Notes

Outline

Tycho Brahe (1546-1601)

Johannes Kepler (1571-1630)

Ellipses

Kepler’s Laws of Planetary Motion

Kepler’s Second Law Animated

Kepler’s Third Law

Isaac Newton (1642-1727)

Newton’s Three Laws

Newton’s Law of Gravitation

Astro Quiz Why are astronauts in the Space Shuttle weightless? 1) The extra inertial of the Shuttle just compensates for the extra gravitational pull on it, so it falls at the same rate as the astronauts. 2) The Shuttle is sufficiently high in its orbit that the Earth’s gravitational pull is negligible. 3) The Shuttle’s engines keep it on a path that matches the Earth’s curve, and there is no air resistance.

Newton explains Kepler’s Laws

Finding the mass of the Earth

Orbital Motion

Orbital and Escape velocity