Freeman John Dyson (born 15 December 1923) is an English-born American physicist, mathematician, and futurist, famous for his work in quantum mechanics, nuclear weapons design and policy, and the search for extraterrestrial intelligence. He was the winner of the Templeton Prize in the year 2000.
- I am acutely aware of the fact that the marriage between mathematics and physics, which was so enormously fruitful in past centuries, has recently ended in divorce.
- Missed Opportunities (1972)
- Thirty-one years ago , Dick Feynman told me about his "sum over histories" version of quantum mechanics. "The electron does anything it likes," he said. "It just goes in any direction at any speed, forward or backward in time, however it likes, and then you add up the amplitudes and it gives you the wave-function." I said to him, "You're crazy." But he wasn't.
- A statement made in 1980, as quoted in Quantum Reality : Beyond the New Physics (1987) by Nick Herbert
- I have felt it myself. The glitter of nuclear weapons. It is irresistible if you come to them as a scientist. To feel it's there in your hands, to release this energy that fuels the stars, to let it do your bidding. To perform these miracles, to lift a million tons of rock into the sky. It is something that gives people an illusion of illimitable power, and it is, in some ways, responsible for all our troubles — this, what you might call technical arrogance, that overcomes people when they see what they can do with their minds.
- As quoted in The Day After Trinity: J. Robert Oppenheimer and the Atomic Bomb (1981), a documentary film directed by Jon Else, written by David Peoples, Janet Peoples, and Jon Else.
- As we look out into the Universe and identify the many accidents of physics and astronomy that have worked together to our benefit, it almost seems as if the Universe must in some sense have known that we were coming.
- The bottom line for mathematicians is that the architecture has to be right. In all the mathematics that I did, the essential point was to find the right architecture. It's like building a bridge. Once the main lines of the structure are right, then the details miraculously fit. The problem is the overall design.
- "Freeman Dyson: Mathematician, Physicist, and Writer". Interview with Donald J. Albers, The College Mathematics Journal, vol 25, no. 1, (January 1994)
- There is no such thing as a unique scientific vision, any more than there is a unique poetic vision. Science is a mosaic of partial and conflicting visions. But there is one common element in these visions. The common element is rebellion against the restrictions imposed by the locally prevailing culture, Western or Eastern as the case may be. It is no more Western than it is Arab or Indian or Japanese or Chinese. Arabs and Indians and Japanese and Chinese had a big share in the development of modern science. And two thousand years earlier, the beginnings of science were as much Babylonian and Egyptian as Greek. One of the central facts about science is that it pays no attention to East and West and North and South and black and yellow and white. It belongs to everybody who is willing to make the effort to learn it.
- "The Scientist as Rebel" in New York Review of Books (25 May 1995)
- The progress of science requires the growth of understanding in both directions, downward from the whole to the parts and upward from the parts to the whole. A reductionist philosophy, arbitrarily proclaiming that the growth of understanding must go only in one direction, makes no scientific sense. Indeed, dogmatic philosophical beliefs of any kind have no place in science.
- "The Scientist as Rebel" in New York Review of Books (25 May 1995)
- The laws of nature are constructed in such a way as to make the universe as interesting as possible.
- Imagined Worlds (1997)
- In desperation I asked Fermi whether he was not impressed by the agreement between our calculated numbers and his measured numbers. He replied, "How many arbitrary parameters did you use for your calculations?" I thought for a moment about our cut-off procedures and said, "Four." He said, "I remember my friend Johnny von Neumann used to say, with four parameters I can fit an elephant, and with five I can make him wiggle his trunk." With that, the conversation was over.
- "A meeting with Enrico Fermi" in Nature 427 (22 January 2004), p. 297 (subscription required)
- The biggest breakthrough in the next 50 years will be the discovery of extraterrestrial life. We have been searching for it for 50 years and found nothing. That proves life is rarer than we hoped, but does not prove that the universe is lifeless. We are only now developing the tools to make our searches efficient and far-reaching, as optical and radio detection and data processing move forward.
- My first heresy says that all the fuss about global warming is grossly exaggerated. Here I am opposing the holy brotherhood of climate model experts and the crowd of deluded citizens who believe the numbers predicted by the computer models. Of course, they say, I have no degree in meteorology and I am therefore not qualified to speak. But I have studied the climate models and I know what they can do. The models solve the equations of fluid dynamics, and they do a very good job of describing the fluid motions of the atmosphere and the oceans. They do a very poor job of describing the clouds, the dust, the chemistry and the biology of fields and farms and forests. They do not begin to describe the real world that we live in. The real world is muddy and messy and full of things that we do not yet understand. It is much easier for a scientist to sit in an air-conditioned building and run computer models, than to put on winter clothes and measure what is really happening outside in the swamps and the clouds. That is why the climate model experts end up believing their own models.
