Scientists of the Scientific Revolution

1. Scientists of the Scientific Revolution Clockwise from top: Kepler, Copernicus, Newton, Galileo, Descartes, and Ptolemy

2. The “Scientific Revolution”

3. Science Challenges the Old Ideas

4. Scientific Revolution” Helio-Centric Theory of the Universe • Sun at the center of the universe, with the planets orbiting the sun • Created by Nicholas Copernicus (1473-1543), a Polish astronomer

5. Discoveries in Astronomy, Physics, and Math • Early scientists • Made significant contributions in astronomy, physics and math • Began to explain complexities of solar system, limits of physical world • Nicolaus Copernicus, Polish astronomer, among first • Copernicus • Found geocentric theory of movement of sun, moon, planets not accurate • Concluded sun, not earth, near center of solar system • Heliocentric theory, earth revolves around sun • Copernicus’ theory • Idea of earth orbiting sun was not completely new • Copernicus developed detailed mathematical explanation of process • Was first scientist to create complete model of solar system

6. On the Revolutions of the Heavenly Spheres • Copernicus’ famous book not published until last year of his life • Knew church would oppose work • Work contradicted teachings of church • Weaknesses of theory • Mathematical formulas did not predict positions of planets well • Copernicus did not want to be ridiculed for weaknesses • Died 1543 after work published, other scientists expanded on ideas

7. Nicholas Copernicus (1473-1543) • Polish priest studied in Italy • returns to Poland and works on Astronomy • writes De Revolutionibus Orbitum Coelestitum (On the Revolutions of Heavenly Spheres) • Earth is just another planet with a 24 hour rotation • retains circular planetary motion (perfection of the sphere).

8. Copernicus • On the Revolutions of the Heavenly Spheres. • Proposed a sun-centered view. (helio-centric) • Universe consisted of 8 spheres. • Planets including earth rotated around the sun but the moon revolved around the earth. • Apparent revolution of the sun and stars around the earth was due to the rotation of the earth. • Did not reject the Ptolemaic vision of the fixed spheres. • His views did not make a big splash either pro or con, but there was growing dissatisfaction with the Ptolemaic view.

9. Nicolaus Copernicus(1473-1543) • Polish astronomer and mathematician • Introduced to scientific world when he attended the University of Krakow in Poland in 1492 • Appointed as a canon in the cathedral of Frauenburg where he remained for the rest of his life • Rheticus, a student Copernicus took on in 1539, convinced Copernicus to allow him to publish his works before death

10. Copernicus’s Scientific Theories: • Considered the founder of modern science • Believed that the earth was round and the earth revolved around the sun (contrary to popular belief) • The heliocentric theory was not new, but Copernicus established the mathematical basis • To avoid the risk of persecution, excommunication, or imprisonment because his were revolutionary and contrary to church beliefs, Copernicus worked in privacy for more than 30 years; just before his death, friends helped to published his work • Copernicus’s theory was first taught in several universities in the 1500s and permeated the scientific world by 1600

11. Copernicus Cont: • “Finally we shall place the Sun himself at the center of the Universe. All this is suggested by the systematic procession of events and the harmony of the whole Universe, if only we face the facts, as they say, 'with both eyes open’.”- Copernicus “The earth also is spherical, since it presses upon its center from every direction.”-Copernicus

12. Nicolaus Copernicus • The Earth moves, in two ways. • It rotates on an axis (period = 1 day). • It revolves around the sun (period = 1 year). ISP 209 - 3A

13. The Copernican Universe

14. The heliocentric model The reasons for seasons – the Earth travels around the sun, and its axis of rotation is tilted by 23.5 degrees to the plane of the orbit. In July, the northern hemisphere is getting more sunlight than in January. ISP 209 - 3A

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16. The Copernican Model ISP 209 - 3A

17. Giordano Bruno: 1548 – 1600 AD • Italian monk • Believed Copernicus was right and that the earth revolved around the sun • Believed the earth was alive because it moves through space • Believed the universe is huge and everything is made up of atoms • He did not do original research; just used reason and speculation. • Bruno wandered around Europe teaching and writing for a living. • He returned to Italy and found trouble

18. Bruno vs the Inquisition • Bruno had been offered a teaching job in Venice and thought his employer would protect him. • Instead, Bruno was arrested by the Inquisition for not supporting the Geo-Centric Theory • After seven years in prison, Bruno was tried as a heretic. • On February 6, 1600, he was burned at the stake for his scientific ideas.

