Astronomy

Aristarchus lived from about the year 310 B.C. to about 230 B.C. Aristarchus was the first Greek philosopher and mathematician to make sense of the solar system. Others before him thought that the Earth is a sphere and that it moves, but he was the first to understand the heliocentric theory, which states that the sun is in the middle. In 288 or 287 B.C. he followed Theophrastus as the head of the Peripatetic School established by Aristotle.

Aristarchus has only one existing book that is "On the Sizes and Distances of the Sun and Moon." In it he calculated the diameter of the Sun, which is about seven times the diameter of the Earth, and estimating the Sun's volume is about 300 times the volume of the Earth (the actual diameter of the Sun is about 300 times the diameter of the Earth.) In this book there is nothing indicating his heliocentric theory. Aristarchus' book on the planetary system with the Sun in the center did not survive. He also added that the universe is many times larger than generally assumed by astronomers, and the fixed stars are at an enormous distance from the Sun and its planets. Aristarchus regarded the Sun as one of the fixed stars, the closest to the Earth.

Aristarchus