Ancient Astronomy

1. Ancient Astronomy

2. Standards & Elements S6E1. Students will explore current scientific views of the universe and how those views evolved. • a. Relate the Nature of Science to the progression of basic historical scientific models (geocentric, heliocentric) as they describe our solar system, and the Big Bang as it describes the formation of the universe.

3. Today’s Agenda • Do the nine questions I said I would put up • Work on the timeline or book for next week • Do two KIMs. Format is

4. KIM Format

5. Astronomy Questions • What is Astronomy?
 • Define: Heliocentric & Geocentric
 • What theory did Galileo overturn?
 • What did Galileo study to lead him to his heliocentric theory?
 • Who was the FIRST astronomer to present the heliocentric model?
 • The Big Bang describes the beginning of the __________.
 • Give a brief summary of the Big Bang Theory.
 • What evidence do we have that proves the Big Band theory?
 • What is the universe continuing to still do today?

6. Astronomy Project Science Story: Create a book that tells the History of Astronomy. Requirements: • Your book must have a cover, color, writing, and artwork on each page. • Scientific information is very important. Emphasize it. • 2D Art - Create a timeline (with graphics) outlining all of the astronomers and their theories. Include years and descriptions of each one. Use sources such as the internet and the textbook. • You must include the following terms/people: views of ancient civilizations (min 2 ea),the Greeks, heliocentric, geocentric, Galileo, Tycho Brahe, Ptolemy, Copernicus, Kepler and Newton.

7. The Earliest Known Astronomy Early cultures were interested in astronomical observations for purposes of time keeping, religion, astrology, etc. Sumerians 5000BC Babylonian 3000 BC Ancient Britain 2500 BC (Stonehenge) Chinese 2000 BC Hindu 1500 BC Mesoamerican 500 BC (Chichen Itza)

8. Sumerians 5000BC • Life came from the oceans. • Oceans were eternal. • Observed moon • Moon god named Nanna. • Calendar based on 12 lunar cycles in a year.

9. Genesis 4000 BC • In the beginning God created the heaven and earth. (obviously God is a baseball fan.) • And the earth was without form, and void; and darkness was upon the face of the deep… The Creation of the Stars and Planets 1508-1512, Fresco, Sistine Chapel, The Vatican, Rome http://egghead.psu.edu/~nlf2/Ren.art/miche6.html

10. Babylonian 3000 BC • Continuation of Sumerian astronomy. • Made sky maps of the stars that were later used to determine precession of the equinoxes. • Developed an accurate solar calendar. • Divided sky into 12 zones around the ecliptic (Zodiac). • Developed astrology. http://www.phys.uu.nl/~vgent/babylon/babybibl.htm

11. Egyptian • Sky goddess, Nut, pulled land from the ocean god, Nun. • Commemorated in the pyramids of Egypt. • Worshiped Ra, the Sun god. • Sun based calendar, which is better than a lunar calendar.

12. Stonehenge 2500 BC Midwinter http://www.english-heritage.org.uk/stonehenge/ Moonrise

13. Chinese 2000 BC • Emperors Hu and Shu created human life from Chaos. • Lightening bolts sent though Chaos’s body for 7 days to make holes for seeing, hearing, etc. • The earth was flat and covered by a huge canopy of stars. • China was center of the world. http://www.humboldt.edu/~teg1/syllabus/465/cosmo.html

14. Hindu 1500 BC • Dome shaped earth. • Supported by six elephants that are standing on a giant tortoise. • The entire thing is resting on a giant snake that hold the stars.

15. Chichen Itza 500 BC Bennet et al. (2002). The Cosmic Perspective, (2nd Ed.) p.97. Addison Wesley, San Francisco.

16. Greek • Mother Earth and Father Heaven created the Cyclopes and the race of people called Titans. • Battle between the Cyclopes and gods created ordinary people.

