Dyson disagreed with thescientific consensus on climate change. He believed that some of the effects of increased CO2 levels are favourable and not taken into account by climate scientists, such as increased agricultural yield, and further that the positive benefits of CO2 likely outweigh the negative effects.[8][9][10] He was sceptical about thesimulation models used to predictclimate change, arguing that political efforts to reduce causes of climate change distract from other global problems that should take priority. He was awarded the 1996Lewis Thomas Prize[11] and the 2000Templeton Prize.[12] He said that "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."[13]
Dyson was born on 15 December 1923, inCrowthorne inBerkshire,England.[1] He was the son of Mildred (née Atkey) and the composerGeorge Dyson, who was later knighted. His mother had a law degree, and after Dyson was born she worked as a social worker.[14] Dyson had one sibling, his older sister, Alice, who remembered him as a boy surrounded by encyclopedias and always calculating on sheets of paper.[15] At the age of four he tried to calculate the number of atoms in the Sun.[16] As a child, he showed an interest in large numbers and in theSolar System, and was strongly influenced by the 1937 bookMen of Mathematics byEric Temple Bell.[17] Politically, Dyson said he was "brought up as a socialist".[18]
From 1936 to 1941 Dyson was a scholar atWinchester College, where his father was Director of Music.[1] At the age of 17 he studied pure mathematics withAbram Besicovitch as his tutor[19] atTrinity College, Cambridge, where he won a scholarship at age 15. During this stay, Dyson also practisednight climbing on the university buildings,[20] and once walked fromCambridge toLondon in a day with his friend Oscar Hahn, nephew ofKurt Hahn, who was a wheelchair user due topolio.[21]
At the age of 19 he was assigned to war work in theOperational Research Section (ORS) ofRAF Bomber Command, where he developed analytical methods for calculating the ideal density for bomber formations to help theRoyal Air Force bomb German targets during theSecond World War.[22][23] After the war, Dyson was readmitted to Trinity College, where he obtained aBA degree in mathematics.[24][25] From 1946 to 1949 he was afellow of his college, occupying rooms just below those of the philosopherLudwig Wittgenstein, who resigned his professorship in 1947.[26]
In 1947 Dyson published two papers innumber theory.[27][28] Friends and colleagues described him as shy and self-effacing, with a contrarian streak that his friends found refreshing but intellectual opponents found exasperating.[1] "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 authorOliver 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."[8]
OnG. I. Taylor's advice and recommendation, Dyson moved to the United States in 1947 as aCommonwealth Fellow for postgraduate study withHans Bethe atCornell University (1947–1948).[29][30] There he made the acquaintance ofRichard Feynman. Dyson recognized the brilliance of Feynman and worked with him. He then moved to the Institute for Advanced Study (1948–1949), before returning to England (1949–51), where he was a research fellow at theUniversity of Birmingham.[31] In 1949, Dyson demonstrated the equivalence of two formulations ofquantum electrodynamics (QED): Richard Feynman's diagrams and the operator method developed byJulian Schwinger andShin'ichirō Tomonaga. He was the first person after their creator to appreciate the power ofFeynman 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 therenormalization problem. Dyson's paper and 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. Also in 1949, in related work, Dyson invented theDyson series. It was this paper that inspiredJohn Ward to derive his celebratedWard–Takahashi identity.[32]
Dyson joined the faculty at Cornell as a physics professor in 1951, though he still had no doctorate. In December 1952, Oppenheimer, the director of theInstitute for Advanced Study inPrinceton, New Jersey, offered Dyson a lifetime appointment at the institute, "for proving me wrong", in Oppenheimer's words.[33] Dyson remained at the Institute until the end of his career.[34][35] In 1957 he became aUS citizen.[a][25][36] From 1957 to 1961 Dyson worked onProject Orion,[37] which proposed the possibility of space-flight usingnuclear pulse propulsion. A prototype was demonstrated using conventional explosives, but the 1963Partial Test Ban Treaty, in which Dyson was involved and which he supported,[38] permitted onlyunderground nuclear weapons testing,[39] and the project was abandoned in 1965.[40]
In 1958 Dyson was a member of the design team underEdward Teller forTRIGA, a small, inherently safenuclear reactor used throughout the world in hospitals and universities for the production ofmedical isotopes.[41]
