Seeing+Stars-+From+Copernicus+to+Galileo

Timeline of Key Events from Copernicus to Galileo ** 1473 -- Nicolas Copernicus (1473-1543) born. 1514 -- The initial appearance of the heliocentric theory of Nicholas Copernicus (1473-1543) is associated with the private circulation of a manuscript known as the // Commentariolus // (The Little Commentary) which was published many years later. 1522 -- Ferdinand Magellan famously completes the first circumnavigation of the globe. 1532 -- Peter Apian (1495-1552) and Fracastoro observe that the tail of the comet his year, later known as Halley's Comet, pointed away from the sun, a detail also recognized by Regiomontanus. 1540 -- Georg Joachim Rheticus (1514-1574), a friend of Copernicus and the presumed author, provides an account of the heliocentric hypothesis in his // Narratio prima // (First Account). 1543 -- One of the most famous publications in natural philosophy was the anatomical book of Andreas Vesalius (1514-1564), // De fabrica (On the Fabric of the Human Body) //. It was arguably the most important anatomical texts of the century, at once criticizing the work of the ancients, principally Galen, which offering new illustrations based on first-hand observation and fresh dissections.In the same year appeared Copernicus' heliocentric theory' in his // De revolutionibus orbium coelestium // (// On the Revolutions of the Celestial Spheres //), by one tradition, these two works, if only symbolically, launched the 'Scientific Revolution'. 1551 -- Deriving his results from Copernicus' data and planetary models, the German astronomer Erasmus Reinhold (1511-1553) publishes his // Prutenic Tables //, which for many astronomers replaced the outdated efforts associated with the Alphonsine Tables (1252). Reinhold's efforts were not seriously challenged until Kepler Rudolphine Tables, which were based on Tycho's data and Kepler's new calculation methods.Founding of the Collegio Romano, as a Jesuit university, many of whose teachers and students were active scientists during the Scientific Revolution. 1554 -- Long considered a major precursor to Galileo Galilei, the Italian Giovanni Battista Benedetti (1530-1590) opposed the work of Aristotle arguing that freely falling bodies move with speeds proportional to weight. 1564 -- Galileo Galilei born at Pisa, Italy, February 16; 1572 -- A famous year known for 'Tycho's Star' or the 'Star of 1572' witnessed a dramatic supernova, the talk of Europe. Tycho published // De nova stella // in the following year, 1573. The star blazed for 18 months as brightly as -4 magnitude. Its key importance, by tradition and as Tycho and others argued, was that the New Star was clearly located beyond the sphere of the Moon. If this were so, it would undermine the Scholastic belief, adapted from Aristotle, that the heavens were immutable. 1576 -- An early account of Copernicus's heliocentric theory, and a description of the cosmos and distribution of the stars as infinitely extended, is offered by the Englishman Thomas Digges (c.1546-1595) in the appendix to a work by his father, Leonard Digges, possibly a Copernican himself. An infinity of stars may have suggested to some the possibility of a plurality of worlds, which in turn eventually raised theological concern. In this year construction began on the observatory made famous by Tycho Brahe's (1541-1601), Uraniborg, the 'Fortress of the Heavens, on the Danish island of Hven (now a possession of Sweden). Here Tycho made observations and collected astronomical data aided, over a period of nearly twenty years, by some 48 assistants. 1577 -- The year of the 'Comet of 1577' made famous by Tycho Brahe, and again challenging a central tenet inherited from Aristotle, that the celestial spheres were 'solid' perhaps even crystalline. Because the path of the comet seemed to many astronomers to be above the sphere of the moon (that is, superlunary) the apparent path of the comet would 'shatter' anything in its path. If Tycho's observations 'shattered the crystalline spheres' then a reasonable question might be 'What moves the planets'. 