- I believe global warming is grossly exaggerated as a problem. It's a real problem, but it's nothing like as serious as people are led to believe. The idea that global warming is the most important problem facing the world is total nonsense and is doing a lot of harm. It distracts people's attention from much more serious problems.
- All the books that I have seen about the science and the economics of global warming, including the two books under review, miss the main point. The main point is religious rather than scientific. There is a worldwide secular religion which we may call environmentalism, holding that we are stewards of the earth, that despoiling the planet with waste products of our luxurious living is a sin, and that the path of righteousness is to live as frugally as possible. ... Environmentalism has replaced socialism as the leading secular religion.
- The New York Review of Books (12 June 2008)
Disturbing the Universe (1979) 
- There is a great satisfaction in building good tools for other people to use.
- If we had a reliable way to label our toys good and bad, it would be easy to regulate technology wisely. But we can rarely see far enough ahead to know which road leads to damnation. Whoever concerns himself with big technology, either to push it forward or to stop it, is gambling in human lives.
- It is characteristic of all deep human problems that they are not to be approached without some humor and some bewilderment.
- A good cause can become bad if we fight for it with means that are indiscriminately murderous. A bad cause can become good if enough people fight for it in a spirit of comradeship and self-sacrifice. In the end it is how you fight, as much as why you fight, that makes your cause good or bad.
- A good scientist is a person with original ideas. A good engineer is a person who makes a design that works with as few original ideas as possible. There are no prima donnas in engineering.
- The conservative has little to fear from the man whose reason is the servant of his passions, but let him beware of him in whom reason has become the greatest and most terrible of passions. These are the wreckers of outworn empires.
Infinite in All Directions (1988) 
- The technologies which have had the most profound effects on human life are usually simple. A good example of a simple technology with profound historical consequences is hay. Nobody knows who invented hay, the idea of cutting grass in the autumn and storing it in large enough quantities to keep horses and cows alive through the winter. All we know is that the technology of hay was unknown to the Roman Empire but was known to every village of medieval Europe. Like many other crucially important technologies, hay emerged anonymously during the so-called Dark Ages. According to the Hay Theory of History, the invention of hay was the decisive event which moved the center of gravity of urban civilization from the Mediterranean basin to Northern and Western Europe. The Roman Empire did not need hay because in a Mediterranean climate the grass grows well enough in winter for animals to graze. North of the Alps, great cities dependent on horses and oxen for motive power could not exist without hay. So it was hay that allowed populations to grow and civilizations to flourish among the forests of Northern Europe. Hay moved the greatness of Rome to Paris and London, and later to Berlin and Moscow and New York.
- God is what mind becomes when it has passed beyond the scale of our comprehension.
Progress In Religion (2000) 
- Progress In Religion : A Talk By Freeman Dyson; his acceptance speech for the Templeton Prize, Washington National Cathedral (9 May 2000)
- I am neither a saint nor a theologian. To me, good works are more important than theology. We all know that religion has been historically, and still is today, a cause of great evil as well as great good in human affairs. We have seen terrible wars and terrible persecutions conducted in the name of religion. We have also seen large numbers of people inspired by religion to lives of heroic virtue, bringing education and medical care to the poor, helping to abolish slavery and spread peace among nations. Religion amplifies the good and evil tendencies of individual souls.
- Religion will always remain a powerful force in the history of our species. To me, the meaning of progress in religion is simply this, that as we move from the past to the future the good works inspired by religion should more and more prevail over the evil.
- One of the great but less famous heroes of World War Two was Andre Trocme, the Protestant pastor of the village of Le Chambon sur Lignon in France, which sheltered and saved the lives of five thousand Jews under the noses of the Gestapo. Forty years later Pierre Sauvage, one of the Jews who was saved, recorded the story of the village in a magnificent documentary film with the title, "Weapons of the Spirit". The villagers proved that civil disobedience and passive resistance could be effective weapons, even against Hitler. Their religion gave them the courage and the discipline to stand firm. Progress in religion means that, as time goes on, religion more and more takes the side of the victims against the oppressors.
- Sharing the food is to me more important than arguing about beliefs. Jesus, according to the gospels, thought so too.
- I am content to be one of the multitude of Christians who do not care much about the doctrine of the Trinity or the historical truth of the gospels. Both as a scientist and as a religious person, I am accustomed to living with uncertainty. Science is exciting because it is full of unsolved mysteries, and religion is exciting for the same reason. The greatest unsolved mysteries are the mysteries of our existence as conscious beings in a small corner of a vast universe.