17. Early Greek Astronomy (Laws of Nature) Thales 636-546 BC (1st known scientific thinker) Anaximander 611-547 BC Pythagoras 570-500 BC (Mathematics, pure thought) Socrates 469-299 BC Democritus 460-370 BC (Atoms) Plato 427-247 BC Aristotle 384-322 BC (Earth centered Universe) Aristarchus 310-230 BC (Sun centered Universe) Archimedes 287-212 BC (physics, sun centered universe) Eratosthenes 276-196 BC (Diameter of Earth) Hipparchus 200-100 BC (star maps & magnitude scale) Ptolemy 87-150? AD (1st working model of universe) AND THEN CAME THE DARK AGES

18. Thales 636-546 BC • Earliest known philosopher-scientist. • Science based on observations and measurements. • Discovered static electricity by rubbing cloth on amber. • Developed trigonometric method for determining distances of approaching ships.

19. Anaximander 611-547 BC • A student of Thales • Earth centered • Moon orbit’s earth • Sun orbits earth • Sky tilted at an angle • Can explain • Daily motion • Eclipses Science starts out using simple models that get more complex over time.

20. The Four Elements • Thales: life is basically water. • Anaximenes: life is basically air. • Others said life was basically fire and earth. • Empedocles said it was all four. • NOTICE: Same data different conclusions. • ALSO they are all wrong conclusions. • These were taught in schools well into the 1800’s. http://www.kheper.net/topics/cosmology/elements.html

21. Pythagoras 570-500 BC • Pure thought, no experiments or observations necessary. • Universe was mathematical. • Developed the five regular solids. • Universe was composed of these pure geometric forms. http://www.kheper.net/topics/cosmology/solids.html

22. Democritus 460-370 BCAtomic Theory • Space consisted of voids and reality • Reality composed of atoms • Atoms were: • Eternal • Invisible (to tiny to be seen) • Indivisible • Incompressible • Solid (no voids within them)

23. Socrates 469-299 BC • Primarily interested in ethics and not science. • Plato’s teacher • Taught Plato logic and how to make an argument. • Plato was Aristotle’s teacher.

24. Plato 427-247 BC • Did not trust observations. • Pure thought like Pythagoreans. • Influenced by mathematics. • Focused on perfect shapes of Pythagoras. • Made 5 perfect solid famous. • Was Aristotle's teacher.

25. Plato’s Perfect Solids Tetrahedron (4 equal faces) Hexahedron (6 equal faces) Octahedron 8 equal faces Dodecahedron 12 equal faces Icosahedron 20 equal faces http://en.wikipedia.org/wiki/Platonic_solid

26. Aristotle (384-322 BC) • Was Plato’s student. • Was Alexander the Great’s teacher. • Alex sent him biological specimens during his conquest of the world. • Aristotle created a zoo and classified many plants and animals. • Aristotle believed in making observations and doing experiments, which is different from Plato.

27. Theory and Experiment • Plato was theoretical. • Aristotle reintroduced observation and experimentation. • Both are necessary to advance scientific knowledge.

28. Aristotle's Physics • Believed in the four elements. • Did not accept atoms as being real. • The natural state of objects is to be at rest, or not moving. • For objects to move a force needed to be applied to them continuously. • Therefore, an object dropped from a moving cart should fall behind the cart.

29. Aristotle’s Earth Centered Universe • The natural state of objects is to be at rest, or not moving. • For objects to move a force needed to be applied to them continuously. • If the Earth moved there would be a constant high speed wind from the east. • Therefore, the Earth must be at rest in center. • The universe is at rest and so is constant and never changes.

30. Aristotle’s Model • Explains • Daily motion • Seasons • Phases of moon • Eclipses • Normal planetary motion

31. Aristotle's Earth • Moon shown by reflected sunlight • During eclipses earth’s shadow was cast onto the moon. • Shadow was curved. • Therefore, earth must be round.

32. Aristarchus (310-230 BC) Sun Centered Universe • Most of his astronomical work was destroyed during the sack of Alexandria and destruction of the Alexandria Library. • Earliest known Sun centered model.

