Group+4

Group 4 Members: Han Zhengning, Jamie Ng Jia Min, Ong Shi Man, Tan Chong Rong, Wang Meng Qing

Topic: Seeing Stars- From Copernicus to Galileo

__Timeline of Key Events__ __Brief Biographies of People Involved__ His father was a a Germanized Slav 1 and merchant from [|Kraków]. His mother was the daughter of a wealthy Toruń merchant. His uncle, the bishop and ruler of Ermland, was the person to whom Copernicus owed his education, career, and security. Copernicus was the youngest of four children. Copernicus never married or had children. Copernicus spoke Latin, Polish, and German with equal fluency. He also spoke Greek and Italian. However, Copernicus used Latin for his main written form of communication. It was the chosen language of the time for written documentation. He attended the Krakow University and found that he had a love for astronomy. After his time at Krakow, Copernicus went to the Universities of Bologna and Padua. He studied civil law for a time but still felt compelled to study astronomy. He was fascinated when he had the opportunity to meet [|Domenico Maria Novara da Ferrara], a very well known astronomer. He began to study under Domenico as his assistant. In 1500, he attended the Great [|Jubilee] and he watched in awe his first lunar eclipse while he was in Rome. A polymath 2, Copernicus is considered one of the most intelligent men of the Renaissance Period. He was an astronomer, mathematician, physician, and intellect with many other capabilities proving that he has been defined correctly by historians as a polymath of his era. Copernicus died in [|Frauenburg (Frombork)] on 24 May 1543. He is reputed to have awoken from a stroke-induced coma, looked at his book, and then died peacefully. ||
 * **Year** || **Event** ||
 * 1543 || Nicolas Copernicus Publishes De Revolutionibus Orbium Coelestium (On the Revolutions of Celestial Bodies) Copernicus' masterwork; he sets out the heliocentric theory. ||
 * 1576-97 || Under the patronage of King Frederick II, Tycho Brahe established Uraniborg, a superb observatory on the Danish island of Hveen. Over the course of 20 years, he and his assistants gathered the most accurate and complete astronomical observations of that time. He designed and made new instruments that were as much as ten times more accurate than those of his predecessors. ||
 * 1591 || Galileo demonstrates the Properties of Gravity, from the top of the leaning tower of Pisa, objects fall to the ground at a constant speed regardless of their weights, refuting the Aristotelian system that the rate of fall of an object is dependent upon its weight. ||
 * 1609 || In 1609, Kepler published New Astronomy with Commentaries on the Motions of Mars. The work published his first two laws of planetary motion: 1) the planets move around the sun not in circles, but ellipses; 2) planets do not move uniformly, but in such a manner that a line drawn from a planet to the sun sweeps out an equal area of the ellipse of its orbit in equal time, even if the ellipse is not perfectly centered on the sun. ||
 * || Galileo introduced both the telescope and the microscope. ||
 * 1610 || His first observations with the telescope were published in 1610, in a 24-page booklet entitled Messenger of the Heavens describing his observations of the surface of the moon, which he proved was rough rather than smooth. He professed the existence of up to ten times as many distant, seemingly fixed stars than were currently known. The second half of the book focused on the moons of Jupiter. ||
 * 1612 || Galileo announced that through the observation of dark spots on the sun, he had concluded that the sun itself was revolving. This announcement sparked off the first conflicts between him and the Church, which found the findings offensive to the Church doctrine. ||
 * 1616 || The Inquisition warned Galileo to "abandon these opinions." A few days later, the works of Copernicus were "suspended till corrected." ||
 * 1618 || Johannes Kepler Reveals His Third and Final Law of Planetary Motion describing the form and operation of planetary orbits, and are the final step leading to the academic rejection of the Aristotelian system. ||
 * 1630 || Galileo's Dialogue on the Two Chief Systems of the World (1632) was an eloquent argument for the Copernican system over the Ptolemaic. He uses the law of physics to refute the Aristotelian concept that the Earth is the center of the solar system. ||
 * 1633 || Galileo is Forced to Recant his Theories The Inquisition forces Galileo to sign a recantation which sentenced him to house arrest for the remaining nine years of his life. His Dialogue is ordered burned as heretical, and his sentence to be read at every university. ||
 * 1662 || The Royal Society of London is Officially Organized by King Charles II The Royal Society brings together the greatest minds of the region in efforts to advance science through cooperation. Similar societies subsequently spring up throughout Europe, creating an intellectual network, which produces many of the scientific advances of the later seventeenth century. ||
 * 1687 || Isaac Newton Publishes Philosophia Naturalis Principia Mathematica, the most respected scientific work of all time,aka principia. Principia lays out Newton's comprehensive model of the universe as organized according to the law of universal gravitation which remains in use today. The Principia represents the integration of the works of all of the great astronomers who preceded Newton, and remains the basis of modern physics and astronomy. ||
 * **Nicolaus Copernicus** ||
 * Nicolaus Copernicus was born on 19 February 1473 in the city of [|Toruń] (Thorn) in [|Prusy Królewskie] (Royal Prussia), a [|prowincja] of the [|Kingdom of Poland].