20. Tycho Brahe(1546-1601) • Danish astronomer • Established an observatory to study heavenly bodies • Accumulated a lot of data on planetary movements • His tables of astronomical observation was used by Kepler to prove Copernicus’s helio-centric hypothesis

21. Brahe Cont: • Believed that the development of astronomy relied on accurate observation • Made lots of astronomical observation with the naked eye • Built and calibrated numerous new instruments including: • Created a domicile and observatory which he called Uraniborg

22. Brahe Cont. Uraniborg Azimuth Quadrant made in 1577. Instrument for measuring altitude Instrument to measure angles

23. Observations Kepler, German Mathematician • Brahe used observatories • Developed system to explain planetary movement • Believed sun revolved around earth • Other five known planets revolved around sun • Hired as Brahe’s assistant to form mathematical theory from measurements of planets • Published result of measurements of orbit of Mars after Brahe’s death Brahe and Kepler • Brahe, Danish Astronomer • Wrote book proving bright object over Denmark sky was newly visible star • Called it supernova, distant exploding star suddenly visible on earth • Book impressed Denmark’s King Frederick II • Gave Brahe money to build two observatories

24. Johannes Kepler (1571-1630) • Student of mathematics and astronomy • studied with Tycho Brahe • tested hypothesis after hypothesis until he determined that planets move in ellipses • Three Laws of Planetary Motion • planets move in ellipses with sun as one focus • velocity of a planet is not uniform • equal area of the plane is covered in equal time by the planets.

25. Johannes Kepler—(1571-1630) • Built on the detailed observations of Tycho Brahe. • Confirmed Copernicus’s heliocentric theory • Worked out the laws that governed planetary motion. • Discovered that orbits were elliptical, not circular. • Killed off the Ptolemaic theory of crystalline spheres and a perfect heaven. • Opens the door to the question of what the planets and stars are made of and what governs their motion.

26. Johannes Kepler(1571-1630) • Used Brahe’s work to successfully prove Copernicus’s helio-centric model mathematically • However, he disproved Brahe’s claim that planets move in circular motion – found that they move in ellipses • Discovered that the speed of planets increase as they near the sun and decrease as they go away from it • Discovered three laws of planetary motion • the planets orbit the sun in elliptical orbits; the sun is at one focus of the ellipse • An imaginary line drawn from the center of the sun to the center of a planet will sweep out equal areas in equal intervals of time • The ratio of the squares of the periods of any two planets is equal to he ratio of the cubes of their average distance from the sun • Worked in optics, discovered two new regular polyhedra, created the first proof of logarithms, and created a way to find the volume of solids of revolution (which influenced calculus) • Proof of logs based off of the work of Napier and Euclid

27. Kepler Cont.: • Very religious (protestant); believed in Intelligent Design, and that God made the Universe according to a mathematical plan • Math was considered a way to find truth, so Kepler thought that this gave man a way to find and understand the truth of the Universe • Worked as an aide to Tycho Brahe and continued Brahe’s work and used it in his own work • Established the idea of observational error

28. Johannes Kepler (1571 – 1630) … discovered three empirical laws of planetary motion in the heliocentric solar system • Each planet moves on an elliptical orbit. • The radial vector sweeps out equal areas in equal times. • The square of the period is proportional to the cube of the radius. (needed for the CAPA) ISP 209 - 3A

29. How did Kepler determine the planetary orbits? Compare the heliocentric model to naked-eye astronomy Mars The inner planet is Earth; the outer one is Mars. Plot their positions every month. Mars lags behind the Earth so its appearance with respect to the Zodiac is shifting. Earth The most complete data had been collected over a period of many years by Kepler’s predecessor, Tycho Brahe of Denmark. ISP 209 - 3A

30. KEPLER “And to us Jupiter, like Mars, and in the morning Mercury and Sirius, appeared four-cornered. And one of the diameters running between the corners was blue, the other red, in the middle the body was yellow, and amazingly bright.Account of personal observations...:” Instrument to show relative distances of planets according to Copernican System

