about how long ago did people find out about earth rotation around the sun?

Question

and before that time what was their belief of earth and sun orbit (please answer it correctly i really need it)thanks so much

Answer 1

The term "rotation" refers to the earth turning on its axis, which takes about 24 hours. That's how we get our days.

The term used for the earth moving around the sun is "revolution". One full revolution around the sun is one year.

The idea of a sun-centered universe, or heliocentric universe, was originally that of Copernicus. But the man who made it all possible, and who was finally able to prove this theory, was Galileo Galilei.

Galileo published his astronomical findings of the sun-centered universe after he invented the telescope in 1609. Early in 1616, Galileo was accused of being a heretic. Galileo was later cleared of these charges of heresy, but was told that he should no longer publicly state his belief that Earth moved around the Sun. Galileo continued his study of astronomy and became more and more convinced that all planets revolved around the Sun. In 1632, he published a book that stated, among other things, that the heliocentric theory of Copernicus was correct. Galileo was once again called before the Inquisition and this time was found guilty of heresy. Galileo was sentenced to life imprisonment in 1633. Because of his age and poor health, he was allowed to serve his imprisonment under house arrest. Galileo died on January 8, 1642.

There ya go.

Answer 2

If you want to make a distinction between "speculating" about the sun being at the center, and "proving" or "knowing" that the sun is at the center, then the answer is, some of the ancients (e.g. Aristarchus) speculated about it but had no meaningful proof, while after Copernicus it became much more a valid scientific theory which was promoted by Galileo, but it still took more study and observations up tot he time of Newton before the system was really understood and could be convincingly defended.

So, the answer as to when we "really" knew, is, in the late 1600s.

Interestingly enough, a survey a couple years ago showed that nearly half of the people in the USA answered that the sun went around the earth when asked whether it was sun around earth or earth around sun! Pathetic, eh?

Answer 3

Matthew G is correct about the right names to use.

Matthew G is also correct if by "people" you take to mean "generally accepted in modern Western Civilization."

Some of the Ancient Greeks were, however, well aware of size of the earth (as a sphere) and of its rotation around the sun.

For instance, Aristarchus believed that the Earth revolved around the Sun. His views, and those of Hipparchus, were not generally accepted at the time, however.

Some of the Greeks also developed odd theories that attempted to explain the apparent motions of the planets and the Sun:

"The Eudoxan system had several critical flaws. One was its inability to predict motions exactly. Callippus' work may have been an attempt to correct this flaw. A related problem is the inability of his models to explain why planets appear to change speed. A third flaw is its inability to explain changes in the brightness of planets as seen from Earth. Because the spheres are concentric, planets will always remain at the same distance from Earth. This problem was pointed out in Antiquity by Autolycus of Pitane (c. 310 BCE).

Apollonius of Perga (c. 262 BC–c. 190 BCE) responded by introducing two new mechanisms that allowed a planet to vary its distance and speed: the eccentric deferent and the deferent and epicycle. The deferent is a circle carrying the planet around the Earth. (The word deferent comes from the Latin ferro, ferre, meaning "to carry.") An eccentric deferent is slightly off-center from Earth. In a deferent and epicycle model, the deferent carries a small circle, the epicycle, which carries the planet. The deferent-and-epicycle model can mimic the eccentric model, as shown by Apollonius' theorem. It can also explain retrogradation, which happens when planets appear to reverse their motion through the zodiac for a short time. Modern historians of astronomy have determined that Eudoxus' models could only have approximated retrogradation crudely for some planets, and not at all for others."

In the 3rd century BCE, Aristarchus of Samos proposed an alternate cosmology (arrangement of the universe): a heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe (hence he is sometimes known as the "Greek Copernicus"). His astronomical ideas were not well-received, however, and only a few brief references to them are preserved. We know the name of one follower of Aristarchus: Seleucus of Seleucia.

Aristarchus also wrote a book On the Sizes and Distances of the Sun and Moon, which is his only work to have survived. In this work, he calculated the sizes of the Sun and Moon, as well as their distances from the Earth in Earth radii. Shortly afterwards, Eratosthenes calculated the size of the Earth, providing a value for the Earth radii which could be plugged into Aristarchus' calculations. Hipparchus wrote another book On the Sizes and Distances of the Sun and Moon, which has not survived. Both Aristarchus and Hipparchus drastically underestimated the distance of the Sun from the Earth.

The closest anyone came to Galileo before Galileo was Tycho Brahe, who posited that most of the planets revolved around the Sun, but that the Earth was stationary and the sun and Moon revolved around it.

See the pictures at the wikipedia entries for more detail.

Answer 4

The earliest traces of the idea that it is the Earth that is actually moving and the Sun that is at the centre of the solar system (the concept of heliocentrism) is found in several Vedic Sanskrit texts written in ancient India. Yajnavalkya (c. 9th–8th century BC) recognized that the Earth is spherical and believed that the Sun was "the centre of the spheres" as described in the Vedas at the time.

Answer 5

some historic Greeks knew the Earth revolves around the solar, however the assumption grew to become into by no ability popular - they argued that if the Earth moved, than we could continuously be conscious stars getting brighter and fainter as we pass closer to and farther faraway from them, and nearby stars could seem to shift returned and forth relative to farther stars (parallax). What they did no longer anticipate grew to become into the indisputable fact that the celebs are so very far away. We do see parallax, yet purely with telescopes. the celebs don't get brighter or fainter with Earth's action by way of fact the replace in distance is extremely small whilst in comparison with the entire distance. even although the classic Greeks although of it, a heliocentric universe grew to become into rejected in Western technology until Copernicus, or maybe then it wasn't until after Galileo that the assumption grew to become into broadly generally occurring.

Answer 6

It was discovered about 300BC by Aristarchus.