Ancient astronmers used shell theory. The earth was center, then came the moon, planets and sun, then other stars. At first it was a circular system. It seemed more "perfect", that degenerated into ellipses as the mathematics didn't work out.
The Ptolemaic system held sway for 1400 years and had the Earth at the centre, with the Sun and all the planets in orbits which were based on circles. The orbits were not simple circles, but small circles (epicycles) based on larger circles. By this means the changes in distance from the Earth, especially for the nearest planets, Venus and Mars, were explained with reasonably good accuracy when compared with observations.
He used his brain in a different way from the illiterate masses back in 150 A.D. in a very Astronomical way.
It held that the planets moved along small circles that moved on larger circles around Earth.
one thing I can tell you is that they thought that the earth was flat.
that is unknown sorry pal
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.
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!
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!
ptolemy is a ancient astronomer who determined the law of gravitational motion
All the models explain retrograde motion because it is such an obvious phenomenon. In Copernicus's model an outer planet goes into retrograde motion when the inner planet overtakes it so that it appears from the inner planet to be going backwards along the ecliptic.
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.
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.
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!
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!
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!
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!
ptolemy is a ancient astronomer who determined the law of gravitational motion
All the models explain retrograde motion because it is such an obvious phenomenon. In Copernicus's model an outer planet goes into retrograde motion when the inner planet overtakes it so that it appears from the inner planet to be going backwards along the ecliptic.
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.
Why would Ptolemy not explain venus phases
The retrograde motion of a planet is the optical illusionthat a planet reverses its orbital direction, as seen from Earth.In reality, the planet does not change direction at all, but because the Earth is also orbiting the sun, the relative motion of the Earth and another planet in their respective orbits make it appear to us as if the planet reverses course for a while.
Retrograde motion is motion in the opposite direction. In the case of celestial bodies, such motion may be real, defined by the inherent rotation or orbit of the body, or apparent, as seen in the skies from Earth.