Presentation on theme: "Cosmogony: model of our place in the Universe. Definition: is the branch of astronomy that deals with the motions of celestial objects."— Presentation transcript:
Cosmogony: model of our place in the Universe
Definition: is the branch of astronomy that deals with the motions of celestial objects.
Most of the reading you will be receiving will come from this website.
Wandering Stars Website with Wandering Stars and Retrograde motion animation:
1.Imaginary sphere around the Earth in which stars in space appear – It is not physical as the ancients believed! 2.Represents only the stars we can see with our eyes. And the are fixed (So no, planets, exoplanets, pulsars, other stars we can’t see, etc…) 3. Earth centered
Earth centered 55 concentric crystalline spheres Buffering spheres in between Attached to one main sphere - Controlled by the Prime Mover Each sphere rotated at a different rate Orbits were in Uniform circular motion
Beliefs of Aristotle and Ptolemy 1.All motion in the heavens is uniform circular motion. 2.The objects in the heavens are made from perfect material, and cannot change their intrinsic properties (e.g., their brightness). 3.The Earth is at the center of the Universe.
Apparent Motion of Planets on the Celestial Sphere Reading and Applet: grade/retrograde.html grade/retrograde.html
Observation Issues Starry Night Pro Simulation 1.Retrograde Motion 2.Varying brightness of the planets
Retrograde Motion ets/Retro/frame.html Handout: Retrograde motion (this handout is not available as digital copy. Please see Mrs. Carter for this handout) Another good retrograde motion simulator: etrograde.swf&movieid=retrograde&width=700&height=600&version= etrograde.swf&movieid=retrograde&width=700&height=600&version=6.0.0
Geocentric Models: Aristotle and Ptolemy Aristotle: Epicycle Ptolemy: Epicycle upon Epicycles retrograde/aristotle.html veningStar/Unit2/unit2_sub1.ht m
Ptolemy’s model of the orbit of Mars name=animations/renaissance/marsorbit.swf& movieid=marsorbit&width=825&height=550&ve rsion=6.0.0
Motions of Mercury and Venus Observations Mercury and Venus were always close to the Sun Conclusions The Spheres of Mercury, Venus and the Sun must be connected. SUNRISE
Development of Modern Astronomy Copernicus Kepler Brahe Galileo NewtonEinstein
Ancient Astronomy From Ancient to Modern (Up to Newton) bk Another video The Universe: Aristotle and Ptolemy Video
The Copernican model: A Sun-Centered Universe (1543) Copernican Heliocentric Universe universe/videos/playlists/beyond-the-big- bang#beyond-the-big-bang-copernicus New views of the heavens Sun Centered Stars do NOT revolve around the Earth Earth rotates in 24 hours But… Planets still have perfectly circular orbits and EPICYCLES ARE STILL NEEDED Retrograde motion and the varying brightness of planets in the Heliocentric Model: ct/retrograde/copernican.html
Copernicus determines Mars is beyond our orbit What time is it in this picture? Link to me: Sun rise – 6:20 am Sun set – 5:55 pm Length of Day ~ 11.5 hours When is the middle of the night?
Aristotle's Common Sense Let’s see how much common sense you have: 1.Why don’t objects fly off the Earth as the Earth spins? 2.Why don’t we leave behind the birds, airplanes and satellites that are in the air as we orbit around the sun? 3.Why don’t we notice an apparent shift in position of the stars as we move around the sun?
TRY THIS 1.Close one eye 2.Line your index finger up with this rectangle 3.Now switch eyes 4.Is your finger still lined up with the rectangle. 5.Switch back and forth between eyes. 6.Observe the apparent change in position of your finger. How does changing the distance your finger is from your eye affect the apparent shift in your fingers position?
Basic Concept Comparison of Large and Small Angles Stellar Parallax simulation: hill.com/olcweb/cgi/pluginpop.cgi?it=swf::800: :600::/sites/dl/free/ x/78778/Paralla x_Nav.swf::Stellar%20Parallax%20Interactive
Aristarchus of Samos (310BC - 230BC) Link to the image to learn more about Aristarchus of Samos and his theory behind why the moon orbited the earth and the earth orbited the Sun.
