How is our knowledge about the earth different from the knowledge of people, even learned men, some 400 years ago?

How is our knowledge about the earth different from the knowledge of p

1.	How is our knowledge about the earth different from the knowledge of people, even learned men, some 400 years ago?
Answer» It is common knowledge today that the earth is a planet revolving round the sun. But there was a time not many centuries ago, when even learned men believed that the earth was fixed in space and the sun and all other heavenly bodies went round it.