33. Archimedes 287-212 BC • Developed simple machines such as levers. • Center of gravity • Archimedes screws • Developed idea of buoyancy called Archimedes Principle.

34. Levers http://www.enchantedlearning.com/physics/machines/Levers.shtml

35. Archimedes Screws http://math.nyu.edu/~crorres/Archimedes/Screw/SourcesScrew.html http://www.math.nyu.edu/~crorres/Archimedes/Screw/Applications.html Archimedes Screw at Sea World

36. Archimedes and Center of Mass m1d1 = m2d2 http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

37. Archimedes and Center of Mass http://curriculum.calstatela.edu/courses/builders/lessons/less/les1/binary_stars_1.html

38. Binary StarsOrbit the Center of Mass Observing binary stars is the only way to learn the mass of stars m1d1 = m2d2 http://csep10.phys.utk.edu/astr162/lect/binaries/visual.html

39. Archimedes Principle • Used to determine volume of an irregular shaped object. • Used to find density of unknown objects, like rocks, the King’s crown, and is called specific gravity. http://physics.weber.edu/carroll/Archimedes/principle.htm

40. Eratosthenes (276-195) Measured Diameter of Earth Bennet et al. (2002). The Cosmic Perspective, (2nd Ed.) p 101. Addison Wesley, San Francisco.

41. Hipparchus (200-100 BC) Star Maps & Magnitude Scale • Made detailed maps of the night sky. • Developed stellar magnitude scale (based on a social class system): • 1st magnitude – brightest stars in the sky • 2nd magnitude- next brightest stars • 3rd • 4th • 5th magnitude – faintest stars barely visible to the unaided eye.

42. Ptolemy (87-150? AD) 1st Mathematical Model of Universe • Based on Aristotle's physics and astronomy. • Earth Centered • Lasted 15 centuries • Almagest – “The Greatest” Bennet et al. (2002). The Cosmic Perspective, (2nd Ed.) p 86. Addison Wesley, San Francisco.

43. Recall Aristotle’s Model

44. Ptolemy’s Model of Universe Disclaimer: This is a theory and not a fact. BUT, it lasted for 15 centuries!!

45. Ptolemy’s Model of Universe

46. Ptolemy’s Model of Universe

47. Ptolemy’s Model of Universe • Could predict positions of planets within the accuracy of unaided eye observations. • It was mathematical • It explained all the observations including retrograde motion. • Used for 15 centuries.

48. THE DARK AGES • Roman Empire fell in 476 AD • Cosmas, a sixth century monk, ~550 AD wrote Topographia Christiana and decribed the earth as flat. Christians were not to believe in pagan ideas of a spherical earth. • Aristotle and Ptolemy were forbidden reading. • Revival of the Sumerian ideas of a flat earth covered by a celestial tent. Land was surrounded by oceans inhabited by sea monsters.

49. THE DARK AGES • St Thomas Aquinas (1225-1274 AD) reintroduced Aristotle and Ptolemy models and round Earth. • Roger Bacon (1214-1292) describes machines similar to cars, airplanes, and space craft. • Johannes Gutenberg (1397-1468) movable printing • Christopher Columbus (1451-1506) already knew Earth was spherical. • Ferdinand Magellan (1480-1521) sailed around the world.

50. Resources Arny, T. (1998). Explorations: An Introduction to Astronomy. Chaisson and McMillian, (1998).Astronomy: A Beginner’s Guide to the Universe. Chaisson and McMillian, (2002). Astronomy Today (4th Ed.) Hakim, J. (2004). The Story of Science: Aristotle Leads the Way. Hewitt, (1998). Conceptual Physics (8th Ed.) http://www.usoe.k12.ut.us/curr/science/sciber00/8th/forces/sciber/newtons.htm Shipman, Wilson, and Todd, (2003). An Introduction to Physical Science (10th Ed).