In 1966, independently ofElliott H. Lieb andWalter Thirring, Dyson and Andrew Lenard published a paper proving that thePauli exclusion principle plays the main role in thestability of matter.[42] Hence it is not the electromagnetic repulsion between outer-shell orbital electrons that prevents two stacked wood blocks from coalescing into a single piece, but the exclusion principle applied to electrons and protons that generates the classical macroscopicnormal force. Incondensed matter physics, Dyson also analysed the phase transition of theIsing model in one dimension andspin waves.[43]
Around 1979 Dyson worked with theInstitute for Energy Analysis onclimate studies. This group, underAlvin Weinberg's direction, pioneered multidisciplinary climate studies, including a strong biology group. Also during the 1970s, Dyson worked on climate studies conducted by theJASON defense advisory group.[8]
Dyson retired from the Institute for Advanced Study in 1994.[46] In 1998 he joined the board of theSolar Electric Light Fund. In 2003 he was president of theSpace Studies Institute, the space research organization founded byGerard K. O'Neill; in 2013 he was on its board of trustees.[47] Dyson was a longtime member of theJASON group.[48]
Dyson won numerous scientific awards, but never aNobel Prize. Nobel physics laureateSteven Weinberg said that theNobel committee "fleeced" Dyson, but Dyson 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."[8] Dyson was a regular contributor toThe New York Review of Books, and published a memoir,Maker of Patterns: An Autobiography Through Letters in 2018.[49]
ReviewingGeorges Charpak and Henri Broch'sDebunked! ESP, Telekenesis and Other Pseudoscience he wrote that “paranormal phenomena may really exist but may not be accessible to scientific investigation. This is a hypothesis. I am not saying that it is true, only that it is tenable, and to my mind plausible.”[51] He wrote a foreword to a treatise on psychic phenomena in which he concluded that "ESP is real... but cannot be tested with the clumsy tools of science".[52]
Dyson married his first wife, the Swiss mathematicianVerena Huber, on 11 August 1950. They had two children,Esther andGeorge, before divorcing in 1958. In November 1958 he married Imme Jung, with whom he had four daughters.[8]
Dyson admitted his record as a prophet was mixed, but thought it is better to be wrong than vague, and that in meeting the world's material needs, technology must be beautiful and cheap.
My bookThe 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 coined the term "green technologies", based onbiology instead ofphysics orchemistry, to describe new species ofmicroorganisms andplants designed to meet human needs. He argued that such technologies would be based onsolar power rather than thefossil fuels whose use he saw as part of what he calls "gray technologies" of industry. He believed thatgenetically engineered crops, which he described as green, can help endrural poverty, with a movement based inethics to end the inequitabledistribution of wealth on the planet.[55]
Dyson favoured the dual origin theory: that life first formed ascells, thenenzymes, and finally, much later,genes. This was first propounded by the Russian biochemist,Alexander Oparin.[56]J. B. S. Haldane developed the same theory independently.[57] In Dyson's version of the theory, life evolved in two stages, widely separated in time. Because of the biochemistry, he regards it as too unlikely that genes could have developed fully blown in one process. Current cells containadenosine triphosphate or ATP andadenosine 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 proposed that in a primitive early cell containing ATP and AMP, RNA and replication came into existence only because of the similarity between AMP and RNA. He suggested that AMP was produced when ATP molecules lost two of their phosphate radicals, and then one cell somewhere performedEigen's experiment and produced RNA.[58]
There is no direct evidence for the dual origin theory, 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 having 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.[59][fact or opinion?]
Artist's concept of Dyson rings, forming a stableDyson swarm, or "Dyson sphere"
In 1960 Dyson wrote a short paper for the journalScience titled "Search for Artificial Stellar Sources of Infrared Radiation".[60] In it he speculated that a technologically advancedextraterrestrialcivilization might surround its native star with artificial structures to maximize the capture of the star's energy. Eventually, the civilization would enclose the star, interceptingelectromagnetic radiation withwavelengths from visible light downward and radiating waste heat outward asinfrared radiation. One method ofsearching for extraterrestrial civilizations would be to look for large objects radiating in the infrared range of theelectromagnetic spectrum.
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 surrounds its parent star.
