richard feynman essay value of science

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The Value of Science

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• BOOKS AND ARTS
• 08 May 2018

Richard Feynman at 100

• Paul Halpern 0

Paul Halpern is a professor of physics at the University of the Sciences in Philadelphia, Pennsylvania. He is the author of 15 science books, most recently The Quantum Labyrinth and Einstein’s Dice and Schrödinger’s Cat .

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Richard Feynman shared the 1965 Nobel Prize in Physics. Credit: Kevin Fleming/Corbis via Getty

A pre-eminent twentieth-century physicist and a Nobel laureate: Richard Feynman was certainly those. He was also much more. As the centenary of his birth rolls around on 11 May, a look at his scientific and cultural legacy recalls his restless multidimensionality. His popular books shattered readers’ preconceptions of scientists as lab-coated nerds and replaced them with a hipper image of a wild non-conformist; his scholarly tomes introduced researchers to revolutionary methods of grappling with modern physics.

Feynman was a master conjuror of physics. A mathematical whizz with exceptional intuition, he seemed to pull solutions out of thin air. He crafted a lexicon for particle interactions: iconic squiggles, loops and lines now known as Feynman diagrams (see D. Cressey Nature 489 , 207; 2012 ). His Nobel-prizewinning work on quantum electrodynamics included methods that even he saw as a sleight-of-hand for removing infinite terms from calculations. Yet, his results — equivalent to more systematic, rigorously expounded mathematical techniques independently proposed by co-laureates Julian Schwinger and Sin-Itiro Tomonaga — matched atomic-physics data beautifully.

Decades before his 1965 Nobel Prize, Feynman was already a legend of the Manhattan Project at Los Alamos, New Mexico, where he helped develop the atomic bomb. His colleagues and supervisors, including scientific director J. Robert Oppenheimer and head of the theoretical division Hans Bethe, were stunned by his computational abilities.

Then there was the playfulness. His pranks, including safe-cracking and sneaking through security fences, and his passion for playing the bongos, were arguably as memorable as his science. Feynman loved telling stories about himself and observing the reaction — the more stunned, amused or horrified the better. In the 1980s, his friend and fellow drummer Ralph Leighton collected some of them in two bestselling volumes: Surely You’re Joking, Mr. Feynman! (1985) and What Do You Care What Other People Think? (1988).

Playful spirit

In the first, Feynman flaunted his rough edges and eccentricities, and much of the book is hilarious. (One story sees him bungling a sprinkler experiment in the cyclotron laboratory at Princeton University in New Jersey, shattering glass tubes and flooding the space with water.) The chronicles of Feynman’s Los Alamos days are exceptionally funny, such as his removal of the secret contents of physicist Edward Teller’s locked desk drawer after Teller told him it was impenetrable. However, the book shows its age in disturbingly sexist sections such as “You just ask them?”, about his predatory behaviour towards women.

His relationships with women were complicated. In What Do You Care , he explained how he encouraged his younger sister Joan, now an acclaimed astrophysicist, to go into science. And he recounted how many of his attitudes had been shaped by his love for his first wife, Arline, who died of tuberculosis in 1945, a few years after they married. Those stories were mostly written during the final stages of Feynman’s life, after he had undergone treatment for cancer. By that point he had undoubtedly become more cognizant of his legacy.

Richard Feynman lecturing at California State University, Long Beach, in 1979. Credit: Caltech Archives

Indeed, beneath his clown’s guise, Feynman was a sensitive man, suffering from both early grief and considerable anguish about the atomic weapons he had helped engender. These demons stymied his research from the end of the Second World War until 1947, when findings reported at the Shelter Island Conference in New York helped to spark his Nobel-prizewinning work. At the meeting, physicist Willis Lamb presented evidence of a discrepancy between predictions for certain energy levels of the hydrogen atom, calculated using the Dirac equation, and experimental results obtained using microwaves to excite the atom. Inspired by Bethe’s quick calculation of this Lamb shift, Feynman developed techniques to solve that problem and beyond, to the widest range of quantum electrodynamic interactions between charged particles.

Golden years

The next two years proved extremely productive in disseminating his extraordinary methods for calculating interactions in particle physics. Feynman published seminal papers such as ‘Classical electrodynamics in terms of direct interparticle action’ ( J. A. Wheeler and R. P. Feynman Rev. Mod. Phys. 21 , 425–433; 1949 ) and ‘Space-time approach to quantum electrodynamics’ ( R. P. Feynman Phys. Rev. 76 , 769–789; 1949 ). These build on each other like revelations in a Sherlock Holmes story — with the last supplying a complete resolution of how electrons interact using photons. Through his diagrams, which surprisingly depict positively charged positrons as electrons moving backward in time, Feynman portrayed the gamut of possible modes of interaction, each contributing to the total picture in a weighted tally called “sum over histories”. In his brilliant vision, quantum reality is a cloud-like smear of particles’ possible paths, as if a commuter from Essex to London could travel the entire route by train, coach, car and bicycle simultaneously.

