THE LIGHT OF THE STARS 3°3 



in 1,000 years by radio-active transformation, or enough to last at the 

 same rate for 1,000,000 years, the thermal energy corresponding to the 

 mass-energy of one gram is 3 X (10) 12 , which is very nearly the same 

 as the 5 X (10) 12 water-units, computed by De Volson Wood for the 

 specific heat of the ether. 13 We seem, at any rate, to be approaching 

 limiting values which are perhaps connected with the transition from 

 ether to matter, or the reverse. If a volume of rotating ether, having 

 a specific heat of 5 X (10) 12 , can be condensed, or in any other way 

 transformed into a volume of matter with specific heat unity, since 

 specific heat is capacity for absorbing thermal energy, the tremendous 

 shrinkage of this capacity during the formation of matter out of ether 

 represents the absorption of so much energy, and the almost complete 

 saturation of the original capacity. It follows that if the process is 

 reversed, the thermal energy of atomic formation must be set free. 



Since radium decays far more rapidly than most elements, the one 

 million years suggested in the preceding illustration must be greatly 

 extended in order to represent the average duration of matter. Simi- 

 larly, the one million light-years deduced for the distance of the fainter 

 nebulae on the Lick Observatory plates is not a limiting distance be- 

 yond which light can not penetrate, but it is a distance at which light 

 is reduced to perhaps eight per cent, of its original intensity, or a quan- 

 tity of that order. It is evident from the phenomena connected with 

 the decay of the radio-active elements, that different elements have dif- 

 ferent durations. The rarer elements are either those which require 

 a very long time and a long process of successive ethereal modifications 

 in their development, or else they are elements which are relatively un- 

 stable, and which decay more rapidly than the others. 



Eutherford gives the radius of an electron as 1.4 X (10)~ 13 cm., on 

 the supposition that the electron is a sphere, in which case its surface 

 will be 2.5 X (10)" 25 sq. cm., and its volume 1.1 X (10) -38 cub. cm. 

 The mass of an electron being, according to Sir J. J. Thomson, 1/1700 

 times that of a hydrogen atom, and the latter weighing 1.1 X(10)~ 24 

 gram, the density of an electron works out 

 /11V 10 _24 \ 



Z> = ( l.7X10 3 )" f " (L1 X 10_38) =5 ' 9 X 101 ° < water=1 )- 

 This value is so extraordinary that obviously we are not dealing with 

 any ordinary problem in material density. The only phenomenon 

 which has any resemblance to it is the increment of mass which the 

 electron acquires at velocities approaching that of light in Kaufmann's 

 experiment. Add to this the fact that the velocity of light is a con- 

 stant, and the conclusion apparently follows that if the velocity of 

 wave-motion in the ether can be diminished to even the smallest ex- 

 tent below that of light, the medium ceases to be ether, and the motion 

 ceases to be ethereal wave-motion, but is left behind as the beginning 

 13 Philosophical Magazine for November, 1885, pp. 402-403. 