- My personal theology is described in the Gifford lectures that I gave at Aberdeen in Scotland in 1985, published under the title, Infinite In All Directions. Here is a brief summary of my thinking. The universe shows evidence of the operations of mind on three levels. The first level is elementary physical processes, as we see them when we study atoms in the laboratory. The second level is our direct human experience of our own consciousness. The third level is the universe as a whole. Atoms in the laboratory are weird stuff, behaving like active agents rather than inert substances. They make unpredictable choices between alternative possibilities according to the laws of quantum mechanics. It appears that mind, as manifested by the capacity to make choices, is to some extent inherent in every atom. The universe as a whole is also weird, with laws of nature that make it hospitable to the growth of mind. I do not make any clear distinction between mind and God. God is what mind becomes when it has passed beyond the scale of our comprehension. God may be either a world-soul or a collection of world-souls. So I am thinking that atoms and humans and God may have minds that differ in degree but not in kind. We stand, in a manner of speaking, midway between the unpredictability of atoms and the unpredictability of God. Atoms are small pieces of our mental apparatus, and we are small pieces of God's mental apparatus. Our minds may receive inputs equally from atoms and from God. This view of our place in the cosmos may not be true, but it is compatible with the active nature of atoms as revealed in the experiments of modern physics. I don't say that this personal theology is supported or proved by scientific evidence. I only say that it is consistent with scientific evidence.
- I do not claim any ability to read God's mind. I am sure of only one thing. When we look at the glory of stars and galaxies in the sky and the glory of forests and flowers in the living world around us, it is evident that God loves diversity. Perhaps the universe is constructed according to a principle of maximum diversity.
- The principle of maximum diversity says that the laws of nature, and the initial conditions at the beginning of time, are such as to make the universe as interesting as possible. As a result, life is possible but not too easy. Maximum diversity often leads to maximum stress. In the end we survive, but only by the skin of our teeth. This is the confession of faith of a scientific heretic. Perhaps I may claim as evidence for progress in religion the fact that we no longer burn heretics.
- All through our history, we have been changing the world with our technology. Our technology has been of two kinds, green and grey. Green technology is seeds and plants, gardens and vineyards and orchards, domesticated horses and cows and pigs, milk and cheese, leather and wool. Grey technology is bronze and steel, spears and guns, coal and oil and electricity, automobiles and airplanes and rockets, telephones and computers. Civilization began with green technology, with agriculture and animal-breeding, ten thousand years ago. Then, beginning about three thousand years ago, grey technology became dominant, with mining and metallurgy and machinery. For the last five hundred years, grey technology has been racing ahead and has given birth to the modern world of cities and factories and supermarkets.
The dominance of grey technology is now coming to an end.
- Our grey technology of machines and computers will not disappear, but green technology will be moving ahead even faster. Green technology can be cleaner, more flexible and less wasteful, than our existing chemical industries. A great variety of manufactured objects could be grown instead of made. Green technology could supply human needs with far less damage to the natural environment. And green technology could be a great equalizer, bringing wealth to the tropical areas of the world which have most of the sunshine, most of the human population, and most of the poverty. I am saying that green technology could do all these good things, bringing wealth to the tropics, bringing economic opportunity to the villages, narrowing the gap between rich and poor. I am not saying that green technology will do all these good things. "Could" is not the same as "will". To make these good things happen, we need not only the new technology but the political and economic conditions that will give people all over the world a chance to use it. To make these things happen, we need a powerful push from ethics. We need a consensus of public opinion around the world that the existing gross inequalities in the distribution of wealth are intolerable. In reaching such a consensus, religions must play an essential role. Neither technology alone nor religion alone is powerful enough to bring social justice to human societies, but technology and religion working together might do the job.
- The gospel of St. Matthew told of the angry Jesus driving the merchants and money-changers out of the temple, knocking over the tables of the money-changers and spilling their coins on the floor. Jesus was not opposed to capitalism and the profit motive, so long as economic activities were carried on outside the temple. In the parable of the talents, he praises the servant who used his master's money to make a profitable investment, and condemns the servant who was too timid to invest. But he draws a clear line at the temple door. Inside the temple, the ground belongs to God and profit-making must stop.
- In the time of Jesus and for many centuries afterwards, there was a free market in human bodies. The institution of slavery was based on the legal right of slave-owners to buy and sell their property in a free market. Only in the nineteenth century did the abolitionist movement, with Quakers and other religious believers in the lead, succeed in establishing the principle that the free market does not extend to human bodies. The human body is God's temple and not a commercial commodity. And now in the twenty-first century, for the sake of equity and human brotherhood, we must maintain the principle that the free market does not extend to human genes. Let us hope that we can reach a consensus on this question without fighting another civil war.
