Eratosthenes was one of the great thinkers of ancient Greece whose accomplishments included accurately measuring the Earth's circumference and discovering a simple method for finding prime numbers. In addition to his contributions in mathematics,...

Eratosthenes was one of the most versatile scholars of the ancient Greek world. As a mathematician and chief librarian at the Museum of Alexandria, in Egypt, he worked at the center of Greek science. He was the founder of mathematically based geography...

The Greek scholar of natural history Eratosthenes of Cyrene (ca. 275-ca.195 BC) was proficient in many fields, but his most outstanding work was probably in mathematics and geography. The Lexicon of Suidas (ca. 10th century A.D.) records the birth of...

The measurement of distance became increasingly important to ancient and classical civilizations as their territorial and cultural horizons expanded. Using elegant mathematical reasoning and limited empirical measurement, in approximately 240 B.C.,...

Greek astronomer Using elegant mathematical reasoning and limited empirical measurement, in approximately 240 B.C., Eratosthenes of Cyrene (in current-day Libya) made an accurate measurement of the circumference of Earth. In addition to providing...

c. 285-c. 205 B.C. Greek North African Mathematician, Astronomer, and Geographer Most famous of the librarians at Alexandria, Eratosthenes provided a measurement for Earth's circumference within 1% of the actual number. He also developed a...

276-194 B.C. Greek astronomer and mathematician who wrote on geography, mathematics, philosophy, geology, chronology, and literary criticism, though only fragments of his texts remain. Eratosthenes studied at Athens and became head of the library of...

Eratosthenes of Cyrene (Greek Eρατοσθένης; 276 BC - 194 BC) was a Greek mathematician, poet, athlete, geographer and astronomer. His contemporaries nicknamed him "beta" (Greek for "number two") because he supposedly proved himself to be the...

In his Oct. 14 column, "Why Things Are - Looks Can Be Deceiving" {Style}, Joel Achenbach writes that the Greek astronomer Eratosthenes calculated the earth's circumference to be about 29,000 miles, or about 16 percent greater than today's commonly accepted value of about 25,000...