Ptolemy

Aristotle was a Greek philosopher who made significant contributions to various fields, including ethics, logic, and metaphysics. Ptolemy, on the other hand, was an astronomer and mathematician who developed the geocentric model of the universe. While Aristotle's work influenced a wide range of disciplines, Ptolemy's contributions were mostly focused on astronomy.

Ptolemy considered the solar system (and the universe) to be a set of crystal concentric spheres rotating around the stationary Earth at its centre.

On the closest sphere was the moon, then Venus and so on out to the stars on the outer sphere. At the time they didn't have any idea how incredibly big everything is.

Eudoxus of Cnidus, a student of Plato, developed the system of concentric spheres in his attempt to explain planetary motion and the movements of the stars. This system later influenced the Ptolemaic astronomical model, which incorporated epicycles to account for observed planetary motion.

In Ptolemy's geocentric model, the sun was believed to orbit around the Earth along with other celestial bodies. The Earth was considered to be the center of the universe, with the sun, moon, and planets moving in circular orbits around it.

Aristotle believed that the Earth was at the center of the universe, with the sun, moon, planets, and stars revolving around it in perfect circular orbits. This geocentric model of the universe dominated Western thought for centuries until it was replaced by the heliocentric model proposed by Copernicus and further developed by Galileo and Kepler.

The Persian Empire was a powerful ancient civilization that was eventually conquered by Alexander the Great in the 4th century BC. After Alexander's death, one of his generals, Ptolemy, established the Ptolemaic Kingdom in Egypt, ruling as pharaoh and starting the Ptolemaic dynasty. This period marked a significant era of cultural and scientific advancement known as the Hellenistic period.

Aristotle's model of the solar system was geocentric, meaning that everything in the solar system revolved around Earth. Ptolemy added in the way the planetary bodies moved, although they still moved geocentrically.

Copernicus' model is simpler than Ptolemy's because it places the sun at the center of the solar system, with planets orbiting around it in nearly circular paths. This heliocentric model eliminates the need for complex epicycles, which Ptolemy used in his geocentric model to explain the retrograde motion of planets. Copernicus's model also provides a more elegant explanation for the observed movements of celestial bodies.

Ptolemy was born on 85 A.D

Ptolemy believed that the Earth was a stationary sphere at the center of the universe and that the Sun, Moon, planets, and stars revolved around it in perfect circular orbits. This geocentric model of the universe was accepted for centuries until the heliocentric model proposed by Copernicus.

Ptolemy believed that Venus, like other planets in his geocentric model of the universe, exhibited phases due to its position relative to the Earth and the Sun. He thought that the varying shapes of Venus as seen from Earth were caused by the changing angles between the three celestial bodies.

There were TONS of them, but Cleopatra was probably the most famous of them all.

Cleopatra was married to her younger brother, Ptolemy XIII, for about one year from 51 BC to 47 BC. Their marriage was part of the tradition of sibling marriages in the Ptolemaic dynasty to maintain royal power.

The difference between Ptolemy's and Copernicus's model was that, Ptolemy's model had the Earth in the middle of the Solar System, with all the other planets (including the Sun and the moons) revolving around it. In Copernicus's model, he had the Sun in the center of the Solar System.

Some said he drowned in the river of NILES, and some say he died of a certain disease. Nobody is sure because history can end up in lots of possibilities.

No, Ptolemy's model of the universe did not exclude reference to heaven. Ptolemy's geocentric model included the concept of celestial spheres, with the outermost sphere considered to be the realm of the fixed stars or heavens.

Read the book. No one should tell the answer here.

If you mean Claudius Ptolemaeus, no. He lived about 1900 years ago.

Both models explain it simply, and even a simple model with circular orbits explains it easily. Normally, as the planets rotate round the Sun, they appear to move along the ecliptic from west to east. But in the short period around opposition, when the planets are opposite the Sun in our sky, and we are closest to them, they appear to move east to west because they are going round more slowly than us - we are overtaking them. That is retrograde motion.

The Ptolemaic is based on the Greek philosophy that all the objects in the sky must follow circular motion in one form or another. With the Earth supposed at the centre, the planets' movements were quite complicated and each planet needed a good number of epicycles.

The idea of epicycles is that you have a large circle (the deferent) and then a small circle (the epicycle) whose centre moves round the deferent. Then the planet travels round that epicycle.

Extra epicycles were required to represent what we now know as the planets' elliptical orbits and the inclination of the orbits to the ecliptic.

The basic idea of the deferent and epicycle is easily explained in terms of Venus's orbit. We now know that with the Sun at the centre, Venus and the Earth travel round circular orbits in 225¾ and 365¼ days with radii of 1.000 units for the Earth and 0.723 units for Venus (we are assuming circular orbits to make the example easier). This is the basis of the Copernican heliocentric model.

If you choose to consider the Earth is at the centre, this motion is exactly replicated by having a deferent with radius of 1.000 units round the Earth, and on it is an epicycle with its centre going round in 365¼ days. The epicycle has a radius of 0.723 units and Venus travels round the epicycle in 225¾ days. This is the basis of Ptolemy's model (in the Ptolemaic model the Sun also went round the Earth in 365¼ days, but at a larger radius beyond the 'sphere' of Venus).

Both these models represent the position of Venus as seen from the Earth with equal accuracy. That is still the case when the extra epicycles are added for ellipticity, inclination et cetera.

So the issue between the Ptolemaic model (geocentric) and the Copernican model (heliocentric) was not accuracy but whether the Earth or Sun was at the centre. There was no way at that time of deciding which was correct, but Copernicus's model did not have such violent motion of Venus, which was one reason Galileo preferred it.

Eventually Kepler came up with an alternative system, and that is the one used today, because it is backed up by later theoretical discoveries of the law of gravity and the laws of motion.

Im thinkin that it was made when he decided to look up at the sky one night and decided he would make an astronomical observation. idk just that's how i would make an oservation of the sky.

[Rosco P. Coltrain]

Ptolemy was a Greco-Roman scholar who lived in the 2nd century AD. He is most famous for his work in astronomy, geography, and astrology, particularly his treatise "Almagest" which was a groundbreaking work on the motions of celestial bodies.

Ptolemy, the astronomer and mathematician, did not receive any awards during his lifetime. However, he is remembered and honored through various posthumous recognitions and awards for his contributions to the field of astronomy, particularly for his work on the "Almagest" and his geocentric model of the universe.

Ptolemy Elrington is a British artist known for creating sculptures from discarded hubcaps and other found objects. He transforms these materials into intricate animal and insect shapes, showcasing his creativity and commitment to recycling and environmental awareness through his art.

Ptolemy called the transparent spheres in his geocentric theory "celestial spheres." He believed that these spheres carried the celestial bodies, such as the planets and stars, in circular motion around the Earth.