As someone who used to write an astronomy column for the San Mateo Daily Journal and a huge astronomy fan, I know most of the ancient astronomers but of course, not all. There was a name that kept reappearing in my research that I wasn’t familiar with. I’m not sure if he’s my favorite astronomer, but he’s definitely one I became fascinated with. That ancient astronomer is Claudius Ptolemy. Again, while I did constellation and star cluster research and most notably with the Messier objects, it was often noted that Ptolemy was the first to document the constellation or star object. This made me curious. Why would Ptolemy be credited for first documenting the heavenly body when they’re still called Messier Objects? That’s because Ptolemy was one of those astronomers who suggested that Earth was the center of our universe, not the sun. When it was proven his theories were wrong, most of his work was forgotten since most of it was either inaccurate or was proved to be inaccurate. On the other hand, he help to shape Messier’s list and was one of the first to suggest using longitudes and latitudes, just to name a couple.
Most would say, Ptolemy was born in 100 and died in 170; but not all, some suggest that he was born in 85 died in 150 or 165. It is agreed that he was Egyptian astronomer, mathematician and geographer of Greek descent who thrived in Alexandria between 127 and 145. Practically nothing is known about his life but his books give you a glimpse into his intelligence.
Ptolemy wrote many sets of books. He most known for the “Almagest” (from a hybrid of Arabic and Greek, meaning the greatest) but Ptolemy called it, “The Mathematical Collection,” because he believed that the motions of the heavenly bodies could be explained in mathematical terms. The Almagest is divided into 13 books, each of which deals with astronomical concepts concerning to stars and objects in the solar system.
It was actually another ancient Greek astronomer who first started a star list, Hipparchus. It’s estimated that he born 190 BC and died120 BC at the age of 70. He compiled the first star catalog that contained 850 stars. Ptolemy expanded the list in the Almagest by 172 stars, bringing the total to 1,022. Again, he believed the earth was the center of the universe. This became known as the Ptolemaic system but today is better known today as the geocentric model.
It would take 1400 years for another famous astronomer to prove Ptolemy wrong. It was Nicolaus Copernicus (February 19, 1473 —May 24, 1543) who proved the sun was the center of the universe. He too wrote a manuscript about it but it was printed after he died in 1543.
Another set of books Ptolemy wrote is called, the ”Geography.” In one of the volumes, he explains how to draw a world map by using longitude and latitude lines in one of the volumes. Since his map were proven to be inaccurate, he’s rarely given credit for being one of the first to explain how to make world maps.
Ptolemy even wrote on astrology and harmonics that would go to influence the Western world.