THE LIGHT OF THE STARS 289 



WHAT BECOMES OF THE LIGHT OF THE STARS? 



Br FRANK W. VERY 



WESTWOOD OBSERVATORY 



ONE of the most astounding things in nature is the enormous energy 

 which the sun is continually dispensing as radiation to surround- 

 ing space. The earth, as viewed from the sun, is a mere point in space, 

 and receives no more than 1/2,200,000,000 of the radiant energy which 

 the sun is outpouring so lavishly. Yet out of this small fraction of the 

 total radiation, practically all the terrestrial activities of wind and 

 wave, tropical hurricanes and avalanches of ice on alpine slopes and the 

 no less potent but milder forces which clothe the earth with verdure, 

 originate. 



If we include all the planets in the solar system, and assess the out- 

 going solar rays at the maximum tariff imposed by the obstructions in 

 their path, it still remains true that only 1/100,000,000 of their power 

 is directly utilized in maintaining the thermal equilibrium and life of 

 the attendant orbs, dependent from day to day for these gifts upon the 

 dispenser of all of this bounty. 



The solar outpouring for even a single day is inconceivably great, 

 yet the same flux of energy has been going on ceaselessly and with very 

 little change in its absolute intensity for at least a hundred million 

 years, as the records of geologic time attest. If only one part of solar 

 radiant energy in one hundred million is directly utilized, what becomes 

 of the other ninety-nine million, nine hundred and ninety-nine thou- 

 sand, nine hundred and ninety-nine? Remember, also, that our sun 

 is but one among hundreds of millions of stars made known to us by 

 our photographic telescopes, all outpouring similar torrents of energy, 

 and the question comes home to us accentuated with many million- 

 fold intensity. 



Professor Comstock 1 has shown that the theoretical and observed 

 distributions of luminosity among the brighter stars may be reconciled, 

 if we suppose either that the intrinsically brightest stars have a " dis- 

 tinct tendency to cluster about the sun," or else that " there is a 

 sensible absorption of light in its transmission through space, of such 

 average amount that a star having a parallax of a tenth of a second 

 appears one magnitude fainter than it would appear in the absence of 

 absorption." Other modes of attacking the problem must be invoked 

 in order to decide between these alternatives. 



1 George C. Comstock, ' ' The Luminosity of the Brighter Lucid Stars, ' ' Pub- 

 lications of the Astronomical and Astrophysical Society of America, Vol. 1, p. 307. 



VOL. LXXXII. — 20 



