Early Buddhism

Scriptures

Gandharan texts Āgamas Pali Canon

Councils

1st Council 2nd Council 3rd Council 4th Council

Schools

First Sangha └ Mahāsāṃghika 　├ Ekavyahāraka 　├ Lokottaravāda 　├ Bahuśrutīya 　├ Prajñaptivāda 　└ Caitika └ Sthaviravāda 　├ Mahīśāsaka 　├ Dharmaguptaka 　├ Kāśyapīya 　├ Sarvāstivāda 　└ Vibhajyavāda 　　└ Theravāda

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The term Early Buddhism can refer to:

• Pre-sectarian Buddhism, which refers to the Teachings and monastic organization and structure, founded by Gautama Buddha.
• The Early Buddhist schools, into which pre-sectarian Buddhism split (without formal schisms, in the sense of Vinaya).

The period of Pre-sectarian Buddhism lasted until about 100 years after the death of Gautama Buddha. The various splits within the monastic organization went together with the introduction and emphasis on Abhidhammic literature by some schools. This literature was specific to each school, and arguments and disputes between the schools were often based on these Abhidhammic writings. However, actual splits were originally based on disagreements on vinaya (monastic discipline), though later on, by about 100 CE or earlier, they could be based on doctrinal disagreement.^[1] Pre-sectarian Buddhism, however, did not have Abhidhammic scriptures, except perhaps for a basic framework, and not all of the early schools developed an Abhidhamma literature.

Several hundreds of years after the advent of Mahayana Buddhism (in the fifth century CE), the early Buddhist schools entered a period of decline in India, while Mahayana Buddhism became stronger. The seventh century Chinese pilgirm Xuanzang reports, however, that non-Mahayana Buddhists continued to comprise a substantial majority of Buddhists in India at that time, and it is likely that this was the case right up to the end of Buddhism in India altogether.

Notes[link]

Sources[link]

• Buswell, Jr., Robert E. (ed.) (2003). Encyclopedia of Buddhism (MacMillan). ISBN 0-02-865718-7.
• Cousins, L.S. (1996). "The Dating of the Historical Buddha: A Review Article" in Journal of the Royal Asiatic Society, Series 3, 6.1 (1996): 57-63. Retrieved 29 Nov 2008 from "Indology" at http://indology.info/papers/cousins/.
• Embree, Ainslie T. (ed.), Stephen N. Hay (ed.), Wm. Theodore de Bary (ed.), A.L. Bashram, R.N. Dandekar, Peter Hardy, J.B. Harrison, V. Raghavan, Royal Weiler, and Andrew Yarrow (1958; 2nd ed. 1988). Sources of Indian Tradition: From the Beginning to 1800 (vol. 1). NY: Columbia U. Press. ISBN 0-231-06651-1.
• Gombrich, Richard F. (1988; 6th reprint, 2002). Theravāda Buddhism: A Social History from Ancient Benares to Modern Colombo (London: Routledge). ISBN 0-415-07585-8.
• Harvey, Peter (1990; 15th printing, 2007). An Introduction to Buddhism: Teachings, History and Practices (Cambridge: Cambridge University Press). ISBN 0-521-31333-3.
• Keown, Damien and Charles S Prebish (eds.) (2004). Encyclopedia of Buddhism (London: Routledge). ISBN 978-0-415-31414-5.
• Robinson, Richard H. and Willard L. Johnson (1970; 3rd ed., 1982). The Buddhist Religion: A Historical Introduction (Belmont, CA: Wadsworth Publishing). ISBN 0-534-01027-X.
• Williams, Paul with Anthony Tribe (2000). Buddhist Thought (London: Routledge). ISBN 0-415-20701-0. Retrieved 29 Nov 2008 from "Google Books" at http://books.google.com/books?id=v0Rpvycf1t0C.

Jack Kornfield
School	Theravada
Personal
Born	(1945-07-16) 16 July 1945 (age 66) United States
Senior posting
Title	Vipassana instructor
Religious career
Website	http://spiritrock.org/

Jack Kornfield (born 1945) is a teacher in the vipassana movement of American Theravada Buddhism.^[1] He trained as a Buddhist monk in Thailand, Burma and India, including as a student of the Thai monk Ajahn Chah. He has taught meditation worldwide since around 1974.

