History of Science and Engineering Annotation << Back HISTORY OF SCIENCE OF THE EARTH. PART I. DEVELOPMENT OF THE SCIENCE OF THE EARTH MOVEMENT IN THE GEOCENTRISM А.S. Volzhin The 1st part of the paper is devoted to the Earth’s motion science development during the age of geocentrism from Pythagoras (VI century b. c.). to Copernicus (XVI century b. c.). At that time the Earth was considered fixed, and astronomers obserbed it as the seemed motion of the Sun and stars towards the Earth. That is why, the research findings about the Sun and stars are directly related to the Earth’s motion. An analysis conducted of the geocentric universe systems of Eudoxus, Kalippa, Aristotle and other philosophers. The analysis revealed that the Sun’s motion model consisted of three motions. The 1st one with a period of one day, the 2nd – a period of the year, and the 3d one, a very slow motion with a period of about 26 000 years. The 3d motion of the Earth, called by the author an orbital running over the Earth, is a rolling in its orbit in the opposite direction of its orbital motion. In one year, while rolling, the Earth makes one revolution over its center of mass (a rotational component), while its center of mass moves in an orbit with a period of 23424,3 years (an incremental component). It is shown that the incremental component of the 3d motion of the Earth was oberved by Eudoxus, Kalipp and Aristotle as a 3d motion of the Sun. Hipparchus discovered it as a change in the longitude of stars and explained this phenomenon by the motion of stars sphere. Ptolemy accounted this movement in his geocentric system as a motion of the vernal equinox. Copernicus described the 3d motion of the Earth as a rotational component. It is outlined that in the modern science there is no description of the third motion, although it considers its incremental component indirectly, in the form of a motion that does not exist in nature, as a material body, the vernal equinox, which is not true. It is revealed that in the era of geocentrism, the Sun’s motion, as a mirror image of the Earth’s motion, consisted of three motions, and the main parameters of these motions have been determined. Key words: the era of geocentrizma; the apparent movement of the Sun; the third movement of the Earth; Eudoxus; Aristotle; Hipparchus; Ptolemy. Contacts: E-mail: Volzhin15@ mail.ru Pp. 55-67.