Freeman John Dyson FRS (born 15 December 1923) is a British-American theoretical physicist and mathematician. He is known for his work in quantum electrodynamics, solid-state physics, astronomy and nuclear engineering. He theorized several concepts that bear his name, such as Dyson's transform, the Dyson tree, the Dyson series, and the Dyson sphere.
Freeman John Dyson
15 December 1923
|Spouse(s)||Verena Huber-Dyson (1950–1958)|
Imme Jung (1958–)
|Children||Esther Dyson, George Dyson, Dorothy Dyson, Mia Dyson, Rebecca Dyson, Emily Dyson|
|Academic advisors||Hans Bethe|
Abram Samoilovitch Besicovitch
He is the son of George Dyson.
Born on 15 December 1923, at Crowthorne in Berkshire, Dyson is the son of the English composer George Dyson, who was later knighted. His mother had a law degree, and after Dyson was born she worked as a social worker. Dyson had one sibling, his older sister, Alice, who remembered him as a boy surrounded by encyclopedias and always calculating on sheets of paper. At the age of four he tried to calculate the number of atoms in the sun. As a child, he showed an interest in large numbers and in the solar system, and was strongly influenced by the book Men of Mathematics by Eric Temple Bell. Politically, Dyson says he was "brought up as a socialist".
From 1936 to 1941, Dyson was a scholar at Winchester College, where his father was Director of Music. At age 17 he studied mathematics with G.H. Hardy at Trinity College, Cambridge (where he won a scholarship at age 15) and at age 19 was assigned to war work in the Operational Research Section (ORS) of the Royal Air Force's Bomber Command, where he developed analytical methods to help the Royal Air Force bomb German targets during the Second World War. After the war, Dyson was readmitted to Trinity College, Cambridge, where he obtained a BA degree in mathematics. From 1946 to 1949, he was a Fellow of his college, occupying rooms just below those of the philosopher Ludwig Wittgenstein, who resigned his professorship in 1947. In 1947, Dyson published two papers in number theory. Friends and colleagues describe him as shy and self-effacing, with a contrarian streak that his friends find refreshing but his intellectual opponents find exasperating. "I have the sense that when consensus is forming like ice hardening on a lake, Dyson will do his best to chip at the ice", Steven Weinberg said of him. His friend, the neurologist and author Oliver Sacks, said: "A favourite word of Freeman's about doing science and being creative is the word 'subversive'. He feels it's rather important not only to be not orthodox, but to be subversive, and he's done that all his life."
On G. I. Taylor's advice and recommendation, Dyson moved to the United States in 1947 as a Commonwealth Fellow to earn a physics doctorate with Hans Bethe at Cornell University (1947–48). Within a week, however, he had made the acquaintance of Richard Feynman. The budding English physicist recognized the brilliance of the flamboyant American, and attached himself as quickly as possible. He then moved to the Institute for Advanced Study (1948–49), before returning to England (1949–51), where he was a research fellow at the University of Birmingham. Dyson never got his PhD degree.
In 1949, Dyson demonstrated the equivalence of two then-current formulations of quantum electrodynamics (QED): Richard Feynman's diagrams and the operator method developed by Julian Schwinger and Shin'ichirō Tomonaga. He was the first person after their creator to appreciate the power of Feynman diagrams, and his paper written in 1948 and published in 1949 was the first to make use of them. He said in that paper that Feynman diagrams were not just a computational tool, but a physical theory, and developed rules for the diagrams that completely solved the renormalization problem. Dyson's paper and also his lectures presented Feynman's theories of QED in a form that other physicists could understand, facilitating the physics community's acceptance of Feynman's work. J. Robert Oppenheimer, in particular, was persuaded by Dyson that Feynman's new theory was as valid as Schwinger's and Tomonaga's. Oppenheimer rewarded Dyson with a lifetime appointment at the Institute for Advanced Study, "for proving me wrong", in Oppenheimer's words.
In 1951, Dyson joined the faculty at Cornell as a physics professor, although still lacking a doctorate, and in 1953, he received a permanent post at the Institute for Advanced Study in Princeton, New Jersey, where he has remained. In 1957, he became a naturalized citizen of the United States and renounced his British nationality. One reason he gave decades later is that his children born in the United States had not been recognized as British subjects.
From 1957 to 1961, he worked on Project Orion, which proposed the possibility of space-flight using nuclear pulse propulsion. A prototype was demonstrated using conventional explosives, but the 1963 Partial Test Ban Treaty, in which Dyson was involved and supported, permitted only underground nuclear weapons testing, so the project was abandoned.
A seminal paper by Dyson came in 1966, when, together with Andrew Lenard and independently of Elliott H. Lieb and Walter Thirring, he proved rigorously that the Pauli exclusion principle plays the main role in the stability of bulk matter. Hence, it is not the electromagnetic repulsion between outer-shell orbital electrons which prevents two wood blocks that are left on top of each other from coalescing into a single piece, but rather it is the exclusion principle applied to electrons and protons that generates the classical macroscopic normal force. In condensed matter physics, Dyson also analysed the phase transition of the Ising model in 1 dimension and spin waves.
