1. The Sun Centered Universe Jeremy Benton Amy Kidd

2. Intro

3. Reasons for Theories of Geocentricity Plato (4 th Century BC) – Theories of the universe included Perfect Circles Based on simplicity Either a mathematic or geometric model of universe

4. Reasons for Theories of Geocentricity Cont. Eudoxus (student of Plato’s) – His theories were more developed, and they included: Geocentricity – one of the first scientists credited with these ideas Crystalline spheres – trasnparent spheres that lie between the earth and the stars that account for all motion in the universe He came up with 26 different crystalline spheres to account for all the motions of the universe.

5. Reasons for Theories of Geocentricity Hipparchus Earth centered Deferents and Epicycles to explain ideas of retrograde motion

6. Reasons for Theories of Geocentricity Claudius Ptolemy of Alexandria (150 AD) – Utilised the geocentric model, that earth was the center of the universe, to predict with far greater accuracy the motions of known celestial bodies. This reinforced the idea of geocentricity over heliocentricty among other astrolgists of the time. – His work many also linked to the bible. Although the bible doesn’t explicitly say that earth revolves around the sun, many interpreted certain verses to mean so, thus creating a link between science and theology (the study of the bible).

7. The link between astrology and theology According to the bible man is God’s greatest creation; therefore the earth must be the center of God’s focus. Anyone who disagreed or didn’t believe these ideas was often severely punished. For hundreds of years, going against the Catholic Church had huge consequences that ruined lives and careers. – “After all, if we were dwelling on one average planet, rotating around one average star, in one average galaxy in an infinite Universe, how could we be the sole focus of God’s attention, and why should His only Son be sent just to this middling planet, as the Bible suggests?” (Thompson, 1988)

8. Heliocentricity Catches Up Copernicus (1543) – He was the first to develop a valid heliocentric model of the solar system. – In his model he included ideas such as: A sun-centered solar system Earth and all other planets revolve around the sun The stars are actually far away from us The earth has more than one motion All previous observed motions were due to the motion of the earth

9. The Consequences of Such a Theory Due to his ideas challenging the predominant view of that time, it took 150 years before his theory was actually accepted. His book De Revolutionibus Orbium Coelestium was placed on the list of forbidden books because it challenged the dominant view held by the Catholic Church. At first many rejected it simply because they were afraid of how this view could challenge other scientific theories of the time, and thus create chaos.

10. His theory of heliocentricity was the first of its kind to match the accuracy of Ptolemy’s geocentric theory. – He was just as accurate, but no more accurate than Ptolemy was. – He also insisted that Ptolemy’s model was not “pleasing to the mind’s eye”.

11. Other challenging theories of the time Tycho Brahe- 1572 – Sun is center – Sun revolves around Earth – Other planets revolve around Sun Theory not accepted by anyone

12. Other challenging theories of the time Johannes Kepler (Assistant of Brahe) – Took both Copernicus’ theory and Brahe’s observations and used them to add the the theories of heliocentricity Earth must be a moving object Earth speeds up the closer it is to the sun He discovered this from his work studying Mars

13. Galileo – 1600’s – Galileo also believed in the theory of Heliocentricity because of his study of Venus’ phases of the moon – If the sun and planets were both orbiting earth, it would be nearly impossible to have a shadow on Venus at all times, as he observed. – The Church had many issues with Galileo’s work over the years. So much so that they put him under house arrest until he died.

14. Impact on Science/society The rejection of the geocentric model allowed for the modern field of physics and astronomy to develop Scientific views regulated by the Church limited science’s potential to progress It also allowed for accurate astronomical models to be developed thus allowing for flight, space travel, satellites etc. Today, the heliocentric model is accepted almost without debate

15. Because of the heliocentric model of the universe, we are now able to do things like go to the moon, or, possible sometime soon, to Mars!

16. A return to old beliefs? With the proposal of the Theory of Relativity, it can be said, in a particular way, that the old geocentric model is not necessarily invalid, for according to it it cannot be determined which of two bodies is rotating around which one.

17. Bibliography http://intro.phys.psu.edu/class/p001projects/ project1/sp12projects/9physic_1_project.pdf http://intro.phys.psu.edu/class/p001projects/ project1/sp12projects/9physic_1_project.pdf http://apologeticspress.org/apcontent.aspx?c ategory=11&article=1151 http://apologeticspress.org/apcontent.aspx?c ategory=11&article=1151 http://gbgm-umc.org/umw/bible/wv-nt2.stm http://hypertextbook.com/eworld/geocentric. shtml