Biography[link]

After graduating from Dartmouth College in 1967, Kornfield joined the Peace Corps and was assigned to the Public Health Service in northeast Thailand, where there are several Buddhist forest monasteries. Here he met Ajahn Chah, who became his teacher. Upon returning to the United States in 1972, Kornfield co-founded the Insight Meditation Society in Barre, Massachusetts, with Sharon Salzberg and Joseph Goldstein.

Kornfield holds a Ph.D. in clinical psychology from Saybrook Institute.^[2] He is also a founding teacher of the Spirit Rock Center in Woodacre, California, where he currently lives.

Teachings[link]

Kornfield's work has focused on integrating Eastern spiritual teachings in an accessible way for Western students.^[3]

Books published[link]

His books include

• Kornfield, Jack; Breiter, Paul (1 September 1985). A still forest pool: the insight meditation of Achaan Chah. Quest Books. ISBN 978-0-8356-0597-7. http://books.google.com/books?id=orfpaVQsAK8C. Retrieved 6 June 2011. 
• Feldman, Christina; Kornfield, Jack (1991). Stories of the spirit, stories of the heart: parables of the spiritual path from around the world. HarperSanFrancisco. ISBN 978-0-06-250321-3. http://books.google.com/books?id=6RQRAQAAIAAJ. Retrieved 6 June 2011. 
• Kornfield, Jack (1 June 1993). A path with heart: a guide through the perils and promises of spiritual life. Bantam Books. ISBN 978-0-553-37211-3. http://books.google.com/books?id=yf-npAo-_dEC. Retrieved 6 June 2011. 
• Goldstein, Joseph; Kornfield, Jack (29 August 1995). The Path of Insight Meditation. Shambhala. ISBN 978-1-57062-069-0. http://books.google.com/books?id=bnMOAAAACAAJ. Retrieved 6 June 2011. 
• Goldstein, Joseph; Kornfield, Jack (6 March 2001). Seeking the heart of wisdom: the path of insight meditation. Shambhala. ISBN 978-1-57062-805-4. http://books.google.com/books?id=LTGbPwAACAAJ. Retrieved 6 June 2011. 
• Kornfield, Jack (2 October 2001). After the Ecstasy, the Laundry: How the Heart Grows Wise on the Spiritual Path. Random House Publishing Group. ISBN 978-0-553-37829-0. http://books.google.com/books?id=OLwDoC1czP8C. Retrieved 6 June 2011. 

Kornfield lectures were featured by Joe Frank on his radio series "The Other Side."

References[link]

External links[link]

• Jack Kornfield audio from the DIY Dharma website
• The Eightfold Path for the Householder [1] from the Urban Dharma website

Richard Feynman
File:Richard Feynman Nobel.jpg
Born	Richard Phillips Feynman (1918-05-11)May 11, 1918 Far Rockaway, Queens, New York, U.S.
Died	February 15, 1988(1988-02-15) (aged 69) Los Angeles, California, U.S.
Residence	United States
Nationality	American
Fields	Physics
Institutions	Manhattan Project Cornell University California Institute of Technology
Alma mater	Massachusetts Institute of Technology (B.S.), Princeton University (Ph.D.)
Doctoral advisor	John Archibald Wheeler
Other academic advisors	Manuel Sandoval Vallarta
Doctoral students	F. L. Vernon, Jr.[1] Willard H. Wells[1] Al Hibbs[1] George Zweig[1] Giovanni Rossi Lomanitz[1] Thomas Curtright[1]
Other notable students	Douglas D. Osheroff Robert Barro W. Daniel Hillis
Known for	Feynman diagrams Feynman point Feynman–Kac formula Wheeler–Feynman absorber theory Bethe–Feynman formula Feynman sprinkler Feynman Long Division Puzzles Hellmann–Feynman theorem Feynman slash notation Feynman parametrization Sticky bead argument One-electron universe Quantum cellular automata
Influences	Paul Dirac
Notable awards	Albert Einstein Award (1954) E. O. Lawrence Award (1962) Nobel Prize in Physics (1965) Oersted Medal (1972) National Medal of Science (1979)
Spouse	Arline Greenbaum (m. 1941–1945) «start: (1941)–end+1: (1946)»"Marriage: Arline Greenbaum to Richard Feynman" Location: (linkback:http://en-wiki.pop.wn.com/index.php/Richard_Feynman)(died) Mary Lou Bell (m. 1952–1954) «start: (1952)–end+1: (1955)»"Marriage: Mary Lou Bell to Richard Feynman" Location: (linkback:http://en-wiki.pop.wn.com/index.php/Richard_Feynman) Gweneth Howarth (m. 1960–1988) «start: (1960)–end+1: (1989)»"Marriage: Gweneth Howarth to Richard Feynman" Location: (linkback:http://en-wiki.pop.wn.com/index.php/Richard_Feynman) (his death)
Signature
Notes He was the father of Carl Feynman and adoptive father of Michelle Feynman. He was the brother of Joan Feynman.

