Seeing+stars+discussion

=SEEING STARS: FROM COPERNICUS TO GALILEO = Timeline ** Around this time, Aristotle also theorised that the universe was a finite, crystal sphere where all the planets and stars moved around the Earth in perfect and circular motions. || AD || Tycho Brahe observed the night sky, and collected the most extensive set of astronomical data at the time. He observed a supernova (SN 1572) and termed it a "Stella Nova", meaning new star. This disproved the Aristotle's idea of a static universe. ||
 * 
 * 388 BC || Plato teaches the concept that the Sun, Moon and planets move around the Earth in perfect circles and in harmony with the universe.
 * 270 BC || Aristarchus of Samos was the pioneer of the heliocentric model, but theory was not popular ||
 * 150 AD || Ptolemy publishes star catalogue and support for the geocentric model in the //Almagest.// His model of the universe, however, is complicated and involves the use of epicycles. ||
 * 1543 AD || Nicolaus Copernicus publishes // De revolutionibus orbium coelestium // (//On the Revolutions of the Heavenly Spheres//), maintaining the ancient idea of circular orbits but proposing a “radical” heliocentric theory as it helps fix the calendar and is a simpler, more elegant model than the Ptolemaic model. ||
 * 1572
 * 1577 AD || Tycho Brahe witnesses a comet going across the sky and seemingly cut through the "crystalline spheres" of Aristotle’s “crystalline-spheres universe”. This shows that the universe is not static/immutable and that Artistotle’s model of the universe is inaccurate ||
 * 1609 AD || Johannes Kepler publishes //Astronomia nova// (//New Astronomy)// and introduces his three laws of planetary motion as well as the concept that the orbits of planets were ellipses, rather than perfect circles. ||
 * 1610 AD || Galileo Galilei publishes // Sidereus Nuncius (The Starry Messenger)// which contains his observations of sun spots, the Medicean Planets (or Galilean Moons of Jupiter), phases of Venus as well as the craters of the Moon. He uses these observations as evidence of a heliocentric Solar System. ||
 * 1632 AD || Galileo Galilei publishes // Dialogo sopra i due massimi sistemi del mondo (Dialogue Concerning the Two Chief World Systems)// and sparks controversy due to his blatant support of the heliocentric world view – has a character called Simpleton who supports the geocentric model of the universe. This book caused him to be placed under house arrest by the Roman Inquisition. ||

-Nicolaus Copernicus -Tycho Brahe -Johannes Kepler -Galileo Galilei
 * **Who were the people involved **
 * (Historical Influences: ** Ptolemy, Aristotle and Plato)

The cosmological views of the late middle ages(Ptolemy and Aristotle)
- Geocentric: a series of concentric spheres with a fixed or motionless earth as its center - Four fundamental elements: earth, air, fire, and water - Spheres around the earth were made of a crystalline, transparent substance and moved in circular orbits(which is the most perfect kind of motion) around the earth - 10 Spheres: the moon, Mercury, Venus, the sun, Mars, Jupiter, Saturn, the fixed stars, the sphere that moved the stars and the prime mover

//Nicolaus Copernicus: - was a member of the Cathedral, a faithful Christian and a mathematician - was summoned to correct the fundamental problem about the old Roman calendar --> // proposed the heli ocentric model as an explanation to the messed up calender (he was trying to determine when Easter should be celebrated) - was not an accomplished observational astronomer so he relied on previous data - 1506-1530: spent working on the manuscript of his book //On the Revolutions of the Heavenly spheres// (he found that some of the ancient views contradicted the Ptolemaic model) - the book was only published in May 1543(shortly before his death) due to his personal hesitation - his publishers introduction to his book stated that his system was just an abstraction, a set of mathematical tools for doing astronomy - broke away from the Aristotelian/Ptolemaic system - believed that the planets travelled in CIRCULAR orbit,and thus had to fall back on Ptolemy's epicycles to correct errors in the patterns he saw - first conceived the idea of "double movement" -- the earth revolves around the Sun and also rotates on its own axis
 * Brief biographical write up **



