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∙ 2010-05-01 22:05:03The Moon.
Wiki User
∙ 2010-05-01 22:05:03The moon
Eudoxus believed in geocentric that means the orbits of the planets go in a perfect circle
Either the heliocentric or the geocentric model would allow predictions of thefuture motions of the planets. It was not the inability to predict that sackedthe geocentric model. It was the simplicity of the heliocentric model. Kepler'shypothetical ellipses helped a lot, and Newton's gravitation sealed the deal,when he showed that heliocentric, elliptical planetary orbits, just as Keplerdescribed them, had to spring forth from gravitation.
The heliocentric 'theory' is not really a theory at all, more an assertion that the Sun is at the centre of the solar system. Copernicus's theory assumes that the Sun is at the centre and provides a model of the planets' orbits that uses circles and epicycles to explain the observed orbits. He said it was simpler than the old "geocentric" (Earth centred) Ptolemaic system, but it was not really, it actually had more epicycles. Note: Perhaps the questioner got mixed up. The Copernican theory IS a heliocentric theory. Perhaps the question is about the geocentric theory and the Copernican theory. Anyway, Kepler simplified the heliocentric theory and now we know that his model is correct.
The similarity between the meanings of these words is that they define a frame of reference. Heliocentric (a Greek based word) refers to things relative to our Sun - for example the orbits of planets (Earth, Mars, Jupiter etc.) are helocentric as the planets orbit around the Sun. Geocentric (another Greek based word) refers to things relative to the Earth - for example the orbits of the Moon and the International Space Station are geocentric as they orbit around the Earth.
The moon
The geocentric model is a Earth-centered model in which everything orbits around Earth. However, unlike the geocentric model, the heliocentric model is a sun-centered model in which everything orbits around the sun.
Eudoxus believed in geocentric that means the orbits of the planets go in a perfect circle
That would be the moon. We've never thought of it that way ... the only object whose status didn't change between the geocentric and heliocentric model. Thanks for showing it to us.
Eccentricity, geocentric model, heliocentric model, Kepler's second and third laws, elliptical orbits, and Newtons gravitation
Tycho supported the geocentric system, usually called the Ptolemaic system, at first, and then devised a system of his own, still geocentric with the Earth at the centre, but with Mercury and Venus in orbit round the Sun. The other planets and the Sun were as before, in orbit round the Earth. Kepler then did detailed mathematical work, based on Tycho's observations but using a heliocentric system, and he came up with the idea of elliptical orbits for the planets. He found that elliptical orbits fitted the observations more accurately than previous models. Newton's later theoretical discoveries of gravity and the laws of motion confirmed Kepler's model, and it became generally accepted. The older models that used combinations of circles were consigned to the history books.
Its main strength is that it is the model which is universally accepted by everyone. Copernicus put forward a heliocentric model that used circular orbits. That meant he couldn't completely eliminate all the complications of the old geocentric model, such as "epicycles". Later Kepler showed that the planets move in elliptical orbits. The basic idea of the heliocentric model is that the Sun is at the centre. One of the main strengths is the simplicity of the heliocentric model. Kepler's version (still used today) of the model with its elliptical orbits is particularly elegant and simple, with no epicycles.
Either the heliocentric or the geocentric model would allow predictions of thefuture motions of the planets. It was not the inability to predict that sackedthe geocentric model. It was the simplicity of the heliocentric model. Kepler'shypothetical ellipses helped a lot, and Newton's gravitation sealed the deal,when he showed that heliocentric, elliptical planetary orbits, just as Keplerdescribed them, had to spring forth from gravitation.
The heliocentric 'theory' is not really a theory at all, more an assertion that the Sun is at the centre of the solar system. Copernicus's theory assumes that the Sun is at the centre and provides a model of the planets' orbits that uses circles and epicycles to explain the observed orbits. He said it was simpler than the old "geocentric" (Earth centred) Ptolemaic system, but it was not really, it actually had more epicycles. Note: Perhaps the questioner got mixed up. The Copernican theory IS a heliocentric theory. Perhaps the question is about the geocentric theory and the Copernican theory. Anyway, Kepler simplified the heliocentric theory and now we know that his model is correct.
The similarity between the meanings of these words is that they define a frame of reference. Heliocentric (a Greek based word) refers to things relative to our Sun - for example the orbits of planets (Earth, Mars, Jupiter etc.) are helocentric as the planets orbit around the Sun. Geocentric (another Greek based word) refers to things relative to the Earth - for example the orbits of the Moon and the International Space Station are geocentric as they orbit around the Earth.
In the 16th century there were two competing systems, the heliocentric (Sun centered) and geocentric (Earth centered), to describe the motion of the Earth, Sun, moon and planets. Five hundred years ago people thought the Earth was a stationary solid and unmoving body and the moon, stars and Sun revolved around the Earth. That was called the geocentric, or Earth centered, system. Nicolaus Copernicus published the statement of his heliocentric, or sun centered, system in his book, De Revolutionibus, in 1543. In the geocentric theory, the Sun is unmoving at the center of the universe and the stars and Earth orbits around the Sun. The moon still orbits around the Earth, however.
In the 16th century there were two competing systems, the heliocentric (Sun centered) and geocentric (Earth centered), to describe the motion of the Earth, Sun, moon and planets.Five hundred years ago people thought the Earth was a stationary solid and unmoving body and the moon, stars and Sun revolved around the Earth. That was called the geocentric, or Earth centered, system.Nicolaus Copernicus published the statement of his heliocentric, or sun centered, system in his book, De Revolutionibus, in 1543. In the heliocentric theory, the Sun is unmoving at the center of the universe and the stars and Earth orbits around the Sun. The moon still orbits around the Earth, however.