Feynman published two excellent primers introducing these quantum methods. Quantum Mechanics and Path Integrals (1965; co-authored with Albert Hibbs) begins with one of his favourite apparatuses, the double-slit experiment, and quickly moves into path integration and other advanced methods. The second, QED (1985; based on a lecture series) is more accessible — explaining the same theory using diagrams and examples.

Starting in the 1950s, Feynman ventured into many other areas of theoretical physics: superfluids, superconductivity, gravitation and the constituents of protons and neutrons, which he called partons. Two later papers that made a huge impact were his model of the weak interaction, ‘Theory of the Fermi interaction’ ( R. P. Feynman and M. Gell-Mann Phys. Rev. 109 , 193; 1958 ), and his proposal for quantum computation, ‘Simulating physics with computers’ ( R. P. Feynman Int. J. Theor. Phys. 21 , 467–488; 1982 ). In each, he tinkered with variations until he reached definitive conclusions.

Feynman was also a renowned educator. Those lucky enough to have attended his lectures have the best sense of how his agile mind operated. He taught a first-year course at the California Institute of Technology (Caltech) in Pasadena: ‘Physics X’, in which students would ask him anything and he’d think on his feet. Feynman loved to astound, and often refused to provide solutions, to spur students on intellectually. The careful notes of attendees have been published as books and articles, bolstering his reputation as a master lecturer. One such from Caltech was the three-volume The Feynman Lectures on Physics (1964). Another, 1959’s The Theory of Fundamental Processes , is based on notes taken by Peter Carruthers and Michael Nauenberg, two students at Cornell University in Ithaca, New York, when Feynman was a visiting lecturer there in 1958. Nauenberg told me how, during the first lecture, Feynman walked in, glanced at the blackboard, wildly erased the equations on it and declared that they would all learn the whole of physics from scratch. Within a few weeks, the course proceeded from elementary quantum mechanics to Feynman’s rules for particle-physics calculations. The Character of Physical Law (1967), another of Feynman’s works, emerged from lectures he delivered at Cornell six years later.

Feynman’s books urge us to explore the world with open-minded inquisitiveness, as if encountering it for the first time. He worked from the idea that all of us could aspire to take the same mental leaps as him. But, of course, not every ambitious young magician can be a Harry Houdini. Whereas other educators might try to coddle those who couldn’t keep up, Feynman never relented. The essence of his philosophy was to find something that you can do well, and put your heart and soul into it. If not physics, then another passion — bongos, perhaps.

Nature 557 , 164-165 (2018)

doi: https://doi.org/10.1038/d41586-018-05082-4

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Richard P. Feynman Papers

• Print Generating
• Collection Overview
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This collection documents the career of Nobel Prize winner Richard Phillips Feynman (1918-1988). It contains correspondence, biographical materials, course and lecture notes, speeches, manuscripts, publications, and technical notes relating to his work in quantum electrodynamics. Feynman served as Richard Chace Tolman Professor of Theoretical Physics at the California Institute of Technology from 1951 until his death.

• Creation: 1933-1988
• Feynman, Richard P. (Richard Phillips), 1918-1988 (Person)

Conditions Governing Access

This collection has not been digitized, and is available only in the reading room of the Caltech Archives. Access is available to anyone conducting research for which it is necessary; please contact the Caltech Archives to make an appointment.

Conditions Governing Use

Copyright to this collection is not held by Caltech. If you wish to quote or reproduce an item created by Richard Feynman beyond the extent of fair use, please contact his heirs' agent, Melanie Jackson Agency, at [email protected]. Copyright to works by others may be held by their respective creators or publishers, or their heirs. If you wish to quote or reproduce them beyond fair use, please contact the copyright holder to request permission. ("Fair use" is a legal principle which permits unlicensed reproduction in certain circumstances. You are responsible for determining whether your own reproduction would fit the legal requirements for fair use.)

