The diameter of our disk-shaped galaxy, the Milky Way, is about 1.0 105 lightyears (ly). The distance to Messier 31, which is Andromeda, the spiral galaxy nearest to the Milky Way, is about 2.0 million ly. If a scale model represents the Milky Way and Andromeda galaxies as dinner plates 40 cm in diameter, determine the distance between the centers of the two plates.