Johannes Kepler: tides are caused by the moon

Saturday December 27th.
It’s the birthday of astronomer Johannes Kepler, born to a poor mercenary in Württemberg, Germany (1571), who tracked the orbital path of Mars and published his three famous laws of planetary motion — which validated Copernicus’s theory of a sun-centered solar system — and later helped Isaac Newton discover the law of gravity. Kepler was nearly blind from a smallpox epidemic when he was three, and he developed the first eyeglass designs for nearsightedness and farsightedness. He was also the first to explain that the tides are caused by the moon, the first to propose that the sun rotates on an axis, and the first to use planetary cycles to calculate the year of the birth of Jesus Christ.
-Writer's Almanac