The study of the origin and structure of the Universe. Earth not unique, nor at rest. No center to an infinite Universe. Earth orbits central fire. Plato's successor at Academy.
Earth rotates on axis once per day about axis.
Sun at center. Earth orbits Sun, and rotates once per day about axis. Weather permitting, we will be spending some time outside, looking at the stars. Dress warmly, and bring your sky charts. Plato, excerpt 6.