Dyson also did work in a variety of topics in mathematics, such as topology, analysis, number theory and random matrices. There is an interesting story involving random matrices. In 1973, the number theorist Hugh Lowell Montgomery was visiting the Institute for Advanced Study and had just made his pair correlation conjecture concerning the distribution of the zeros of the Riemann zeta function. He showed his formula to the mathematician Atle Selberg, who said it looked like something in mathematical physics and he should show it to Dyson, which he did. Dyson recognized the formula as the pair correlation function of the Gaussian unitary ensemble, which has been extensively studied by physicists. This suggested that there might be an unexpected connection between the distribution of primes (2, 3, 5, 7, 11, ...) and the energy levels in the nuclei of heavy elements such as uranium.
Around 1979, Dyson worked with the Institute for Energy Analysis on climate studies. This group, under the direction of Alvin Weinberg, pioneered multidisciplinary climate studies, including a strong biology group. Also during the 1970s, he worked on climate studies conducted by the JASON defense advisory group.
Dyson retired from the Institute for Advanced Study in 1994. In 1998 he joined the board of the Solar Electric Light Fund. As of 2003 he was president of the Space Studies Institute, the space research organization founded by Gerard K. O'Neill; As of 2013 he is on its Board of Trustees. Dyson is a longtime member of the JASON group.
Dyson has won numerous scientific awards but never a Nobel Prize. Nobel physics laureate Steven Weinberg has said that the Nobel committee has "fleeced" Dyson, but Dyson himself remarked in 2009, "I think it's almost true without exception if you want to win a Nobel Prize, you should have a long attention span, get hold of some deep and important problem and stay with it for ten years. That wasn't my style." Dyson is a regular contributor to The New York Review of Books.
With his first wife, the Swiss mathematician Verena Huber-Dyson, Dyson had two children, Esther and George. In 1958, he married Imme Jung, a masters runner, and they had four more children, Dorothy, Mia, Rebecca, and Emily Dyson.
Dyson's eldest daughter, Esther, is a digital technology consultant and investor; she has been called "the most influential woman in all the computer world." His son, George, is a historian of science, one of whose books is Project Orion: The Atomic Spaceship 1957–1965.
My book The Sun, the Genome, and the Internet (1999) describes a vision of green technology enriching villages all over the world and halting the migration from villages to megacities. The three components of the vision are all essential: the sun to provide energy where it is needed, the genome to provide plants that can convert sunlight into chemical fuels cheaply and efficiently, the Internet to end the intellectual and economic isolation of rural populations. With all three components in place, every village in Africa could enjoy its fair share of the blessings of civilization.
Dyson cheerfully admits his record as a prophet is mixed, but "it is better to be wrong than to be vague." "To answer the world's material needs, technology has to be not only beautiful but also cheap."
Dyson favors the dual origin concept: Life first formed cells, then enzymes, and finally, much later, genes. This was first propounded by the Russian Alexander Oparin. J. B. S. Haldane developed the same theory independently. Dyson has simplified things by saying simply that life evolved in two stages, widely separated in time. He regards it as too unlikely that genes could have developed fully blown in one process, because of the biochemistry. Current cells contain adenosine triphosphate or ATP and adenosine 5'-monophosphate or AMP, which greatly resemble each other but have completely different functions. ATP transports energy around the cell, and AMP is part of RNA and the genetic apparatus. Dyson proposes that in a primitive early cell containing ATP and AMP, RNA and replication were invented accidentally because of the similarity between AMP and RNA. He suggests that AMP was produced when ATP molecules lost two of their phosphate radicals, and then one cell somewhere performed Eigen's experiment and produced RNA.
There is no direct evidence for the dual origin concept, because once genes developed, they took over, obliterating all traces of the earlier forms of life. In the first origin, the cells were probably just drops of water held together by surface tension, teeming with enzymes and chemical reactions, and a primitive kind of growth or replication. When the liquid drop became too big, it split into two drops. Many complex molecules formed in these "little city economies" and the probability that genes would eventually develop in them was much greater than in the prebiotic environment.
One should expect that, within a few thousand years of its entering the stage of industrial development, any intelligent species should be found occupying an artificial biosphere which completely surrounds its parent star.
In 1960, Dyson wrote a short paper for the journal Science, titled "Search for Artificial Stellar Sources of Infrared Radiation". In it, he theorized that a technologically advanced extraterrestrial civilization might completely surround its native star with artificial structures in order to maximize the capture of the star's available energy. Eventually, the civilization would completely enclose the star, intercepting electromagnetic radiation with wavelengths from visible light downwards and radiating waste heat outwards as infrared radiation. Therefore, one method of searching for extraterrestrial civilizations would be to look for large objects radiating in the infrared range of the electromagnetic spectrum.
