Universal Emptiness
The ideal of mechanics is the empty space where few objects interact whose behavior is determined only by their masses. Pretty close to that ideal comes the space between the large heavenly bodies of our solar system. And in fact, the laws of gravitation and inertia and so on were first derived from observations of the stars, especially of the planets’ motions.
On earth it was essential that situations could be found or arranged, where disturbing factors, such as friction, did not carry too much weight and thus could be ignored. (Billiard) balls rolling on slick surfaces or hanging on strings while colliding are suitable here, as well as free falling bodies. Comparisions of their movements with those of the celestial bodies gave rise to the discoveries of impressively universal new laws.
How much our world is formed by this ideal of mechanics is reflected not only by the slick surfaces to be found everywhere, for example, but above all by our brains, our deep mental (mis)concepts: True reality must be hard and slick and as hostile as the empty outer space.