Man’s View of the Universe

1. Man’s View of the Universe

2. Aristotle • Lived in Ancient Greek BC. • Thought the Heavens were composed of fifty-five concentric, crystalline spheres. • His views of the universe explained that the spheres moved with constant angular velocity, and the objects attached to them were always the same distance from Earth because they moved on spheres.

3. Ptolemy • Lived in Roman Province of Egypt 150 A.D. • His Ptolemaic Universe was contributed to the modification of Aristotle’s universe. • There were three incorrect held beliefs that helped from ancient views of the universe for more than a thousands years. 1- All motion in the heavens is uniform circular motion. 2- The objects in the heavens are made from perfect material, and cannot change their intrinsic properties. 3- The Earth is at the center of the universe. • Epicycles were geocentric models to explain the variations of speed and direction of motion. Designed by Apollonius of Perga.

4. Copernicus • Lived in 16th Century A.D.(1473-1543) • Heliocentric means that the Sun was the center of the Solar System, not Earth. • Geocentric is a theory that Earth is at the center and the Sun and other objects go around it. • Old ideas were – • 1. the planets that were in a system naturally vary in brightness because they were not always the same distance from Earth. • 2. Retrograde motion (motion in the opposite direction) could be explained in terms of geometry and a faster motion for planets with smaller orbits. • Another idea is a Sun-centered Solar System • People wouldn’t accept Copernicus’s ideas until 100 years after his death. • Aristech proposed the Sun-centered Solar System 2000 years ago • Geocentric and Heliocentric was embraced by both Aristotle and Ptolemy

5. Brahe • 1546-1601 A.D. • Three major contributions were- • 1. Precise observations by devising instruments. • 2. Observations particularly Mars. • 3. Observe of Supernova( new star) • Nose was cut off by sword fighting with a student, died of a urinary infection.

6. Keplar • 1571-1630 A.D. • A ellipse is a flatten circle. • He was able to use Brahe’s research because he died and his family kept it away from Keplar. • Perihelion is the closet distance from the planets to the sun. • Aphelion is the farest distance from a planet to the sun. • His first law of planetary motion is that the planet’s orbits are ellipses. • Second law is the planets sweep out equal areas of its obit in equal time. • He also saw the Supernova (SN- 1604).

7. Galileo • 1564-1642 • His work with motion was Newton’s 1st law Inertia • He’s ideas were by virture of a series of experiments, realizing the analysis of Aristotle was wrong because he need to account properly for a hidden force. • He also realized that as the motional forces were decreased, the object would move further and further before stopping.

8. Aristotle vs. Galileo • Aristotle said objects on Earth stopped moving once applied forces were removed • He also said that spheres in the heavens only moved because of the action of the Prime Mover, continually applied the force to outer spheres. • Aristotle believed the motion of the heavens were a different set of laws than those that governed men on Earth. • Galileo believed that the laws that governed the heavens were the same laws that Aristotle said that governed motion of the Earth’s surface.

9. Questions Any questions at this point?

10. Sites • http://www.marcdatabase.com/~lemur/lemur.com/gallery-of-antiquarian-technology/philosophical-instruments/galileo-singer • http://upload.wikimedia.org/wikipedia/commons/b/b3/Impetustheorie-avicenna.png • http://csep10.phys.utk.edu/astr161/lect/retrograde/aristotle.html • http://images.search.yahoo.com/search/images/view?back=http%3A%2F%2Fimages.search.yahoo.com%2Fsearch%2Fimages%3Fei%3DUTF-8%26p%3DAristotle%26fr2%3Dtab-web%26fr%3Dmy-vert-web-top&w=350&h=417&imgurl=staff.tpjcian.net%2Ftan_kok_wui_adrian%2Fimages%2Faristotle_altemps.jpg&rurl=http%3A%2F%2Fstaff.tpjcian.net%2Ftan_kok_wui_adrian%2FGPLecture.htm&size=54.8kB&name=aristotle_altemps.jpg&p=Aristotle&type=JPG&oid=7a49521e48bb2722&no=10&tt=48148 • http://en.wikipedia.org/wiki/Ptolemy • http://images.google.com/imgres?imgurl=http://www.mpa-garching.mpg.de/mpa/research/current_research/hl2005-3/f1-s.jpg&imgrefurl=http://www.mpa-garching.mpg.de/mpa/research/current_research/hl2005-3/hl2005-3-en.html&h=598&w=300&sz=39&hl=en&start=5&um=1&tbnid=KY_h1iSK9AwZ3M:&tbnh=135&tbnw=68&prev=/images%3Fq%3DBrahe%2Bsupernova%26um%3D1%26hl%3Den%26client%3Dopera%26rls%3Den%26sa%3DG • http://images.google.com/imgres?imgurl=http://content.answers.com/main/content/wp/en/thumb/4/4d/300px-Keplers_supernova.jpg&imgrefurl=http://www.answers.com/topic/supernova&h=300&w=300&sz=17&hl=en&start=2&um=1&tbnid=-MGEjMr6dIzDOM:&tbnh=116&tbnw=116&prev=/images%3Fq%3Dsupernova%26um%3D1%26hl%3Den%26client%3Dopera%26rls%3Den%26sa%3DN

11. Sites • http://en.wikipedia.org/wiki/Tycho_Brahe • http://en.wikipedia.org/wiki/Image:Kepler_Mars_retrograde.jpg • http://www.genciencia.com/images/250px-Johannes_Kepler.jpeg • http://en.wikipedia.org/wiki/Image:Galileo.arp.300pix.jpg • http://images.search.yahoo.com/search/images/view?back=http%3A%2F%2Fimages.search.yahoo.com%2Fsearch%2Fimages%3Fp%3DNicolaus%2BCopernicus%26sp%3D1%26fr2%3Dsp-top%26ei%3DUTF-8%26fr2%3Dtab-web%26fr%3Dslv8-%26ei%3DUTF-8%26SpellState%3Dn-1583767677_q-JeMxFoNmKwHxRNU92hlCkAAAAA%40%40&w=200&h=262&imgurl=upload.wikimedia.org%2Fwikipedia%2Fcommons%2F2%2F28%2FCopernicus.jpg&rurl=http%3A%2F%2Fnds-nl.wikipedia.org%2Fwiki%2FNicolaus_Copernicus&size=28.6kB&name=Copernicus.jpg&p=Nicolaus+Copernicus&type=jpeg&no=2&tt=2,773&oid=6b191e4172a52408&ei=UTF-8