The rate of progress is so rapid that what one learns at school or university is always a bit out of date.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.

---

We don't let animals suffer, so why humans?

---

The laws of physics demand the existence of something called ‘negative energy’.

---

So remember to look up at the stars and not down at your feet. Try to make sense of what you see and hold on to that childlike wonder about what makes the universe exist.

---

The more you learn, the more you know. The more you know, the more you forget. The more you forget, the less you know. So why bother to learn.

---

The twentieth century saw man's view of the universe transformed: we realized the insignificance of our planet in the vastness of the universe, and we discovered that time and space we curved and inseparable , that the universe was expanding, and that it had a beginning in time.

---

I'm happy if I have added something to our understanding of the universe.

---

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.

---

What I meant by 'we would know the mind of God' is, we would know everything that God would know, if there were a God. Which there isn't. I'm an atheist.

---

How do we know that we are not just characters in a computer-generated soap opera?

---