Although Newtonian physics provided a sensible explanation for why the Earth should rotate on its axis and orbit the Sun, there was still no direct evidence for Earth’s motion. The first such evidence was provided by James Bradley, who attempted to reproduce Hooke’s parallax measurements and instead discovered the aberration of starlight. This slight displacement of a star’s apparent position occurs because of the Earth’s orbital motion and the finite speed of light. It was not until the late 1830s that astronomers finally detected annual stellar parallax, again confirming Earth’s orbital motion. Astronomers also sought direct evidence for Earth’s rotation. French astronomers confirmed that the Earth bulges out slightly at the equator, an effect that Newton had predicted as a result of Earth’s rotation. Experiments on the deflection of falling bodies also seemed to confirm Earth’s rotation, but the results were clouded in uncertainty. It was Foucault’s famous pendulum that provided the best direct evidence for the rotation of the Earth. These and other successes helped to establish the validity of Newtonian physics and brought about the successful conclusion of the Copernican Revolution.

In 1671 Robert Hooke thought he had detected an annual parallax for the star Gamma Draconis, thus proving that the Earth orbits the Sun. Setting aside the uncertainty of Hooke’s meagre measurements, there remained the problem of how the Earth could orbit the Sun. Hooke thought he knew: the planets orbited the Sun because of a combination of straight line inertial motion and an attraction toward the Sun. But it was left to Hooke’s rival, Isaac Newton, to work out the mathematical details. While working out these details Newton established an entirely new physics based on three fundamental laws of motion and a universal gravitational attraction between all massive objects. Newton’s physics explained not only the orbits of planets, but also the motion of projectiles, the orbits of the Moon and comets, the precession of the equinoxes, and the tides. Newton’s physics was hailed in England but many European natural philosophers initially dismissed universal gravitational attraction as an “occult quality.”