“In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.”

American astronomer, planetary scientist and science communicator

Carl Edward Sagan was an American astronomer, planetary scientist and science communicator. He worked at Harvard as an assistant professor before moving to Cornell University, where he became the David Duncan Professor of Astronomy and Space Sciences and directed the Laboratory for Planetary Studies. Sagan took an active role in the Mariner, Viking and Voyager programs. He also wrote more than 600 scientific papers and articles, along with several popular science books, beginning with The Cosmic Connection. His The Dragons of Eden won the Pulitzer Prize for General Nonfiction.