How does the Foucault pendulum work in a geocentric universe?
Jason says he cannot picture how the Foucault pendulum functions in a geocentric universe and asks for an explanation in simple terms.
Answer
Think of the amusement park ride where you stand against the padded wall of a spinning cylinder and get pinned so hard you cannot lift a limb; that force is the centrifugal force, and notice how strong it is even at a slow rotation. Whenever you have rotation you get at least three inertial forces. First the Euler force, the tangential jerk you feel as the ride starts, which then goes to zero. Then the centrifugal force, pushing you outward against the wall. Then the Coriolis force, an inward-turning force: if you throw a beach ball straight across the spinning ride, it curves, going right if the ride turns clockwise and left if it turns counterclockwise. All three act together, and that combined force, carried through whatever fills space, is what turns the freely-moving Foucault pendulum, because it is not impeded by anything on earth. The same forces explain why hurricanes turn counterclockwise in the northern hemisphere and clockwise in the southern, divided at the equator, which is itself a sign that the earth is at the center. These inertial forces attach to a body and move it just as gravity does.