The punctual occurrence at the predicted time, August 21st, 1560, of a total solar eclipse led Tycho to regard astronomy as "something divine"; he purchased the Ephemerides of [|Johann Stadius] (3rd ed., 1570), and the works of [|Ptolemy] in Latin, and gained some insight into the theory of the planets. During his life, Tycho Brahe benefited greatly from [|King Frederik]'s generous support. He received an island called Hveen from the king and for over 20 years, Brahe used the island as his base from which to make astronomical observations. In 1573 Tycho broke all the rules and married a commoner, Kirstine Barbara Jörgensdatter, who is believed to have been the daughter of the parson of Kågeröd. Tycho and Kirstine Barbara had eight children: Kirstine, Magdalene, Claus, Sophie, Elisabeth, Sidsel, Tyge and Jörgen. In 1597, Tycho Brahe lost the Danish king's support, so he went to Wandsbech in what is today known as Germany. He eventually settled in Prague where he continued his astronomical observations. Tycho died in Prague 4 in 1601. Tycho Brahe was well-known for his accurate and comprehensive astronomical and planetary observations. After Tycho’s death she bought an estate in Bohemia, where she lived out her remaining years. She died in 1604 and was buried in her husband’s grave at the Teyn Church in Prague. ||
 * **Tycho Brahe** ||
 * The Danish 1 astronomer Tycho Brahe was born on the 14th of December 1546 to a family of Knudstrup in [|Scania], then a Danish province and he was early adopted by his uncle, Jørgen Brahe who sent him, in April 1559, to study philosophy and rhetoric at Copenhagen 2 . Tycho Brahe’s father was Otte Brahe of Knutstorp, who was born in 1518. Otte was County Sheriff at Helsingborg’s 3 castle between 1567-71, and died there on the 9th of May 1571. Tycho’s mother, Beate Bille, was born on the 29th of April 1526 at Skarhult. She was chief lady-in-waiting to [|Queen Sophie] . Beate Bille died on the 18th of October 1605. Both are buried in Kågeröd’s church.

In 1584 he entered the Protestant seminary at Adelberg, and in 1589 he began his university education at the Protestant university of Tübingen. Here he studied theology and read widely. Following Kepler's graduation from the University of Tübingen in 1591, he became interested in astronomy, particularly the theories of Nicolaus Copernicus (1473–1543), who stated that the Earth moved around the Sun in a circle. In 1597, Kepler married Barbara Muehleck. Of their five children only one boy and one girl reached adulthood. Kepler sought the job of assistant to Tycho Brahe (1546–1601), astrologer (one who interprets the positions of stars and planets and their effect on human affairs) and mathematician to [|Rudolph II] (1552–1612), in Prague, Czechoslovakia. Kepler took his new position in 1600. When Brahe died the following year, Kepler was appointed to replace him. His first job was to prepare Brahe's collection of studies in astronomy for publication, which came out between 1601 and 1602. Kepler wandered over Europe in the last three years of his life. Kepler died on November 15, 1630. ||
 * **Johannes Kepler** ||
 * Johannes Kepler was born on December 27, 1571, in [|Weil], Germany. His paternal grandfather, Sebald Kepler, was a respected craftsman who served as mayor of the city; his maternal grandfather, Melchior Guldenmann, was an innkeeper and mayor of the nearby village of Eltingen. His father, Heinrich Kepler, was "an immoral, rough and quarrelsome soldier," according to Kepler, and he described his mother in similar unflattering terms. Johannes was their first child. From 1574 to 1576 Johannes lived with his grandparents; in 1576 his parents moved to nearby [|Leonberg] , where Johannes entered the Latin school.