1588 -- Although steeped in controversy, the geo-heliocentric model of Tycho Brahe was brought to light in 1588. Here Brahe argued for a model whereby the planets are imagined to revolve around the Sun while, in turn, the Sun revolved around the fixed, central earth. 1596 -- In his first publication in astronomy, Johannes Kepler's // Cosmographic Mystery // presented a stridently Copernican worldview dedicated to drawing together mathematical astronomy, physics, and a quasi-Pythogorean religious perspective in hope of a new astronomy. 1599 -- Tycho Brahe, having been ousted from Uraniborg by the King of Denmark, moves to Benateky, outside Prague, under the patronage of Rudolph II, Emperor of the Holy Roman Empire. 1601 --Tycho Brahe dies 24 October in Prague and Kepler soon appointed Imperial Mathematician on 6 November; Kepler was able to retain Tycho's astronomical data following a lawsuit with Tycho's heirs. 1604 -- In optics, Johannes Kepler publishes his // Ad vitellioem paralipomena quibus astronomiae pars optica traditor // (// The Optical Part of Astronomy //) where he argues that light rays are rectilinear, that they diminish in intensity by the inverse square of their distance as they travel from the light source. Kepler also argues that the retina is the seat of vision, and it is there that a 'pictura' is formed, an inverted image that is somehow transmitted to the 'seat of judgment'. 1607 -- Galileo Galilei (1564-1642) demonstrates that a projectile follows a parabolic path. 1609 -- Galileo Galilei constructs his first telescope and turns it toward the heavens; his instruments begin at magnifications of approximately 3X and 10X, the most powerful achieving a magnification of 30X, an instrument he eventually gave away as a gift. Johannes Kepler's (1571-1630) // Astronomia nova // (// New Astronomy //) shows that Mars moves non-uniformly in an elliptical path and proposes a quasi-magnetic power or virtue emanating from the sun (a curious bi-polar magnet) as partial explanation for the planetary motions. 1610 -- In his highly influential // Sidereal Messenger //, Galileo Galilei publishes his telescopic findings with subtle Copernican twists. Among his observations, Galileo argues there are innumerable stars invisible to the naked eye, mountains on the Moon (which he eventually measures), and four moons circling Jupiter. These observations were made for the most part in 1609; later in 1610 Galileo observes the phases of Venus, which suggested to him that waning and waxing planet must circle the Sun. Further, Galileo noted that Saturn appeared to have 'handles' (anses) and troubled over what could give rise to such an appearance; Huygens would later propose a brilliant hypothesis which served as one of the most subtle arguments for the motion of earth. 1611 -- Johannes Kepler's // Dioptrics // analyzes optical refraction and proposes a practical means to improve the Galilean telescope. 1613 -- In his // Letters on Sunspots // Galileo took exception with the views presented by the Jesuit astronomer, Christopher Scheiner (1573-1650). Here Galileo appears clearly in the Copernican camp and also provides an early formulation for the principle of inertia. 1614 -- In mathematics, John Napier (1550-1617) in his // Mirifici logarithmorum canonis descripto //(// Description of the Wonderful Principle of Logarithms //) establishes rules for logarithms and supplies useful tables. 1616 -- The year of the infamous Injunction against Galileo, the famous Italian astronomer is warned by the Inquisition not to hold or defend the hypothesis asserted in Copernicus' // On the Revolutions //, though it has been debated whether he was admonished not to 'teach in any way' the heliocentric theory. This work was in turn placed on the Index of Prohibited Books until corrected. 1618 -- A famous 'controversy on comets' erupted in this year involving Galileo and prominent Jesuit astronomers. 