Week 2: History

The Greeks knew the Earth was round by observing what?

Who was it who calculated the distance from the Earth to the Sun and reasoned the Sun must be larger than the Earth or Moon? Then proceeded to propose the Sun centered Solar System.

Who discovered the precession of the Earth by comparing his detailed star charts to those of the Babylonians 150 years earlier?

The Earth's precession is how many years?

What causes the Earth's presession?

The Earth's axis is tilted at:

The Earth's axis being tilted at 23 1/2 degrees causes:

HOw long does it take for the Moon to complete one orbit around Earth?

How far away is the Moon from the Earth?

The Moon's length across is?

The Moon's mass compared to the Earth's mass?

Who was it who calculated the size of the earth to within 10% of the now accepted value by noticing the Sun light hit the bottom of a well?

What is it that the backward motion a planet makes in the sky?

Who was it who devised the Earth centered planetary system. He explained retrograde motion by using smaller circles that were offset from the original orbital circle?

Who tried to perfect Ptolomy's Earth centered system but was unable to do so? He also believed that the Sun goes around the Earth but the planets moce around the Sun?

Who was it who placed the Sun at the center of the solar system but had the planets move in oerfect circles which solved the problems of retrograde motion but not the problem that planets speed up and slow down in their orbits?

Who was it who discovered the 3 laws of planetary motion?

Planets move in ellipses, planets sweep out equal area in equal time, and planets move more slowly the farther away they are from the Sun are all what?

Who used the telescope to discover: sunspots, venus had phases, the Milky Way is composed of stars, Jupiter has moons and the Moon has craters and mountains?

Who was it who demonstrated that objects of different mass fall at the same rate so they hit the ground at the same time?

Who was it who invented the pendulum clock based on his observations that a pendulum swings independent of its mass and only dependent upon its length?

Who discovered the Law of Gravity?

What is the Law of Gravity?

Objects in motion stay in motion, objects accelerate directly proportional to the force applied, and for every force on an object, there is an ewual and opposite force are all examples of what?

Who was it who predicted the return of a coment which made people take note of Newton's law of gravity?