Claudius Ptolemy

Claudius Ptolemy

Claudius Ptolemy was born around 100 AD, in Alexandria Egypt. Claudius Ptolemy was known as an Egyptian astronomer, mathematician, and geographer during the second century AD. Ptolemy established a system of mathematical astronomy that continued to be used in the countries until the 16th century.   Ptolemy’s observations and theories were retained in a 13-part work entitled Mathematike Syntaxis. Very little is known about his life, but scholars have been able to conclude some parts of his life from his writings.
Ptolemy believed the Earth was round, but he also believed that Earth was the center of what was called the Ptolemaic system. The Ptolemaic system is one of Ptolemy’s theories that states that the Earth is the center of this system and the Sun, Moon, all planets and stars revolve around it.   It also states that the sun, moon, planets, and stars all move different speeds and Earth remained still. Ptolemy thought that the stars were points of light established in a rotating sphere.   He also believed that each had its own orbit. Ptolemy made a consolidation of these orbits, known as epicycles.   Ptolemy believed that the moon was the closest to Earth followed by the stars, and than planets. Ptolemy gave each star a latitude, longitude and magnitude (brightness). Ptolemy’s system was accepted as correct throughout Europe until 1543.

Although Ptolemy’s measurements were not accurate they were good enough to be used for 1,400 years. In 1543 Nicolaus Copernicus published his book, argued in it that that Ptolemy’s system was inaccurate. He also stated that the Earth was actually a moving planet and not a stationary planet.   Copernicus doubted on the reliability of Ptolemy’s assumptions and arguments. Later on Tycho Brahe made more accurate measurements of the positions of the planets. Brahe also made claims that some of Ptolemy’s stars in his catalog were inaccurate and or unreal.
Ptolemy had other accomplishments to astronomy.   For...