Aristarchus of Samos

(ca. 320 BC, Samos, Greece - 250 BC, Alexandria, Egypt) --
In surviving treatise A. "On the size and distance of the Sun and the Moon" provides a clever way to determine the distance from the Sun and the Moon to the Earth through the angle of lines drawn from the eye to the sun and the moon at a time when it is half-lit. Based on the data A. without the use of trigonometric functions found that the distance from the Sun to the Earth 19 times more (instead of 370) than the distance from Earth to the Moon, and that the diameter of the sun at 6.75 times (instead of 109) larger than the Earth.

One of the greatest services a. hypothesis is the emergence of the heliocentric system of the world. Only after 18 centuries, his theory was further developed in the writings of Nicolaus Copernicus. A. argued that the sun and the stars are stationary and infinitely removed from the earth and the earth rotates around its own and yet moves around the sun in a circle, inclined to the equator. A. deal with the optics, improved the astronomical gnomon, has developed the beginning of calculations inscribed with the chords.