We can make a similar examination, but with greater uncertainty, of the extraterrestrial hypothesis that holds that a wide range of UFOs viewed on the planet Earth are space vehicles from planets of other stars.
Carl SaganHe sought a way to preserve the past. John Hershel was one of the founders of a new form of time travel.... a means to capture light and memories. He actually coined a word for it... photography. When you think about it, photography is a form of time travel. This man is staring at us from across the centuries, a ghost preserved by light.
Carl SaganIn 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.
Carl SaganNevertheless, (Jefferson) believed that the habit of skepticism is an essential prerequisite for responsible citizenship. He argued that the cost of education is trivial compared to the cost of ignorance, of leaving government to the wolves. He taught that the country is safe only when the people rule.
Carl Sagan