The very act of understanding is a celebration of joining, merging, even if on a very modest scale, with the magnificence of the Cosmos.

There are as many atoms in one molecule of DNA as there are stars in a typical galaxy.

Think of how many religions attempt to validate themselves with prophecy. Think of how many people rely on these prophecies, however vague, however unfulfilled, to support or prop up their beliefs. Yet has there ever been a religion with the prophetic accuracy and reliability of science? ... No other human institution comes close.

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.

It seems madness to say, 'We're worried that they're going to become addicted to marijuana' -- there's no evidence whatever that it's an addictive drug, but even if it were, these people are dying, what are we saving them from?

Our perceptions are fallible. We sometimes see what isn't there. We are prey to optical illusions. Occasionally we hallucinate. We are error-prone.

The surface of the Earth is the shore of the cosmic ocean.