Dyson conceived that such structures would be clouds ofasteroid-sizedspace habitats, thoughscience fiction writers have preferred a solid structure: either way, such an artifact is often called aDyson sphere, although Dyson used the term "shell". Dyson said 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 created decades earlier by science fiction writerOlaf Stapledon in his 1937 novelStar Maker, a source which Dyson credited publicly.[61][b]
Freeman Dyson was interviewed by Robert Wright in 2003 and the Dyson Sphere topic was broached. In response he stated that the paper he wrote on this concept was intended to be a joke and had nothing to do with work. He added that it amused him that he had become famous only for the things he didn't think were serious. At the time of writing, this interview is available on YouTube (here).
Dyson also proposed the creation of aDyson tree, agenetically engineered plant capable of growing inside acomet. 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 outerSolar 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, $181,600 in 2022 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 was interested in space travel since he was a child, reading such science fiction classics asOlaf Stapledon'sStar Maker. As a young man, he worked forGeneral Atomics on the nuclear-poweredOrion spacecraft. He hoped Project Orion would put men on Mars by 1965, and Saturn by 1970. For a quarter-century, Dyson was unhappy about how the government conducted 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.
Dyson still hoped for cheap space travel, but was 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 centred 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.
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 proposed that animmortal group of intelligent beings could escape the prospect ofheat death by extending time to infinity while expending only a finite amount of energy.[62] This is also known as the Dyson scenario.[63]
His concept "Dyson's transform" led to one of the most importantlemmas ofOlivier Ramaré's theorem: that every even integer can be written as a sum of no more than six primes.[64]
Dyson andHugh Montgomery discovered an intriguing connection between quantum physics andMontgomery's pair correlation conjecture about the zeros of the zeta function. The primes 2, 3, 5, 7, 11, 13, 17, 19,... are described by theRiemann zeta function, and Dyson had previously developed a description of quantum physics based on m by m arrays of totally random numbers.[66] Montgomery and Dyson discovered that theeigenvalues 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 hisOdlyzko–Schönhage algorithm to calculate many zeros.[67]
There are in nature one, two, and three-dimensionalquasicrystals. Mathematicians define a quasicrystal as a set of discrete points whoseFourier 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 theRiemann hypothesis.[68]
Innumber theory, the crank of a partition is a certaininteger associated with the partition. Dyson first introduced the term without a definition in a 1944 paper in a journal published by the Mathematics Society ofCambridge University.[70] He then gave a list of properties this yet-to-be-defined quantity should have. In 1988,George E. Andrews andFrank Garvan discovered a definition for the crank satisfying the properties Dyson had hypothesized.[71]
Astrochicken is the name given to athought experiment Dyson expounded in his bookDisturbing the Universe (1979). He contemplated how humanity could build a small,self-replicating automaton that couldexplore space more efficiently than a crewed craft could. He attributed the general idea toJohn von Neumann, based on a lecture von Neumann gave in 1948 titledThe General and Logical Theory of Automata. Dyson expanded on von Neumann'sautomata theories and added a biological component.[72]
Dyson suggested that philosophers can be broadly if simplistically, divided into lumpers and splitters. These roughly correspond toPlatonists, who regard the world as made up of ideas, andmaterialists, who imagine it divided into atoms.[73]
Dyson agreed that technically humans and additional CO2 emissions contribute to warming. However, he felt that the benefits of additional CO2 outweighed any associated negative effects.[9] He said that in many ways increased atmospheric carbon dioxide is beneficial,[74] and that it is increasing biological growth, agricultural yields and forests.[9] He believed that existingsimulation models ofclimate change fail to account for some important factors, and that the results thus contain too great a margin of error to reliably predict trends.[75][76] He argued that political efforts to reduce the causes of climate change distract from other global problems that should take priority,[77] and viewed the acceptance of climate change as comparable to religion.[9]
In 2009, Dyson criticisedJames Hansen's climate-change activism. "The person who is really responsible for this overestimate of global warming is Jim Hansen. He consistently exaggerates all the dangers... Hansen has turned his science into ideology."[8] Hansen responded that Dyson "doesn't know what he's talking about... If he's going to wander into something with major consequences for humanity and other life on the planet, then he should first do his homework- which he obviously has not done on global warming".[8] Dyson replied 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."[78] Dyson stated in an interview that the argument with Hansen was exaggerated byThe New York Times, stating that he and Hansen are "friends, but we don't agree on everything."[79]
Since originally taking an interest in climate studies in the 1970s, Dyson suggested thatcarbon dioxide levels in the atmosphere could be controlled by planting fast-growing trees. He calculated that it would take a trillion trees to remove all carbon from the atmosphere.[80][8] 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."[17]
At RAF Bomber Command, Dyson and colleagues proposed removing two gun turrets fromAvro Lancaster bombers, to cut the catastrophic losses due to German fighters in theBattle of Berlin. A Lancaster without turrets could fly 50 mph (80 km/h) faster and be much more manoeuvrable.
