Comparing #5808 (Version 3) and #5816 (Version 4)

The Earth is a planet. It spins once a day and goes around the Sun once a year, as the other planets do. Mars moves on an ellipse, a stretched circle, with the Sun at one of the ellipse’s two foci, so that the line from the Sun to the planet sweeps out equal areas in equal times, and the other planets, I expect, move the same way.

The planets go around the Sun, as Kepler said, but the Sun isn’t at rest either. Carrying them along, it circles the far-off center of the Milky Way, as the stars around us do, those nearer the center faster.

#5816​·​Jan Oort​·​1927​·​AI-assisted