Galileo’s work in the 17th century helped unlock many secrets of astronomy and natural motion. Galileo's achievements include: building the first high-powered astronomical telescope; inventing a horse-powered pump to raise water; showing that the velocities of falling bodies are not proportional to their weights; describing the true parabolic 2 paths of cannonballs and other projectiles; coming up with the ideas behind [|Newton's] laws of motion; and confirming the Copernican theory of the solar system. His works include Sidereus Nuncius (The Sidereal Messenger, 1610), Il saggiatore (The Assayer, 1623), and Dialogo sopra i due massimi sistemi del mondo tolemaico, e copernicano (Dialogue Concerning the Two Chief World Systems, 1632). Following a papal trial in which he was found vehemently suspect of heresy, Galileo was placed under house arrest and his movements restricted by the Pope. From 1634 onward he stayed at his country house at [|Arcetri], outside of Florence. He went completely blind in 1638 and was suffering from a painful [|hernia] and [|insomnia], so he was permitted to travel to Florence for medical advice. He continued to receive visitors until 1642, when, after suffering fever and heart palpitations, he died. || __Major Discoveries/ Achievement and its Significance__ He thought that if the heliocentric system was used instead of the geocentric system, the calculations of astronomy would be easier, the odd movements of the planets when they were revolving around the sun could be explained and the calendar would become correct. In the end, he published his ideas, thoughts and findings in a book called De Revolutionibus Orbium Coelestium. ||
 * **Galileo Galilei** ||
 * The italian scientist, Galileo Galilei was born in Pisa, Italy, on February 15, 1564. Galileo Galilei's parents were Vincenzo Galilei and Guilia Ammannati. Galileo was their first child and spent his early years with his family in Pisa. The family moved to Florence, Italy, in 1574. That year Galileo started his formal education in the nearby monastry 1 of [|Vallombrosa] . Seven years later he studied medicine at the University of Pisa. In 1583 Galileo developed new interests and began his studies in mathematics and physics, which ended his medical studies. Because of financial difficulties, Galileo had to leave the University of Pisa in 1585 before earning his degree.
 * **Achievement** || The Publishing of De Revolutionibus Orbium Coelestium (On the Revolutions of Celestial Bodies), written by Nicolaus Copernicus ||
 * || During the time around the 16th century, calendars were not correctly aligned with the seasons and the major days for celebration were not on the accurate date on the calendar. Therefore, in order to solve this problem and to simplify the explanation of the planets and the sun in the universe, Nicolaus Copernicus rediscovered the idea of a sun-centred system which was thought by Aristarchus, centuries before Nicolaus Copernicus was born.
 * **Significance** || * Though he could not succeed in formulating his system quite logically, yet it was his heliocentric theory that prompted geniuses like Newton, Galileo and Kepler to develop a new celestial mechanics in the 17th century.
 * Calendar would become correct and time is easier to follow.
 * The Copernican system by banishing the idea that the Earth was the center of the Solar System, immediately led to a simple explanation of both the varying brightness of the planets and retrograde motion:
 * 1) The planets in such a system naturally vary in brightness because they are not always the same distance from the Earth.
 * 2) The retrograde motion could be explained in terms of geometry and a faster motion for planets with smaller orbits, as illustrated in the following animation. ||

When Kepler left his teaching post at Graz, he moved to Prague and started to work with the renowned Danish astronomer, Tycho Brahe. He also became Tycho Brahe’s assistant. After Tycho Brahe died in 1601, he inherited Tycho's post as Imperial Mathematician. Before Tycho Brahe’s death, he was tasked by him to analyse the data and observations he had made of Mars. Initially, he thought that the orbits of planets were in perfect circles. However, many difficulties arose when he was calculating the position of the planet. Of all the planets, the predicted position of Mars had the largest errors and therefore this posed the greatest problem. As Kepler had studied the work on conic sections by the ancient Greek geometer Apollonius, he knew about the idea that the circle, the ellipse, the parabola and the hyperbola could be all generated by a continuous process of cutting the cone at different angles, for example cutting the cone in a slanted way. Kepler was interested in this idea and he thought that the orbits of the planets could be in another shape, like the ellipse, which looked like a tilted oval. Since Tycho’s data and observation were accurate and precise, Kepler managed to show that Mars’ orbit would accurately fit an ellipse. From here, Kepler discovered that the orbit of Mars was an ellipse and this suggested that the orbits of other planets were elliptical too instead of in perfect circles. This resulted in the discovery of elliptical orbits. ||
 * **Discovery** || The Discovery of Elliptical Orbits by Johannes Kepler (1605 – 1609) ||
 * || Many astronomers who lived before the discovery that orbits are elliptical, like Nicolaus Copernicus, believed that the planets’ orbits were in perfect circles. However, a German astronomer, Johannes Kepler eventually discovered and proved that the planets’ orbits were elliptical.
 * **Significance** || * They also provided one of the foundations for [|__Isaac Newton__] 's theory of [|__universal gravitation__].
 * People weren't ready to accept that the Earth wasn't the center of the universe and couldn’t understand the motions of the planets. His research revolutionized astronomy. ||

