Claudius Ptolemy

claudius ptolemy

Today we are going to talk about one of the men who contributed a lot of information to science. Is about Claudius Ptolemy. He is a man who was a Greek astronomer, mathematician and geographer and, although there is very little information about his life, this scientist has survived to this day. It is not known exactly where he was born, or on what date. It is not known where he died but we know his great contribution.

Therefore, we are going to dedicate this article to tell you all the biography and exploits of Claudio Ptolemy.

Biography of Claudius Ptolemy

world map by claudius ptolemy

Although it is not known exactly where Claudius Ptolemy was born, it is estimated that it was in Egypt. All its activity is framed between the dates of your first observation you made in AD 127 This observation was made during the eleventh year of Hadrian's reign. On the other hand, one of his latest observations is dated AD 141. In the star catalog he adopted the first year of the reign of Emperor Antoninus Pius as the reference date for all coordinates. This reference year was 138 AD

Claudius Ptolemy stands out for being the last great representative of all Greek astronomy. And it is that his main activity was developed in the observer of the temple of Serapis in Canopus. This observatory was located near Alexandria. The main and most famous work of Claudius Ptolemy for which he became best known is the Mathematical Syntax. This work is divided into 13 volumes that was classified as a large and extensive work. In this way, it could be distinguished from other collections of astronomical texts by other authors. The importance that his work had may become relevant for the advancement of science.

The admiration that inspired all the work of Claudius Ptolemy introduced a custom of referring to it using the Greek term megisté. This term means as great and the maximum. Such was the repercussion of the work that the Caliph al-Mamun had in full Arabic translated in 827. The name of al-Magisti as said translation that comes from the title of Almagest. This title was adopted in the medieval West from the first translation into the Arabic version. This translation was made in Toledo in 1175.

Characteristics of the work of Claudius Ptolemy


Using all the data collected by the predecessors, Claudius Ptolemy built a world system that represented with a high degree of prescription all the apparent movements of both the sun, the moon and the 5 planets known at that time. He especially used the data collected by Hipparchus since they focused on this. He was able to establish these movements with a certain degree of precision thanks to geometric resources and complex calculations. The basis of this knowledge was based on a geocentric system. In this system it was the planet Earth that is immobile at the center of the universe. From this, all celestial objects, including the sun, the moon and the rest of the planets, revolve around our planet.

The planets known at that time were Mercury, Venus, Jupiter, and Saturn. In this system the Earth occupied a slightly eccentric position with respect to the center of all the circumferences on which the rest of the celestial bodies moved. These lines of position were known as different circles. The only celestial body that traversed its deferent circle with a uniform movement was the sun. On the other hand, the moon and the rest of the planets moved through another circle. This circle was called an epicycle. The center of the epicycle rotates on the deferent and It allows him to explain to Claudio Ptolemy all the irregularities that could be observed in the movements of the celestial bodies.

Claudius Ptolemy's system

model of the universe

This system was able to provide an interpretation of all planetary motions that fit fairly well with the principles of Aristotelian cosmology that existed at that time. It also remained the sole model until the Renaissance. During the time of rebirth, there were greater precision when observing celestial bodies and there was more information thanks to the multiple astronomical observations. Most of the information regarding astronomy in this period was made at the end of the medieval period. With this knowledge, it became necessary to introduce dozens of new epicycles that made everything related to astronomy excessively complicated to understand.

In fact, the heliocentric model exposed by Copernicus It was the work that began the disappearance of all the astronomy of Claudius Ptolemy since it had a greater simplicity considered as one of those main strengths.

But keep in mind that Claudius Ptolemy He was not only an astronomer but also a geographer. Given his knowledge of geography, he was able to exert a great influence thanks to great geographical discoveries. In his 8-volume work called Geography Mathematical techniques were compiled for drawing different precise maps using different projection systems. It also collects an extensive collection of necessary and corresponding geographic coordinates with different places in the world then known.

To elaborate this work, Claudius Ptolemy adopted the estimation made by Posidonius about the circumference of the Earth. This estimate was lower than the true value and exaggerated the extent of the Eurasian continent in the east-west direction. This situation alerted Christopher Columbus to embark on his journey, which was the one to discover America.

Other works

Another of Claudio Ptolemy's works It is divided into 5 volumes and is known by the name of Optics. Said work of that one on the theory of mirrors and on reflection and refraction of light. These phenomena were physical and the consequences of this were taken into consideration for astronomical observations. He is also credited with the authorship of an astrology treatise called Tetrabiblos that it presented all the characteristics and other writings and that it was worth much of the area that it had in the Middle Ages.

I hope that with this information you can learn more about the biography and exploits of Claudio Ptolemy.

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