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.
I agreed emphatically withHenry 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 theVietnam 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..."[82] 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 theInstitute for Defense Analyses, was obtained, with some redactions, by theNautilus Institute for Security and Sustainability under theFreedom of Information act in 2002.)[83] It was sufficiently objective that both sides of 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.[84]
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, and 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.[12]
Dyson partially disagreed with the remark by his fellow physicistSteven 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."[86]
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.
Dyson identified himself as agnostic about some of the specifics of his faith.[87][88] For example, in reviewingThe God of Hope and the End of the World byJohn Polkinghorne, Dyson wrote:
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.
InThe God Delusion (2006), evolutionary biologist and atheist activistRichard Dawkins singled out Dyson for accepting theTempleton Prize in 2000: "It would be taken as an endorsement of religion by one of the world's most distinguished physicists."[89] In 2000, Dyson declared that he was a (non-denominational) Christian,[12] and he disagreed with Dawkins on several subjects, such as that group selection is less important than individual selection on the subject ofevolution.[90] Dyson said "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."[12]
In the same lecture, he said:
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.[12]
Dyson published a number of collections of speculations and observations about technology, science, and the future. In 1996, he was awarded theLewis Thomas Prize for Writing about Science.[11]
In 2003, Dyson was awarded the Telluride Tech Festival Award of Technology inTelluride, Colorado.[108]
In 2011, Dyson received as one of twenty distinguishedOld Wykehamists at theAd Portas celebration, the highest honor thatWinchester College bestows.[109]
In 2011, Dyson received the Arthur C. Clarke Lifetime Achievement Award from the Arthur C. Clarke Foundation.[110]
"On Simultaneous Diophantine Approximations".Proceedings of the London Mathematical Society. s2-49 (1):409–420. 1946.doi:10.1112/plms/s2-49.6.409.ISSN0024-6115.
"Birds and Frogs"(PDF).Notices of the American Mathematical Society.56 (2):212–223. February 2009.ISSN1088-9477.Archived(PDF) from the original on 4 March 2011. Retrieved23 April 2015.
^ab"I had finally become an American ... The decision to abjure my allegiance toQueen Elizabeth might have been a difficult one, but the Queen's ministers made it easy for me."[113]
^"Some science fiction writers have wrongly given me the credit of inventing the artificial biosphere. In fact, I took the idea from Olaf Stapledon, one of their own colleagues"(Dyson 1979, p. 211)
^Dyson, Freeman (1 June 2011).Living Through Four Revolutions (Speech). Perimeter Institute Public Lecture Series. Waterloo, Ontario, Canada. Archived fromthe original on 19 April 2020. Retrieved14 July 2018.
^"Summit Overview Photo".Awards Council member, theoretical physicist and futurist Dr. Freeman Dyson presenting the American Academy of Achievement's Golden Plate Award to Dr. Francis H.C. Crick, recipient of the Nobel Prize as the co-discoverer of the structure of DNA, during the 1987 Banquet of the Golden Plate ceremonies in Scottsdale, Arizona.
Aaserud, Finn (17 December 1986)."Freeman Dyson".Oral History Interviews (Interview). Interviewed by Finn Aaserud. Princeton, New Jersey: American Institute of Physics.
Aharony, A.; Feder, J., eds. (1989), "Fractals in Physics: Essays in Honor of Benoit B. Mandelbrot",Proceedings of the International Conference Honoring Benoit B. Mandelbrot on His 65th Birthday, Vence, France, 1–4 October 1989
Ramaré, O. (1995)."On šnirel'man's constant".Annali della Scuola Normale Superiore di Pisa. Classe di Scienze. Serie IV.22 (4):645–706. Retrieved13 March 2009.