Following are some Stephen Hawking quotes which we have in our database of Quotes of Stephen Hawking.
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.
Science is beautiful when it makes simple explanations of phenomena or connections between different observations. Examples include the double helix in biology and the fundamental equations of physics.
I believe alien life is quite common in the universe, although intelligent life is less so. Some say it has yet to appear on planet Earth.
My advice to other disabled people would be, concentrate on things your disability doesn't prevent you doing well, and don't regret the things it interferes with. Don't be disabled in spirit as well as physically.
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.
In my school, the brightest boys did math and physics, the less bright did physics and chemistry, and the least bright did biology. I wanted to do math and physics, but my father made me do chemistry because he thought there would be no jobs for mathemati
Stem cell research is the key to developing cures for degenerative conditions like Parkinson's and motor neuron disease from which I and many others suffer. The fact that the cells may come from embryos is not an objection, because the embryos are go
With genetic engineering, we will be able to increase the complexity of our DNA, and improve the human race. But it will be a slow process, because one will have to wait about 18 years to see the effect of changes to the genetic code.
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.
Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill.
I was never top of the class at school, but my classmates must have seen potential in me, because my nickname was 'Einstein.'
We are in danger of destroying ourselves by our greed and stupidity. We cannot remain looking inwards at ourselves on a small and increasingly polluted and overcrowded planet.
If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans.
Even if it turns out that time travel is impossible, it is important that we understand why it is impossible.
Life on Earth is at the ever-increasing risk of being wiped out by a disaster, such as sudden global nuclear war, a genetically engineered virus or other dangers we have not yet thought of.
Although September 11 was horrible, it didn't threaten the survival of the human race, like nuclear weapons do.
I am just a child who has never grown up. I still keep asking these 'how' and 'why' questions. Occasionally, I find an answer.
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.
I would like nuclear fusion to become a practical power source. It would provide an inexhaustible supply of energy, without pollution or global warming.
My goal is simple. It is a complete understanding of the universe, why it is as it is and why it exists at all.
Obviously, because of my disability, I need assistance. But I have always tried to overcome the limitations of my condition and lead as full a life as possible. I have traveled the world, from the Antarctic to zero gravity.
The radiation left over from the Big Bang is the same as that in your microwave oven but very much less powerful. It would heat your pizza only to minus 271.3*C - not much good for defrosting the pizza, let alone cooking it.
We are all different. There is no such thing as a standard or run-of-the-mill human being, but we share the same human spirit.
While physics and mathematics may tell us how the universe began, they are not much use in predicting human behavior because there are far too many equations to solve. I'm no better than anyone else at understanding what makes people tick, particular
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.
In less than a hundred years, we have found a new way to think of ourselves. From sitting at the center of the universe, we now find ourselves orbiting an average-sized sun, which is just one of millions of stars in our own Milky Way galaxy.
I believe the universe is governed by the laws of science. The laws may have been decreed by God, but God does not intervene to break the laws.
There is no heaven or afterlife for broken-down computers; that is a fairy story for people afraid of the dark.
Many badly needed goals, like fusion and cancer cure, would be achieved much sooner if we invested more.
I can't say that my disability has helped my work, but it has allowed me to concentrate on research without having to lecture or sit on boring committees.
Theoretical physics is one of the few fields in which being disabled is no handicap - it is all in the mind.
There are plenty of dead scientists I admire, but I can't think of any living ones. This is probably because it is only in retrospect that one can see who made the important contributions.
It is generally recognised that women are better than men at languages, personal relations and multi-tasking, 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
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
If the rate of expansion one second after the Big Bang had been smaller by even one part in a hundred thousand million million, it would have recollapsed before it reached its present size. On the other hand, if it had been greater by a part in a million,
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.
When we understand string theory, we will know how the universe began. It won't have much effect on how we live, but it is important to understand where we come from and what we can expect to find as we explore.
