Gravity
Gravity
Agenda Today 1 Kepler's Laws 2 Newton's Law of gravity 3 gravitational field and potential energy 4 Einstein's theory of gravity
Agenda Today 1 Kepler’s Laws 2 Newton’s Law of gravity 3 gravitational field and potential energy 4 Einstein’s theory of gravity
天何所沓？十二焉分？ 日月安属？列星安陈？ Sphere of the Fixed Stars Celestial Region Sphere of the Moon (Terrestrial Region) Fire A标 Water
天何所沓？十二焉分？ 日月安属？列星安陈？
Ptolemy's model of universe motion
Ptolemy’s model of universe
The heroes OANNIS KETTLER Cilgi tmbgu soi N R山G-+s
The heroes
Kepler's laws The law of orbit:All planets move in elliptical with the sun at one focus The Law of area:A line joining any planet to the sun sweeps out equal areas in equal times vdt Planet 11
Kepler’s laws The law of orbit: All planets move in elliptical with the sun at one focus The Law of area: A line joining any planet to the sun sweeps out equal areas in equal times
Angular momentum(角动量) L=rxp The law of period: the square of the period of any planet is proportional to the cube of the planet's mean distance from the sun. T R
Angular momentum（角动量）: The law of period: the square of the period of any planet is proportional to the cube of the planet’s mean distance from the sun
Newton's Law of gravity: G RR / G:gravitational constant
Newton’s Law of gravity: G： gravitational constant
For any planet, GMML-MT 2 r2 20 V= T We have: 4z2 Kepler's law of GM. period
For any planet, T r v r v M r GM M p s p 2 2 2 We have: 3 2 2 4 r GM T s Kepler’s law of period
B Credit:Richard Mushotzky (GSFONASA),ROSAT,ESA,NASA A Distance The existence of dark matter
The existence of dark matter