In 1609 Galileo heard about a new instrument had been invented in the Netherlands that allow the objects which are far away seem closer to the observer. Galileo tried to create the instrument using a variety of lenses and finally, he succeeded in making a basic telescope. After some attempts, he produced a telescope that made objects appear 1 000 times larger and more than thirty times closer than seen with the naked eye. As he was most interested in its use to look at the skies, he looked at the sky through the telescope. On 7 January 1610, Galileo saw three very bright objects which were near to Jupiter and he thought that those bright object were stars. After observing these over a number of nights, he noticed that the pattern changed and on January 13 1610, a fourth bright object became visible. After a few weeks, Galileo had observed that the four bright objects never left the vicinity of Jupiter and appeared to be carried along with the planet. They also changed their position with respect to each other and Jupiter. Finally, Galileo concluded that what he was observing were not stars, but planetary bodies that orbit around Jupiter. The observation of the sky through his telescope let Galileo Galilei discover that Jupiter has moons. || References: __[]__ __[|http://www.biography-center.com/biographies/697-Copernicus_Nicolaus.html] [|http://www.biographybase.com/biography/Ferrara_Domenico_Maria_Novara_da.html] [|http://www.notablebiographies.com/Co-Da/Copernicus-Nicolaus.html#ixzz0f7J6L0ma] [|http://en.wikipedia.org/wiki/Nicolas_Copernicus] [|http://starchild.gsfc.nasa.gov/docs/StarChild/whos_who_level2/brahe.html] [|http://Galileo.phys.Virginia.EDU/classes/109N/1995/lectures/tychob.html] [|http://www.absoluteastronomy.com/topics/Johannes_Stadius] [|http://www.danskekonger.dk/eng/biografi/FreII.html] [|http://www.rosenborgslot.dk/v1/genstand.asp?GenstandID=11&countryID=2] [|http://www.notablebiographies.com/Jo-Ki/Kepler-Johannes.html] [|http://www-history.mcs.st-and.ac.uk/Biographies/Kepler.html] [|http://galileo.rice.edu/sci/kepler.html] [|http://chestofbooks.com/reference/American-Cyclopaedia-4/Emperor-Of-Germany-Rudolph-II.html] [|http://en.wikipedia.org/wiki/Weil_am_Rhein] [|http://en.wikipedia.org/wiki/Leonberg] [|http://en.wikipedia.org/wiki/Galileo_Galilei] [|http://www.notablebiographies.com/Fi-Gi/Galileo.html] [|http://www.answers.com/topic/galileo-galilei] [|http://www.gap-system.org/~history/Biographies/Galileo.html] [|http://www.britannica.com/EBchecked/topic/622365/Vallombrosa] [|http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005b61_25.pdf] [|http://csep10.phys.utk.edu/astr161/lect/retrograde/copernican.html] [|http://www.wikipedia.org] [] [] [] []__ Raffles Girls School (Secondary) Secondary 3 History Notes on Scientific Revolution __[] [] []__ __[|http://physics.ucr.edu/~wudka/Physics7/Notes_www/node41.html]__
 * **Discovery** || The Discovery of Jupiter has Moons by Galileo Galilei (1609 – 1612) ||
 * || Another major discovery and achievement in the field of astronomy during the Scientific Revolution is the discovery that Jupiter has moons by a famous Italian astronomer, Galileo Galilei.
 * **Significance** || * Galileo’s discovery showed the importance of the telescope as a tool for astronomers by proving that there were objects in space that cannot be seen by the naked eye.
 * This incontrovertible discovery of celestial bodies orbiting something other than the Earth dealt a serious blow to the then-accepted [|__Ptolemaic world system__], or the geocentric theory in which everything orbits around the [|__Earth__] . ||