Very — On a Possible Limit to Gravitation. 33 



Akt. V. — On a Possible Limit to Gravitation;* by 

 Frank W. Very. 



General Statement of the Argument. 



It is assumed that gravitation acts by means of longi- 

 tudinal waves of alternate condensation and expansion 

 in a universal medium which is also a magnetic medium, 

 or "magnetic aura," composed of least parts, or mag- 

 netons, and which is subject to magnetic laws. Hence 

 the gravitational wave at any instant is assumed to coin- 

 cide with a magnetic equip otential surface and to follow 

 in its progressions the curves of magnetic lines of force. 

 Reasons are given for believing that the sphere of action 

 of a given galactic mass of stellar material does not 

 extend to infinity, but is contained within a definite aural 

 "cell," or is limited by the vortical motions of a partic- 

 ular body of the universal aura which is independent of 

 neighboring similar bodies, possibly because there is 

 repulsion between them, so that interference is impos- 

 sible. Speaking relatively, the galaxies are rather 

 closely packed, in total disagreement with the sparsity 

 of stellar distribution; and the galaxies have also much 

 greater speeds than the relative speeds of the stars which 

 compose them ; but nevertheless the galaxies show hardly 

 any appearance of collision or interpenetration — noth- 

 ing which cannot be explained as variation in a general 

 magnetic control. 



In confirmation of this view may be cited Van Maa- 

 nen's measures of the internal motions in Messier 101. 

 The motions are away from the center, as if controlled 

 by currents in the general medium, that is, these motions 

 are not such as would be anticipated under the gravita- 

 tional attraction of a central mass ; and the flow appears 

 to follow a law of the inverse cube of the distance which 

 would be appropriate to a magnetic control. An attempt 

 is made in this paper to devise a scheme of an atom, 

 composed of least gravitative units, which shall be 

 capable of performing these functions and of sustaining 

 these relations to a general magnetic medium; and it is 

 shown that gravitational waves having a frequency not 



* This paper was presented at the Twenty-first meeting of the American 

 Astronomical Society at Albany, August, 1917 (abstract in Publications of 

 the Society, vol. 3, p. 335), but has been slightly modified since then. 



Am. Jour. Sci.— Fourth Series, Vol. XLVI1I, No. 283.— July, 1919. 

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