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What geometric arrangements did ptolemy use to explain retrograde motion?
Wiki User
∙ 13y ago
Earths faster motion makes Mars appear to be going backwards, the backwards motion, in fact, is what caused retrograde motion. --Ptloemy used Epicycles to explain how geocentrical models worked.
Wiki User
∙ 12y ago
Wiki User
∙ 8y agoAll the classical models of Ptolemy, Copernicus, Tycho and Kepler explained retrograde motion, they had to because it is one of the most obvious of the planets' manoeuvres.
The different models had different ways of explaining it. Ptolemy's model has the Earth at the centre and uses two circles called a deferent and an epicycle to explain the movements of the planets quite accurately. The large circle is the deferent and the centre of the epicycle goes round it, then the planet goes round the epicycle. As the planet approaches Earth it appears to go backwards.
The later models with the Sun at the centre accounted for retrograde motion naturally as the Earth overtook the outer planets around the time of their closest approach (i.e. opposition).
Wiki User
∙ 15y agoptolemaic used Epicycles to explain how a geocentric model worked.
Wiki User
∙ 13y agoThe geometric that plotemy use is the Epicycles or series of concentric sphere
Wiki User
∙ 13y agohe used Epicycles. he thought about the earth/sun?
Wiki User
∙ 8y agoRetrograde motion was explained in Ptolemy's model by the use of epicycles in the planets' orbits.
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How did Ptolemy account for the retrograde motion in his model of the Solar system?
Ptolemy used epicycles to explain the retrograde motions of planets.Each plant was assumed to move around a small circle that turns upon a large circle.
The observed retrograde motion of planets led ptolemy to add blank to Aristotles system?
Epicycles
What were ptolemy's accomplishments?
Ptomleys accomplishments were his theory was that the Earth was the center of the universe. He also used to write about different things such as astronomy, geography, and logic.
What did Ptolemy think about the phases of Venus'?
Why would Ptolemy not explain venus phases
Why was it difficult for ancient astronomers to explain about the apparent retrograde motion?
If, as ancient astronomers thought, that our Earth was the center point of rotation for other planets, then it is difficult to explain why those planets would move in a direction opposite to their rotation. Ptolemy came up with a solution that worked, but it was a cumbersome one. Nicolae Copernicus was able to show that this retrograde motion could be explained easily if it were assumed that our Sun was the actual center of rotation of the planets.
Describe what produces the retrograde motion of mars. what geometric arrangement did Ptolemy use to explain this motion?
Earths faster motion makes Mars appear to be going backwards, the backwards motion, in fact, is what caused retrograde motion. --Ptloemy used Epicycles to explain how geocentrical models worked.
How did Ptolemy account for the retrograde motion in his model of the Solar system?
Ptolemy used epicycles to explain the retrograde motions of planets.Each plant was assumed to move around a small circle that turns upon a large circle.
Did Galileo's observations confirm the validity of retrograde motion of the planets?
No, Ptolemy did.
How was Ptolemy's idea of retrograde different from Copernicus' idea of retrograde motion?
We now understand that all the planets travel round the Sun, and a planet's retrograde motion happens as the Earth overtakes the other planet in its orbit. That was also Copernicus's view although we now use Kepler's theory, but on this point the two models are in agreement. In Ptolemy's model the Earth is stationary in the centre, and the planets move on circles and epicycles, explained as follows. Using Mars as an example and assuming the orbits of Earth and Mars are circular for simplicity, the Earth is at the centre and there is then a circle (or deferent) round it with a radius of 1.524 units. The epicycle is a smaller circle whose centre travels round the deferent in 687 days. The epicycle has a radius of 1.000 units and Mars travels round this in 365¼ days. That was Ptolemy's geometric construction to explain the motion of Mars, and the retrograde motion happens when Mars on its epicycle moves close to the Earth.
The observed retrograde motion of planets led ptolemy to add blank to Aristotles system?
Epicycles
Copernicus ideas that supported his ideas about the sun being at the centre of the Solar System?
he was a polish priest scientist stated retrograde motion occured whenever earth passes around another plant gained acceptance from people had a much simpliar way to explain retrograde motion than Ptolemy
What were ptolemy's accomplishments?
Ptomleys accomplishments were his theory was that the Earth was the center of the universe. He also used to write about different things such as astronomy, geography, and logic.
What did Ptolemy think about the phases of Venus'?
Why would Ptolemy not explain venus phases
Why was it difficult for ancient astronomers to explain about the apparent retrograde motion?
If, as ancient astronomers thought, that our Earth was the center point of rotation for other planets, then it is difficult to explain why those planets would move in a direction opposite to their rotation. Ptolemy came up with a solution that worked, but it was a cumbersome one. Nicolae Copernicus was able to show that this retrograde motion could be explained easily if it were assumed that our Sun was the actual center of rotation of the planets.
What was the date Ptolemy discovered retrograde motion?
Yes. We now understand that all the planets travel round the Sun, and a planet's retrograde motion happens as the Earth overtakes the other planet in its orbit. The Earth goes round more quickly than all the outer planets from Mars onwards. In Ptolemy's model the Earth is stationary in the centre, and the planets move on circles and epicycles. Using Mars as an example and assuming the orbits of Earth and Mars are circular for simplicity, the Earth is at the centre and then Ptolemy's model has a circle (or deferent) round it with a radius of 1.524 units. The epicycle is a smaller circle whose centre travels round the deferent in 687 days. The epicycle has a radius of 1.000 units and Mars travels round this in 365 days. That was Ptolemy's geometric construction to explain the motion of Mars, which it does pretty accurately, and the retrograde motion happens when Mars on its epicycle moves close to the Earth. Ptolemy used additional epicycles to allow for what we now call eccentricity in Mars's orbit, and also for what we now understand is the orbit's inclination to the ecliptic.
What did Ptolemy and Copernicus use to try to explain the universe?
copernicus
What was Ptolemy trying to explain in his model by haven't the planets move on smaller circles that move big circles?
ptolemy did something
