Pa. They have. This earth is a vast ball, hung in the air, and continually spinning round, and that is the cause why the sun and stars seem to rise and set. At noon we have the sun over our heads, when the antipodes have the stars over theirs; and at midnight the stars are over our heads, and the sun over theirs. So whither should they fall to more than we?—to the stars or the sun?
Lu. But we are up, and they are down.
Pa. What is up, but from the earth and toward the sky? Their feet touch the earth, and their heads point to the sky, as well as ours; and we are under their feet, as much as they are under ours. If a hole were dug quite through the earth, what would you see through it?
Lu. Sky, with the sun or the stars; and now I see the whole matter plainly. But pray what supports the earth in the air?
Pa. Why, whither should it go?
Lu. I don’t know—I suppose where there was most to draw it. I have heard that the sun is a great many times bigger than the earth. Would it not go to that?
Pa. You have thought very justly on the matter, I perceive. But I shall take another opportunity of showing you how this is, and why the earth does not fall into the sun, of which, I confess, there seems to be some danger. Meanwhile, think how far the falling of an apple has carried us?
Lu. To the antipodes, and I know not where.
Pa. You may see thence what use may be made of the commonest fact by a thinking mind.