Greek Astronomy

PART 1


1) Greek Astronomy does not only report to Ancient Greeks (borned in Greece) time. What also eras (and nations) are included in Greek Astronomy? (3)

It includes all those who spoke greek in Classical Antiquity, which was the general time period of culture centred around the Mediterranean sea. This group also contains the Ancient Greek, Hellenistic, Greco-Roman and Late Antiquity eras. It is not limited to the Greek people or the country of Greece, because by that time Greek was used in many parts of the world as the language of scholarship, due to Alexander's conquests.

2) Which 6 celestial objects are referred in Homer’s Iliad and the Odyssey. (2)

a) Sirius, the Dog Star ^^
b) the constellation Orion
c) the star cluster Hyades
d) the constellation Boötes
e) the star cluster Pleiades (I love words that are spelled like that XD)
f) the constellation Ursa Major

3) Until they realized it was only one planet, Venus had two names for early greeks. What were those names? Why did that happened? (3)

The two names were Hesperus which means evening star, and Phosphorus which means light bringer. This mistake was due to the fact that certain planets become invisible when their orbit is closer to the sun. Venus can be seen in the morning and evening, respectively. And since Greek astronomers couldn't view the entire orbit, they thought that the planet was two different ones, when it was in fact simply appearing in two different places.

4) Who realized it was only one planet? (1)

Pythagoras is the one who eventually realized this.

5) Astronomy was placed among the 4 mathematical arts. What are the other three? (1)

The other three are Arithmetic, Geometry, and Music.

6) What’s the two sphere model? (5)

It is a geocentric model, which works with the theory that the Earth is the center of the universe with the sun and everything else revolving around it. It divides the cosmos, or universe, into two regions. One is a spherical earth, obviously in the center of the model, and stationary. The other is a spherical heavenly realm focused on Earth, which was said to contain many rotating spheres of aether. Aether was believed to be an element apart from the mortal Air, Fire, Earth and Water, and can be known as the 'Fifth Element.'

I will combine these two questions:
7) In which two books can we see it explained? (1)
8) Who wrote them? (1)

They are described in the Timaeus and the Republic, both of which were written by Plato.

9) Explain the Euxoden system. (5)

The works of Eudoxus were lost, so our information on his system is based on secondary sources. He assigned each planet a set of concentric spheres. Then by tilting the axes of the spheres, and giving each a different time of revolution, he was able to approximate when each of the planets would be visible to the human eye. By doing so he was the first to try a mathematical description of the motions of the planets.

10) Tell and explain one flaw pointed to this system. (3)

One of the most important flaws of this system was that it was unable to explain why the planets change in their degree of brightness when viewed from Earth. Because the spheres are concentric, the planets would always remain at the same distance from Earth.

PART 2

Now that you done the first part (if you have) what do you think it was the contribution of Greek Astronomy to modern Astronomy? Is modern Astronomy still under its influence? I wanted you to think of these questions others you might come up to that explain the relation between Greek Astronomy and Modern Astronomy.
No less than 100 words but no more than 300. (15)

It is often difficult, and many times impossible, to trace exactly what event or realization triggered another. Modern astronomy is a compilation of centuries’ worth of observations and calculations.

The Greeks were mistaken about many things. For example, they thought that the earth was in the center of the universe. And when Aristarchus of Samos created a model which placed the Sun at the center of the universe, nobody believed him, when in fact he was right.

But I don’t think that individual observations had as much an influence on modern astronomy as their whole attitude did. These people really wanted to find out the answers. Some of them spent their entire lifetime trying to make one model or diagram or mathematical equation work out. They treated astronomy as a branch of math, as something that could be figured out. This urge to figure things out is something that most humans are born with, and the fact that the Greeks tried so hard to figure out the movements of the planets but still didn’t succeed completely, that may have driven modern astronomers to find the right answers, the accurate ones.


Source used: http://en.wikipedia.org/wiki/Greek_astronomy

GREEK ASTRONOMY

PART 1


1) Greek astronomy includes thoses who spoke Greek in classical antiquity. It also include the ancient Greek, Hellenistic, Greco-Roman, and Late Antiquity eras. Greek language had become the language of scholarship throughout the Hellenistic world following the conquests of Alexander, so it is not limited to Greece.

2) Homer refers to the following celestial objects:
1)the constellation Boötes
2)the star cluster Hyades
3)the constellation Orion
4)the star cluster Pleiades
5)Sirius, the Dog Star
6)the constellation Ursa Major

3) Venus’s two names were Hesperus, evening star, and Phosphorus, light-bringer. This was because early Greeks thought that the evening and morning appearances of Venus were two different objects.

4) Pythagoras came to recognize that both objects were the same planet.

5) The Pythagoreans placed astronomy among the four mathematical arts along with arithmetic, geometry, and music.

6) According to David Lindberg, a modern historian of science:
In their work we find (1) a shift from stellar to planetary concerns, (2) the creation of a geometrical model, the "two-sphere model," for the representation of stellar and planetary phenomena, and (3) the establishment of criteria governing theories designed to account for planetary observations. (Lindberg 1992, p. 90)
It is a geocentric model, that divides the cosmos into two regions:
1)A spherical Earth, central and motionless.
2)A spherical heavenly realm centered on the Earth.
http://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/Ptolemaicsystem-small.png/180px-Ptolemaicsystem-small.png" border="0" alt=""/>

Renaissance woodcut illustrating the two-sphere model.

7) It is explained in Timaeus and Republic

8) Plato wrote them.

9) By tilting the axes of the spheres, and by assigning each a different period of revolution, he was able to get a mathematical description of the motions of the planets.

10) One is the inability of his models to explain why planets appear to change speed.

PART 2

The Greeks have had a major influence in modern Astronomy. Greek astronomer Aristarchus, was the first to maintain the earth rotated around the sun and that the earth revolved on its axis once every 24 hours. It was dismissed at the time, but centuries later would be proved correct. Also Polish astronomer Copernicus who assigned the Sun as center and the planets revolved around it. These studies formed the basis for modern Astronomy.


Sources:

[url] http://en.wikipedia.org/wiki/Greek_astronomy [/url]
[url] http://www.unixl.com/dir/humanities/history/history_of_technology/astronomy/[/url]