Claudius Ptolemaeus (Ptolemy)

Born: c. 100 AD, Alexandria, Egypt

Died: c. 170 AD, Alexandria, Egypt

Studied: Math, astronomy, geography

Biography

Brief overview of the scientist’s life, childhood, social circles and more!

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Discoveries

The biggest accomplishments of the scientist’s life

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Fun Facts

The cool facts you probably won’t find in most textbooks!

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Briography: Who was Ptolemy?

Claudius Ptolemaeus, more commonly known as Ptolemy, was a brilliant mathematician and astronomer during the 2nd century AD. Ptolemy was born, lived and thrived in Alexandria, Egypt, a global scientific and intellectual hub. But, who was Ptolemy?

Unfortunately, we know almost nothing about Ptolemy’, other than what we learn from his writings. We know very little, or nothing of his family, social life or any personal details. Plus, while we do not know exactly when Ptolemy was born or died, his work seems to indicate that he lived until around 170 AD.

Discoveries: What is Ptolemy known for?

In astronomy, Ptolemy’s writing The Almagest (meaning “The Greatest”) was a highly influential work of the time. Literally, Ptolemy spent decades observing the night skies. As a result, through mathematics, Ptolemy’s Almagest described the length of years, motion of the Sun and more.

In fact, Ptolemy’s description of the universe was accepted for 1,200 years. Ultimately, his work would heavily influence later Arabic and European astronomy.

Yet Ptolemy’s later text, Hypotheseis ton planomenon (meaning “Planetary Hypothesis”) would help him leave his greatest legacy, the “Ptolemaic System.” In this model, Ptolemy described a universe with Earth at the center, and other bodies attached to their own spheres, orbiting around the Earth. All of Ptolemy’s spheres were concentric, meaning they were nested within one another, like Russian Nesting Dolls.

Ptolemy even studied astrology as a legitimate, though inexact science. In his four-volume work, Apotelesmatika (meaning “Astrological Influences”), Ptolemy attempted to describe the heavens’ physical impact on terrestrial Earth. 

Fun facts about Ptolemy

  • Despite being born in Alexandria, Egypt, Ptolemy was actually Roman. This is because Egypt was under control of the Roman Empire at this time.
  • Many of Ptolemy’s––and other great ancient scholars’––works were destroyed along with the Library of Alexandria. However, while it is unclear exactly how the library was destroyed, it was believed to shelf over 70,000 volumes. Bummer!
  • Both Christopher Columbus and Ferdinand Magellan used Ptolemy’s world map on their famous journeys. However, the map was notably inaccurate!
  • In later centuries, much doubt was cast over the originality of Ptolemy’s Almagest. Many believed that Ptolemy liberally borrowed much of his work from other ancient scientists, like Hipparchus.