Dyson conceived that such structures would be clouds of asteroid-sized space habitats, though science fiction writers have preferred a solid structure: either way, such an artifact is often called a Dyson sphere, although Dyson used the term "shell". Dyson says that he used the term "artificial biosphere" in the article to mean a habitat, not a shape. The general concept of such an energy-transferring shell had been advanced decades earlier by author Olaf Stapledon in his 1937 novel Star Maker, a source Dyson has credited publicly.
Dyson has also proposed the creation of a Dyson tree, a genetically engineered plant capable of growing on a comet. He suggested that comets could be engineered to contain hollow spaces filled with a breathable atmosphere, thus providing self-sustaining habitats for humanity in the outer Solar System.
Plants could grow greenhouses ... just as turtles grow shells and polar bears grow fur and polyps build coral reefs in tropical seas. These plants could keep warm by the light from a distant Sun and conserve the oxygen that they produce by photosynthesis. The greenhouse would consist of a thick skin providing thermal insulation, with small transparent windows to admit sunlight. Outside the skin would be an array of simple lenses, focusing sunlight through the windows into the interior ... Groups of greenhouses could grow together to form extended habitats for other species of plants and animals.
I've done some historical research on the costs of the Mayflower's voyage, and on the Mormons' emigration to Utah, and I think it's possible to go into space on a much smaller scale. A cost on the order of $40,000 per person [1978 dollars, $143,254 in 2013 dollars] would be the target to shoot for; in terms of real wages, that would make it comparable to the colonization of America. Unless it's brought down to that level it's not really interesting to me, because otherwise it would be a luxury that only governments could afford.
Dyson has been interested in space travel since he was a child, reading such science fiction classics as Olaf Stapledon's Star Maker. As a young man, he worked for General Atomics on the nuclear-powered Orion spacecraft. He hoped Project Orion would put men on Mars by 1965, Saturn by 1970. He's been unhappy for a quarter-century about how the government conducts space travel:
The problem is, of course, that they can't afford to fail. The rules of the game are that you don't take a chance, because if you fail, then probably your whole program gets wiped out.
He still hopes for cheap space travel, but is resigned to waiting for private entrepreneurs to develop something new and inexpensive.
No law of physics or biology forbids cheap travel and settlement all over the solar system and beyond. But it is impossible to predict how long this will take. Predictions of the dates of future achievements are notoriously fallible. My guess is that the era of cheap unmanned missions will be the next fifty years, and the era of cheap manned missions will start sometime late in the twenty-first century.
Any affordable program of manned exploration must be centered in biology, and its time frame tied to the time frame of biotechnology; a hundred years, roughly the time it will take us to learn to grow warm-blooded plants, is probably reasonable.
Dyson also proposed the use of bioengineered space colonies to colonize the Kuiper Belt on the outer edge of our Solar System. He proposed that habitats could be grown from space hardened spores. The colonies could then be warmed by large reflector plant leaves that could focus the dim, distant sunlight back on the growing colony. This was illustrated by Pat Rawlings on the cover of the National Space Society's Ad Astra magazine.
A direct search for life in Europa's ocean would today be prohibitively expensive. Impacts on Europa give us an easier way to look for evidence of life there. Every time a major impact occurs on Europa, a vast quantity of water is splashed from the ocean into the space around Jupiter. Some of the water evaporates, and some condenses into snow. Creatures living in the water far enough from the impact have a chance of being splashed intact into space and quickly freeze-dried. Therefore, an easy way to look for evidence of life in Europa's ocean is to look for freeze-dried fish in the ring of space debris orbiting Jupiter.
Freeze-dried fish orbiting Jupiter is a fanciful notion, but nature in the biological realm has a tendency to be fanciful. Nature is usually more imaginative than we are. ... To have the best chance of success, we should keep our eyes open for all possibilities.
Dyson has proposed that intelligent beings may be capable of thinking an infinite number of thoughts in an open/expanding universe.
Dyson also has some credits in pure mathematics. His concept "Dyson's transform" led to one of the most important lemmas of Olivier Ramaré's theorem: that every even integer can be written as a sum of no more than six primes.
The Dyson series, the formal solution of an explicitly time-dependent Schrödinger equation by iteration, and the corresponding Dyson time-ordering operator an entity of basic importance in the mathematical formulation of quantum mechanics, are also named after Dyson.
Dyson and Hugh Montgomery discovered together an intriguing connection between quantum physics and Montgomery's pair correlation conjecture about the zeros of the Zeta function. The primes 2, 3, 5, 7, 11, 13, 17, 19, ... are described by the Riemann Zeta function, and Dyson had previously developed a description of quantum physics based on m by m arrays of totally random numbers. What Montgomery and Dyson discovered is that the eigenvalues of these matrices are spaced apart in exactly the same manner as Montgomery conjectured for the nontrivial zeros of the Zeta function. Andrew Odlyzko has verified the conjecture on a computer, using his Odlyzko–Schönhage algorithm to calculate many zeros. Dyson recognized this connection because of a number-theory question Montgomery asked him. Dyson had published results in number theory in 1947, while a Fellow at Trinity College, Cambridge and so was able to understand Montgomery's question. If Montgomery had not been visiting the Institute for Advanced Study that week, this connection might not have been discovered.
