Measured the motions of planets without a telescope.
Who is Tycho?
100
Property ranging from 0 to 1 that describes the shape of an ellipse.
What is eccentricity? e=0 is a circle. e=1 is a line. Most planets have e near 0.
100
Newton's Law that restated Galileo's result.
What is Newton's 1st law, the law of inertia? An object at rest (or in motion) stays at rest (or in motion).
200
First to use a telescope to look at the sky and developed the idea of inertia.
Who is Galileo?
200
For earth, this distance that describes the size of an orbit, is 1 AU.
What is the semimajor axis? The distance from the center of earth's orbit to it's edge, almost the same as the distance from the earth to the sun.
200
According to Newton's 2nd Law, this causes a change in speed or direction.
What is an unbalanced force? Remember a change in either speed or direction is acceleration.
300
First to describe the orbits of planets as ellipses.
Who is Kepler?
300
According to Kepler's 2nd Law, each month a planet will "sweep" out this in it's orbit.
What is equal areas?
300
According to Newton's 3rd law, this is what you do when the earth pulls on you with gravity.
What is pull back (with an equal but opposite force)? You exert gravity on the earth, but it is too big to notice.
400
First to describe a heliocentric model of the universe.
Who is Copernicus?
400
Where a planet moves the fastest, if a planet must travel a greater distance in it's orbit in the same amount of time by Kepler's 2nd law.
What is close to the sun? It will move slower farther from the sun because it has a smaller distance to travel in an equal time to sweep out the same area.
400
This is what you need to make a chair full of books accelerate as fast as an empty chair.
What is more force? If you increase mass, you need to increase force for the same acceleration.
500
Beginning with Galileo's result, he explained why objects move the way they do.
Who is Newton?
500
Planet that takes the longest time to orbit the sun.
What is the most distant planet (Neptune)? According to Kepler's 3rd law the bigger the orbit (semimajor axis) the longer the time to orbit (period).
500
This is what you get if you push a chair full of books with the same force as an empty chair.
What is less acceleration? You won't speed up as fast with more mass and the same force.