Cosmology Aristotle To Hawking

Front 1

What was Thales ideas about the make up of the earth?

Back 1

The earth was a disc or cylinar suported by water. Heavenly vault seperated waters above from waters below. Water was the fundamental substance.

Front 2

Eratosthenes came up with a way to calculate to size of the earth. How did he acheive this?

Back 2

He used 2 sticks a different points on the earths surface and measured the angel of the shadows to find out what the size of the angel between the two points. This equation is figured out from simple geometry.

Front 3

Anaximendar also believed that the earth was like a cylinder. What was the point that was different in his view?

Back 3

That the earth was an unsupported and was the center of the universe.

Front 4

What was different about the way that Anaximines percieved the earth and universe?

Back 4

The earth was a disc supported by air. Air is the fundamental substance. That the stars were attatched by a crystalline sphere.

Front 5

What did Empedocles propose?

Back 5

He proposed the doctrine of 4 elements.

Front 6

What were the 4 elements?

Back 6

Earth, Water, Air, Fire

Front 7

What were Anaxagoras' thoughts about the moon?

Back 7

The moon shines by reflected sunlight. He also thought that the earth and the moon were cylindars.

Front 8

What were Leucippus Democritus' thoughts on the universe?

Back 8

He believed the universe was infinite, that there could be other earths and suns.

Front 9

The followers of Pythagoras came up with ideas about cosmology. What were they?

Back 9

They thought of the earth as moving. They also thought that at the center of the universe is a central fire. Everything rotated around the central fire.

Front 10

Heraclides of Pontus had what beliefs of the universe?

Back 10

The the universe was infinite. That the earth was fixed at the center (of stars) which rotated daily. He aslo said that mercury and venus revolved around the sun.

Front 11

Aristarchus of Samos believed...?

Back 11

that the earth revolved around the sun and that the sun is at the center of the stars.

Front 12

Plato and Socrates contributed what to cosmology?

Back 12

Pretty much nothing.

Front 13

What was Eudoxus' contribution to cosmology?

Back 13

He came up with homocentric spheres, which are a collection of speres with the same center.

Front 14

How many speres in total did Eudoxus use? And what was each circle used for?

Back 14

He had 27 in his model. 1 for the stars, 3 for each the sun and the moon, and 4 for each of the 5 planets.

Front 15

There was one major flaw in Eudoxus' setup what was it?

Back 15

The flaw was that the distance from the earth always stayed the same for the planets.

Front 16

What was Aristotle's view of the universe?

Back 16

He believed that the universe was finite and bounded by the sphere of starts.

Front 17

What was the 2 sphere frame work?

Back 17

the 2 shpere frame work extends metaphysically to 2 realms of the universe: 1)earthly realm-out to the lunar shpere, realm of the 4 elements 2)heavenly realm-pure and changing, 5th element quintessance or aether, pure crystalline solid.

Front 18

What did Aristotle add to Eudoxus' homocentric spheres?

Back 18

he composed counter rings between the planets. which bumped the amount of circles to 57.

Front 19

Why did Aristotle believe that the earth and universe have no beginning and no end?

Back 19

because out of nothing comes nothing.

Front 20

What did Apollonius of Perga contribute to cosmology?

Back 20

He came up with 1)eccentric circle 2) deferent and epicycle

Front 21

What was Ptolemy's explanation for the movement of the planets?

Back 21

he use the crank mechanism.

Front 22

What is the crank mechanism?

Back 22

the center of the epicycle moves around the earth. the crank pushes and pulls the planet in and out from the earth.

Front 23

What is an equant?

Back 23

is a point where the motion looks uniform.

Front 24

How many circles did Ptolemy use?

Back 24

40 circles

Front 25

When was Aristotle's works reintroduced into Europe?

Back 25

In the 12th century.

Front 26

What is violent motion?

Back 26

is when an object needs an external agent, requires the continuous action of a force.

Front 27

Who came up with the idea that there is no wind caused by the earth rotating because the air moves along with the earth?

Back 27

Nicole Oresme and Jean Buridan

Front 28

How did Plutarch account for why the moon does not fall into the earth?

Back 28

"for everything is born in it's own direction wntil changed by another object"

Front 29

How many circles did Copernicus use?

Back 29

48 circles.

Front 30

According to Copernicus what accounts for the motion of the stars?

Back 30

The apparent motion of the stars is due to a rotating earth.

Front 31

What is parallax?

Back 31

Parallax is the angular shift of an object from one point to another. Failure to observe parallax means that the stars are very far away.

Front 32

what makes it the sun look as though it moves eastward through the stars?

Back 32

the eastward motion of the earth around the sun accounts for the apparant eastward motion of the sun through the stars.

Front 33

What occur naturally in Coperancus' plan of the universe?

Back 33

1) retrograde motion 2) variable brightness 3)variable times for passage through the ecliptic 4)association of mercury and venus with the sun 5) order of the planets.

Front 34

What is an Astronomical Unit?

Back 34

it is the average distance between the earth and the sun.

Front 35

In what year did Tycho Brahe observe a supernova?

Back 35

1572

Front 36

What destoyed the idea of the unchanging heavens?

Back 36

That a nova never moved with the fixed stars.

Front 37

What did Brahe observe about comets?

Back 37

That they didn't have a paralax which ment that they are further away than the moon.

Front 38

What was the Tychonic system?

Back 38

the earth spun but didn't move, sun and moon moved around the earth, the planets moved around the sun.