// minds behind maths

Johannes Kepler

1571–1630 · Astronomy

Johannes Kepler was a German astronomer and mathematician who worked out how the planets actually move. Using the remarkably precise observations of Tycho Brahe, he found that planets travel in ellipses with the Sun at one focus (first law), sweep out equal areas in equal times so they move faster when closer to the Sun (second law), and obey a fixed relationship between orbital period and distance, the square of the period being proportional to the cube of the orbit's size (third law, published in 1619). These three laws replaced centuries of circular-orbit assumptions and later gave Newton the foundation for his law of universal gravitation.

Source: Wikipedia — Johannes Kepler

Formulas that trace back to Johannes Kepler