I was born on January 8, 1942, exactly three hundred years after the death of Galileo. I estimate, however, that about two hundred thousand other babies were also born that day. I don't know whether any of them was later interested in astronomy.
I think the brain is essentially a computer and consciousness is like a computer program. It will cease to run when the computer is turned off. Theoretically, it could be re-created on a neural network, but that would be very difficult, as it would requir
We think we have solved the mystery of creation. Maybe we should patent the universe and charge everyone royalties for their existence.
'The Simpsons' appearances were great fun. But I don't take them too seriously. I think 'The Simpsons' have treated my disability responsibly.
As scientists, we step on the shoulders of science, building on the work that has come before us - aiming to inspire a new generation of young scientists to continue once we are gone.
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 a
Although almost every theoretical physicist agrees with my prediction that a black hole should glow like a hot body, it would be very difficult to verify experimentally because the temperature of a macroscopic black hole is so low.
I used to think information was destroyed in black hole. This was my biggest blunder, or at least my biggest blunder in science.
For years, my early work with Roger Penrose seemed to be a disaster for science. It showed that the universe must have begun with a singularity, if Einstein's general theory of relativity is correct. That appeared to indicate that science could not p
Some people would claim that things like love, joy and beauty belong to a different category from science and can't be described in scientific terms, but I think they can now be explained by the theory of evolution.
I don't have much positive to say about motor neurone disease. But it taught me not to pity myself because others were worse off, and to get on with what I could still do.
I have found far greater enthusiasm for science in America than here in Britain. There is more enthusiasm for everything in America.
Maybe I don't have the most common kind of motor neuron disease, which usually kills in two or three years.
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.
No one undertakes research in physics with the intention of winning a prize. It is the joy of discovering something no one knew before.
There is a real danger that computers will develop intelligence and take over. We urgently need to develop direct connections to the brain so that computers can add to human intelligence rather than be in opposition.
I believe everyone should have a broad picture of how the universe operates and our place in it. It is a basic human desire. And it also puts our worries in perspective.
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.
Time travel was once considered scientific heresy, and I used to avoid talking about it for fear of being labelled a 'crank.'
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.
My discovery that black holes emit radiation raised serious problems of consistency with the rest of physics. I have now resolved these problems, but the answer turned out to be not what I expected.
God is the name people give to the reason we are here. But I think that reason is the laws of physics rather than someone with whom one can have a personal relationship. An impersonal God.
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.
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.
We only have to look at ourselves to see how intelligent life might develop into something we wouldn't want to meet.
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?
I think those who have a terminal illness and are in great pain should have the right to choose to end their own life, and those that help them should be free from prosecution.
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?
There are grounds for cautious optimism that we may now be near the end ofthe search for the ultimate laws of nature.
The universe is governed by science. But science tells us that we can't solve the equations, directly in the abstract.
Observations indicate that the universe is expanding at an ever increasing rate. It will expand forever, getting emptier and darker.
Science predicts that many different kinds of universe will be spontaneously created out of nothing. It is a matter of chance which we are in.
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.
Some forms of motor neuron disease are genetically linked, but I have no indication that my kind is. No other member of my family has had it. But I would be in favour of abortion if there was a high risk.
In the past, there was active discrimination against women in science. That has now gone, and although there are residual effects, these are not enough to account for the small numbers of women, particularly in mathematics and physics.
If we do discover a complete theory, it should be in time understandable in broad principle by everyone. Then we shall all, philosophers, scientists, and just ordinary people be able to take part in the discussion of why we and the universe exist.
My ideal role would be a baddie in a James Bond film. I think the wheelchair and the computer voice would fit the part.
I think it quite likely that we are the only civilization within several hundred light years; otherwise we would have heard radio waves.
To my mathematical brain, the numbers alone make thinking about aliens perfectly rational. The real challenge is to work out what aliens might actually be like.
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?
Most sets of values would give rise to universes that, although they might be very beautiful, would contain no one able to wonder at that beauty.