There are in nature one, two, and three dimensional quasicrystals. Mathematicians define a quasicrystal as a set of discrete points whose Fourier transform is also a set of discrete points. Odlyzko has done extensive computations of the Fourier transform of the nontrivial zeros of the Zeta function, and they seem to form a one-dimensional quasicrystal. This would in fact follow from the Riemann hypothesis.
Dyson agrees that anthropogenic global warming exists: "[one] of the main causes of warming is the increase of carbon dioxide in the atmosphere resulting from our burning of fossil fuels such as oil and coal and natural gas". But he believes that existing simulation models of climate fail to account for some important factors, and hence the results contain too much error to reliably predict future trends:
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 we live in ...
and, in 2009:
What has happened in the past 10 years is that the discrepancies between what's observed and what's predicted have become much stronger. It's clear now the models are wrong, but it wasn't so clear 10 years ago.
He is among signatories of a letter to the UN criticizing the Intergovernmental Panel on Climate Change (IPCC), and has also argued against ostracizing scientists whose views depart from the acknowledged mainstream of scientific opinion on climate change, stating that "heretics" have historically been an important force in driving scientific progress. "[H]eretics who question the dogmas are needed ... I am proud to be a heretic. The world always needs heretics to challenge the prevailing orthodoxies."
Dyson's views on global warming have been strongly criticized. In reply, he notes that "[m]y objections to the global warming propaganda are not so much over the technical facts, about which I do not know much, but it's rather against the way those people behave and the kind of intolerance to criticism that a lot of them have."
In 2008, he endorsed the now common usage of "global warming" as synonymous with global anthropogenic climate change, referring to "measurements that transformed global warming from a vague theoretical speculation into a precise observational science."
He has, however, argued that political efforts to reduce the causes of climate change distract from other global problems that should take priority:
I'm not saying the warming doesn't cause problems; obviously it does. Obviously we should be trying to understand it. I'm saying that the problems are being grossly exaggerated. They take away money and attention from other problems that are much more urgent and important. Poverty, infectious diseases, public education and public health. Not to mention the preservation of living creatures on land and in the oceans.
In an opinion piece in the Boston Globe of 3 Dec 2015 he wrote,
[T]he environmental movement [has been] hijacked by a bunch of climate fanatics, who have captured the attention of the public with scare stories. ...
China and India have a simple choice to make. Either they get rich [by burning prodigious quantities of coal and causing] a major increase of atmospheric carbon dioxide, or they stay poor. I hope they choose to get rich. ...
The good news is that the main effect of carbon dioxide ... is to make the planet greener, [by] feeding the growth of green plants of all kinds [and] increasing the fertility of farms and fields and forests."
Since originally taking interest in climate studies in the 1970s, Dyson has suggested that carbon dioxide levels in the atmosphere could be controlled by planting fast-growing trees. He calculates that it would take a trillion trees to remove all carbon from the atmosphere.
In a 2014 interview, he said, "What I'm convinced of is that we don't understand climate ... It will take a lot of very hard work before that question is settled."
At the British Bomber Command, Dyson and colleagues proposed removing two gun turrets from the RAF Lancaster bombers, to cut the catastrophic losses due to German fighters in the Battle of Berlin. A Lancaster without turrets could fly 50 mph (80 km/h) faster and be much more maneuverable.
All our advice to the commander in chief [went] through the chief of our section, who was a career civil servant. His guiding principle was to tell the commander in chief things that the commander in chief liked to hear ... To push the idea of ripping out gun turrets, against the official mythology of the gallant gunner defending his crew mates ... was not the kind of suggestion the commander in chief liked to hear.
On hearing the news of the bombing of Hiroshima:
I agreed emphatically with Henry Stimson. Once we had got ourselves into the business of bombing cities, we might as well do the job competently and get it over with. I felt better that morning than I had felt for years ... Those fellows who had built the atomic bombs obviously knew their stuff ... Later, much later, I would remember [the downside].
I am convinced that to avoid nuclear war it is not sufficient to be afraid of it. It is necessary to be afraid, but it is equally necessary to understand. And the first step in understanding is to recognize that the problem of nuclear war is basically not technical but human and historical. If we are to avoid destruction we must first of all understand the human and historical context out of which destruction arises.
In 1967, in his capacity as a military adviser, Dyson wrote an influential paper on the issue of possible US use of tactical nuclear weapons in the Vietnam War. When a general said in a meeting, "I think it might be a good idea to throw in a nuke now and then, just to keep the other side guessing ..." Dyson became alarmed and obtained permission to write a report on the pros and cons of using such weapons from a purely military point of view. (This report, Tactical Nuclear Weapons in Southeast Asia, published by the Institute for Defense Analyses, was obtained, with some redactions, by the Nautilus Institute for Security and Sustainability under the Freedom of Information act in 2002.) It was sufficiently objective that both sides in the debate based their arguments on it. Dyson says that the report showed that, even from a narrow military point of view, the US was better off not using nuclear weapons. Dyson stated on the Dick Cavett show that the use of nuclear weaponry was a bad idea for the US at the time because "our targets were large and theirs were small." (His unstated assumption was that the Soviets would respond by supplying tactical nukes to the other side.)
