COSMIC RAYS MILLIKAN AND CAMERON 229 



cosmic-ray activity of a particular star, the sun, namely, to the con- 

 clusion that the observed cosnnic rays do not originate in the stars at 

 all, hut that they must originate under the extreme influences of 

 exactly tJie opposite sort existing in interstellar space. 



These considerations bring us then from two entirely new points 

 of view to the conclusion that the heat output of the stars must be 

 derived from an entirely different source from the atom-building 

 processes which produce the cosmic rays. MacMillan -** first, then 

 Jeans -^ and Eddington,""* from considerations based wholly upon 

 the lifetimes of the stars, have repeatedly emphasized the necessity 

 of finding a source for this output other and greater than the process 

 of atom building, but we can now go further and say that the 

 process of energy emission by atom building does not take place in 

 the stars at all, or at least in such amount as to make the stars an 

 appreciable factor in the output of cosmic rays, for if it did the 

 star would have to be radiating heat much faster than is the case. 

 As is well known, the foregoing astronomers, and practically all of 

 the writers in this field have found this new source of stellar heat 

 not in an atom^-huilding process^ hut rather in an atom-annihilating 

 process which they assume to be going on in the interior of stars, 

 positive electrons being thought to be continually transforming their 

 entire mass into ether waves in accordance with the demands of 

 Einsteins' equation. As indicated above, we have sought in vain 

 among our cosmic rays for a ray of penetrating power corresponding 

 to this act. It will be recalled that the mass which disappears in the 

 creation out of hydrogen of one gram-atom of silicon — this produced 

 the hardest cosmic rays that we can say with certainty that we have 

 yet observed, for the iron rays are still to some degree hypothetical — 

 was 0.23 g. The complete annihilation of the mass of hydrogen 

 would obviously then produce, in accordance with Einstein's equa- 



1 0778 

 tion, a ray having approximately four times (accurately -^^^ 



times) the energy and penetrating power of our hardest definitely 

 observed ray. Our failure to find this ray^ however., is no argument 

 at all against the existence of the process in the interior of stars 

 where the pressures are colossal and tJie densities tnust he enormous. 

 Indeed our failure to find this ray means rather that, if the act 

 occurs at all, as MacMillan, Eddington, and Jeans think it must, it 

 is obliged to occur precisely in the interior of stars where the result- 



« MacMillan, W. D. Astrophys. .Tourn., 48, 35, 1918 ; also 51, 309, 1920 ; also Science, 

 na. 67, 1920; also Scicntia, Jan. 2G, 1923; also Science, 02, July 24 and 31, Aiis. 7, 1925, 



» Jeans, J. H. Problems of Cosmogony and Stellar Dynamics, Cambridge, 1919, p. 286 ; 

 Nature, IIG, 801, 1925, and 121, 467, 1928. 



*• Eddington, A. S. The Internal Constitulion of the Stars, Cambridge, 1926, ("Ii. XI; 

 also Nature, 117, 26, 1926. 



24034—29 16 