1619 -- Johannes Kepler's // Harmonice mundi // (// Harmonies of the World //) presents his so-called 'Third Law' which draws attention to the relationship between the annual periods of the planets and their mean distances from the sun. 1622 -- Tommaso Campanella (1568-1639) published his // Apologia pro Galilaeo // writing in support of Galileo's Copernicanism and providing supporting arguments, among many other things, for the relationship between science and religion. Christian Severin (Longomontanus) (1563-1647), Tycho Brahe's former assistant, reminds astronomers of the geometrical equivalence of the Ptolemaic, Tychonic, and Copernican models; Longomontanus devises a simple variation on the Tychonic model by retaining Tycho's configuration but asserting that the central earth rotated daily, thus removing that requirement for the sphere of fixed stars. 1623 -- Galileo publishes his strategic essay, // The Assayer // where he argues against Aristotle and the Scholastics in favor of mathematical and experimental methods, moving deftly across many topics, from statics and dynamics to his theory of matter. 1627 -- Johannes Kepler's // Rudolphine Tables //, based on Tycho's data and his own laws of planetary motion, provide the most accurate astronomical tables up to that time. 1631 -- Pierre Gassendi, familiar with Kepler's astronomical tables, becomes the first to observe a transit of the planet Mercury across the disc of the sun. His data for Mercury were used by Boulliau in his // Astronomia Philolaïca // (Paris 1645). 1632 -- In one of the major publications of the century, Galileo's // Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican // argues for a Copernican system; Galileo uses every tactic available to him, drawing on his telescopic findings, his new view of motion, and not a little rhetorical skill. 1633 -- Galileo is called before the Inquisition in Rome; he is vehemently suspected of heresy for supporting and teaching the Copernicanism hypothesis. After he abjured, Galileo was placed under house arrest for the remainder of his life, his visitors, his mail, and his daily actions were monitored. While the// Dialogue on the Two Chief World Systems // was placed on the Index of Prohibited Books, Galileo lived to see it translated into Latin, for a larger European audience, and he also saw his second major work, the // Discours on the Two New Science // published (Leiden, 1638). 1634 -- Kepler's // Somnium // (// The Dream //) was published after his death, a fanciful account of a voyage to the Moon. The work provides subtle arguments for the Copernican hypothesis and is arguably among the first pieces of 'science fiction' writing. 1638 -- Galileo's second major book, the // Discours on Two New Sciences //, was published outside of Italy in Protestant Leiden. The work drew together much of Galileo's earlier efforts on the problem of motion; the second 'new science' (where Galileo, in retrospect, was less successful) dealt with the strength of materials. The Englishman John Wilkins (1614-1672) published his // Discovery of a World in the Moone //, a curious work that drew together many of the findings of Kepler and Galileo into an imaginative landscape. Aimed at what might be called the general reader, Wilkin's book (perhaps like Kepler's // The Dream //) lays claim to one of the earliest writings in 'science fiction'. 1639 -- The first observation of a transit of Venus across the Sun, a rare phenomenon used in the eighteenth and nineteenth centuries for determining the distance of the earth from the Sun, is made by the brilliant but short-lived Jeremiah Horrocks (1618-1641) at Toxteth Park near Liverpool. Few others offered observations of this telling event, as sky conditions were not favorable on the continent, certainly not in France. 1641 -- René Descartes' // Meditations // presents his famous (or infamous) 'grand bi-furcation of the universe', that is, his dualistic metaphysical belief in // res cogitans // (mind) and // res extensa // (matter), the foundational belief of mechanistic natural philosophy. Source : []
 * Seeing Stars: From Copernicus to Galileo **
 * Done by: Michelle Ng, Hu Lingyi, Tsai Min Yi, Pavithra R, and Kimberly Ho **

