0
What models had planets moving along circular orbits Ptolemy or Copernicus model?
Wiki User
∙ 10y ago
Both Ptolemy and Copernicus used the circle as the basic element of the orbits, but they both knew that a simple circle was not correct in describing the movements of the planets accurately.
The way they worked round the problem was to use epicycles. An epicycle was a small circle whose centre moved round the main circle, and the planet remained stationary on the epicycle. In other words the line joining the planet to the centre of the epicycle stays in the same direction all the time. This is actually a good approximation to an elliptical orbit because it reproduces the effect of the planet moving closer and further away once during one revolution, and geometrically it is equivalent to having the planet going round a circle but with the Sun offset from the centre (by a different amount for each planet).
That is why the model lasted for as long as it did - 1500 years, until Tycho Brahe made observations and recorded the planets' positions with such high accuracy that Kepler was able to deduce the ellipse as the more correct form for planets' orbits. He did this by studying Tycho's measurements of the orbit of Mars, which has a higher eccentricity factor than all the main planets except Mercury which is difficult to observe, and there was just enough difference for Kepler to spot it.
The major difference between Ptolemy's model and Copernicus's was that the Earth was at the centre when the Ancient Greeks studied the problem, and the Sun had an orbit, while Copernicus in the early 16th century imagined the Sun at the centre. Later scientific discoveries by Newton and his successors demonstrated the sun-centred theory as superior.
Wiki User
∙ 10y ago
Add your answer:
Earn +20 pts
What were the similarities between Ptolemy's model and Copernicus' model?
Both Copernicus heliocentric and the Ptolemaic models agreed on the need for epicycles. These were miniature orbits that the celestial bodies travelled on as well as their normal orbits.Copernicus still invigaed the bodies orbiting in perfect circles and had to put these in to explain some of the movements of the planets. This may have contributed to his ideas being largely dismissed as it was just as complicated as the already established model. It was not until Kepler proposed elliptical orbits was this problem resolved.
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 is a Solar System that planets revolve around the earth?
The name for the model of a solar system in which planets (and the Sun) revolve around the Earth is called geocentric. Modern astronomy rejects the idea, dating back to Copernicus who was a proponent of the notion that the planets orbited around the Sun (heliocentric). The heliocentric model is thus also called the Copernican, and the geocentric (with models presented most famously by Aristotle and Ptolemy) is called the Ptolemaic.
Why models of the ealry ptolemy solar system were replaced by the copernican model?
The Ptolemaic Model followed a geocentric model of the solar system. This was then challenged by Nicolaus Copernicus, who claimed a heliocentric model which sparked an integral part of the Scientific Revolution called, the Copernican Revolution. Copernicus' proposal was followed by the Tychonic Model, with attempted to compromise with the geo- and heliocentric models. Then, Kepler improved by suggesting elliptical orbits. The Copernican Revolution came to a close with further speculation from Galileo Galilei and Isaac Newton TL;DR Because they were wrong
What were the similarities between Ptolemy's model and Copernicus' model?
Both Copernicus heliocentric and the Ptolemaic models agreed on the need for epicycles. These were miniature orbits that the celestial bodies travelled on as well as their normal orbits.Copernicus still invigaed the bodies orbiting in perfect circles and had to put these in to explain some of the movements of the planets. This may have contributed to his ideas being largely dismissed as it was just as complicated as the already established model. It was not until Kepler proposed elliptical orbits was this problem resolved.
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.
How does Ptolemy's models model of the universe compare Aristotle's model?
Both Models Show That Celestial Objects Have Circular Paths
Which scientist made highly accurate measurements that disproved the theories of ptolemy and Copernicus?
Tycho Brahe designed new equipment to measure planets' positions with unprecedented accuracy. Tycho's observations of the planets' orbits led to his alternative model which still had the Earth at the centre with the Sun orbiting it, but with the five other known planets orbiting the Sun. But Tycho's measurements were used by his assistant Kepler to produce an entirely new theory in 1609 with the planets in elliptical orbits, all orbiting the Sun as in Copernicus's model of 1543. Kepler's theory is still used today. It's important to remember that the theories of Ptolemy and Copernicus are not 'wrong', it would be better to say they are not as accurate as Kepler's theory. As models, all three of them predict the planets' positions fairly accurately.
How does Ptolemy's model of universe compare with Aristotle's model?
Both Models Show That Celestial Objects Have Circular Paths
How does Ptolemy's. model of the universe compare with Aristotle's model?
Both Models Show That Celestial Objects Have Circular Paths
How does Ptolemy model of the universe compare with Aristotle's model?
Both Models Show That Celestial Objects Have Circular Paths
How does ptolemy's model of the universe compare with aristotle's model?
Both Models Show That Celestial Objects Have Circular Paths
What did Claudius Ptolemy believe in?
Ptolemy developed several mathematical models to describe the motions of the sun, the moon, the planets and the stars. The book that describes these models is called "The Almagest" or "Ptolemy's Almagest". The models all assume: 1. The earth is stationary. 2. All objects travel with uniform speed on a perfectly circular orbit. However, a model that placed the earth in the centre of the orbits of all other objects would not work because it does not account for various anomalies, including the varying length of seasons, the irregularity of eclipses of the moons and the retrograde motion of the planets. Ptolemy used two mathematical devices to deal with the anomalies: eccentricity (an offset from the centre of a circle) and epicycles - circular orbits whose centre (or eccentric) itself traveled in a uniform circular orbit. Much of the material in The Almagest was already known to Greek astronomers. Ptolemy's contribution was to consolidate all known results, make large improvements to the models, and to write it all down in a way that became a standard for the way to present the results of scientific enquiry. His book was the standard text book for astronomers until his models were ultimately improved by Copernicus, Kepler and Newton. Ptolemy also wrote a treatise on Astrology, based on his deep knowledge of the motions of the heavenly bodies. This work is called The Tetrabiblos.
What is a Solar System that planets revolve around the earth?
The name for the model of a solar system in which planets (and the Sun) revolve around the Earth is called geocentric. Modern astronomy rejects the idea, dating back to Copernicus who was a proponent of the notion that the planets orbited around the Sun (heliocentric). The heliocentric model is thus also called the Copernican, and the geocentric (with models presented most famously by Aristotle and Ptolemy) is called the Ptolemaic.
What was the first scientist to dispute Ptolemy's model of a genetic or earth centered?
Copernicus devised an alternative model to explain the planets' movements among the stars. It was similar to Ptolemy's model in that it was composed of circles and epicycles, but it differed in placing the Sun at the centre instead of the Earth. So Ptolemy's model was geocentric while Copernicus's was heliocentric. Copernicus had no way of testing the validity of his model except that it was geometrically simpler, especially for the inner planets Mercury, Venus and Mars which needed much smaller epicycles in Copernicus's model. We now know that the large epicyces in the Ptolemaic model were necessary to compensate for the Earth's movement round the Sun. Galieo's discoveries with the telescope raised more serious doubts about Ptolemy's model when he found that Venus showed phases that could not be explained by the Ptolemaic model. The gibbous phase is not explained by Ptolemy's model because it does not allow Venus to go behind the Sun as seen from Earth. Tycho produced a model that was geocentric but also explained the phases of Venus. Finally all three models were rejected in favour of Kepler's model, which has the Sun at the centre and the planets in elliptical orbits. This is the model used today, with very minor modifications due to the General Theory of Relativity.
