Claudio Ptolemy: biography and contributions of this researcher

Claudius Ptolemy was a Greek astronomer, mathematician and geographer born in Egypt when this country was a Roman province. The contributions of this scientist were fundamental, especially during the Middle Ages and early Renaissance.

We do not know much about the life of Ptolemy, but some of his works have transcended, especially thanks to the intellectuals medieval Islamic studies that echoed the valuable knowledge that Claudius Ptolemy was building throughout his life.

Next we are going to talk a little about the life of this researcher of Ancient Greece through a short biography of Claudius Ptolemy and we will see what his work was and why it was so important.

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Short biography of Claudius Ptolemy

Claudius Ptolemy was a Greek astronomer, geographer, mathematician and astrologer born in Egypt in Classical Antiquity. He is known for his proposal of the geocentric model of the universe, known as the Ptolemaic system, which He had a noticeable repercussion among Christian and Muslim intellectuals of the Middle Ages and part of the Renaissance. He is also credited with creating the first maps with coordinates of the main places on the planet in terms of latitude and longitude.

His ideas and theories of geography and astronomy were very important until the 16th century, when Copernicus formulated his theory that the planets revolved around the Sun, including the Earth, an idea that until then was just the right idea. contrary. Ptolemy's work is strongly influenced by Hipparchus of Nicea, a Greek astronomer who lived several centuries before him.

What do we know about the life of Claudius Ptolemy?

It is not known very well when Claudius Ptolemy was born. There are sources that suggest that it must have been around the year 85 AD. C., but other authors consider that it was in the year 100 d. C. This doubt persists, and will probably never be resolved, as there are not many historical records that detail what happened to his life.

It is estimated that the place of his birth was in Upper Egypt, specifically in the city of Ptolemaida Hermia, located towards the right side of the river Nile, near the present Menshiyeh. This was one of three cities founded by the Greeks in northern Egypt, the other two being Alexandria and Naucratis.

There is not much biographical information on Ptolemy, but it can be said that he worked and lived his entire life in Egypt. The sources that contribute something of the life of Claudius Ptolemy point out that he was dedicated to astronomy and astrology, mainly. It is also known that he was interested in mathematics and geography, and that he did numerous works where he dealt with the knowledge and methods that he possessed about these disciplines.

Nor do we know much about his death, although it is believed to have occurred around 165 AD. C. in the city of Alexandria, same where he worked as one of the librarians and collectors of knowledge of him. If it is true that he was born in 100 AD. C., he would have died with 69 or 70 years.

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Ptolemaic empiricism

One of the most remarkable things about Claudius Ptolemy's work was that he carried out his studies emphasizing empiricism. He applied this approach to all of his works, which set him apart from other scientists of the time.

Many of the descriptions that Ptolemy made were not intended to be real and exact replications of the phenomena that he studied, but he tried to understand and justify why they occurred based on what he watched.

Influence of Hipparchus of Nicaea

It is difficult not to speak of Hipparchus of Nicaea when talking about the life of Claudius Ptolemy, as this Greek geographer, mathematician and astronomer greatly influenced the work and work of Ptolemy. As with Claudius Ptolemy, there is not much information about Hipparchus, knowing that he lived between 190 and 120 BC. The vital information of Hipparchus of Nicea is known to us thanks to the historian and geographer Strabo and from Ptolemy himself.

Claudius Ptolemy repeatedly described Hipparchus' achievements and discoveries and credited him with multiple inventions. Among these inventions was a small telescope that was essential to improve the process of measuring angles, an instrument by means of which it was possible to establish that the The period of the solar year lasted 365 and 6 hours, a very close approximation to what we have today of what a natural solar year lasts (365 days, 6 hours, 9 minutes and 9.76 seconds).

The influence of Hipparchus on the work of Ptolemy was also notorious. thanks to the first publication that the Greek-Egyptian made: the Almagest.

I pass him through the Library of Alexandria

For much of his life, Claudius Ptolemy devoted himself to astronomical observation in the city of Alexandria.. This he did between the reigns of the emperors Hadrian (117-138 AD). C.) and Antonino Pío (138-171 d. C.).

Claudius Ptolemy is considered It is part of the so-called Second Period of the Alexandrian School, which corresponds to a period in which the Roman Empire had expanded throughout the Mediterranean and its surroundings.