//Brahe: - was a high-ranking Danish nobleman and accomplished observational astronomer - was granted // an island near Copenhagen by King Frederick II ,his patron [//"built a castle outfitted a library observatories and instruments he designed for more precise astronomical observations"//] - gathered highly accurate and precise data through consistent observation of the night sky when he plotted the movement of every star - Rejected the Aristotelian-Ptolemaic system, accepted Copernicus's view that earth moved but not his heliocentric idea - supported the Earth-centred conception (geocentric model), but suggested that the moon and the sun move around the Earth while the other planets revolved around the sun. His theory was well received as it not only made astronomical and astrological predictions to be more accurate and easy to carry out, but also did not go against the theology back then. - perceived the heavens to be NOT static/immutable but always changing (eg. he witnessed a comet going across the sky in 1577 and a supernove in 1572) - had an beautiful artificial nose (made up of either gold or copper) as he lost his nose in a fight - Last year spent in Prague as a imperial mathematician to Emperor Rudolf II who took a keen interest in astronomy, astrology and Hermetic tradition. - took on an assistant (Johannes Kepler)

//Kepler:// - a convinced Copernican - was trained as a Lutheran minister but abandoned theology at the university at Tubingen for mathematics and astronomy - assistant to Brahe and obtained his huge tables od astronomical data after he died - imperial Mathematician to Rudolf II - suggested that the orbits of the planets were elliptical, with the Sun at one focus of the ellipse instead of at the centre - came up with the three laws of planetary motion: 1) orbits of the planets around the sun were elliptical with 2 focii, the sun being one of them 2) planets move around the Sun at varying speeds when at varyind distance from the sun, the area of the distance covered is always equal (refer to diagram) 3) square of a planet's period of revolution is proportional to the cube of its average distance from the sun (P square = A cube)



Galileo: - Dropped out of medicine school when he ran out of money - Loved Mathematics - Was a lecturer in Mathematics at the University of Pisa, later at Padua - The first to use a telescope to observe the spheres/skies, using lenses he improved himself (at that time, the telescope was mainly used to observe ships as they approached the harbour) - Found that celestial bodies are not perfect nor immutable (eg. the sun had sun spots, there were craters on the Moon) - Discovered the Galilean Moons of Jupiter: Io, Europa, Callisto and Ganymede - In 1610, published //The Starry Messenger// - Showed in his book //Dialogue Between the Two Great World Systems// that the movement of Earth is possible but could not prove that it was necessary - In 1633, he was found guilty and forced to recant his errors - 8 years studying mechanics: a field he made significant contributions in (eg. inertia) - A firm proponent of Copernicus's heliocentric system //**- P opularized the Copernican system through his flair in writing especially through his controversial book, " **//A Dialogue Between the Two Great World Systems//".// However, his discoveries and theories challenged the church's beliefs and he challenged the interpretation of the Bible. Thus, he was condemned. //Essence of conflict between Galileo and Church 1) Idea of Heliocentrism -- not the true essence of the conflict, the true essence of the conflict is that the Church felt deeply about a commoner/layman challenging the credibility of its interpretation of the Bible 2) Galileo's adversarial attitude -- the Church was not closed off to new ideas but his never-ending insistence that his concept was the truth annoyed the Church 3) Galileo quoted the Bible -- layman/commoner who did not study theology had no right to question the interpretations of the Bible or quote the Bible for different purposes (not religious purposes) 4) 30 Year War -- the Church needed the garner the full support of the people and had no reason to bother about Galileo during such a crucial period. Galileo was a genius but he might have been in the wrong place at the wrong time. In summary, Galileo was a great genius of the scientific revolution -- he fought for the truth and was daring enough to stand up against authority; used experiments and observations to prove his theories and discoveries // **Ptolemy/Aristotle
 * - ** Came from a noble but poor family
 * - ** witnessed the phases of Venus changing like the moon
 * <span style="font-family: Tahoma,Geneva,sans-serif;">Major achievements and their significance and importance
 * ======Geocentrism, perfect circular orbits Heaven beyond the earth unchanging, immutable Crystal spheres. A) Impossible, B) Non-circular orbit irregular? If you throw a stone, logically it will fall down, explains gravity? Physics? How does it apply? Accelerations, physical changes.======