Richard Phillips Feynman ( /ˈfaɪnmən/; May 11, 1918 – February 15, 1988)^[2] was an American physicist known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, and the physics of the superfluidity of supercooled liquid helium, as well as in particle physics (he proposed the parton model). For his contributions to the development of quantum electrodynamics, Feynman, jointly with Julian Schwinger and Sin-Itiro Tomonaga, received the Nobel Prize in Physics in 1965. He developed a widely used pictorial representation scheme for the mathematical expressions governing the behavior of subatomic particles, which later became known as Feynman diagrams. During his lifetime, Feynman became one of the best-known scientists in the world. In a 1999 poll of 130 leading physicists worldwide by the British journal Physics World he was ranked as one of the ten greatest physicists of all time.^[3]

He assisted in the development of the atomic bomb and was a member of the panel that investigated the Space Shuttle Challenger disaster. In addition to his work in theoretical physics, Feynman has been credited with pioneering the field of quantum computing,^[4][5] and introducing the concept of nanotechnology.^[6] He held the Richard Chace Tolman professorship in theoretical physics at the California Institute of Technology.

Feynman was a keen popularizer of physics through both books and lectures, notably a 1959 talk on top-down nanotechnology called There’s Plenty of Room at the Bottom and the three volume publication of his undergraduate lectures, The Feynman Lectures on Physics. Feynman also became known through his semi-autobiographical books (Surely You’re Joking, Mr. Feynman! and What Do You Care What Other People Think?) and books written about him, such as Tuva or Bust!.

He also had a deep interest in biology, and was a friend of the geneticist and microbiologist Esther Lederberg, who developed replica plating and discovered bacteriophage lambda.^[7] They had several mutual physicist friends who, after beginning their careers in nuclear research, moved into genetics, among them Max Delbrück and Aaron Novick.

Biography[link]

Early life[link]

Richard Phillips Feynman was born on May 11, 1918,^[8] in Far Rockaway, Queens, New York.^[9] His family originated from Russia and Poland; both of his parents were Ashkenazi Jewish.^[10] They were not religious and by his youth Feynman described himself as an “avowed atheist”.^[11] Feynman (in common with the famous physicist Edward Teller) was a late talker; by his third birthday he had yet to utter a single word. The young Feynman was heavily influenced by his father, Melville, who encouraged him to ask questions to challenge orthodox thinking. From his mother, Lucille, he gained the sense of humor that he had throughout his life. As a child, he had a talent for engineering, maintained an experimental laboratory in his home, and delighted in repairing radios. His younger sister Joan also became a professional physicist.^[12][13]

Education[link]

In high school, his IQ was determined to be 125—high, but “merely respectable” according to biographer James Gleick.^[14] Feynman later scoffed at psychometric testing. In the year 1933, in which he turned 15, he taught himself trigonometry, advanced algebra, infinite series, analytic geometry, and differential and integral calculus.^[15] Before entering college, he was experimenting with and re-creating mathematical topics, such as the half-derivative, using his own notation. In high school, he was developing the mathematical intuition behind his Taylor series of mathematical operators.^[16]

His habit of direct characterization sometimes rattled more conventional thinkers; for example, one of his questions, when learning feline anatomy, was “Do you have a map of the cat?” (referring to an anatomical chart).

