"We got through all of Genesis and part of Exodus before I left. One of the main things I was taught from this was not to begin a sentence with And. I pointed out that most sentences in the Bible began with And, but I was told that English had changed since the time of King James. In that case, I argued, why make us read the Bible? But it was in vain. Robert Graves was very keen on the symbolism and mysticism in the Bible at that time."

"There should be no boundary to human endeavor."

"My expectations were reduced to zero when I was 21. Everything since then has been a bonus. - December 12, 2004"

"Intelligence is the ability to adapt to change."

"I believe in universal health care. And I am not afraid to say so."

"Scientists have become the bearers of the torch of discovery in our quest for knowledge."

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

"The downside of my celebrity is that I cannot go anywhere in the world without being recognized. It is not enough for me to wear dark sunglasses and a wig. The wheelchair gives me away."

"It was Einstein's dream to discover the grand design of the universe, a single theory that explains everything. However, physicists in Einstein's day hadn't made enough progress in understanding the forces of nature for that to be a realistic goal."

"For millions of years, mankind lived just like the animals. Then something happened which unleashed the power of our imagination. We learned to talk and we learned to listen. Speech has allowed the communication of ideas, enabling human beings to work together to build the impossible. Mankind's greatest achievements have come about by talking, and its greatest failures by not talking. It doesn't have to be like this. Our greatest hopes could become reality in the future. With the technology at our disposal, the possibilities are unbounded. All we need to do is make sure we keep talking."

"Sometimes I wonder if I'm as famous for my wheelchair and disabilities as I am for my discoveries."

"Time travel used to be thought of as just science fiction, but Einstein's general theory of relativity allows for the possibility that we could warp space-time so much that you could go off in a rocket and return before you set out."

"I believe things cannot make themselves impossible."

"I'm not afraid of death, but I'm in no hurry to die. I have so much I want to do first."

"The whole history of science has been the gradual realization that events do not happen in an arbitrary manner, but that they reflect a certain underlying order, which may or may not be divinely inspired."

"I have found far greater enthusiasm for science in America than here in Britain. There is more enthusiasm for everything in America."

"I don't have much positive to say about motor neuron disease, but it taught me not to pity myself because others were worse off, and to get on with what I still could do. I'm happier now than before I developed the condition."

"So long as the universe had a beginning, we could suppose it had a creator. But if the universe is really completely self-contained, having no boundary or edge, it would have neither beginning nor end: it would simply be. What place, then, for a creator?"

"Time and space are finite in extent, but they don't have any boundary or edge. They would be like the surface of the earth, but with two more dimensions."

"Women. They are a complete mystery."

"It's time to commit to finding the answer, to search for life beyond Earth. Mankind has a deep need to explore, to learn, to know. We also happen to be sociable creatures. It is important for us to know if we are alone in the dark."

"I think the human race doesn't have a future if it doesn't go into space."

"It is no good getting furious if you get stuck. What I do is keep thinking about the problem but work on something else. Sometimes it is years before I see the way forward. In the case of information loss and black holes, it was 29 years."

"It is generally recognized that women are better than men at languages, personal relations and multitasking, but less good at map-reading and spatial awareness. It is therefore not unreasonable to suppose that women might be less good at mathematics and physics. It is not politically correct to say such things....But it cannot be denied that there are differences between men and women. Of course, these are differences between the averages only. There are wide variations about the mean."

"I swear to use my scientific knowledge for the good of Humanity. I promise never to harm any person in my search for enlightenment.I shall be courageous and careful in my quest for greater knowledge about the mysteries that surround us. I shall not use scientific knowledge for my own personal gain or give it to those who seek to destroy the wonderful planet on which we live.If I break this oath, may the beauty and wonder of the Universe forever remain hidden from me."

"Someone told me that each equation I included in the book would halve the sales."

"When one's expectations are reduced to zero one really appreciates everything one does have."

"If time travel is possible, where are the tourists from the future?"

"I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road."

"God not only plays dice, He also sometimes throws the dice where they cannot be seen."

"We must develop as quickly as possible technologies that make possible a direct connection between brain and computer, so that artificial brains contribute to human intelligence rather than opposing it."

"Before 1915, space and time were thought of as a fixed arena in which events took place, but which was not affected by what happened in it. Space and time are now dynamic quantities... space and time not only affect but are also affected by everything that happens in the universe."

"We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special."

"Yet if there really were a complete unified theory, it would also presumably determine our actions-so the theory itself would determine the outcome of our search for it! And why should it determine that we come to the right conclusions from the evidence? Might it not equally well determine that we draw the wrong conclusion? Or no conclusion at all?"

"One, remember to look up at the stars and not down at your feet. Two, never give up work. Work gives you meaning and purpose and life is empty without it. Three, if you are lucky enough to find love, remember it is there and don't throw it away."

"There are grounds for cautious optimism that we may now be near the end ofthe search for the ultimate laws of nature."

"Time travel was once considered scientific heresy, and I used to avoid talking about it for fear of being labelled a 'crank.'"

"We lived in a tall, narrow Victorian house, which my parents had bought very cheaply during the war, when everyone thought London was going to be bombed flat. In fact, a V-2 rocket landed a few houses away from ours. I was away with my mother and sister at the time, but my father was in the house."

"My advice to any heartbroken young girl is to pay close attention to the study of theoretical physics. Because one day there may well be proof of multiple universes. It would not be beyond the realms of possibility that somewhere outside of our own universe lies another different universe. And in that universe, Zayn is still in One Direction."

"The people who actually make the advances in theoretical physics don't think in these categories that the philosophers and the historians of science subsequently invent for them."

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

"There is a fundamental difference between religion, which is based on authority, and science, which is based on observation and reason. Science will win because it works."

"Keeping an active mind has been vital to my survival, as has been maintaining a sense of humor."

"A few years ago, the city council of Monza, Italy, barred pet owners from keeping goldfish in curved bowls... saying that it is cruel to keep a fish in a bowl with curved sides because, gazing out, the fish would have a distorted view of reality. But how do we know we have the true, undistorted picture of reality?"

"I don't think the human race will survive the next thousand years, unless we spread into space."

"A zero-gravity flight is a first step toward space travel."

"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."

"Time can behave like another direction in space under extreme conditions."

"Success in creating AI would be the biggest event in human history. Unfortunately, it might also be the last, unless we learn how to avoid the risks."

"God may exist, but science can explain the universe without the need for a creator."