0
Still curious? Ask our experts.
Chat with our AI personalities
Judy
Coach
ViviAdd your answer:
Earn +20 pts
What did Ptolemy believe the earth went round?
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.
What astronomer discovered that the orbits of the planets are elliptical rather than round?
Johannes Kepler.
Why do you think planets do not have same orbits?
It's because each planets is a collection of all the debris that was going round in a similar orbit before the planets were formed. So the planets only survived to the present day by having different orbits.
Is Copernicus theory correct?
No physical theory is completely correct, because measurements always have a built-in error that you hope is small. But Copernicus's theory explaining in detail how the planets move was accurate enough for its time and was only found lacking later when observational techniques became sufficiently refined to show its errors. In modern times we have better theories for planetary orbits but Copernicus's general idea that all the planets orbit round the Sun is now generally accepted since Newton's theoretical discoveries, which were applied to showed that the Sun is far more massive than anything else in the solar system.
What do planets do when they orbit the earth?
There are no planets orbiting the Earth because all eight of them orbit the Sun. But the Moon orbits the Earth, and all it does is go round and round in a rather complicated orbit which is disturbed by the Sun's gravity.
