One of the smartest, most interesting people I ever knew once told me about a time when he got really interested in the problem of calculating the orbits of the planets based on the idea tha the Earth was stationary and everything was moving relative to it (this being one of the corollaries of the idea of a relativistic universe); I immediately thought of that project when I saw Aryeh Nirenberg’s timelapse of the Milky Way where the sky is held stationary and the Earth is rotated — such a simple and powerful way to illustrate relative motion! (via Kottke)