Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Many passengers would rather have stayed home.

In many cultures it is customary to answer that God created the universe out of nothing. But this is mere temporizing. If we wish courageously to pursue the question, we must, of course ask next where God comes from? And if we decide this to be unanswerable, why not save a step and conclude that the universe has always existed?

But, Jefferson worried that the people - and the argument goes back to Thucydides and Aristotle - are easily misled. He also stressed, passionately and repeatedly, that it was essential for the people to understand the risks and benefits of government, to educate themselves, and to involve themselves in the political process. Without that, he said, the wolves will take over.

Many religions have attempted to make statues of their gods very large, and the idea, I suppose, is to make us feel small. But if that's their purpose, they can keep their paltry icons. We need only look up if we wish to feel small.

If all the suns but ours collapsed tonight, how many lifetimes would it take us to realize that we were alone?

Any sufficiently crisp question can be answered by a single binary digit-0 or 1, yes or no.

In more than one respect, the exploring of the Solar System and homesteading other worlds constitutes the beginning, much more than the end, of history.