Which of Galileo's observations disproved the Geocentric model of the Universe?

Answer 1

From ancient Greece until the early 17th Century, the dominant theory was that the Earth was the centre of all things and everything else was in orbit around the Earth.

Galileo disproved this by observing, over a series of nights, the movement of four stars (at that time, and to some extent in the present day, "star" was used to describe any point of light in the night sky, with the exception of the Moon) near Jupiter. From their motion relative to Jupiter (including their disappearance behind it and re-emergence at the other side) he was able to conclude that these stars were in orbit around Jupiter and not the Earth, and that was the end of Aristotelian cosmology.

Answer 2

He saw that there were satellies around Jupiter which showed that the Earth was not the centre of rotation of the solar system, but it did not disprove that the Sun went round the Earth. He also saw that Venus went through a full set of phases like the moon. Heliocentrism was also made proposed and supported by Copernicus and Kepler. Galileo just help to prove it with his observations of the Galilean moons and Venus.

Answer 3

He used a telescope and first found Jupiter and the Galilean (they're named after him) moons orbiting it. He then looked at the planets and plotted their courses from a geocentric viewpoint. He saw the planets would be going in very complex and illogical patterns, so he thought that the planets orbited the Sun, like the Galilean moons that orbit Jupiter. He published a book before the Church could stop him and people started to believe him.

Answer 4

Copernicus' theory, also known as the heliocentric theory, basically stated that the sun was the center of the solar system and that the earth and the other planets revolved around it. This opposed Aristotle's geocentric theory.

Answer 5

He found the earth was not in the center and found there are more than sun and earth. He found stars and other things that we see today in the night sky.

Comment: Amongst other things, he found 4 moons around Jupiter, craters on

the Moon and that Venus had phases like the Moon has. Also he observed

Saturn's rings.

Answer 6

1. Galileo discovered four moons in orbit around the planet Jupiter. Because the moons orbited Jupiter, they could not orbit theearth.

2. Galileo discovered that the Venus has phases (similar to the earth). Also varies in size (radius of the partial Venus disk) on different nights. When Venus is a silver / crescent (almost a "new Venus"), it was bigger than when it was almost full. The cycle repeats over the course of several months.

a.) Because the radius of Venus changes, it must be at different distances from the earth in different months. (It is not traveling in a circle around the earth.) Because the phases coincided with the size variation, it must be orbiting the sun, and be closer to the sun than earth. (Too bad I cannot draw a diagram).

Galileo had several other proofs as well.

Answer 7

Kepler discovered that if you assume the following three rules, they quite accurately

explain all the motions we see the planets make in the sky over periods of many years:

1). Each planet moves along a path that is an ellipse with the sun at one focus.

2). The line from the sun to the planet sweeps out equal areas in equal

amounts of time. So the planet must move fastest when it's closest to the sun,

and slowest when it's farthest from the sun.

3).

(The square of the time the planet takes to complete one orbit)

divided by

(The cube of half the length of the ellipse that the planet is traveling)

is the same number for every planet in the solar system.

The planet's size or mass make no difference. The length of its 'year' only

depends on the size and shape of its orbit.

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Kepler didn't prove anything. His laws, and Newton's 'law' of gravity that shows

why Kepler's laws must happen that way, are all 'only theories'. It so happens

that they very closely explain what we see actually happening in the sky, and

when we do things based on these laws ... like send people to the moon or

spacecraft to other planets, they work pretty well. But that doesn't 'prove' them.

They're still 'just theories'. They can't be proven, not in a million years. But they

can be dis-proven in a second. If you come in with a different theory that explains

what we see in the sky better than Kepler and Newton do, and makes predictions

that work better, then their theories will go straight to the dumpster, yours will be

accepted, and you'll be invited to all the Physics Department parties.

The real bottom line is: The scientist's job is not to prove things. It's his job to

dis-prove things. A new idea is only accepted when all the scientists working

together can't find any good reason why it's not true. Good scientists don't go

around looking for evidence to support their theories. They work to put together

a theory that supports the evidence they already have.

That's how science works.

Answer 8

Copernicus's model resembled the ancient system of Ptolemy in that it used circles and epicycles. Both theories gave orbits that were circular but with the Sun off-centre. But Copernicus's theory differed by putting the Sun at the centre instead of the Earth.

That basic fact was used by Kepler in his work that discovered that the planet's orbits are very nearly circular but not quite, and are correctly described as ellipses, albeit with low eccentricity. Later the explanation of elliptical orbits came from Newton's theoretical discoveries in gravity, dynamics and calculus.

So the time-line goes Ptolemy-Copernicus-Kepler-Newton.

Answer 9

he discovered that the planets dont orbit the sun.

Answer 10

The heliocentric model proposed the sun, and all the planets orbited the Earth.