DISCUSSION OF "A KINETIC THEORY OF 

 GRAVITATION." 



(Plate I.) 



By CHARLES F. BRUSH. 



(Read April 24, 19 14.) 



I. Gravitation is Due to Intrinsic Energy of the Ether. 



At the Minneapolis meeting of the American Association for the 

 Advancement of Science I had the honor to onthne " A Kinetic 

 Theory of Gravitation,"^ which is in substance briefly as follows : 



The ether is assumed to be endowed with vast intrinsic kinetic 

 energy in wave form of some sort capable of motive action on 

 particles, atoms or molecules of matter, and propagated in every 

 conceivable direction so that the wave energy is isotropic. The 

 waves are of such low frequency, or otherwise of such character, 

 that they pass through all bodies without obstruction other than that 

 concerned in gravitation. Distribution of the ether's energy is uni- 

 form throughout the universe except as modified by the presence of 

 matter. 



Atoms or particles are imagined to be continually buffeted in all 

 directions by the ether waves like particles of a precipitate suspended 

 in turbulent water. There are no collisions because neighboring 

 particles follow very nearly parallel paths. 



Each particle or atom of matter is regarded as a center of ac- 

 tivity due to its energy of translation initially derived from the ether. 

 There is continual absorption and restitution of the ether's energy, 

 normally equal in amount ; but the ether is permanently robbed of as 

 much of its energy as is represented by the mean kinetic energy of 

 the particle or atom. The particle or atom thus has a field of influ- 

 ence extending in all directions, or casts a spherical energy shadow, 

 so to speak, the depth or density of the shadow varying with the 

 inverse square of distance. The energy shadow of a body of matter 



'^Science, March 10, 1911; Nature, March 23, jqci. 



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