Dyson opposed the Vietnam War, the Gulf War and the invasion of Iraq. He supported Barack Obama in the 2008 US presidential election and The New York Times has described him as a political liberal. He was one of 29 leading US scientists who wrote Obama a strongly supportive letter about his administration's 2015 nuclear deal with Iran.
Dyson is a nondenominational Christian and has attended various churches, from Presbyterian to Roman Catholic. Regarding doctrinal or Christological issues, he has said, "I am neither a saint nor a theologian. To me, good works are more important than theology."
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 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.
Dyson partially disagrees with the famous remark by his fellow physicist Steven Weinberg that "With or without religion, good people can behave well and bad people can do evil; but for good people to do evil—that takes religion."
Weinberg's statement is true as far as it goes, but it is not the whole truth. To make it the whole truth, we must add an additional clause: "And for bad people to do good things—that [also] takes religion." The main point of Christianity is that it is a religion for sinners. Jesus made that very clear. When the Pharisees asked his disciples, "Why eateth your Master with publicans and sinners?" he said, "I come to call not the righteous but sinners to repentance." Only a small fraction of sinners repent and do good things but only a small fraction of good people are led by their religion to do bad things.
While Dyson has called himself a Christian, he identifies himself as agnostic about some of the specifics of his faith. For example, here is a passage from Dyson's review of The God of Hope and the End of the World from John Polkinghorne:
I am myself a Christian, a member of a community that preserves an ancient heritage of great literature and great music, provides help and counsel to young and old when they are in trouble, educates children in moral responsibility, and worships God in its own fashion. But I find Polkinghorne's theology altogether too narrow for my taste. I have no use for a theology that claims to know the answers to deep questions but bases its arguments on the beliefs of a single tribe. I am a practicing Christian but not a believing Christian. To me, to worship God means to recognize that mind and intelligence are woven into the fabric of our universe in a way that altogether surpasses our comprehension.
In The God Delusion (2006), biologist Richard Dawkins criticized Dyson for accepting the religious Templeton Prize in 2000; "It would be taken as an endorsement of religion by one of the world's most distinguished physicists." In 2000 Dyson declared that he is a (non-denominational) Christian, and he has disagreed with Dawkins on several occasions, as when he criticized Dawkins' understanding of evolution.
|Freeman Dyson: Let's look for life in the outer solar system, TED Talks, February 2003|
|Freeman Dyson 1 - My middle class upbringing, Web of Stories (1st of a series)|
|Big Ideas: Freeman Dyson on Living Through Four Revolutions, TVO, 1 June 2011 at Perimeter Institute, Waterloo, Canada|
Prominent physicist Freeman Dyson recalls the time he spent developing analytical methods to help the British Royal Air Force bomb German targets during World War II.
The cash part of this award is over $1 million. Three facts are significant about this award. First, the same award was given to an agnostic Mathematician Freeman Dyson, the Buddhist Dalai Lama, Mother Theresa, and Charles R. Filmore, son of the founder of the mind-science cult, Unity.
Dyson is not a hard-nosed materialist and, in fact, criticizes his colleagues who champion that viewpoint. Officially, he calls himself an agnostic, but his writings make it clear that his agnosticism is tinged with something akin to deism.
Astrochicken is the name given to a thought experiment expounded by theoretical physicist Freeman Dyson. In his book Disturbing the Universe (1979), Dyson contemplated how humanity could build a small, self-replicating automaton that could explore space more efficiently than a manned craft could. He attributed the general idea to John von Neumann, based on a lecture von Neumann gave in 1948 titled The General and Logical Theory of Automata. Dyson expanded on von Neumann's automata theories and added a biological component to them.
Astrochicken, Dyson explained, would be a one-kilogram spacecraft unlike any before it. It would be a creation of the intersection of biology, artificial intelligence and modern microelectronics—a blend of organic and electronic components. Astrochicken would be launched by a conventional spacecraft into space, like an egg being laid into space. Astrochicken would then hatch and start growing a solar-energy collector. The solar collector would feed an ion drive engine that would power the craft. Once Astrochicken entered a planet's vicinity, it would collect material from the moons and rings of the planet, taking in nutrients. It could land and take off using an auxiliary chemical rocket similar to that used by bombardier beetles. It would periodically transmit details of its journey when it could make radio contact with Earth.
The term "astrochicken" does not occur in Dyson's earliest essays regarding von Neumann-inspired automata. The concept was announced in a lecture Dyson was giving in Adelaide, Australia, on the subject of space exploration with biotechnology. An audience member called out "Oh, you mean this is an astro-chicken." and the whimsical name caught on, with Dyson beginning to use it himself in subsequent essays he wrote on his theoretical biotechnology spacecraft.
