Chapter 2-The Earth's Motions Flashcards
Ptolemaic Theory
The earth was in the center of the universe.
Geocentric Theory
The earth is at the center of the universe.
Eccentric
In circular motion, and off-center rotation.
Retrograde motion
The apparent backward movement of the superior planets.
Epicycle
In the Ptolemaic geocentric model of the solar system, a small crystal sphere centered on the surface of the deferent of certain planets to account for that planet’s retrograde motion at certain points in its orbit.
Deferent
In the Ptolemaic geocentric model of the solar system, a crystal sphere surrounding the earth for each of the visible planets, the moon, and the sun, all of which revolved around the earth.
Heliocentric theory
The sun is at the center of the universe.
Copernican
The sun is in the center of the universe.
Law of universal gravitation
The principle that states any two objects attract each other with a force proportional to the product of their masses and inversely proportional to the square of the distance between them.
Rotate
A spinning motion.
Axis
An imaginary line that the earth rotates around.
Revolve
To circle around a point that does not lie within the object, as a planet around the sun.
Inertia
The tendency of any object to resist a change in its motion.
Coriolis effect
The tendency of objects intentionally moving in a straight path over the earth surface to be deflected due to the earths rotation.
Foucault pendulum
A pendulum first used by Jean Foucault called in 1851 to demonstrate that the earth rotates on its axis.
