CHAPTER VII.
Several objections, made to the Theory of Concentric Spheres, answered, particularly the one that it contravenes religious opinions; demonstrating that the earth, and the other orbs of the universe, are formed on the best possible plan for the maintenance and support of organic life.
Some of the most prominent objections which I have heard advanced against the theory of concentric spheres are the following:
1st. That if the earth be not a solid globe, but a hollow concentric sphere, the quantity of matter being diminished, the attraction of gravitation must be lessened so much that all moveable bodies resting on the earth would be thrown off by centrifugal force, in the line of a tangent from the surface of the sphere.
2d. That according to the established laws of gravity, a hollow sphere could not exist in nature: that matter would be gravitated to the centre, and particularly about the polar openings, so as to make it collapse.
3d. That if the orbs were hollow spheres, the mutual influence of the planets on each other would be so far destroyed, that they would cease to revolve in regular orbits.
4th. That the interior of the sphere can never receive the light and heat of the sun; is involved in perpetual darkness, and more suited to the infliction of punishment on perverse and rebellious spirits, than for the residence of beings, fitted and designed for the pursuit and enjoyment of happiness.
5th. And finally, the adherents of the new theory have been charged with atheism, deism, and such like epithets, as though they intended to overturn the works of God, and thwart the laws of nature.
1st. As to the first objection, I would enquire, has it yet been ascertained with mathematical certainty, in what exact proportion one particle of matter attracts another? And may there not be some law of nature with which we are not yet well acquainted? All the experiments, hitherto made on the attractive power of gravity, were made on the principle, and under the belief, that the earth is a solid globe; and consequently the deductions were drawn accordingly. Suppose the attraction of gravitation, inherent in matter, to be so much increased, that a hollow sphere would possess the same attractive power, as if it were a solid globe, would not all the results and consequences be exactly the same? This being the case,—and I know no reason why we should conclude differently,—the whole force of the objection appears to fall to the ground. According to Newton's principle of gravity, the matter of the sphere would attract all particles of matter placed on the surface, as well upon the concave as convex, in nearly equal proportions; and the centrifugal force, which, on the outer side of the sphere, tends to throw bodies off, on the concave side, would have an opposite effect. Hence, a person standing, or trees growing, on the interior surface, would be in no more danger of being precipitated to the next sphere, between them and the centre, than those on the outer part of the sphere, when they should be turned (what is familiarly called) down.