Astronomy Essay

Astronomy is a natural science focusing on the study of celestial objects such as moons, stars, planets, nebulae and galaxies. Astronomy is considered to be one of the oldest natural sciences; early civilizations throughout history such as the Babylonians, Egyptians and Greeks performed methodical observations of the sky. The Babylonians had different astronomical records regarding the position of the moon, sun and stars, on the other hand the Egyptians used astronomy to know the time and afterwards they developed a calendar based on the solar year. The following paper will focus on the ancient Greek astronomy, interestingly the origin of the word astronomy is Greek it comes from two words; astron meaning "star" and nemien refers to "to name". This paper will explain and highlight the methods used, famous figures and the achievements attained during the ancient Greek astronomy era.

Before analyzing what the Greek astronomers achieved or came up with, it's important to identify the tools that they used to list their observations. During the early civilizations there weren’t any telescopes or computers that are used today to explore the astronomical field with new experiments and observations. In other words the ancient Greeks did not have the luxury of technology and had to rely on ancient tools that had the same aims as the tools of today, their main goal was to observe the stars, sun, moon and understand the movement of the celestial objects. Greek astronomers developed or used existing tools such as the astrolabes; which in Greek means "star takers". The instrument was composed of two discs, and they were mainly used to locate the stars during certain times of the day. As mentioned astrolabes were used to predict the stars pos...

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.... Throughout the book Ptolemy compared his own observations with those of Hipparchus, regarding the motion of the sun; Ptolemy found the lengths of the seasons and introduced a simple model for the sun which was a circular motion of uniform angular velocity however the earth would be displaced from the center referred to as eccentricity. He also used his own observations and those of Hipparchus to show that the fixed stars always maintain the same position relative to each other. Concerning his planetary theory, according to his model the path of a planet consisted of a circular motion on an epicycle while the center of the epicycle moving around a circle whose was offset from the earth. It is important to mention that the planetary theory introduces by Ptolemy was considered to be a noticeable achievement, since it predicted the motion of the planets fairly well.