Kinetic Theories of Gravitation/Boucheporn, 1849

M. F. de Boucheporn read a memoir to the French Academy of Sciences, July 30, 1849, entitled "Researches on physical laws considered as consequences of the only essential properties of matter, impenetrability and inertia;" the object proposed being to show the considerations leading to the conclusion that all physical law rests simply on these necessary attributes of matter, " without the supposition of any force."

He commences with the general recognition, "It is an idea quite old in science that the movements of the heavenly bodies may be explained by an external impulsion or by the action of a universal fluid. This was the earliest idea of French philosophy, being that of Descartes, and even Newton himself had thought of connecting with it the great law of gravitation."

Boucheporn proceeds to cite some of the principles and results developed. " 1st. The intensity of an impulse propagated in the aetherial [241] medium follows the law of the inverse square of the distance from the center of disturbance. 2d. The resistance of the aether does not sensibly affect the velocity of a body when this is sufficiently less than that of aetherial propagation ; but this resistance becomes a uniform pressure on the entire surface of a body, (supposed spherical,) and even determines its sphericity. 3d. Taking as unity the density of the fluid, the quantity of motion impressed by a body on the aether is equal to its volume multiplied by the square of its velocity ; which is also the measure of the total pressure on the surface of a body. 4th. Propagated to the interior of the heavenly bodies, the pressure would produce the effect that all layers of equal thickness will inclose the same quantity of matter, and that the mean density is three times that of the surface. This kind of homogeneity would not be affected by the action of heat. In short, from such great internal condensation, it may be conjectured that the heavenly bodies are almost entirely impermeable by the aether, as will shortly appear from an astronomical law. 5th. As to attraction ; the displacement of the aether by the movement of a body A, will produce in all parts of the fluid a sort of aspiration toward the point being left by its center; any other body B receiving these aspiring waves on its nearer hemisphere will have lost all or a part of its own pressure; and the half pressure (volume multiplied by the squared velocity) which acts on the opposite hemisphere, no longer being counterbalanced, wdl give an impulse to the body B in the direction of A. Such would be the principle of attraction. ..."

The writer finds a verification of his principles in the relation existing between the respective masses of the planets and the product of their volumes by the square of their velocities, omitting the cases of Uranus and Neptune. Also by determining the velocity of an attracting body from that of its satellite, knowing only the ratio of the radius to the distance; and lastly, by determining the amount on fall of heavy bodies from the angular velocity of the earth, irrespective of its mass!