The human race shouldn't have all its eggs in one basket, or on one planet. Let's hope we can avoid dropping the basket until we have spread the load.

The rate of progress is so rapid that what one learns at school or university is always a bit out of date. Only a few people can keep up with the rapidly advancing frontier of knowledge, and they have to devote their whole time to it and specialize in a small area. The rest of the population has little idea of the advances that are being made or the excitement they are generating.

In A Brief History Of Time I used the word "God" like Einstein did as a shorthand for the laws of physics. However, this is not what most people mean by God, so I have decided not to use the term. The laws of physics can explain the universe without the need for a God.

Half the battle is just showing up.

The boundary condition of the universe is that it has no boundary.

The past, like the future, is indefinite and exists only as a spectrum of possibilities.

To confine our attention to terrestrial matters would be to limit the human spirit.