Compare and contrast a heliocentric model of the solar system and a geocentric model?
Heliocentric puts the sun in the middle of the solar system while geocentric is where the earth is in the middle of the solar system.
Describe Aristotle's model of the heavens?
Its on a sphere, and the 5th element was found in the heavens.
How were Aristotle's predictions of heavenly motion qualitative rather than quantitative?
They did not have any quantitative predictions of motion; where and when to find the planets.
Why was Aristarchus of Samos' model not accepted at the time he proposed it?
because people believed in the geocentric model and believed that the earth was the center of the universe.
Describe what occurs during planetary retrograde motion and give an example of how this looks when we see a planet do this from Earth?
Its the apparent motion of a planet to move in a direction opposite to that bodies within its system.
Describe how Ptolemy adapted Aristotle's model of the universe into a mathematical one in the Almagest.
describe the deferents
describe equants
describe epicycles.
The epicycle is the little cirlce along which the planets move, which in terms move along the larger circle, the deferent. This deferent has its center, eccentric, which is a constant spot, between the equant and the earth.
How did the Ptolemaic model explain the apparent retrograde motion of the planets?
Ptomely used the idea of epicycles or smaller circles which were the paths for planets and which then turned around larger circles around the Earth to explain what he called retrograde motion. He had observed that planets sometimes moved in one directions
What three incorrect ideas held back the development of modern astronomy from the time of Aristotle until the 16th century?
Earth was he center of the universe uniform circular motion exist in the heavens objects in the heavens were made from a perfect, unchanging substance not found on the earth heavens dont change.
How is parallax used to measure the distance to nearby stars?
Parallax is the shift in position of an object caused by your own motion.
How would you demonstrate parallax with your own eyes?
If you look at an object and cover first one eye then the other, the object will appear to be changing position.
How did the Copernican theory explain retrograde motion?
Copernicus said that the planets closer to the sun moved faster than the ones that were farther away causing what looked like backward motion.
Compare Tycho Brahe's model of the solar system to that of Ptolemy's?
Tyco Brahe's model of the solar system placed the Earth at the center and the sun and moon and stars revolve around the earth. The other five planets revolved around the sun. It was a geocentric system. But he said the heavens were not unchanging.
What did Tycho Brahe see in the sky that convinced him that the heavenly firmament was not as unchanging/perfect as previously believed?
he observed a supernova (exploding star) which disappeared after 18 months--conclusion the heavens are not unchanging
he observed a comet--which proved that not everything is non-changing and not everything is a circular motion.
he measured the movement o
How did Johannes Kepler and Tycho Brahe collaborate to arrive at the three laws of planetary motion?
Johannes Kepler analyzed the data of his mentor Tycho Brahe with three statements that described the motion of planets in a sun-centered solar sy
How did Kepler deviate from the beliefs of Aristotle and Copernicus in his first law?
Kepler was one of the 1st scientists to suggest that the planets revolve around the sun, rather than the earth being the center.
What causes a planet to be at a place of perihelion and then later at aphelion in its orbit?
Perihelion is the point in the orbit of a planet,asteroid or comet at which it is closest to the sun. Aphelion is the point in the orbit of a planet, asteroid, or comet at which it is furthest from the sun.
What does Kepler's second law imply about the speed of a planet around the sun?
It implies that a planet moves fastest when it is close to the sun and slowest when it is far from the sun.
Where is the Earth in its orbit when it is traveling the fastest?
At perihelion: when it is closest to the sun.
Explain what an astronomical unit (A.U.) is and why it is practical for measuring in Astronomy.
An A.U. is the mean distance between the Earth and the sun, about 98 million miles or 150 million kilometers.
Explain in your words the two ways that Galileo demonstrated that sunspots (dark spots) were on the sun as opposed to being a planet or other object simply moving in front of it.
-sun spots move and change their shapes and originate on the sun, not planets close to the sun
-the rate of motion of the sun spots was not uniform: slower near the edge of the sun and faster towards the center of the sun.
Explain the significance of Galileo's observations of the phases of Venus.
The observation of the phases of Venus (like the moon's phases) proved that Venus moved around the sun, therefore providing proof for a sun-centered (heliocentric) universe.