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What was Ptolemy trying to explain in his model by having the planets move on smaller circles that move on the bigger circles?
Wiki User
∙ 13y ago
Ptolemy is trying to explain in his model that each circle represents 1 planet's rotation and it's a scale drawing of the distance apart from each one!
Wiki User
∙ 13y ago
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What was ptolemy theory on planets?
The astronomical system of Ptolemy, in which the earth is at the center of the universe with the sun, moon, planets, and stars revolving about it in circular orbits.Ptolemaic system Ptolemy believed that Earth was at the center of the universe and that the Sun and planets orbited Earth (with the planets also moving in smaller circles called epicycles). In this system, the centers of Mercury's and Venus's epicycles always lie on the line shown in the diagram between the Earth and the Sun.
How was Copernicus' model of the universe different from Ptolemy's model?
The main difference was that Ptolemy's model was geocentric (Earth-centred) and Copernicus's was heliocentric (Sun-centred). Ptolemy's model came from ancient times while Copernicus's was much later (1543). Both models represented the planets' orbits by using combinations of circles and epicycles to explain the way the planets move among the stars. Copernicus found that the orbits of the inner planets could be explained more simply. That is to say that the epicycles used for all the orbits were smaller, and for the inner planets a lot smaller. Both models represented the planets' positions with reasonable accuracy given the crude observational methods used in those days. Until gravity and the laws of dynamics were discovered about 150 years after the publication of Copernicus's system, there was no way of deciding which model was the 'right' one.
What was the the model solar system that was thought to be correct before Copernicus?
It was Ptolemy's model. Ptolemy's model came from ancient times while Copernicus's was much later (1543).Both models represented the planets' orbits by using combinations of circles and epicycles to explain the way the planets move among the stars.Copernicus found that the orbits of the inner planets could be explained more simply. That is to say that the epicycles used for all the orbits were smaller, and for the inner planets a lot smaller.Both models represented the planets' positions with reasonable accuracy given the crude observational methods used in those days.Until gravity and the laws of dynamics were discovered about 150 years after the publication of Copernicus's system, there was no way of deciding which model was the 'right' one.
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 the asteroids are larger or smaller than planets?
are asteroids smaller or larger than planets
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
What was ptolemy trying to explain in his model by having the planets move on smaller circles that move on bigger circles?
Ptolemy is trying to explain in his model that each circle represents 1 planet's rotation and it's a scale drawing of the distance apart from each one!
What was Ptomeny trying to explain in his model by having the planets move on smaller circles that move on bigger circles?
to explain the motion of planets, especially the phenomenon of retrograde motion where planets appear to temporarily reverse their direction of motion. Ref: Andrew Liddle "An Introduction to modern Cosmology".
What was ptolemy theory on planets?
The astronomical system of Ptolemy, in which the earth is at the center of the universe with the sun, moon, planets, and stars revolving about it in circular orbits.Ptolemaic system Ptolemy believed that Earth was at the center of the universe and that the Sun and planets orbited Earth (with the planets also moving in smaller circles called epicycles). In this system, the centers of Mercury's and Venus's epicycles always lie on the line shown in the diagram between the Earth and the Sun.
What was Ptolemy trying to explain in his model by having the planets move on smaller circle that move on bigger circle?
Ptolemy is trying to explain in his model that each circle represents 1 planet's rotation and it's a scale drawing of the distance apart from each one!
How was Copernicus' model of the universe different from Ptolemy's model?
The main difference was that Ptolemy's model was geocentric (Earth-centred) and Copernicus's was heliocentric (Sun-centred). Ptolemy's model came from ancient times while Copernicus's was much later (1543). Both models represented the planets' orbits by using combinations of circles and epicycles to explain the way the planets move among the stars. Copernicus found that the orbits of the inner planets could be explained more simply. That is to say that the epicycles used for all the orbits were smaller, and for the inner planets a lot smaller. Both models represented the planets' positions with reasonable accuracy given the crude observational methods used in those days. Until gravity and the laws of dynamics were discovered about 150 years after the publication of Copernicus's system, there was no way of deciding which model was the 'right' one.
What was the the model solar system that was thought to be correct before Copernicus?
It was Ptolemy's model. Ptolemy's model came from ancient times while Copernicus's was much later (1543).Both models represented the planets' orbits by using combinations of circles and epicycles to explain the way the planets move among the stars.Copernicus found that the orbits of the inner planets could be explained more simply. That is to say that the epicycles used for all the orbits were smaller, and for the inner planets a lot smaller.Both models represented the planets' positions with reasonable accuracy given the crude observational methods used in those days.Until gravity and the laws of dynamics were discovered about 150 years after the publication of Copernicus's system, there was no way of deciding which model was the 'right' one.
What planet circles the sun faster than any other planets?
Mercury circles the sun in 88 days. That is the fastest orbiting planet. It is because of it's position with the sun. It is the closest so it has a smaller orbit.
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.
Are the inner planets smaller than the outer planets?
yes the inner planets are much smaller then the outer planets
Did ptolemy believe in helio?
His theory was geo. The heliocentric theory is modern and has the Sun at the centre of the solar system with the planets going round it in nearly-circular orbits. Ptolemy's theory, a geocentric one, had the Earth at the centre, with everything else orbiting round it, but Ptolemy found an ingenious way of accounting for the planets' movements in the sky quite accurately. Ptolemy's method describes the planets' orbits in terms of a basic circular orbit, called the deferent but what goes round the deferent is a smaller circle, the epicycle, and the planet goes round the epicycle. It isn't difficult to see that this geometrical construction 'takes out' the Earth's movement round the Sun and explains the planets' movements as we see them from the Earth, while allowing the Earth to be fixed at the centre.
Are the rockey planets larger or smaller than the gas planets?
smaller
