If we admit that this medium, the properties of which would
explain the attraction, is the same as the luminous ether, we may
first ask ourselves whether the action of gravitation is itself also
due to oscillations. Some authors have endeavoured to found a theory
on this hypothesis, but we are immediately brought face to face with
very serious difficulties. Gravity appears, in fact, to present quite
exceptional characteristics. No agent, not even those which depend
upon the ether, such as light and electricity, has any influence on
its action or its direction. All bodies are, so to speak, absolutely
transparent to universal attraction, and no experiment has succeeded
in demonstrating that its propagation is not instantaneous. From
various astronomical observations, Laplace concluded that its
velocity, in any case, must exceed fifty million times that of light.
It is subject neither to reflection nor to refraction; it is
independent of the structure of bodies; and not only is it
inexhaustible, but also (as is pointed out, according to M.
Pages:
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273