- Like all the new technologies that have arisen from scientific knowledge, biotechnology is a tool that can be used either for good or for evil purposes. The role of ethics is to strengthen the good and avoid the evil.
- Unfortunately a large number of people in many countries are strongly opposed to green technology, for reasons having little to do with the real dangers. It is important to treat the opponents with respect, to pay attention to their fears, to go gently into the new world of green technology so that neither human dignity nor religious conviction is violated. If we can go gently, we have a good chance of achieving within a hundred years the goals of ecological sustainability and social justice that green technology brings within our reach.
- I have five minutes left to give you a message to take home. The message is simple. "God forbid that we should give out a dream of our own imagination for a pattern of the world". This was said by Francis Bacon, one of the founding fathers of modern science, almost four hundred years ago. Bacon was the smartest man of his time, with the possible exception of William Shakespeare.
- I am saying to modern scientists and theologians: don't imagine that our latest ideas about the Big Bang or the human genome have solved the mysteries of the universe or the mysteries of life. Here are Bacon's words again: "The subtlety of nature is greater many times over than the subtlety of the senses and understanding". In the last four hundred years, science has fulfilled many of Bacon's dreams, but it still does not come close to capturing the full subtlety of nature.
- To talk about the end of science is just as foolish as to talk about the end of religion. Science and religion are both still close to their beginnings, with no ends in sight. Science and religion are both destined to grow and change in the millennia that lie ahead of us, perhaps solving some old mysteries, certainly discovering new mysteries of which we yet have no inkling.
- After sketching his program for the scientific revolution that he foresaw, Bacon ends his account with a prayer: "Humbly we pray that this mind may be steadfast in us, and that through these our hands, and the hands of others to whom thou shalt give the same spirit, thou wilt vouchsafe to endow the human family with new mercies". That is still a good prayer for all of us as we begin the twenty-first century.
- Science and religion are two windows that people look through, trying to understand the big universe outside, trying to understand why we are here. The two windows give different views, but they look out at the same universe. Both views are one-sided, neither is complete. Both leave out essential features of the real world. And both are worthy of respect.
- Trouble arises when either science or religion claims universal jurisdiction, when either religious dogma or scientific dogma claims to be infallible. Religious creationists and scientific materialists are equally dogmatic and insensitive. By their arrogance they bring both science and religion into disrepute. The media exaggerate their numbers and importance. The media rarely mention the fact that the great majority of religious people belong to moderate denominations that treat science with respect, or the fact that the great majority of scientists treat religion with respect so long as religion does not claim jurisdiction over scientific questions.
- In the little town of Princeton where I live, we have more than twenty churches and at least one synagogue, providing different forms of worship and belief for different kinds of people. They do more than any other organizations in the town to hold the community together. Within this community of people, held together by religious traditions of human brotherhood and sharing of burdens, a smaller community of professional scientists also flourishes.
- The great question for our time is, how to make sure that the continuing scientific revolution brings benefits to everybody rather than widening the gap between rich and poor. To lift up poor countries, and poor people in rich countries, from poverty, to give them a chance of a decent life, technology is not enough. Technology must be guided and driven by ethics if it is to do more than provide new toys for the rich.
- Scientists and business leaders who care about social justice should join forces with environmental and religious organizations to give political clout to ethics. Science and religion should work together to abolish the gross inequalities that prevail in the modern world. That is my vision, and it is the same vision that inspired Francis Bacon four hundred years ago, when he prayed that through science God would "endow the human family with new mercies".
Quotes about Dyson 
- You'll have received an application from Mr Freeman Dyson to come to work with you as a graduate student. I hope that you will accept him. Although he is only 23 he is in my view the best mathematician in England.
- Mr Dyson is absolutely unusual in his ability and accomplishments. I can say without reservation that he is the best I have ever had or observed.
- Freeman J. Dyson's homepage
- Brief biography at University of St Andrews
- Disturbing the Universe: Interview with Freeman Dyson (18 January 1980)
- Wired magazine interview: Freeman Dyson's Brain (February 1998)
- Freeman Dyson: Gravity is Cool, or, Why our Universe is Hospitable to Life Oppenheimer lecture (9 March 2000)
- Freeman Dyson wins $1m religion prize (9 May 2000)
- Progress In Religion : A Talk By Freeman Dyson Edge magazine 68 (16 May 2000)
- In Praise of Open Thinking Open Source Convention (OSCON) 2004 in Portland, Oregon.
- NPR interview with Freeman Dyson (2 November 2004)
- Re:Infinite in All Directions