In space no one can hear you scream; and in a black hole, no one can see you disappear. - Stephen Hawking

I have lived with the prospect of an early death for the last 49 years. I'm not afraid of death, but I'm in no hurry to die. I have so much I want to do first ... I regard the brain as a computer which will stop working when its components fail. There is no heaven or afterlife for broken down computers; that is a fairy story for people afraid of the dark.

I don't think the human race will survive the next thousand years, unless we spread into space. There are too many accidents that can befall life on a single planet. But I'm an optimist. We will reach out to the stars.

To apply quantum theory to the entire universe... is tricky... particles of matter fired at a screen with two slits in it... exhibit interference patterns just as water waves do.

Feynman showed that this arises because a particle does not have a unique history.

That is, as it moves from its starting point A to some endpoint B, it doesn’t take one definite path, but rather simultaneously takes every possible path connecting the two points.

From this point of view, interference is no surprise because, for instance, the particle can travel through both slits at the same time and interfere with itself.

In this view, the universe appeared spontaneously, starting off in every possible way.