Today, Dyson's Astrochicken resonates with several theories of how space exploration might proceed in the future. Computer scientist Rodney Brooks has proposed sending a multitude of cheap, bug-like robots to explore Mars instead of solitary, expensive rovers. Cheaper and smaller means of studying space have also been the primary design philosophy of NASA for many years, perhaps best exemplified by the Mars Pathfinder mission. Physicist and noted author Michio Kaku wrote in his work Hyperspace, "Small, lightweight, and intelligent, Astrochicken is a versatile space probe that has a clear advantage over the bulky, exorbitantly expensive space missions of the past, which have been a bottleneck to space exploration. ... It will not need huge quantities of rocket fuel; it will be bred and programmed to 'eat' ice and hydrocarbons found in the rings surrounding the outer planets".
As a noted author of essays on the possibilities of science in the future, Dyson's theories, such as the Dyson sphere and the Dyson tree, have become popular in the scientific and science fiction communities. The more whimsically named "Astrochicken" has not achieved this same level of fame.Circular ensemble
In the theory of random matrices, the circular ensembles are measures on spaces of unitary matrices introduced by Freeman Dyson as modifications of the Gaussian matrix ensembles. The three main examples are the circular orthogonal ensemble (COE) on symmetric unitary matrices, the circular unitary ensemble (CUE) on unitary matrices, and the circular symplectic ensemble (CSE) on self dual unitary quaternionic matrices.Colonization of trans-Neptunian objects
Freeman Dyson has proposed that trans-Neptunian objects, rather than planets, are the major potential habitat of life in space. Several hundred billion to trillion comet-like ice-rich bodies exist outside the orbit of Neptune, in the Kuiper belt and Inner and Outer Oort cloud. These may contain all the ingredients for life (water ice, ammonia, and carbon-rich compounds), including significant amounts of deuterium and helium-3. Since Dyson's proposal, the number of trans-Neptunian objects known has increased greatly.
Colonists could live in the dwarf planet's icy crust or mantle, using fusion or geothermal heat and mining the soft-ice or liquid inner ocean for volatiles and minerals. Given the light gravity and resulting lower pressure in the ice mantle or inner ocean, colonizing the rocky core's outer surface might give colonists the largest number of mineral and volatile resources as well as insulating them from cold. Surface habitats or domes are another possibility, as background radiation levels are likely to be low.Colonists of such bodies could also build rotating habitats or live in dug-out spaces and light them with fusion reactors for thousands to millions of years before moving on. Dyson and Carl Sagan envisioned that humanity could migrate to neighbouring star systems, which have similar clouds, by using natural objects as slow interstellar vessels with substantial natural resources; and that such interstellar colonies could also serve as way-stations for faster, smaller interstellar ships. Alternatively Richard Terra has proposed using the materials from the Oort-cloud objects to build vast starlight collecting arrays to power habitats, thus making an Oort-cloud community essentially independent of its central star and fusion fuel supplies.Decision 3012
"Decision 3012" is the third episode of the seventh season of the animated sitcom Futurama. It originally aired on Comedy Central on June 27, 2012. The plot is a parody of the Birther Movement.Dyson's eternal intelligence
Dyson's eternal intelligence concept (the Dyson Scenario), proposed by Freeman Dyson in 1979,
proposes a means by which an immortal society of intelligent beings in an open universe
may escape the prospect of heat death by extending subjective time to infinity even though expending only a finite amount of energy.
Bremermann's limit can be invoked to deduce that the amount of time to perform a computation on 1 bit is inversely proportional to the change in energy in the system. As a result, the amount of computations that can be performed grows over time. The increase in energy available slows logarithmically, but never stops. Therefore, for any specific computation rate, that requires a specific amount of energy, there will come a time when that energy is available to be used.
The intelligent beings would begin by storing a finite amount of energy. They then use half (or any fraction) of this energy to power their thought. When the energy gradient created by unleashing this fraction of the stored fuel was exhausted, the beings would enter a state of zero-energy-consumption until the universe cooled. Once the universe had cooled sufficiently, half of the remaining half (one quarter of the original energy) of the intelligent beings' fuel reserves would once again be released, powering a brief period of thought once more. This would continue, with smaller and smaller amounts of energy being released. As the universe cooled, the thoughts would be slower and slower, but there would still be an infinite number of them.In 1998 it was discovered that the expansion of the universe appears to be accelerating rather than decelerating due to a positive cosmological constant, implying that any two regions of the universe will eventually become permanently separated from one another.
Frank J. Tipler has cited Dyson's writings, and specifically his writings on the eternal intelligence, as a major influence on his own highly controversial Omega Point theory.