31. Kepler’s Solution Kepler solved main problem of Copernican theory • Copernicus assumed planets orbited in circle • Kepler found assumption untrue • Proved planets orbited in oval pattern, ellipse • Wanted to prove Copernicus wrong, instead proved heliocentric theory correct • Kepler’s mathematical solar system model also correct

32. Galileo Galilei (1564-1642) • Astronomy • used a telescope, proved the heavens are not perfect (craters on moon) • supported Heliocentric system • Laws of Motion • dropping weights from the Tower of Pisa • imagined motion without constraint!!!! • Thought of inertia • Problems with the church • argues for separation of science and theology because we are endowed with reason • 1633 banned by Church and house arrest • must recant heliocentric system to save neck.

33. Reactions to Galileo • Italy and Spain • More freedom in France, England and Holland • University of Padua was under Venice, the most anti-clerical state in Europe; Copernicus, Galileo and Harvey studied there • Protestants as hostile as Catholics on Biblical grounds, less state control in Protestant nations and in the end Protestant nations become more liberal than at first.

34. Galileo Galilei: 1564 – 1642AD • Italian • Was a Professor of Mathematics at Pisa University • Became interested in science after reading the works of Copernicus and Bruno • These books convinced him that the earth revolved around the sun. • He also made huge discoveries in physics. • He proved that a pendulum swings the same time no matter the size. • He used mathematical rules to explain this; it was the first time math had been used to describe an object in motion.

35. Galileo • In 1609, he switched from being a physicist to being an astronomer. • He heard about the newly-invented telescope and built his own. • He used it to discover 4 moons of Jupiter and the mountains on the moons. • These discoveries proved once again that Aristotle’s theories were wrong. • The moon wasn’t a perfect round ball as the ancient Greeks believed, but had bumps and craters.

36. Galileo Continued • Watched as the planets Venus and Saturn travel around the sun • This proved that the Earth was not the center of the solar system. • Galileo wrote a book in 1610 about his discoveries • This is where his trouble with the Catholic Church begins.

37. Galileo Galilei: • In 1609 Galileo built his own telescope to observe the night skies • Galileo worked with Kepler who discovered by using convex lens it would increase the magnification • Galileo’s telescope developed in 1609, modeled based off other telescopes • Could magnify three times more than other telescopes; his later telescope magnified twenty times • He could see the moon, four satellites, a supernova, the phases of Venus, and sunspots

38. Galileo Galilei (1564-1642) • First European to make systematic observations of the heavens using a telescope. • Established that the planets were made of material stuff quite similar to the earth. • The Starry Messenger. • Publicized the shift in scientific thinking away from the Ptolemaic view.

39. Galileo Galileo (1564-1642) • The Starry Messenger • Published in 1610 • Stunned contemporaries and did more to make Europe aware of the new picture of the universe than the mathematical theories of Copernicus and Kepler • Galileo, the Church and Inquisition • Dialogue on the Two Chief World Systems: Ptolemaic & Copernican • Placed under house arrest and during his final eight years Galileo studied mechanics discovering the principles of inertia & force

40. Science and the Church • Galileo’s Theories • Brought him into direct conflict with the church • Church leaders pressured him not to support ideas of Copernicus • Dialogue concerning Two Chief World Systems, 1632, showed support • Trial • Pope Urban VII ordered Galileo to Rome to stand trial before Inquisition • Church wanted to stamp out heresy, or dissenting views • Trial held, April 1633 • House Arrest • Galileo stated would not use Copernican theory in work • Received lenient sentence in return • Pope ordered Galileo under house arrest, where he spent rest of life

42. Galileo and the Church • In 1616, Galileo promised to give up his ideas. • But he then published a book making fun of the Catholic’s teaching of the Geo-Centric Theory. • In his book, he uses a fictional dialogue or conversation to make fun of the Church. • The character who backed the Church’s views was called Simplicius, which means stupid. • In 1633 after a series of warnings against his teaching, Galileo was put on trial before the Inquisition • The charge was heresy with the likely punishment of death • He was 70 years old at the time

43. Galileo’s Letter to Castelli “I am inclined to think that the authority of Holy Scripture is intended to convince men of those truths which are necessary for their salvation, and which being far above man's understanding cannot be made credible by any learning, or any other means than revelation by the Holy Spirit.  But that the same God has endowed us with senses, reason, and understanding, does not permit us to use them, and desires to acquaint us in any other way with such knowledge as we are in a position to acquire for ourselves by means of those faculties, that it seems to me I am not bound to believe, especially concerning those sciences about which the Holy Scriptures contain only small fragments and varying conclusions; and this is precisely the case with astronomy, of which there is so little that the planet are not even all enumerated....”

