History
Originally, the Greeks had very little interest in astronomy and only had a very simple understanding of the universe and how it worked. To them, the only use of understanding the stars and planets was for a guide to help you find your way. Greek astronomy would have ended here if it weren't for the philosophers and their need to question life. They started to wonder what was out in space and what made the Sun rise and set every day. These questions inspired several Greeks, a few of which were actually the philosophers, who then began to study the skies and make many new discoveries.
During these first years, as more astronomers were appearing in Greece, they all started to center their work around the idea that time should be based on the Sun, Moon, and stars. Time keeping was what almost all of the astronomers were focusing on. They all proposed different calendars with varying lengths of months and years, trying to find one that would stay in phase with the Sun and the seasons. For instance, one Greek, Solon, made a calendar that was based on a two year cycle with 12 months of 29 days and 13 months of 30 days. Solon's calendar, which had about 369 days to a year, needed frequent adjustments so that it could stay in phase with the moon and the seasons. This was a problem with almost all of the calendars that the Greeks designed. Another man, Oenopides, suggested a different calendar that had a 59 year cycle with 730 months. Many other calendars were also designed by various astronomers such as Philolaus and Meton.
In addition to designing calendars, the Greeks found a lot of interest in watching the stars and locating patterns in them. These constellations that they found were almost always based on one of their myths. For instance, the famous constellation, Pegasus, was located by the Greeks and is based on a myth where a horse is born from sea foam and the blood of Medusa and then becomes the horse of a Greek hero. The constellation is named after the horse, Pegasus, and according to the Greeks, was given a place in the heavens by Zeus. Another Greek constellation is Orion, who was a handsome hunter according to Greek mythology. Orion is one of the brightest constellations and it can be seen from all most anywhere in the world. The Greek astronomers alone charted over half of the constellations known today.
During these first years, as more astronomers were appearing in Greece, they all started to center their work around the idea that time should be based on the Sun, Moon, and stars. Time keeping was what almost all of the astronomers were focusing on. They all proposed different calendars with varying lengths of months and years, trying to find one that would stay in phase with the Sun and the seasons. For instance, one Greek, Solon, made a calendar that was based on a two year cycle with 12 months of 29 days and 13 months of 30 days. Solon's calendar, which had about 369 days to a year, needed frequent adjustments so that it could stay in phase with the moon and the seasons. This was a problem with almost all of the calendars that the Greeks designed. Another man, Oenopides, suggested a different calendar that had a 59 year cycle with 730 months. Many other calendars were also designed by various astronomers such as Philolaus and Meton.
In addition to designing calendars, the Greeks found a lot of interest in watching the stars and locating patterns in them. These constellations that they found were almost always based on one of their myths. For instance, the famous constellation, Pegasus, was located by the Greeks and is based on a myth where a horse is born from sea foam and the blood of Medusa and then becomes the horse of a Greek hero. The constellation is named after the horse, Pegasus, and according to the Greeks, was given a place in the heavens by Zeus. Another Greek constellation is Orion, who was a handsome hunter according to Greek mythology. Orion is one of the brightest constellations and it can be seen from all most anywhere in the world. The Greek astronomers alone charted over half of the constellations known today.
Theories and General Concepts
Most ancient Greeks did not believe that the Earth orbited around the Sun, or that the Earth even moved at all. They thought that the Earth was the center of the universe and that everything, the planets, the sun, and the stars, revolved around it. This theory came from the Greek astronomer Aristotle, who thought that there were invisible spheres surrounding the Earth in layers, and that each one had either a planet or a star attached to it. The planets and stars then revolved around the sphere that they were attached to, making them "orbit" the Earth. Most of the other Greek astronomers, like Ptolemy, agreed with this idea, but Aristarchus and Philolaus thought differently. Philolaus was the first Greek to have the idea that the Earth moves, however, he didn't think that it orbited around the Sun. His belief was that everything in the universe went in a circle around a central fire, which you could never see because of a counter Earth in between Earth and the fire. After Philolaus, Aristarchus also had the idea that the Earth moved. He designed a counter theory to Aristotle's Geocentric idea, known as the Hellensistic theory. The Hellenistic theory involves the Earth and all the other planets rotating in circles around the Sun, which is at the middle. However, this idea was not accepted in Greece and it wasn't until much later that the Greeks believed that the Earth moved.
One of the things that defined Greek astronomy and set it out from the other civilizations was that it was very mathematically based. Astronomy in most ancient civilizations was very religious and most explanations for things were related to the people's beliefs. However, in Greece, astronomy was extremely scientific and everything was
very mathematical. To the Greeks, everything about the universe had to make sense mathematically and all the planets and stars had to relate scientifically with each other. They believed that nothing about astronomy could be random, so they would be able to figure out the way the universe works through logic and math.
One of the things that defined Greek astronomy and set it out from the other civilizations was that it was very mathematically based. Astronomy in most ancient civilizations was very religious and most explanations for things were related to the people's beliefs. However, in Greece, astronomy was extremely scientific and everything was
very mathematical. To the Greeks, everything about the universe had to make sense mathematically and all the planets and stars had to relate scientifically with each other. They believed that nothing about astronomy could be random, so they would be able to figure out the way the universe works through logic and math.