Galileo Galilei was a scientist who studied objects in space. He firmly believed that the planets revolved around the sun. This was not commonly accepted during his time, though, and Galileo often struggled to convince others of heliocentrism. A Can you believe people didn't believe him?

B These days, though, everybody knows he was totally right.

C Those folks who disagreed with him were dead wrong, though, and now everyone knows it.

D Over time, however, he was proven to be correct.