Aristarchus of Samos

Mathematician and astronomer

Born: c. 310 b. c.e.; Samos

Died: c. 230 b. c.e.; Alexandria

Category: Mathematics; astronomy and cosmology

Life Little is known of the life of Aristarchus of Samos (ar-uh-STAHR-kuhs of sah-MOHS) except that he spent at least some years at the museum in Alexandria. He is known for the first heliocentric (Sun-centered) theory of the universe. The scientist Archimedes noted that Aristarchus suggested that the Sun and fixed stars remained still while Earth rotated on its axis and revolved around the Sun.

The only work written by Aristarchus that survived is On the Sizes and Distances of the Sun and Moon. In this treatise, Aristarchus made the first truly scientific attempt to estimate the size of the solar system. He calculated that the Sun was eighteen to twenty times farther away from Earth than the Moon, which was actually short by a factor of twenty. Still, Aristarchus’s measurement was ignored because he also thought the fixed stars were an enormous distance away compared with the Sun.

Influence The mathematics required for the theory of a moving Earth was unreasonable according to the observations made by later Greek astronomers. Aristarchus was forgotten until mathematicians began to praise him during the Scientific Revolution of the seventeenth century in order to convince their contemporaries to accept the heliocentric system of Copernicus.

Further Reading

Gingerich, Owen. “Did Copernicus Owe a Debt to Aristarchus?” Journal for the History of Astronomy 16 (1985): 37-42.

Heath, Thomas L. Aristarchus of Samos: The Ancient Copernicus. Reprint. Mineola, NY: Dover, 2004.

This diagram illustrates Aristarchus's observations and calculations regarding the Sun, Moon, and Earth. the believed that Earth rotated on its axis and revolved around the Sun. (Library of Congress)

Hirshfield, Alan W. “The Triangles of Aristarchus.” Mathematics Teacher 97, no. 4 (April, 2004): 228-231.

Wall, Byron Emerson. “Anatomy of a Precursor: The Historiography of Aristarchus of Samos.” Studies in History and Philosophy of Science 6 (1975): 201-228.

Amy Ackerberg-Hastings

See also: Archimedes; Cosmology; Science.