PHYS 183 Lecture Notes - Lecture 5: Inverse-Square Law, Semi-Major And Semi-Minor Axes, Universal Law

• School: McGill University
• Department: Physics
• Course: PHYS 183
• Professor: Gilbert Holder

Document Summary

Keple(cid:396)"s la(cid:449)s as stated a(cid:396)e pu(cid:396)el(cid:455) phe(cid:374)o(cid:373)e(cid:374)ologi(cid:272)al, i. e. (cid:373)e(cid:396)el(cid:455) des(cid:272)(cid:396)i(cid:271)e o(cid:271)se(cid:396)(cid:448)atio(cid:374)s of planets mathematically: no deeper understanding. Mo(cid:396)e (cid:373)ea(cid:374)i(cid:374)gful u(cid:374)de(cid:396)sta(cid:374)di(cid:374)g: keple(cid:396)"s la(cid:449)s follo(cid:449) f(cid:396)o(cid:373) (cid:373)o(cid:396)e ge(cid:374)e(cid:396)al p(cid:396)i(cid:374)(cid:272)iples, (cid:449)hi(cid:272)h appl(cid:455) to more than just the planets: physics. Made astonishing number of discoveries: saw craters, shadows on the moon: not a perfect sphere, sa(cid:449) su(cid:374)spots, dis(cid:272)o(cid:448)e(cid:396)ed su(cid:374)"s (cid:396)otatio(cid:374, discovered 4 moons of jupiter: not everything orbits earth, phases of venus: fit nicely in copernican view. Hounded by church, placed under house arrest for years, forced to recant beliefs. First to realize that as an object falls towards earth, it accelerates in the same way independent of its mass. Drop two objects from the same height, they hit the ground simultaneously (neglecting air friction) Acceleration is rate of change of speed: meters per second per second = m/s2. Weight vs mass: mass is amount of atoms and molecules, weight is the way the mass is coupled to the gravitational pull.