Tipler's theory differs from Dyson's theory on several key points, most notable of which is that Dyson's eternal intelligence presupposes an open universe while Tipler's Omega Point presupposes a closed/ contracting universe. Both theories will be invalidated if the observed universal expansion continues to accelerate.Dyson conjecture
In mathematics, the Dyson conjecture (Freeman Dyson 1962) is a conjecture about the constant term of certain Laurent polynomials, proved by Wilson and Gunson. Andrews generalized it to the q-Dyson conjecture, proved by Zeilberger and Bressoud and sometimes called the Zeilberger–Bressoud theorem. Macdonald generalized it further to more general root systems with the Macdonald constant term conjecture, proved by Cherednik.Dyson series
In scattering theory, a part of mathematical physics, the Dyson series, formulated by Freeman Dyson, is a perturbative series, and each term is represented by Feynman diagrams. This series diverges asymptotically, but in quantum electrodynamics (QED) at the second order the difference from experimental data is in the order of 10−10. This close agreement holds because the coupling constant (also known as the fine structure constant) of QED is much less than 1. Notice that in this article Planck units are used, so that ħ = 1 (where ħ is the reduced Planck constant).Dyson sphere
A Dyson sphere is a hypothetical megastructure that completely encompasses a star and captures a large percentage of its power output. The concept is a thought experiment that attempts to explain how a spacefaring civilization would meet its energy requirements once those requirements exceed what can be generated from the home planet's resources alone. Only a tiny fraction of a star's energy emissions reach the surface of any orbiting planet. Building structures encircling a star would enable a civilization to harvest far more energy.
The first contemporary description of the structure was by Olaf Stapledon in his science fiction novel Star Maker (1937), in which he described "every solar system... surrounded by a gauze of light traps, which focused the escaping solar energy for intelligent use." The concept was later popularized by Freeman Dyson in his 1960 paper "Search for Artificial Stellar Sources of Infrared Radiation". Dyson speculated that such structures would be the logical consequence of the escalating energy needs of a technological civilization and would be a necessity for its long-term survival. He proposed that searching for such structures could lead to the detection of advanced, intelligent extraterrestrial life. Different types of Dyson spheres and their energy-harvesting ability would correspond to levels of technological advancement on the Kardashev scale.
Since then, other variant designs involving building an artificial structure or series of structures to encompass a star have been proposed in exploratory engineering or described in science fiction under the name "Dyson sphere". These later proposals have not been limited to solar-power stations, with many involving habitation or industrial elements. Most fictional depictions describe a solid shell of matter enclosing a star, which is considered by Dyson himself the least plausible variant of the idea. In May 2013, at the Starship Century Symposium in San Diego, Dyson repeated his comments that he wished the concept had not been named after him.Dyson tree
A Dyson tree is a hypothetical genetically-engineered plant (perhaps resembling a tree) capable of growing in a comet, suggested by the physicist Freeman Dyson. Plants could produce a breathable atmosphere within hollow spaces in the comet (or even within the plants themselves), utilising solar energy for photosynthesis and cometary materials for nutrients, thus providing self-sustaining habitats for humanity in the outer solar system analogous to a greenhouse in space or a shell grown by a mollusc.
A Dyson tree might consist of a few main trunk structures growing out from a comet nucleus, branching into limbs and foliage that intertwine, forming a spherical structure possibly dozens of kilometers across.Esther Dyson
Esther Dyson (born 14 July 1951) is a Swiss-born American journalist, author, businesswoman, investor, commentator and philanthropist. She is a leading angel investor focused on breakthrough efficacy in healthcare, government transparency, digital technology, biotechnology, and space.
Dyson is currently focusing her career on health and continues to invest in health and technology startups.On 7 October 2008, Space Adventures announced that Dyson had paid to train as a back-up spaceflight participant for Charles Simonyi's trip to the International Space Station aboard the Soyuz TMA-14 mission which took place in 2009.George Dyson (science historian)
George Dyson (born 26 March 1953) is an American non-fiction author and historian of technology whose publications broadly cover the evolution of technology in relation to the physical environment and the direction of society. He has written on a wide range of topics, including the history of computing, the development of algorithms and intelligence, communication systems, space exploration, and the design of water craft.
Lecturing widely at academic institutions, corporations, and tech conferences, Dyson gives a historical context to the evolution of technology in modern society and provides thought-provoking ideas on the directions in which technology and the Internet might develop.Gordon Freeman
Gordon Freeman is a fictional character and the main protagonist of the Half-Life video game series, created by Gabe Newell and designed by Newell and Marc Laidlaw of Valve Corporation. His first appearance is in Half-Life. Gordon Freeman is an American man from Seattle, who graduated from MIT with a PhD in Theoretical Physics. He was an employee at Black Mesa Research Facility. Controlled by the player, Gordon is often tasked with using a wide range of weapons and tools to fight alien creatures such as headcrabs, as well as Combine machines and soldiers.
Gordon Freeman's character has been well received by critics and gamers, and various gaming websites often consider him to be one of the greatest video game characters of all time, including UGO and GameSpot.Infinite in All Directions
Infinite In All Directions (1988) is a book on a wide range of subjects, including history, philosophy, research, technology, the origin of life and eschatology, by theoretical physicist Freeman Dyson. The book is based on the author's Gifford Lectures delivered in Aberdeen in 1985. Infinite in All Directions can roughly be summarized as a treatise on the universe and humanity's role and its responsibilities.Oersted Medal
The Oersted Medal recognizes notable contributions to the teaching of physics. Established in 1936, it is awarded by the American Association of Physics Teachers. The award is named for Hans Christian Ørsted. It is the Association's most prestigious award.
