Hipparchus was the Ancient Greek astronomer considered to be the founder of trigonometry. Hipparchus also compiled the first star catalog and uncovered the movements of the ecliptic and celestial equator, commonly known as the precession of the equinoxes. It's also believed that Ptolemy?s theorem was derived from the works of Hipparchus.
Hipparchus is thought to have been born about 190 BCE in Nicea, now known as Turkey. His appearance is unknown, but records of his work determine that he made his first advances as an astronomer in Rhodes and Alexandria from 162 to 127 BCE. During this time, Hipparchus was vocal in his disbelief of the once-popular notion that the Sun and Moon revolved around the Earth, which was the center of the universe.
Hipparchus? formulation of geometric chord tables and his technique to solve spherical triangles led to the creation of trigonometry. His sole preserved work is a critical account entitled ?Commentary on the Phaenomena of Eudoxus and Aratus,? although he is known to have penned fourteen major works.
Hipparchus was brought back into the public eye with the proposal that the renowned Roman sculpture, ?The Farnese Atlas? used the data from Hipparchus? star catalog, making it the only surviving and somewhat accurate ancient celestial globe. This hypothesis has not been entirely approved by specialists able to verify this theory.