Feynman attended Far Rockaway High School, a school also attended by fellow laureates Burton Richter and Baruch Samuel Blumberg.^[17] A member of the Arista Honor Society, in his last year in high school, Feynman won the New York University Math Championship; the large difference between his score and those of his closest competitors shocked the judges.^[18]

He applied to Columbia University, but was not accepted.^[19][20] Instead he attended the Massachusetts Institute of Technology, where he received a bachelor’s degree in 1939, and in the same year was named a Putnam Fellow. While there, Feynman took every physics course offered, including a graduate course on theoretical physics while only in his second year.

He obtained a perfect score on the graduate school entrance exams to Princeton University in mathematics and physics—an unprecedented feat—but did rather poorly on the history and English portions.^[18] Attendees at Feynman’s first seminar included Albert Einstein, Wolfgang Pauli, and John von Neumann. He received a Ph.D. from Princeton in 1942; his thesis advisor was John Archibald Wheeler. Feynman’s thesis applied the principle of stationary action to problems of quantum mechanics, inspired by a desire to quantize the Wheeler–Feynman absorber theory of electrodynamics, laying the groundwork for the “path integral” approach and Feynman diagrams, and was titled “The Principle of Least Action in Quantum Mechanics”.

This was Richard Feynman nearing the crest of his powers. At twenty-three … there was no physicist on earth who could match his exuberant command over the native materials of theoretical science. It was not just a facility at mathematics (though it had become clear … that the mathematical machinery emerging from the Wheeler–Feynman collaboration was beyond Wheeler’s own ability). Feynman seemed to possess a frightening ease with the substance behind the equations, like Albert Einstein at the same age, like the Soviet physicist Lev Landau—but few others.

— James Gleick, Genius: The Life and Science of Richard Feynman

The Manhattan Project[link]

This unreferenced section requires citations to ensure verifiability.

Feynman (center) with Robert Oppenheimer (right) relaxing at a Los Alamos social function during the Manhattan Project

At Princeton, the physicist Robert R. Wilson encouraged Feynman to participate in the Manhattan Project—the wartime U.S. Army project at Los Alamos developing the atomic bomb. Feynman said he was persuaded to join this effort to build it before Nazi Germany developed their own bomb.

He was assigned to Hans Bethe’s theoretical division, and impressed Bethe enough to be made a group leader. He and Bethe developed the Bethe–Feynman formula for calculating the yield of a fission bomb, which built upon previous work by Robert Serber.

He immersed himself in work on the project, and was present at the Trinity bomb test. Feynman claimed to be the only person to see the explosion without the very dark glasses or welder’s lenses provided, reasoning that it was safe to look through a truck windshield, as it would screen out the harmful ultraviolet radiation.

As a junior physicist, he was not central to the project. The greater part of his work was administering the computation group of human computers in the Theoretical division (one of his students there, John G. Kemeny, later went on to co-design and co-specify the programming language BASIC). Later, with Nicholas Metropolis, he assisted in establishing the system for using IBM punched cards for computation. Feynman succeeded in solving one of the equations for the project that were posted on the blackboards. However, they did not “do the physics right” and Feynman’s solution was not used.

Feynman’s other work at Los Alamos included calculating neutron equations for the Los Alamos “Water Boiler”, a small nuclear reactor, to measure how close an assembly of fissile material was to criticality. On completing this work he was transferred to the Oak Ridge facility, where he aided engineers in devising safety procedures for material storage so that criticality accidents (for example, due to sub-critical amounts of fissile material inadvertently stored in proximity on opposite sides of a wall) could be avoided. He also did theoretical work and calculations on the proposed uranium hydride bomb, which later proved not to be feasible.

Feynman was sought out by physicist Niels Bohr for one-on-one discussions. He later discovered the reason: most physicists were too in awe of Bohr to argue with him. Feynman had no such inhibitions, vigorously pointing out anything he considered to be flawed in Bohr’s thinking. Feynman said he felt as much respect for Bohr as anyone else, but once anyone got him talking about physics, he would become so focused he forgot about social niceties.

Due to the top secret nature of the work, Los Alamos was isolated. In Feynman’s own words, “There wasn’t anything to do there”. Bored, he indulged his curiosity by learning to pick the combination locks on cabinets and desks used to secure papers. Feynman played many jokes on colleagues. In one case he found the combination to a locked filing cabinet by trying the numbers a physicist would use (it proved to be 27–18–28 after the base of natural logarithms, e = 2.71828…), and found that the three filing cabinets where a colleague kept a set of atomic bomb research notes all had the same combination. He left a series of notes as a prank, which initially spooked his colleague, Frederic de Hoffmann, into thinking a spy or saboteur had gained access to atomic bomb secrets. On several occasions, Feynman drove to Albuquerque to see his ailing wife in a car borrowed from Klaus Fuchs, who was later discovered to be a real spy for the Soviets, transporting nuclear secrets in his car to Santa Fe.

