Heliocentric T heory

1. Heliocentric Theory WENJUN TAO BOYUAN LIN YUAN YANG JIAYIN WANG JIAHUI YUAN

2. What is heliocentric theory ? The heliocentric model is a theory that places the Sun as the center of the universe, and the planets orbiting around it.

3. Nicolaus Copernicus and Heliocentric Theory

4. Copernicus Copernicus' interest in astronomy While in Italy, he became acquainted with Domenico Maria de Novara with whom he conducted astronomical observations. These gave him the opportunity to examine by direct observation a small but very important detail of the existing cosmological system.

5.  The occultation of Aldebaran offered an excellent occasion for this examination. Copernicus calculated that the phenomenon would take place on the evening of March 9, 1497. His calculations, proved that, in contradiction to Ptolemaic theory, the distance between the earth and the moon is the same no matter whether the moon is full or in one of its quarters.

7. Copernicus started to read diligently various ancient authors: Aristotle, Plato and others, searching for clues of other concepts of the universe, besides those of Ptolemy. He discovered that in the writings of Cicero, Plutarch and other ancients there were some statements concerning certain Greek philosophers, especially those of the school, who thought the earth might be moving.

8. From about 1510 to 1514, Copernicus developed the first general outline of his new heliocentric system and presented it in a short manuscript, the Commentariolus The work was not written to be published. Rather it was distributed among his closest friends in manuscript form.

10. Copernicus' assumptions

11. 1. There is no one center of all the celestial circles or spheres. 2. The center of the earth is not the center of the universe, but only of gravity and of the lunar sphere. 3. All the spheres revolve about the sun as their mid-point, and therefore the sun is the center of the universe. 4. The ratio of the earth‘s distance from the sun to the height of the firmament is smaller than the ratio of the earth’s radius to its distance from the sun.

12. 5. Whatever motion appears in the firmament arises not from any motion of the firmament, but from the earth's motion. 6. What appear to us as motions of the sun arise not from its motion but from the motion of the earth and our sphere. The earth has, then, more than one motion. 7. The apparent retrograde and direct motion of the planets arises not from their motion but from the earth's.

13. History

14. Ptolemy • Ptolemy is the man widely credited with taking the geocentric theory mainstream.

15. Aristotle • Aristotle argued that there are no universals that are unattached to existing things. Universals exist within each thing on which each universal is predicated. According to Aristotle, the form of apple exists within each apple, rather than in the world of the forms.

16. What is "The geocentric theory" ? The geocentric theory is the belief that the Earth is the center of the universe and that all other objects orbit around it.

17. The theory was thought to be proved by two observations: first, the stars, sun, and planets appear to revolve around the Earth each day, Second, since the Earth is solid and stable, it is not moving. Geocentrism was not replaced until the 1600′s.

18. The view of modernscience Kepler's laws of planetary motion were used as arguments in favor of the heliocentric hypothesis. Bessel proved that parallax of a star was greater than zero. He measured the parallax of 0.314 arcseconds of a star named 61 Cygni. In the same year Friedrich Georg Wilhelm Struve and Thomas Henderson measured the parallaxes of other stars, Vega and Alpha Centauri.

19. Effect Change the cosmic view of people Defend the power of churches people began to find truth in science through experimentation rather than religion with no proof people began to see "astronomical phenomena" as "natural compound products of simple operations repeated in perpetuity" rather than the actions of Gods.