           Who were the persons involved? Provide a brief biographical write-up about them.
 * Nicolaus Copernicus(1475 - 1543) lived from 19 February 1473 to 24 May 1543, and was one of the first recognized astronomers to formulate a comprehensive heliocentric cosmology. He was one of the researchers “summoned” to try to solve the problem of the calendar going out of sync with the stars. As a faithful Christian as well as mathematician, he found it hard to believe that God would create such a complicated and messy world, with such complicated calculations involved. As a result, he came up with his heliocentric model of the universe, which was more elegant as well as offered a more simple and accurate explanation of the movement of the stars. Although Copernicus was quite conservative and refuse to reject some old ideas, his heliocentric model paved the way for future scientific investigations. **


 * Tycho Brahe (1546 – 1601)** was a Danish nobleman who was famous for making very accurate planetary recordings. No one before Tycho had attempted to make so many planetary observations. These observations were used by his assistant Keplar to derive the laws of planetary motion. Although Brahe still stuck to the geocentric model, he had his old system called the “Tychonic” system, which proved to be more successful than the old Ptolemaic system, as well as avoided the flaws in the Copernican system.


 * Johannes Kepler (1571 –1630)** was a German mathematician, astronomer and astrologer, and key figure in the 17th century scientific revolution. He is best known for his eponymous laws of planetary motion, codified by later astronomers based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican Astronomy. They also provided one of the foundations for Isaac Newton's theory of universal gravitation.

Kepler lived in an era when there was no clear distinction between astronomy and astrology. AS he was a religious man, he also included religious arguments into his work. He described his astronomy as “celestial physics”. He discovered that the Earth and planets travel about the sun in elliptical orbits. He gave three fundamental laws of planetary motion. He also did important work in optics and geometry.

Kepler was born in the small town of Weil der Stadt in Swabia and moved to nearby Leonberg with his parents in 1576. His father was a mercenary soldier and his mother the daughter of an innkeeper. Johannes was their first child. His father left home for the last time when Johannes was five, and is believed to have died in the war in the Netherlands. As a child, Kepler lived with his mother in his grandfather's inn. Kepler's early education was in a local school and then at a nearby seminary, from which, intending to be ordained, he went on to enrol at the University of Tübingen, then (as now) a bastion of Lutheran orthodoxy.


 * Galileo Galilei(1564 - 1642)** was an Italian [|physicist], [|mathematician], [|astronomer], and [|philosopher] who played a major role in the [|Scientific Revolution]. He has been called the “father of observational astronomy”. He improved the telescope and used it to observe the phases of Venus and also discovered the four largest satellites of Jupiter.

His father was a musician and wool trader, who wanted his son to study medicine as there was more money in medicine. At age eleven, Galileo was sent off to study in a Jesuit monastery. After four years, Galileo had announced to his father that he wanted to be a monk. This was not exactly what father had in mind, so Galileo was hastily withdrawn from the monastery. In 1581, at the age of 17, he entered the University of Pisa to study medicine, as his father wished.      <span style="font-family: arial,helvetica,sans-serif; font-size: 13px; font-weight: normal; line-height: 20px;"> <span style="font-family: arial,helvetica,sans-serif; font-size: 13px; font-weight: normal; line-height: 20px;"> <span style="font-family: arial,helvetica,sans-serif; font-size: 13px; font-weight: normal; line-height: 20px;"> <span style="font-family: arial,helvetica,sans-serif; font-size: 13px; font-weight: normal; line-height: 20px;"> <span style="font-family: arial,helvetica,sans-serif; font-size: 13px; font-weight: normal; line-height: 20px;">**

What were the major discoveries and acheievements and why were these discoveries and achievements important and/or significant? **                    - - Third law helped Newton form theory for law of universal gravitation. - Destroyed Ptolemic system, freed people to think in new ways regarding planetary motion. - Defined a new problem: why are planetary orbits elliptical/ and why are planets orbiting at all. || - Combined abstract maths and practical experiments to produce a new physics to explain how objects moved “normally” on moving earth - Increased use of mathematics to explain physical nature. || - Provided solid proof that the earth is not the only one with stuff (moons) in orbit around it. - opened people’s minds to using math to describe phenomenon - published works made people more aware of new idea of universe. (eg copernician theories and new ideas about planetary motion) || [] __ Personal Information __ - Born in Poland
 * || What contributions/achievements || Significance of achievements/contributions ||
 * Johannes Kepler || - Three laws of planetary motion
 * 1) Every planet follows an elliptical orbit around the sun.
 * 2) An imaginary line from the center of the sun to the center of a planet sweeps out the same area in the same given time. One way of understanding this is by picturing it as planets move faster when they are closer to the sun, so even though they are closer so the area they sweep out would seem less, it is the same because in the same time frame the planet covers more distance.
 * 3) The square of a planet's period (year) is proportional to the cube of its distance from the sun: [[image:file:///C:/DOCUME~1/ADMINI~1/LOCALS~1/Temp/msohtml1/01/clip_image001.jpg width="72" height="23" caption="p^2 is proportional to r^3"]] || - - Solved the problem of planetary motion.
 * Galileo Galilei || - Used telescope to look at night sky, observed sunspots and moon craters. And Jupiter’s moons.
 * Nicolaus Copernicus ** (1475-1543)

