I find science so much more fascinating than science fiction. It also has the advantage of being true.

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

All of the rocky and metallic material we stand on, the iron in our blood, the calcium in our teeth, the carbon in our genes were produced billions of years ago in the interior of a red giant star. We are made of star stuff.

Widespread intellectual and moral docility may be convenient for leaders in the short term, but it is suicidal for nations in the long term. One of the criteria for national leadership should therefore be a talent for understanding, encouraging, and making constructive use of vigorous criticism.

In Italy, the Inquisition was condemning people to death until the end of the eighteenth century, and inquisitional torture was not abolished in the Catholic Church until 1816. The last bastion of support for the reality of witchcraft and the necessity of punishment has been the Christian churches.

The Hindu religion is the only of the World's great faiths dedicated to the idea that the Cosmos itself undergoes an immense, indeed an infinite, number of deaths and rebirths.

There are in fact 100 billion galaxies, each of which contain something like a 100 billion stars. Think of how many stars, and planets, and kinds of life there may be in this vast and awesome universe.