If I had a time machine, I'd visit Marilyn Monroe in her prime or drop in on Galileo as he turned his telescope to the heavens.
I entered the health care debate in response to a statement in the United States press in summer 2009 which claimed the National Health Service in Great Britain would have killed me off, were I a British citizen. I felt compelled to make a statement to ex
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 realist
Before I lost my voice, it was slurred, so only those close to me could understand, but with the computer voice, I found I could give popular lectures. I enjoy communicating science. It is important that the public understands basic science, if they are n
Evolution has ensured that our brains just aren't equipped to visualise 11 dimensions directly. However, from a purely mathematical point of view it's just as easy to think in 11 dimensions, as it is to think in three or four.
There is no physical law precluding particles from being organised in ways that perform even more advanced computations than the arrangements of particles in human brains.
As Irving Good realised in 1965, machines with superhuman intelligence could repeatedly improve their design even further, triggering what Vernor Vinge called a 'singularity.'
The Planck satellite may detect the imprint of the gravitational waves predicted by inflation. This would be quantum gravity written across the sky.
The media need superheroes in science just as in every sphere of life, but there is really a continuous range of abilities with no clear dividing line.
In Britain, like most of the developed world, stem-cell research is regarded as a great opportunity. America will be left behind if it doesn't change policy.
Throughout history, people have studied pure science from a desire to understand the universe rather than practical applications for commercial gain. But their discoveries later turned out to have great practical benefits.
I think the discovery of supersymmetric partners for the known particles would revolutionize our understanding of the universe.
According to 'M' theory, ours is not the only universe. Instead, 'M' theory predicts that a great many universes were created out of nothing.
Why are we here? Where do we come from? Traditionally, these are questions for philosophy, but philosophy is dead.
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 tha
My father was a research scientist in tropical medicine, so I always assumed I would be a scientist, too. I felt that medicine was too vague and inexact, so I chose physics.
It's a pity that nobody has found an exploding black hole. If they had, I would have won a Nobel prize.
I hope I have helped to raise the profile of science and to show that physics is not a mystery but can be understood by ordinary people.
We think that life develops spontaneously on Earth, so it must be possible for life to develop on suitable planets elsewhere in the universe. But we don't know the probability that a planet develops life.
My first popular book, 'A Brief History of Time,' aroused a great deal of interest, but many found it difficult to understand.
The voice I use is a very old hardware speech synthesizer made in 1986. I keep it because I have not heard a voice I like better and because I have identified with it.
Some scientists think it may be possible to capture a wormhole and enlarge it many trillions of times to make it big enough for a human or even a spaceship to enter.
If we want to travel into the future, we just need to go fast. Really fast. And I think the only way we're ever likely to do that is by going into space.
Our minds work in real time, which begins at the Big Bang and will end, if there is a Big Crunch - which seems unlikely, now, from the latest data showing accelerating expansion. Consciousness would come to an end at a singularity.
I wouldn't be here today if it were not for the NHS. I have received a large amount of high-quality treatment without which I would not have survived.
As a child, I wanted to know how things worked and to control them. With a friend, I built a number of complicated models that I could control.
I had not expected 'A Brief History of Time' to be a best seller. It was my first popular book and aroused a great deal of interest. Initially, many people found it difficult to understand. I therefore decided to try to write a new version that
The doctor who diagnosed me with ALS, or motor neuron disease, told me that it would kill me in two or three years.
I am in touch with a company that hopes to replicate my voice. However, they are not replicating my original voice - if they did that, I would sound like a man in his 20s, which would be very strange! They are actually trying to replicate the synthesizer
If you believe in science, like I do, you believe that there are certain laws that are always obeyed.
I first had the idea of writing a popular book about the universe in 1982. My intention was partly to earn money to pay my daughter's school fees.
I don't care much for equations myself. This is partly because it is difficult for me to write them down, but mainly because I don't have an intuitive feeling for equations.