some of the elements found in the sun 

 and the stars are the same. 



But the spectroscope is able to tell us something more 

 than this ; it tells us whether the star is moving toward us 

 or away from us, and at what speed it is moving. Some 

 stars are moving at the rate of thirty miles a second. It is a 

 mistake to speak of the stars as being fixed, because all 

 heavenly bodies are in motion. Some stars have been 

 traveling at the rate of twenty-five or more miles a second 

 for countless years, and yet within historic times, since man 

 has begun to make any accurate records of the position of 

 stars, they seem to be in the same relative positions as they 

 were thousands of years ago. They are so far away that 

 this distance they have traveled makes no appreciable 

 difference that men can detect in the position of the stars. 

 This illustrates again the enormous distances that separate 

 us from the stars. 