On occasion, Feynman would find an isolated section of the mesa to drum in the style of American natives; “and maybe I would dance and chant, a little”. These antics did not go unnoticed, and rumors spread about a mysterious Indian drummer called “Injun Joe”. He also became a friend of laboratory head J. Robert Oppenheimer, who unsuccessfully tried to court him away from his other commitments after the war to work at the University of California, Berkeley.

Feynman alludes to his thoughts on the justification for getting involved in the Manhattan project in The Pleasure of Finding Things Out. As mentioned earlier, he felt the possibility of Nazi Germany developing the bomb before the Allies was a compelling reason to help with its development for the US. However, he goes on to say that it was an error on his part not to reconsider the situation when Germany was defeated. In the same publication, Feynman also talks about his worries in the atomic bomb age, feeling for some considerable time that there was a high risk that the bomb would be used again soon so that it was pointless to build for the future. Later he describes this period as a “depression.”

Early academic career[link]

Following the completion of his Ph.D. in 1942, Feynman held an appointment at the University of Wisconsin–Madison as an assistant professor of physics. The appointment was spent on leave for his involvement in the Manhattan project. In 1945, he received a letter from Dean Mark Ingraham of the College of Letters and Science requesting his return to UW to teach in the coming academic year. His appointment was not extended when he did not commit to return. In a talk given several years later at UW, Feynman quipped, “It’s great to be back at the only university that ever had the good sense to fire me”.^[21]

After the war, Feynman declined an offer from the Institute for Advanced Study in Princeton, New Jersey, despite the presence there of such distinguished faculty members as Albert Einstein, Kurt Gödel, and John von Neumann. Feynman followed Hans Bethe, instead, to Cornell University, where Feynman taught theoretical physics from 1945 to 1950.^[16] During a temporary depression following the destruction of Hiroshima by the bomb produced by the Manhattan Project, he focused on complex physics problems, not for utility, but for self-satisfaction. One of these was analyzing the physics of a twirling, nutating dish as it is moving through the air. His work during this period, which used equations of rotation to express various spinning speeds, soon proved important to his Nobel Prize-winning work. Yet because he felt burned out, and had turned his attention to less immediately practical but more entertaining problems, he felt surprised by the offers of professorships from other renowned universities.^[16]

Despite yet another offer from the Institute for Advanced Study, Feynman rejected the Institute on the grounds that there were no teaching duties: Feynman felt that students were a source of inspiration and teaching a diversion during uncreative spells. Because of this, the Institute for Advanced study and Princeton University jointly offered him a package whereby he could teach at the university and also be at the Institute. That he also turned this down suggests the effects of his depression^{[not in citation given]}. (see Surely You’re Joking Mr. Feynman!). Somewhat later, feeling better, Feynman accepted an offer from the California Institute of Technology (Caltech) — and as he says in his book Surely You’re Joking Mr. Feynman! — because a desire to live in a mild climate had firmly fixed itself in his mind while installing tire chains on his car in the middle of a snowstorm in Ithaca.

Feynman has been called the “Great Explainer”.^[22] He gained a reputation for taking great care when giving explanations to his students and for making it a moral duty to make the topic accessible. His guiding principle was that if a topic could not be explained in a freshman lecture, it was not yet fully understood. Feynman gained great pleasure^[23] from coming up with such a “freshman-level” explanation, for example, of the connection between spin and statistics. What he said was that groups of particles with spin ½ “repel”, whereas groups with integer spin “clump.” This was a brilliantly simplified way of demonstrating how Fermi–Dirac statistics and Bose–Einstein statistics evolved as a consequence of studying how fermions and bosons behave under a rotation of 360°. This was also a question he pondered in his more advanced lectures and to which he demonstrated the solution in the 1986 Dirac memorial lecture.^[24] In the same lecture, he further explained that antiparticles must exist, for if particles only had positive energies, they would not be restricted to a so-called “light cone.”

