Today’s Comments D2L Quiz 3 & 4 available (#4 has first few questions from next lecture) Test 1 on Feb. 10. Special tutor session with Gustavo: Thurs, Feb. 5, 3-5pm Best test prep: 1. objectives, 2. D2L quizzes, 3. lectures/notes, 4. book Sunset – Part 1 Due Feb. 12 (in 2 weeks) Sunrise and Sunset times http://www.timeanddate.com/sun/usa/minneapolis Phone App: Sunrise Sunset Moon Phases Due Mar. 2 Moon visible times: (Moonrise and Moonset) http://www.timeanddate.com/moon/usa/minneapolis Phone App: Phases of the Moon Free Exploradome Planetarium Feb. 3 in T bldg plaza, 1st floor 9am to 12pm – come for a 20-30 minute presentation, every half hour. Shows at 9, 9:30, 10, 10:30, 11 and 11:30am. Check-in with me. Counts for lecture that DAY & lab for the WEEK

Prior to the Copernican Revolution – Greek Astronomy Western only – Please investigate other cultures Greeks (influenced by Babylonia, Mesopotamia, Egypt, Rome) ~700 BC to ~140 AD Some ideas and people Know the starred* items

Everything orbits around… Earth Sun Heliocentric Model* (from Copernicus, 1473-1543AD) Geocentric Model* (from Aristotle, 384-322BC)

Prior to the Copernican Revolution – Greek Astronomy ~700 BC Early astronomy was about time keeping (when to sow and reap crops) Prior to the Copernican Revolution – Greek Astronomy

Prior to the Copernican Revolution – Greek Astronomy Hesiad, Works and Days ... when the Pleiades rise it is time to use the sickle, but the plough when they are setting; 40 days they stay away from heaven; when Arcturus ascends from the sea and, rising in the evening, remain visible for the entire night, the grapes must be pruned;… Needed better observations to keep the various calendars synchronized. Prior to the Copernican Revolution – Greek Astronomy

Prior to the Copernican Revolution – Greek Astronomy Greeks ~Fifth Century BC What is the sun? Fire? Tiny lights in the sky? Why do 7 lights wander among the others? (7 Planetes*) science.msfc.nasa.gov/ ssl/pad/solar/surface.htm imagine.gsfc.nasa.gov/.../ news/22apr02.html http://artsci.shu.edu/physics/1007/retro2.gif Prior to the Copernican Revolution – Greek Astronomy

Prior to the Copernican Revolution – Greek Astronomy Pythagoras of Samos ~500 BC Earth is a sphere Sphere is perfection in math Crystal spheres for 7 planetes Sun, Moon, 5 others Already thinking geocentric http://library.thinkquest.org/C0126626/fate/geocentric.jpg Prior to the Copernican Revolution – Greek Astronomy

Prior to the Copernican Revolution – Greek Astronomy Plato ~360 BC Heavens are perfect, unchanging (from mathematical perfection) Heavenly motion must be in circles and uniform Prior to the Copernican Revolution – Greek Astronomy

Prior to the Copernican Revolution – Greek Astronomy Aristotle ~350 BC Plato’s student Earth: Corrupt, changeable, imperfect (separation of heavens and Earth) Arguments for geocentric model* No parallax of stars* and Moon would be left behind* Parallax is the apparent change in position of an object due to the change in position of the observer Parallax thumb demonstration Prior to the Copernican Revolution – Greek Astronomy

Prior to the Copernican Revolution – Greek Astronomy Aristarcus ~300 BC Heliocentric solar system (first evidence)* Measured size of Sun Measured that Sun was much further away than Moon Prior to the Copernican Revolution – Greek Astronomy

Prior to the Copernican Revolution – Greek Astronomy Ptolemy ~140 AD Geocentric model* (often called the Ptolemaic system) Mathematical model of universe* Perfect Bodies and orbits circles, spheres Uniform motion Epicycles* (retrograde motion)* Prior to the Copernican Revolution – Greek Astronomy

From Moon Lectures Already know this: New information: Minute to Minute: the Sun, Moon, stars, planets appear to rise in East and set in West due to Earth’s spin (rotation). Day to Day: Moon moves West to East due to Moon’s orbit (revolution) around Earth. New information: Day to Day: Planets typically move West to East due to their orbits around the Sun. Retrograde Day to Day Motion: Planets move East to West due to their orbits around the Sun and the difference in speeds of Earth and other planet.

Retrograde Motion (Day to Day) Sometimes planets moved backwards against the background of stars. All other planets have retrograde motion in our sky: inner planets and outer planets Retrograde motion is East to West and observed day to day. Minute to minute motion across sky is still East to West due to Earth’s rotation.

