• 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. 
  • 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.
  • Quiet people have the loudest minds.
  • Life would be tragic if it weren't funny.
  • Intelligence is the ability to adapt to change.
  • Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe? The usual approach of science of constructing a mathematical model cannot answer the questions of why there should be a universe for the model to describe. Why does the universe go to all the bother of existing?
  • 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.
  • It surprises me how disinterested we are today about things like physics, space, the universe and philosophy of our existence, our purpose, our final destination. Its a crazy world out there. Be curious.
  • My expectations were reduced to zero when I was 21. Everything since then has been a bonus.
  • Remember to look up at the stars and not down at your feet. Try to make sense of what you see and wonder about what makes the universe exist. Be curious. And however difficult life may seem, there is always something you can do and succeed at.
  • It matters that you don't just give up.
  • The victim should have the right to end his life, if he wants. But I think it would be a great mistake. However bad life may seem, there is always something you can do, and succeed at. While there's life, there is hope.
  • I have noticed that even those who assert that everything is predestined and that we can change nothing about it still look both ways before they cross the street
  • I believe the simplest explanation is, there is no God. No one created the universe and no one directs our fate. This leads me to a profound realization that there probably is no heaven and no afterlife either. We have this one life to appreciate the grand design of the universe and for that, I am extremely grateful.
  • [In the Universe it may be that] Primitive life is very common and intelligent life is fairly rare. Some would say it has yet to occur on Earth.
  • I think computer viruses should count as life ... I think it says something about human nature that the only form of life we have created so far is purely destructive. We've created life in our own image.
  • One of the basic rules of the universe is that nothing is perfect. Perfection simply doesn't exist.....Without imperfection, neither you nor I would exist
  • My goal is simple. It is a complete understanding of the universe, why it is as it is and why it exists at all.
  • The universe doesn't allow perfection.
  • The role played by time at the beginning of the universe is, I believe, the final key to removing the need for a Grand Designer, and revealing how the universe created itself. … Time itself must come to a stop. You can’t get to a time before the big bang, because there was no time before the big bang. We have finally found something that does not have a cause because there was no time for a cause to exist in. For me this means there is no possibility of a creator because there is no time for a creator to have existed. Since time itself began at the moment of the Big Bang, it was an event that could not have been caused or created by anyone or anything. … So when people ask me if a god created the universe, I tell them the question itself makes no sense. Time didn’t exist before the Big Bang, so there is no time for God to make the universe in. It’s like asking for directions to the edge of the Earth. The Earth is a sphere. It does not have an edge, so looking for it is a futile exercise.
  • 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.
  • If time travel is possible, where are the tourists from the future?
  • People who boast about their I.Q. are losers.
  • I'm not afraid of death, but I'm in no hurry to die.
  • The thing about smart people is that they seem like crazy people to dumb people.
  • 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.
  • Not only does God play dice but... he sometimes throws them where they cannot be seen.
  • I don't think the human race will survive the next thousand years, unless we spread into space.