Although there is not much information about it, it is believed that Claudius Ptolemy did a great job in the Library of Alexandria. This building was one of the greatest centers of knowledge in the Ancient World, and that is why Ptolemy had the opportunity to access great texts by astronomers and geometricians before his time.

If this were true, Claudius Ptolemy would have been the person in charge of compiling and systematizing all this knowledge, especially those referring to astronomy, data that could date from the 3rd century BC. He also made multiple contributions in the field of astronomy, especially regarding the movement of the planets, thanks to the vast knowledge that he acquired in his work as a librarian.

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The Almagest

Working in the library of Alexandria, Claudius Ptolemy wrote a book that would eventually become his most important work and his greatest contribution to astronomy from a mathematical perspective: the Almagest. It was originally titled "Hè megalè syntaxis" (The Great Composition) in thirteen volumes, however, with the passage of time would end up receiving the name by which it is currently known, much more emblematic.

“Almagest” is a word that comes from the medieval term “almagestum” which, in turn, derives from the Arabic “al-magisti”, translatable as “the greatest”. The reason why it is currently called this is that, despite being originally written in Greek, it aroused much interest in the medieval Islamic world. The caliph al-Mamun (786-833) had it translated into Arabic in 827, and with the passage of time it would reach Christian Europe in this language.

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His works on astronomy and astrology

The Almagest was inspired by the study of Hipparchus of Nicea while Ptolemy was working in the Library of Alexandria. In the work, reference is made to the fact that the Earth is the center of the universe and that, for this reason, it remains immobile. The Sun, Moon and stars revolve around our planet and, according to Ptolemy, all celestial bodies draw perfectly circular orbits. In this work he also tells us about the measurements of the Sun, the Moon and a set of celestial bodies that came to be a total of 1,028 stars.

In ancient times it was very common for people to believe that personality was influenced by the position of the Sun, the Moon or other celestial bodies. at the time of his birth. Astrology was a deeply rooted belief shared even among the scientific elites of the time, who came to consider it a whole science. Ptolemy was no exception.

This Greek-Egyptian mathematician wrote a famous treatise on astrology called "Tetrabiblos" (Four Books), an extensive work in which he discusses the governing principles of astrology and the horoscopes. In her He defended the theory that ailments, diseases and other health problems were caused by the influence of the Sun, the Moon, the stars and the planets. Each star had an influence on specific parts of the body.

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The contributions of him to the optics

One of his most interesting works is called "Optics", composed of five volumes where deals with the theory of mirrors and, also, the reflection and refraction of light.

These phenomena were taken into consideration in his astronomical observations and it can be said that an advance in this aspect, since few scientists considered luminous and visual phenomena as he did in Egypt Greek classical.

His research on geography

Another of his most important works was "Geography", a text that he completed since Marino de Tiro (60 d. C-130 d. C.) he couldn't finish it. It is a compendium of mathematical techniques to draw more precise geographical maps, collecting different systems of projection and collection of coordinates of the main points of the world known by that then. Although his maps were a precedent for making more accurate maps, Ptolemy made the mistake of exaggerating the extent of Asia and Europe.

His maps are one of the oldest evidences of topographic charts with coordinates, longitude and latitude. Although they had important errors, it can be said that they were a great advance for the cartography of their time. His work served to perfect the methods of map projection and he presented the terms equivalent to what today we know as parallels and meridians, tracing the imaginary lines of altitudes and lengths.

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Use of simple language

Scholars of the figure of Claudio Ptolemy highlight the simple language of the works that have survived the passage of time. Ptolemy was aware of the importance of keeping his message simple, understandable to all who read his works, be they educated men such as great mathematicians or simple people with a minimum of literacy.

Ptolemy wanted the knowledge of which he was aware to reach many people, no matter what his mathematical background was. It could be said that he was advanced and had a reasoning typical of cathedral thought, wanting what he had discovered to transcend time. He wished that what he knew at the time would serve so that the people of the future could discover more from what he had discovered.

He knew that the easier his works were to understand, the more translations would be done and the more influence he would gain.. For this reason it is said that, thanks to this, several centuries later the knowledge collected and formulated by Claudius Ptolemy would serve the Genoese explorer Christopher Columbus, especially those referring to the calculation of geographical distances and maps of very far away. Ptolemy believed that the Earth was a sphere, which is why Columbus believed it possible to go west to India.