Well-known recipients include Nobel laureates Robert Andrews Millikan, Edward M. Purcell, Richard Feynman, Isidor I. Rabi, Norman F. Ramsey, Hans Bethe, and Carl Wieman; as well as Arnold Sommerfeld, George Uhlenbeck, Jerrold Zacharias, Philip Morrison, Melba Phillips, Victor Weisskopf, Gerald Holton, John A. Wheeler, Frank Oppenheimer, Robert Resnick, Carl Sagan, Freeman Dyson, Daniel Kleppner, and Lawrence Krauss, and Anthony French, David Hestenes, Robert Karplus, Robert Pohl, and Francis Sears.
The 2008 medalist, Mildred S. Dresselhaus, is the third woman to win the award in its 70-plus-year history.Project Orion (nuclear propulsion)
Project Orion was a study of a spacecraft intended to be directly propelled by a series of explosions of atomic bombs behind the craft (nuclear pulse propulsion). Early versions of this vehicle were proposed to take off from the ground with significant associated nuclear fallout; later versions were presented for use only in space. Six tests were launched.
The idea of rocket propulsion by combustion of explosive substance was first proposed by Russian explosives expert Nikolai Kibalchich in 1881, and in 1891 similar ideas were developed independently by German engineer Hermann Ganswindt. General proposals of nuclear propulsion were first made by Stanislaw Ulam in 1946, and preliminary calculations were made by F. Reines and Ulam in a Los Alamos memorandum dated 1947. The actual project, initiated in 1958, was led by Ted Taylor at General Atomics and physicist Freeman Dyson, who at Taylor's request took a year away from the Institute for Advanced Study in Princeton to work on the project.
The Orion concept offered high thrust and high specific impulse, or propellant efficiency, at the same time. The unprecedented extreme power requirements for doing so would be met by nuclear explosions, of such power relative to the vehicle's mass as to be survived only by using external detonations without attempting to contain them in internal structures. As a qualitative comparison, traditional chemical rockets—such as the Saturn V that took the Apollo program to the Moon—produce high thrust with low specific impulse, whereas electric ion engines produce a small amount of thrust very efficiently. Orion would have offered performance greater than the most advanced conventional or nuclear rocket engines then under consideration. Supporters of Project Orion felt that it had potential for cheap interplanetary travel, but it lost political approval over concerns with fallout from its propulsion.The Partial Test Ban Treaty of 1963 is generally acknowledged to have ended the project. However, from Project Longshot to Project Daedalus, Mini-Mag Orion, and other proposals which reach engineering analysis at the level of considering thermal power dissipation, the principle of external nuclear pulse propulsion to maximize survivable power has remained common among serious concepts for interstellar flight without external power beaming and for very high-performance interplanetary flight. Such later proposals have tended to modify the basic principle by envisioning equipment driving detonation of much smaller fission or fusion pellets, in contrast to Project Orion's larger nuclear pulse units (full nuclear bombs) based on less speculative technology.
To Mars by A-Bomb: The Secret History of Project Orion was a 2003 BBC documentary film about the project.Space Studies Institute
Space Studies Institute is a non-profit organization that was founded in 1977 by the late Princeton University Professor Dr. Gerard K. O'Neill. The stated mission is to "open the energy and material resources of space for human benefit within our lifetime".
In 2009 SSI moved its operations from its long-term base in Princeton, New Jersey, to Mojave, California. SSI is involved in several initiatives, including a solar sail project that it is developing with Carnegie Mellon University and an effort to find asteroids that could be mined for valuable materials. The use of extraterrestrial resources in space settlement has received increasing attention in recent years.SSI's research priorities:
Low cost space access
Fully reusable propulsion systems
Mass driver engines
Use of non-terrestrial materials
Produce evidence that establishes that manufacturing and extraction industries on the Moon or on asteroids is cost-effective
Develop closed environment life support systems for space.The Institute has sponsored research studies on several transport systems for the development of space. Their first program was in the development of prototype mass driver systems. They are also studying the use of an Orbital Transfer Vehicle as a component of space manufacturing. Other areas of research include a search for Earth-Sun Trojan asteroids, a design study of a Lunar Polar Probe to search for water and useful volatiles at the poles of the Moon, and studies of reuse of the Space Shuttle external tank. Dr O'Neill performed a pioneering study of a large space habitat named Island Three that could house 10,000,000 people.TRIGA
TRIGA (Training, Research, Isotopes, General Atomics) is a class of nuclear research reactor designed and manufactured by General Atomics. The design team for TRIGA, which included Edward Teller, was led by the physicist Freeman Dyson.The Pleasure of Finding Things Out
The Pleasure of Finding Things Out is a collection of short works from American physicist Richard Feynman, including interviews, speeches, lectures, and printed articles. Among these is his famous 1959 lecture "There's Plenty of Room at the Bottom", his report on the Space Shuttle Challenger disaster, and his speech on scientific integrity in which he coined the term "cargo cult science". The original foreword was written by Freeman Dyson.
Laureates of the Wolf Prize in Physics