THE SMALLEST PARTICLES OF MATTER 25 



In 1897 Lord Kelvin advanced views as to the age of the earth, 

 based on Helmholtz' contraction theory. 15 Professor T. C. Cham- 

 berlin (Chicago) replied thus to Kelvin's statements: 10 



"What the internal constitution of the atoms may be is still an open 

 question. It is not improbable that they are complex organizations 

 and seats of enormous energies. Certainly, no careful chemist would 

 affirm either that atoms are really elementary or that there may not be 

 locked up in them energies of the first order of magnitude. No 

 cautious chemist would probably venture to assert that the component 

 atomolecules, to use a convenient phrase, may not have energies of 

 rotation, revolution, position and be otherwise comparable in kind 

 and proportion to those of a planetary system. Nor would he prob- 

 ably be prepared to affirm or deny that the extraordinary conditions 

 which reside in the center of the sun may not set free a portion of 

 this energy. The Helmholtzian theory takes no cognizance of latent 

 and occluded enemies of an atomic or ultra-atomic nature." 



Professor H. A. Bethe of Cornell has advanced 17 a theory, now 

 generally regarded as reasonable, that the heat radiated by the sun 

 is mainly due to a series of nuclear transformations which may be 

 indicated thus: 



13 



(1) 6 V* + JV > 7 N 



(2) 7 N" > 6 C 13 + 1 e° 



(3) .C^H 1 > 7 N" 



(4) 7 N"+ 1 H 1 - 



8 v -' 



,0 



(5) 8 15 > 7 N 13 + ie ° 



(6) 7 N ,5 + 1 H 1 ^C^+oHe 4 



The final result of these changes is the transformation of hydro- 

 gen into helium and positrons (ie°), with the release of about 

 thirty million electron volts. We know nothing of what is hap- 

 pening within the body of the sun, but to maintain its high rate 

 of radiation, it must be losing mass at the rate of about 4,000,000 

 tons per second. It is consoling to remember that since the total 

 mass of the sun is estimated to be 2.2 X 10 27 tons, it would require 

 about a million years for the sun to lose one ten-millionth of its 

 mass, provided that nothing fell into it. 



So terrific is the development of solar energy, that apart from 

 the gigantic craters which we call "sun-spots," huge bursts of incan- 

 descent matter are being continually ejected from the sun's sur- 

 face at the rate of thousands of miles per hour, and some of these 

 "prominences" jump half a million or more miles outward. 

 During the total eclipse of 1919 (see Figure 2) there was seen a 



