Aristotelian physics laws of physics". The Persian polymath Abū Rayhān al-Bīrūnī (973-1048) was the first to realize that acceleration is connected with non-uniform motion (as later expressed by Newton's second law of motion). During his debate with Avicenna, al-Biruni also criticized the Aristotelian theory of gravity firstly for denying the existence of levity or gravity in the celestial spheres; and, secondly, for its notion of circular motion being an innate property of the heavenly bodies. In 1121, al-Khazini, in "The Book of the Balance of Wisdom", proposed that the gravity and gravitational potential energy of a body varies depending on its distance
Kepler's laws of planetary motion Kepler's laws of planetary motion In astronomy, Kepler's laws of planetary motion are three scientific laws describing the motion of planets around the Sun. Most planetary orbits are nearly circular, and careful observation and calculation are required in order to establish that they are not perfectly circular. Calculations of the orbit of Mars, whose published values are somewhat suspect, indicated an elliptical orbit. From this, Johannes Kepler inferred that other bodies in the Solar System, including those farther away from the Sun, also have elliptical orbits. Kepler's work (published between 1609 and 1619) improved the heliocentric theory of Nicolaus Copernicus,