44. Galileo and the Church • Some historians believe Galileo was tortured, because he suffered from weakened muscles in his gut from the stretching rack. • Others say he was just shown the torture chamber to scare him. • To save his life, Galileo confessed that the Earth did not go around the sun. • According to legend, he muttered under his breath: “But it still moves.” • He was sentenced to life imprisonment and ended up locked in his own home where he went blind and had to give up his scientific work.

45. Galileo the Heretic • Church found his findings dangerous. Why? • Removed Humans from the center of the earth, • Did away with the perfection of circular orbits and • No longer had God in a fixed place. • Inquisition condemns this view; he recants under pressure. • Is placed under house arrest for the last 8 years of he life. • Attitude of the church crimped further scientific inquiry into the heavens in Italy

46. Galileo + Church: • While at the University of Padua, Galileo became very much involved with Copernicus’s heliocentric theory of the universe • Galileo’s invention of the telescope enabled him to make observations that supported and proved the Copernican theory and encouraged him to publicly support it • For this and for other letters, works, etc. that criticized the scripture as simply symbolical, Galileo was summoned to Rome where he was tried by the Inquisition in 1633 • They forced him to recant his belief in the Copernican Theories • In April of 1633 Galileo is interrogated before the Inquisition. He agrees to plead guilty to a lesser charge in exchange for a more lenient sentence. • Galileo was sentenced to house arrest in Siena • Only in 1992 did the Church officially admit their mistake with the Galileo Trial • The Trial caused fear among scientists and encouraged them to keep their findings from the Church and thus from the public • In February 1632, Galileo published his book, Dialogue Concerning the Two Chief Systems of the World – Ptolemaic and Copernican

47. Galileo’s Forced Statement I, Galileo, son of the late Vincenzo Galilei, Florentine, aged seventy years, arraigned personally before this tribunal, and kneeling before you, Most Eminent and Reverend Lord Cardinals, Inquisitors-General against heretical depravity throughout the entire Christian commonwealth, having before my eyes and touching with my hands, the Holy Gospels, swear that I have always believed, do believe, and by God's help will in  the future believe, all that is held, preached, and taught by the Holy Catholic and Apostolic Church. But whereas -- after an injunction had been judicially intimated to me by this Holy Office, to the effect that I must altogether abandon the false opinion that the sun is the center of the world and immovable, and that the earth is not the center of the world, and moves, and that I must not hold, defend, or teach in any way whatsoever, verbally or in writing, the said false doctrine, and after it had been notified to me that the said doctrine was contrary to Holy Scripture -- I wrote and printed a book in which I discuss this new doctrine already condemned, and adduce arguments of great cogency in its favor, without presenting any solution of these, and for this reason I have been pronounced by the Holy Office to be vehemently suspected of heresy, that is to say, of having held and believed that the Sun is the center of the world and immovable, and that the earth is not the center and moves: 

48. Galileo’s Abjuration before the Inquisition, 1633 …because I have been enjoined, by this Holy Office, altogether to abandon the false opinion which maintains that the sun is the center and immovable, and forbidden to hold, defend, or teach, the said false doctrine in any manner… therefore, with a sincere heart and unfeigned faith, I abjure, curse, and detest the said errors and heresies, and generally every other error and sect contrary to the said Holy Church; and I swear that I will never more in future say, or assert anything, verbally nor in writing, which may give rise to a similar suspicion of me; but that if I shall know any heretic, or any one suspected of heresy, I will denounce him to this Holy Office, or to the Inquisitor and Ordinary of the place in which I may be. 

49. Galileo’s sketch of the moon as seen from his telescope A photograph of the moon “What do you think of the foremost philosophers of this university? In spite of my oft repeated efforts and invitations, they have refused, with the obstinacy of a glutted adder, to look at the planets or Moon or my telescope.” (letter to Kepler) ISP 209 - 3A

50. Galileo • Scenes from the Trial of Galileo Replica of Galileo’s Telescope