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.

It is sometimes said that scientists are unromantic, that their passion to figure out robs the world of beauty and mystery. But is it not stirring to understand how the world actually works — that white light is made of colors, that color is the way we perceive the wavelengths of light, that transparent air reflects light, that in so doing it discriminates among the waves, and that the sky is blue for the same reason that the sunset is red? It does no harm to the romance of the sunset to know a little bit about it.

The desire to be connected with the cosmos reflects a profound reality, but we are connected; not in the trivial ways that astrology promises, but in the deepest ways.

I don't want to believe. I want to know.

There is never only ONE of anything in nature.

The well-meaning contention that all ideas have equal merit seems to me little different from the disastrous contention that no ideas have any merit.

I'd like the [Cosmos] series to be so visually stimulating that somebody who isn't even interested in the concepts will just watch for the effects. And I'd like people who are prepared to do some thinking to be really stimulated.