- Studied first in Krakow (Poland), then in Bologna and Padua (Italy)

- Faithful Christian, conservative. __ Motivations for contributions __ - Felt that God would not create a universe as messy and ramshackle as in the theory proposed by his predecessor, Ptolemy.

- Being a Mathematician, he felt that Ptolemy’s Geocentric system was too complex and failed to accord with the observed motions of the heavenly bodies. __ Contributions to the Scientific Revolution __ - Became aware of the ancient view that contradicted the Ptolemic, Geocentric worldview.

- Wrote the famous manuscript: //On the Revolutions of the Heavenly Spheres// which served as an intellectual springboard for a complete criticism of the Geocentric worldview.

- Argued that the Earth and not the Sun moved through the heavens as he felt that if the Sun was in the center of the universe, it made the mathematics involved simpler, made the orbits of the other planets make sense and could put right the calendar.

- Although he retained most of the elements of the Ptolemic model, such as epicycles, he improved on the Ptolemic model to a certain extent. For example, in Copernicus’s model, the epicycles were smaller and he explained the retrograde motion of the planets as optical illusion.

- Argued that the further the planets were from the Sun the longer they took to revolve around it, thus making it easier to determine the order of the planets.

- He did not reject Aristotle’s principle of the existence of heavenly spheres moving in circular orbits and argued that the universe consisted of 8 spheres with the Sun at the center and the sphere of fixed stars at rest in the eighth sphere. Thought the heavenly bodies moved in perfect circles.

- Explained that what appeared to be the movement of the Sun and the stars around the Earth was caused by the movement of the Earth around its axis and the journey of the earth around the Sun. __ Impacts of discoveries __ - Significant shift from Geocentric to Heliocentric worldview.

- Raised serious questions about Aristotle’s astronomy and Physics (despite Copernicus’s adherence to Aristotle)

- Created uncertainty about the human role in the universe as well as God’s location.

- Discoveries came under attack by Protestant reformers, who adhere to a literal interpretation of the Bible.

- As more and more astronomers became attracted to Copernicus’s ideas, they were denounced by the Catholic Church.

- Although he has used no new evidence and although his system was no more accurate than the Ptolemic system, he still provided another way of confronting some of the difficulties inherent in Ptolemic astronomy.

- Although the Copernican system did not replace old astronomy, it allowed those who were also discontented with the Ptolemic view to think in new directions.

- Obtained a simple explanation of heavenly perfection that did away with the clumsiness of Ptolemy’s Mathematical calculations. __ Personal information __ - Danish nobleman
 * Tyco Brahe ** (1546-1601)

- Trained in his youth as an astronomer.

- Drank himself to death. __ Contributions to the Scientific Revolution __ - Rejected Copernican system, advocated Geocentric worldview.

- Observed a completely new star, something that was deemed impossible by Aristotle.

- Built the Uraniborg castle, which he outfitted with a library, observatories; and instruments he had designed for more precise astronomical observations.

- Observed the movements of the whole heavens by carefully mapping out the motion of each significant object in the night sky, accurate to within a tiniest fraction of a degree.

- Collected the finest set of astronomical data ever seen in Europe.

- Rejected the Aristotelian-Ptolemaic system. However, at the same time, he rejected the geocentric worldview. __ Impacts of discoveries __ - Tychonic system was immensely successful.

- Allowed accurate astronomical and astrological to be made more easily than the old Ptolemic system, at the same time, it avoided the upsetting theological implications of the Copernican system, as the Tychonic system supported the Geocentric worldview which was held by the Church.