PHY 102 1st EditionLecture 3Outline of Last LectureI. Celestial MotionsA. Sun Patternsa. Daytime skyb. Rotation of the earthB. EquinoxesC. Moon PatternsOutline of Current Lecture I. Yearly Solar Motionsa. Position of the sun in the skyb. North to South motion of the sunII. General Planetary Motiona. Inferior Planetsb. Superior PlanetsIII. ZodiacIV. Theories of Heliocentrism and othersa. Philolaus Cosmologyb. Earthshinec. Homocentric Spheres of Eudoxusd. UnacceptanceCurrent LectureI. Yearly Solar Motionsa. Why does the sun change position in the sky?These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Sun changes its path every day1. Moves west to east among the stars like the moon2. About 1 degree eastward each dayii. Possible explanations:1. Sun, moon, stars could all move at different rates around the earth2. Earth is the one rotatingiii. The sun has an apparent motion among the background starsb. Why does the sun have a North to South motion?i. The ecliptic’s motion on the horizon mimics the sun’s motion along the horizon1. Winter:2. Summer: ii. Summer – north polar axis points toward the suniii. Winter – north polar axis points away from the suniv. 23 degree tilt causes the seasons and the apparent pathway of the sunII. General Planetary Motionsa. Inferior planetsi. Closer to the sun, always within a few degreesii. Mercury, venus – can ONLY see during sunrise and sunsetb. Superior planetsi. Can be viewed opposite the sunii. Jupiter moves eastward among the stars, then westward, then back eastward, looping over its own pathIII. ZODIACa. Series of constellations along which the sun and the planets moveb. Planets and stars were all considered living things in ancient societyc. Signs of the Zodiac are when the sun is in line with a certain constellationd. Astrology – how the parts of the sky affect things on the earthi. Stars used to tell storiesii. Stars sometimes called the “cathedral of the heavens”iii. Mostly BUNKIV. Theories of Heliocentrism and othersa. Philolaus’s Cosmologyi. “central fire” was the center of the universe, light we could never seeb. Explanation of “earth shine”i. The moon is still partially illuminated but not from the sun1. Due to the sun’s rays bouncing off the earth, hitting the moon, andbouncing back to the earthc. Homocentric Spheres of Eudoxusi. Nested spheres show the retrograde motion of the planetsii. Each sphere has its own axis which rotates at a different speediii. Multiple spheres for each planet’s rotationd. Aristarchusi. Showed relative sizes of earth & moon from the eclipse shadowii. Studied the shadow of the earth on the moon at a lunar eclipseiii. MISCONCEPTION: phases of the moon are NOT caused by the earth’s shadowiv. Concludes that the moon is 1/3 earth’s diametere. Unacceptancei. Heliocentrism not accepted because of “lack of evidence”1. Parallax 1a. Angle of the earth to the stars would be different at different positions around the sun assuming that the stars are at equal distances from the sun2. Parallax 2a. Visibility of the stars would differ based on the position of the earth around the