Few scientists now dispute that today's soaring levels of carbon dioxide and other gases in the atmosphere will cause global temperature averages to rise by as much as nine degrees Fahrenheit sometime after the year 2000.

One trend that bothers me is the glorification of stupidity, that the media is reassuring people it's alright not to know anything. That to me is far more dangerous than a little pornography on the Internet.

There are naive questions, tedious questions, ill-phrased questions, questions put after inadequate self-criticism. But every question is a cry to understand the world. There is no such thing as a dumb question.

Any civilization that doesn't develop space travel dies.

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

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience..... To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.

That kind of skeptical, questioning, "don't accept what authority tells you" attitude of science - is also nearly identical to the attitude of mind necessary for a functioning democracy. Science and democracy have very consonant values and approaches, and I don't think you can have one without the other.