Chapter 3 Flashcards
The Science of Astronomy (22 cards)
Egyptian’s Contributions
Dividing the day into 12 equal parts
Archaeoastronomy
The study that combines archeology and astronomy
Greek Philosophers 3 Major Innovations
- Not relying on supernatural explanations
- Using mathematics and evidence to explore new ideas
- Debates in thoughts and observations
Geocentric Model
Earth being the center and the universe
Thales (c. 624-546)
Known for predicting of the Solar Eclipse
Pythagoras
Considered that the Earth be a perfect spherical shape
Ptolemaic Model
Placed Earth at the center but each planet moved around Earth on a small circle that moved along a larger circle
Hipparchus
Synthesized earlier ideas into a singular system
Copernican Revolution
Shift into learning that the Earth orbits around the Sun
Tycho Brahe
He saw a Supernova and his accurate astronomical observations, which were the most precise possible before the invention of the telescope
Supernova
The explosion of a distant star
Kepler (1517-1630)
Found that the orbit of the planets was elliptical not perfectly circular
Semi-major axis
Half the distance across the long axis of an eclipse
Avg. of an orbiting object
Eccentricity
a measure of how much an eclipse deviates from a perfect circle
Kepler’s 1st Law of Planetary Motion
The orbit of each planet about the Sun is all ellipse with the Sun at one focus
Perihelion
The point which an object orbiting the Sun closest to the Sun
Aphelion
The point at which an object is farthest to the Sun
Kepler’s 2nd Law of Planetary Motion
A planet moves faster in the part of it’s orbit nearer the Sun and slower the farther from the Sun
Kepler’s 3rd Law of Planetary Motion
More distant planet’s orbit the Sun at a slower pace
p^2=a^3
planets orbital period (p^2)
semi-major axis of its orbit (a^3)
3 Objections
- Object in motion stays in motion unless something acts upon it
- no heavenly perfection
- observable stellar paradox
