PART II. POLAR MAGNETIC PHENOMENA AND TERRELLA EXPERIMENTS. CHAP. VI. 721 



>eaking would also in this case be absorbed in accordance with the law of traversed masses, we see 

 once that on this point our hypothesis will scarcely meet with any difficulty. 



With regard to the first question, namely how the light in the case supposed would be absorbed 



empty space, it is not so easy to say what influence electric atoms, dispersed through space in such 



ultitudes, would have upon the light that comes to us from the stars; but it is hardly credible that any 



teoretic investigation would show as its result that the stellar heavens would then be darkened in a 



anner that is at variance with reality. 



Atoms with bound electrons may be imagined to absorb light and heat waves by co-oscillations of 

 o bound electrons. The absorption conditioned in this way does not attain a noticeable value until the 

 >riod in the entering waves agrees with that of the oscillations proper of the bound electrons. It may 

 )w be imagined that the oscillations of these bound electrons may in their turn be transferred to 

 ther waves, or that one or more electrons may separate and form cathode-rays. We know that cathode- 

 ,ys can be emitted by a metal surface by irradiation with ultra-violet light, and that electrons can be 

 ;t free from a metallic surface when that surface absorbs rays of light. 



There is also another question which naturally presents itself for investigation: Will the assumed 

 ;nsity of flying corpuscles in space bring about any appreciable resistance to the motion of the heav- 

 ily bodies? 



Let us look at the case as regards the earth, when it was assumed that there were 10 iron atoms 

 ;r cubic centimetre in space. 



We will assume the least favorable case, namely that the earth intercepts all the atoms it meets. 

 uring a revolution round the sun, the earth encompasses a volume of 1.2 X io 32 cubic centimetres. If 

 e mass of the iron atom be put at 5.6 X io - 3 gr. and io atoms be assumed per cubic centimetre, 

 c earth will intercept 6.7 X io 10 gr. in one year. 



According to the equation (M + J M}V^ MV^, the velocity of the earth will then be dimin- 

 H-d by 



If the earth's velocity be put at 3 X 10 cm. per second, its mass at 6.06 X io 27 gr., then F Fi 

 1.7 X io n cm. per second. According to this, the earth, supposed for the sake of simplicity to be 

 sting in its orbit, would be retarded 5.4 X io~ 4 cm. per annum, or the length of the year would be 

 :creased by 1.8X10 10 seconds. 



We see from the above that it is not impossible that future investigations will show that without 

 inning into conflict with experience in any way here mentioned, we may reckon that there are more 

 lan ten thousand times greater masses gathered as flying corpuscles in "empty" space than the masses 

 ; the stars and nebulae. 



And it may be imagined that an average equilibrium exists between disintegration of the heavenly 

 ies on the one side, and gathering and condensation of flying corpuscles on the other('). 



(') In a paper, "De 1'origine des mondes", Archives des Sciences, Geneva, June isth, 1913, the author has made the views 

 here set forth the subject of detailed consideration. 



