AST 111 Lecture Notes - Lecture 5: Nicolaus Copernicus, Semi-Major And Semi-Minor Axes, Ellipse
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AST 111: Lect 5: Gravitation and the Waltz of Planets
-The ancients knew the Earth was a sphere
- They were able to make observations showing the Earth was round
- They were also able to get very close to the actual circumference of the Earth
and the circumference of the Moon
- They could also determine the distance between the Earth and Moon
- They tried to figure out the distance from the Earth to the Sun
oAlthough they were far off, they still recognized that the Sun was the
biggest and furthest away from Earth
- Even though the knew the sun was biggest, they still thought of the universe as a
geocentric one
oThe model lasted until the 15th century
-The days of the week are named after the 7 celestial bodies the ancients knew of
-Mars (and the other planets) doesn’t always go East
- They retrograde (go against the normal motion)
- The greeks thought the planets were on crystal spheres, and this is why they
retrograded
- Ptolemy said this:
http://www.public.asu.edu/~atpcs/atpcs/Univ10e/chapter04-01.html
-Aristotle’s Ideas about our existence
- He is considered a Natural Scientist
- Did a lot of great work in zoology
- He thought the Earth had a sphere of change
-The people of early modern astronomy
1.Nicolaus Copernicus
- A polish man of the Roman Catholic Church
- Avid amateur astronomer
- Revived the heliocentric idea
- Made the Earth a planet