Tycho Brahe ( ) Danish Astronomer Instruments These instruments were able to measure parallax
Observations of Tycho Brahe Reading: ect/history/brahe.html Precise observations of Mars’s position
NO OBSERVED PARALLAX – MUST NOT BE CLOSE BY! (This was something that changed!) Could not measure parallax for the stars!
Tychonic Geo-Heliocentric Model Characteristics The Moon and Sun orbited the Earth The other planets orbited the Sun Link to animation
Drama Time It’s been said that maybe Kepler killed Brahe. Use the internet to research Johannes Kepler and Tycho Brahe to see what you can find about this rumor. Why hasn’t Hollywood made this movie yet!! Total Drama.
All orbits are slightly eccentric
All Planet Orbits
The Earth is not always the same distance from the Sun
Kepler’s 3 Laws of Planetary Motion LAW 1: ALL PLANETS ORBITS ARE ELLIPSES Reading: Applet
Ellipses One focus is the sun Aphelion – furthest point from the sun Perihelion – nearest point to the sun Major axis – long axis Minor axis – short axis ery.com/Elipse.html
Eccentricities: Bound & Unbound Orbits
Equal Areas in equal Times
Kepler's Laws Animations Link with excellent animations: ml Handout: Kepler's 2 nd and 3 rd Laws Review: n_Orbits
Distances in the Solar System
Read this article about the AU
Using the AU Calculating distances to the planets in Astronomical Units
Galileo and the telescope Reading amics.html Web link to Galileo Videos 1.http://www.history.com/shows/the- universe/videos/playlists/beyond-the-big-bang#beyond- the-big-bang-galileo-galileihttp://www.history.com/shows/the- universe/videos/playlists/beyond-the-big-bang#beyond- the-big-bang-galileo-galilei
Galileo’s idea of Inertia 1.Inertia: tendency of an object to resist changes in its velocity 2.Velocity is the change in an objects motion (either speed or direction)
Galileo’s idea on Falling Objects Galileo’s Experiment Reenactment replace Galileo’s Experiment on the Moon 0
Galileo's Observations Galileo used a telescope to make observations of objects that were too far or dim to see with the unaided eye.
One of the Greatest Religious Debates in History Galileo and the Church 1.http://www.youtube.com/watch?v=NAra0BV jJp4&feature=relatedhttp://www.youtube.com/watch?v=NAra0BV jJp4&feature=related 2.http://www.youtube.com/watch?v=P3X_OZq 7f70&feature=relmfuhttp://www.youtube.com/watch?v=P3X_OZq 7f70&feature=relmfu 3.http://www.youtube.com/watch?v=RsqHCnL Mz_A&feature=relmfuhttp://www.youtube.com/watch?v=RsqHCnL Mz_A&feature=relmfu 4.http://www.youtube.com/watch?v=ebZxMjv Au8Y&feature=relmfuhttp://www.youtube.com/watch?v=ebZxMjv Au8Y&feature=relmfu
These observations include: An imperfect Moon Moon through a Telescope like Galileo’s Moon Dance Video ions.html
Galileo's Observations Phases of Venus
According to the Geocentric Model imations/renaissance/ptolemaic.swf&movieid=ptolemaic &width=900&height=660&version= imations/renaissance/ptolemaic.swf&movieid=ptolemaic &width=900&height=660&version=6.0.0 According to the Heliocentric model imations/renaissance/venusphases.swf&movieid=venusp hases&width=870&height=600&version=6.0.0
Galileo's Observations Moons around Jupiter
Galileo’s Observations Ears on Saturn (it’s rings) 749/are_saturns_rings_disappearing/
Galileo’s Observations Stars in the Milky Way
FUN FRIDAY Carl Sagan on the history of Astronomy I&feature=fvsr