** <span style="font-family: Tahoma,Geneva,sans-serif; font-weight: normal;"> **Who is the most revolutionary?** __ Copernicus __ +FOR -a breakthrough in the knowledge of astronomy -inspired many other natural philosophers - Raise serious question about Aristotle's astronomy and physics - create uncertainty about the human role in the universe as well as God's location -AGAINST -presented his idea in a conservative manner -relied a lot of the Aristotle/Ptolemy ideas like circular orbits and epicycles. <span style="font-family: Tahoma,Geneva,sans-serif;">__   <span style="-webkit-text-decorations-in-effect: none; font-family: Tahoma,Geneva,sans-serif; text-decoration: none;">__    <span style="-webkit-text-decorations-in-effect: none; font-family: Tahoma,Geneva,sans-serif; text-decoration: none;">__    <span style="-webkit-text-decorations-in-effect: none; font-family: Tahoma,Geneva,sans-serif; text-decoration: none;">__    <span style="-webkit-text-decorations-in-effect: none; font-family: Tahoma,Geneva,sans-serif; text-decoration: none;">__ Galileo __    __     __     __     __    +FOR -defied the church in presenting his ideas -proved the spheres to be imperfect -AGAINST <span style="color: #000000; font-family: Tahoma,sans-serif;">-he is building on the ideas of the natural philosophers that came before him, such as Copernicus and Kepler

Question 1: How did all these ideas affect Science?
-These ideas sent a message to people that ancient theories could be wrong, opening up new possiblities in science and allowed natural philosophers to look at changes in other fields. -Some of the ideas/discoveries make life easier for people(eg. more accurate calendar for farmers to follow), arousing new interest in scientific research since it proved to be useful in benefitting mankind.<span style="font-family: Tahoma,Geneva,sans-serif; font-weight: normal;"> - Humbling - Humans are no longer in the center of the universe - Created uncertainty about their natural world -- Copernicus? - set the ball rolling, brave enough to come up with the revolutionary heliocentric idea -- Brahe? - mapped the movement of the stars accurately -- Kepler? - came up with the three laws that governed planetary motion, which is still in use today --Galileo? - Provided proof/evidence of the heliocentric universe, used technology and created new apparatus to aid his observations and experimentations,relied on empirical evidence, publicized his ideas openly and without fear
 * Question 2: How did the perception of the universe change during the SR? Who contributed the most of this? **

**Question 3: Which scientists had the greatest impact on the development of science?** I think it would be Galileo as his observations were proof of a heliocentric universe and he used technology in experimentation (the Scientific Method). In addition, he published ideas in the vernacular and these ideas had a widespread reach, leading to commoners and not only natural philosophers to start questioning if the concept of the geocentric universe was right. His unique approach of standing up for the truth and for Science against authorities was also a bold movement that few scientists in his era would have dared to do, thus reflecting his strong-will to promote the 'truth of Science' to everyone. -Wikipedia, the free encyclopedia -YouTube video "the day the universe changed infinitely reasonable" <span style="font-family: Tahoma,Geneva,sans-serif;"> -School notes -Class discussion -Western Civilization- Jackson J. Spielvogel -The Scientific Revolution edited by Mitchell Young -[] -[] <span style="-webkit-border-horizontal-spacing: 2px; -webkit-border-vertical-spacing: 2px; border-collapse: collapse; font-family: 'Apple Garamond'; font-size: 20px; line-height: 30px;">
 * <span style="font-family: Tahoma,Geneva,sans-serif;">References **

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