Perfect circles, spheres, uniform motion Ptolemy Geocentric Model Perfect circles, spheres, uniform motion Mars’ Epicycle Earth Mars

Copernican Revolution Both models explain observations… Retrograde motion of planets Copernican Revolution

Copernican Revolution Retrograde motion – Geocentric Planets ride on epicycles Sometimes appear to move backwards Copernican Revolution

Copernican Revolution Retrograde motion – Heliocentric One planet overtakes another planet. Slower planet appears to move backwards. Copernican Revolution

Copernican Revolution Retrograde motion – Heliocentric New (and correct) explanation of retrograde motion of the planets. Retrograde (westward) motion of a planet occurs when the Earth passes the planet. Ptolemy’s epicylces unnecessary Copernican Revolution

Prior to the Copernican Revolution – Greek Astronomy Dark Ages in Europe (5th to 15th centuries AD) Roman libraries sacked Often violent mix of Latin and Arabic cultures Plague, famine, war Islamic Golden Age of Science Long time between Ptolemy ~140 AD to Copernicus ~1500 AD. Prior to the Copernican Revolution – Greek Astronomy

Summary Before Copernicus ~700BC to 140 AD Geocentric Model Dominated Pythagoras of Samos Plato Aristotle* Aristarchus* Ptolemy*

Observation Projects OBSERVING PROJECTS (in order of due date) Each line below is worth 10 points for a total of 80 points. Planetarium (Exploradome at MCTC): Feb. 3 Sunset – Part 1 Start: Jan. 20; Due: Feb. 12 Moon Phases Start: Jan. 22; Due: Mar. 3 Safe Sun Prep Work Start: Mar. 19; Due: Mar. 26+ Sunset – Part 2 Start: Apr. 2; Due: Apr. 28 Moon Craters Start: Jan. 29; Due: May 5 Star Gazing Start: Jan. 29; Due: May 5 Telescope Start: Jan. 29; Due: May 5

Observations Star Gazing Observation Telescope Observation Main Goal: See constellations in night sky Telescope Observation Main Goal: Look at night sky through a telescope Moon Craters Observation Main Goal: see Moon’s craters under magnification Jan. 29 to May 5 to complete 7 Options for each of these 3 observations Class website has more details. Turn in verification sheet (unless you check-in with me at the event). 3 on calendar starting today; 5 that you can be working on including sunset and moon phases

6 Locations for Star Gazing, Telescopes & Moon Craters Options Eagle Lake Observatory at Baylor Regional Park (complete star gazing and telescopes together and possible moon craters) - every other Sat. until Nov. Easiest way to complete but about an hour drive & $5/car Jackson Middle School Observatory (dates TBD) – Champlin, MN Eisenhower Community Center (dates TBD) – Hopkins, MN 7-10pm (call 952-988-4070 for reservations) University of MN (Fridays TBD) – Minneapolis, MN Macalester College (Thursdays TBD) – St. Paul, MN St. Thomas College (weeknights TBD) – St. Paul, MN Trying to get an option at MCTC for this but not sure if it will happen.

7th Option (at home) for Star Gazing, Telescopes & Moon Craters Star Gazing Observation Star gaze with friends and write a short report Telescope Observation Use your/friends’ telescope and write a report (talk to me) Moon Craters Observation Use binoculars (from my office) and write short report

Star Gazing Observation Main Goal: See constellations in night sky Jan. 29 to May 5 to complete 7 Possible Options Must have an expert point out constellations OR write a report Eagle Lake Observatory at Baylor Regional Park (complete star gazing and telescopes together and possible moon craters) – every other Sat. until Nov. Best view and experience but about an hour drive & $5/car Jackson Middle School Observatory (date TBD) – Champlin, MN Eisenhower Community Center (dates TBD) – Hopkins, MN 7-10pm (call 952-988-4070 for reservations) University of MN (Fridays) – Minneapolis, MN Macalester College (Mondays or Thursdays) – St. Paul, MN St. Thomas College (weeknights TBD) – St. Paul, MN Star gaze with friends and write a short report Class website has more details. Turn in verification sheet.

Telescope Observation Main Goal: Look at night sky through a telescope Jan. 29 to May 5 to complete 7 Possible Options Eagle Lake Observatory at Baylor Regional Park (complete star gazing and telescopes together and possible moon craters) - every other Sat. until Nov. Best view and experience but about an hour drive & $5/car Jackson Middle School Observatory (dates TBD) – Champlin, MN Eisenhower Community Center (dates TBD) – Hopkins, MN 7-10pm (call 952-988-4070 for reservations) University of MN (Fridays TBD) – Minneapolis, MN Macalester College (Thursdays TBD) – St. Paul, MN St. Thomas College (weeknights TBD) – St. Paul, MN Use your/friends’ telescope and write a report (talk to me) Class website has more details. Turn in verification sheet.

Moon Craters Observation Main Goal: see Moon’s craters under magnification Jan. 29 to May 5 to complete 7 Possible Options (Must have visible Moon, ideal is half Moon) Eagle Lake Observatory at Baylor Regional Park (complete star gazing and telescopes together and possible moon craters) - every other Sat. until Nov. Best view and experience but about an hour drive & $5/car Jackson Middle School Observatory (dates TBD) – Champlin, MN Eisenhower Community Center (dates TBD) – Hopkins, MN 7-10pm (call 952-988-4070 for reservations) University of MN (Fridays TBD) – Minneapolis, MN Macalester College (Thursdays TBD) – St. Paul, MN St. Thomas College (weeknights TBD) – St. Paul, MN Use binoculars (from my office) and write short report Class website has more details. Turn in verification sheet.