AST 111 Lecture Notes - Lecture 16: Pendulum Clock, Photon, Jet Propulsion Laboratory
18 Dec 2020
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Document Summary
They were used to predict the existence of the planet neptune. They provide quantitative description, and predict the motion of things. Sir william herschel- discovered the planet uranus in 1781. The motion of each planet is perturbed by the presence of the other planets in the solar. Newton"s laws were used to develop this theory-perturbation theory. John c. adams- in october 1845, he used the perturbation theory and the observations of perturbations of uranus to discover the existence of an eighth planet. Urbain leverrier- in june 1846 he independently predicted the existence of an eighth planet. Johannes galle- september 23, 1846, working from berlin obervatory, he discovered the planet neptune using leverrier"s predicted location. Circular velocity- 8 km/sec or more for an object to avoid falling back to earth"s surface. Escape velocity- 11 km/sec or more for an object to leave earth"s gravitational field. An object that leaves earth"s gravitational field will enter orbit around the sun.