He opposed rote learning or unthinking memorization and other teaching methods that emphasized form over function. He put these opinions into action whenever he could, from a conference on education in Brazil to a State Commission on school textbook selection. Clear thinking and clear presentation were fundamental prerequisites for his attention. It could be perilous even to approach him when unprepared, and he did not forget the fools or pretenders.^[25]

During one sabbatical year, he returned to Newton’s Principia Mathematica to study it anew; what he learned from Newton, he passed along to his students, such as Newton’s attempted explanation of diffraction.^{[citation needed]}

Caltech years[link]

The Feynman section at the Caltech bookstore

Feynman did significant work while at Caltech, including research in:

• Quantum electrodynamics. The theory for which Feynman won his Nobel Prize is known for its accurate predictions.^[26][27] This theory was begun in the earlier years during Feynman’s work at Princeton as a graduate student and continued while he was at Cornell. This work consisted of two distinct formulations, and it is a common error to confuse them or to merge them into one. The first is his path integral formulation, and the second is his Feynman diagrams. Both formulations contained his sum over histories method in which every possible path from one state to the next is considered, the final path being a sum over the possibilities (also referred to as sum-over-paths.)^[28] For a number of years he lectured to students at Caltech on his path integral formulation of quantum theory. The lecture notes have recently been reedited by Daniel F. Styer and published as a Dover paperback. Not only did Styer correct several hundred typographical and other minor errors, but he included many footnotes explaining, for example, several places where the author used heuristic or plausible reasoning. The second formulation of quantum electrodynamics (using Feynman diagrams) was specifically mentioned by the Nobel committee. The logical connection with the path integral formulation is interesting. Feynman did not prove that the rules for his diagrams followed mathematically from the path integral formulation. Some special cases were later proved by other people, but only in the real case, so the proofs don’t work when spin is involved. The second formulation should be thought of as starting anew, but guided by the intuitive insight provided by the first formulation. Freeman Dyson published a paper in 1949 which, among many other things, added new rules to Feynman’s which told how to actually implement Renormalization. Students everywhere learned and used the powerful new tool that Feynman had created. Eventually computer programs were written to compute Feynman diagrams, providing a tool of unprecedented power. It is possible to write such programs because the Feynman diagrams constitute a Formal language with a grammar.

• Physics of the superfluidity of supercooled liquid helium, where helium seems to display a complete lack of viscosity when flowing. Applying the Schrödinger equation to the question showed that the superfluid was displaying quantum mechanical behavior observable on a macroscopic scale. This helped with the problem of superconductivity; however, the solution eluded Feynman.^[29] It was solved with the BCS theory of superconductivity, proposed by John Bardeen, Leon Neil Cooper, and John Robert Schrieffer.

• A model of weak decay, which showed that the current coupling in the process is a combination of vector and axial currents (an example of weak decay is the decay of a neutron into an electron, a proton, and an anti-neutrino). Although E. C. George Sudarshan and Robert Marshak developed the theory nearly simultaneously, Feynman’s collaboration with Murray Gell-Mann was seen as seminal because the weak interaction was neatly described by the vector and axial currents. It thus combined the 1933 beta decay theory of Enrico Fermi with an explanation of parity violation.

Richard Feynman at Fermilab

He also developed Feynman diagrams, a bookkeeping device which helps in conceptualizing and calculating interactions between particles in spacetime, notably the interactions between electrons and their antimatter counterparts, positrons. This device allowed him, and later others, to approach time reversibility and other fundamental processes. Feynman’s mental picture for these diagrams started with the hard sphere approximation, and the interactions could be thought of as collisions at first. It was not until decades later that physicists thought of analyzing the nodes of the Feynman diagrams more closely. Feynman famously painted Feynman diagrams on the exterior of his van.^[30]

