Probably a dozen times since their death I've heard my mother or father, in an ordinary conversational tone of voice, call my name. They had called my name often during my life with them ... It doesn't seem strange to me.

People are not stupid. They believe things for reasons. The last way for skeptics to get the attention of bright, curious, intelligent people is to belittle or condescend or to show arrogance toward their beliefs.

Science cuts two ways, of course; its products can be used for both good and evil. But there's no turning back from science. The early warnings about technological dangers also come from science.

The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars.

The gears of poverty, ignorance, hopelessness and low self-esteem interact to create a kind of perpetual failure machine that grinds down dreams from generation to generation. We all bear the cost of keeping it running. Illiteracy is its linchpin.

[Kepler] preferred the hard truth to his dearest illusions, and that is the heart of science.

[S]cience has itself become a kind of religion.