From his diagrams of a small number of particles interacting in spacetime, Feynman could then model all of physics in terms of those particles’ spins and the range of coupling of the fundamental forces.^[31] Feynman attempted an explanation of the strong interactions governing nucleons scattering called the parton model. The parton model emerged as a complement to the quark model developed by his Caltech colleague Murray Gell-Mann. The relationship between the two models was murky; Gell-Mann referred to Feynman’s partons derisively as “put-ons”. In the mid 1960s, physicists believed that quarks were just a bookkeeping device for symmetry numbers, not real particles, as the statistics of the Omega-minus particle, if it were interpreted as three identical strange quarks bound together, seemed impossible if quarks were real. The Stanford linear accelerator deep inelastic scattering experiments of the late 1960s showed, analogously to Ernest Rutherford’s experiment of scattering alpha particles on gold nuclei in 1911, that nucleons (protons and neutrons) contained point-like particles which scattered electrons. It was natural to identify these with quarks, but Feynman’s parton model attempted to interpret the experimental data in a way which did not introduce additional hypotheses. For example, the data showed that some 45% of the energy momentum was carried by electrically neutral particles in the nucleon. These electrically neutral particles are now seen to be the gluons which carry the forces between the quarks and carry also the three-valued color quantum number which solves the Omega-minus problem. Feynman did not dispute the quark model; for example, when the fifth quark was discovered in 1977, Feynman immediately pointed out to his students that the discovery implied the existence of a sixth quark, which was duly discovered in the decade after his death.

After the success of quantum electrodynamics, Feynman turned to quantum gravity. By analogy with the photon, which has spin 1, he investigated the consequences of a free massless spin 2 field, and was able to derive the Einstein field equation of general relativity, but little more.^[32] However, the computational device that Feynman discovered then for gravity, “ghosts”, which are “particles” in the interior of his diagrams which have the “wrong” connection between spin and statistics, have proved invaluable in explaining the quantum particle behavior of the Yang–Mills theories, for example QCD and the electro-weak theory.

In 1965, Feynman was appointed a foreign member of the Royal Society.^[33] At this time in the early 1960s, Feynman exhausted himself by working on multiple major projects at the same time, including a request, while at Caltech, to “spruce up” the teaching of undergraduates. After three years devoted to the task, he produced a series of lectures that eventually became the Feynman Lectures on Physics, one reason that Feynman is still regarded as one of the greatest teachers of physics. He wanted a picture of a drumhead sprinkled with powder to show the modes of vibration at the beginning of the book. Outraged by many rock and roll and drug connections that could be made from the image, the publishers changed the cover to plain red, though they included a picture of him playing drums in the foreword. Feynman later won the Oersted Medal for teaching, of which he seemed especially proud.^[34]

His students competed keenly for his attention; he was once awakened when a student solved a problem and dropped it in his mailbox; glimpsing the student sneaking across his lawn, he could not go back to sleep, and he read the student’s solution. The next morning his breakfast was interrupted by another triumphant student, but Feynman informed him that he was too late.

Partly as a way to bring publicity to progress in physics, Feynman offered $1000 prizes for two of his challenges in nanotechnology, claimed by William McLellan and Tom Newman, respectively.^[35] He was also one of the first scientists to conceive the possibility of quantum computers.

Many of his lectures and other miscellaneous talks were turned into books, including The Character of Physical Law and QED: The Strange Theory of Light and Matter. He gave lectures which his students annotated into books, such as Statistical Mechanics and Lectures on Gravity. The Feynman Lectures on Physics^[36] occupied two physicists, Robert B. Leighton and Matthew Sands as part-time co-authors for several years. Even though they were not adopted by most universities as textbooks, the books continue to be bestsellers because they provide a deep understanding of physics. As of 2005, The Feynman Lectures on Physics has sold over 1.5 million copies in English, an estimated 1 million copies in Russian, and an estimated half million copies in other languages.^{[citation needed]}

In 1974, Feynman delivered the Caltech commencement address on the topic of cargo cult science, which has the semblance of science but is only pseudoscience due to a lack of “a kind of scientific integrity, a principle of scientific thought that corresponds to a kind of utter honesty” on the part of the scientist. He instructed the graduating class that “The first principle is that you must not fool yourself—and you are the easiest person to fool. So you have to be very careful about that. After you’ve not fooled yourself, it’s easy not to fool other scientists. You just have to be honest in a conventional way after that.”^[37]

In 1984–86, he developed a variational method for the approximate calculation of path integrals which has led to a powerful method of converting divergent perturbation expansions into convergent strong-coupling expansions (variational perturbation theory) and, as a consequence, to the most accurate determination^[38] of critical exponents measured in satellite experiments.^[39]