Biographical / Historical

Physicist Richard Feynman won his scientific renown through the development of quantum electrodynamics, or QED, a theory describing the interaction of particles and atoms in radiation fields. As a part of this work he invented what came to be known as "Feynman Diagrams," visual representations of space-time particle interactions. For this work he was awarded the Nobel Prize in physics, together with J. Schwinger and S. I. Tomonaga, in 1965. Later in his life Feynman became a prominent public figure through his association with the investigation of the space shuttle Challenger explosion and the publication of two best-selling books of personal recollections. Feynman was born in the borough of Queens in New York City on May 11, 1918. He grew up and attended high school in Far Rockaway, New York. In 1939, he received his BS degree in physics from the Massachusetts Institute of Technology. He then attended Princeton University as a Proctor Fellow from 1940 to 1942, where he began his investigation of quantum electrodynamics under the supervision of J. A. Wheeler. He was awarded his PhD in 1942 for his thesis on the least action principle. While still at Princeton, Feynman was recruited for the atomic bomb project. He was transferred to Los Alamos in 1942, where he headed a team undertaking complicated calculations using very primitive computers. While at Los Alamos, Feynman became good friends with Hans Bethe, who at the end of the war secured a position for Feynman as an associate professor of physics at Cornell. Feynman remained at Cornell from 1945 to 1951. During this time he formalized his theory of quantum electrodynamics and began to publish his results. He also participated in the Shelter Island Conference of 1947, which helped to determine the course of American physics in the atomic age. At this conference he introduced his theory of QED to the leading American physicists. In 1951, Feynman accepted an offer to become the Richard Chace Tolman Professor of Theoretical Physics at the California Institute of Technology, a position he filled until his death. While at Caltech Feynman continued his work at the leading edge of theoretical physics, making important contributions to the study of liquid helium, particle physics, and later quantum chromodynamics. He also began his distinguished career as a teacher and lecturer. In 1961 and 1962 he delivered to Caltech's freshmen the introductory lectures that were later published as The Feynman Lectures on Physics . In 1986, Feynman was asked to serve on the Presidential Commission investigating the space shuttle Challenger accident. In a dramatic fashion, Feynman publicly demonstrated the inelasticity of the shuttle's O-rings at near freezing temperatures, a leading cause of the disaster. He also contributed an extended appendix to the Committee's report, highlighting the technical and administrative deficiencies of the National Aeronautics and Space Administration's space program. Feynman's many interests outside of science, such as his fondness for codes and safecracking, his bongo drums, his theatrical appearances, his artwork, plus his experiments in out-of-body experiences, are well documented in his autobiographies, as well as in his papers at Caltech. Feynman continued his scientific work and his lecturing activities up until his death on February 15, 1988, after a long battle with a rare form of cancer.

39 linear feet (93 boxes)

Language of Materials

Additional description, arrangement.

The two groups of papers have been kept separate, although box numbering is continuous throughout the collection. The guide to the collection is in two parts, and researchers must expect to consult both parts. At the time the second group of papers was processed, an effort was made to create an arrangement parallel to that of group 1. However, the different content and larger scope of group 2 eventually resulted in a somewhat different scheme. Correspondence: The Feynman collection contains a large amount of both incoming and outgoing correspondence. Feynman's scientific contacts include many of the greatest names in twentieth-century physics: Hans Bethe, Niels Bohr, Enrico Fermi, Stephen Hawking, Werner Heisenberg, J. Robert Oppenheimer, Hideki Yukawa—to name only a few. In Group 1, correspondence has been spread over four series: correspondence (largely with individual colleagues), miscellaneous or general correspondence, publication correspondence, and, in the biographical series, a small number of personal letters. For Group 2, an attempt was made to pull both personal, general, and publication correspondence into one main series, Series 1. However, when letters demonstrated both intellectual and physical links with other documents, their original contextual relationships were maintained. Thus, publication correspondence will be found both in Series 1 and in Series 6. Fan mail surrounding Feynman's television appearances, his two autobiographies, and his Nobel Prize has been placed in Series 2, Biographical, as has other correspondence relating to his business and consulting activities documented there. Course and Lecture Notes: Feynman's lecture courses at institutions in Southern California other than Caltech, and even outside the U.S., are represented in Group 2. Of special interest are the courses Feynman gave, in addition to those he attended, at Hughes Aircraft Company, and the sets of lectures that were later published as Statistical Mechanics and QED (originally the Mautner Lectures, which were in turn predated by the Robb Lectures, first delivered at the University of Aukland, New Zealand). Material pertaining to the publication of these lecture series is found in Group 2 correspondence under the respective publishers. Talks, Speeches, Conferences: In this category are those lectures delivered for a special occasion or purpose, usually as single lectures, but sometimes as a series, and in both formal and informal settings. This category overlaps somewhat with Course Notes and Lectures. In Group 1, these materials are to be found under Professional Organizations and Meetings (Series 3) and Manuscripts (Series 5). In Group 2, they are arranged under Series 5 in chronological order, when dated, and in a sub-series of undated talks. Folders in this category contain a wide variety of talk-related documents, from holograph notes to correspondence to slides, figures, or transparencies. Publications: Group 1 contains a small series of publication correspondence (Group 1, Series 4), mostly pertaining to Feynman's book or monograph publishers; in Group 2, similar correspondence has been placed in the main correspondence series (Group 2, Series 1). Group 2's Series 6 lists Feynman's publications by title in chronological order. Folders contain a variety of material, from holograph notes to correspondence to proofs and prints. Researchers should note that formal reprints have been grouped at the end of Group 2, in Section 9. Working Notes and Calculations: The vast majority of Feynman's working notes are located in Group 2. A representative sample from his early years appears in Group 1, Series 5. Of special interest in this group are notebooks from his student days, beginning circa 1933. The notes in Group 2 capture the breadth and depth of Feynman's thought, as well as reflecting many aspects of his personality. They cover a wide range of subjects, from quantum electrodynamics and later quantum chromodynamics to biology and computers. The notes also reflect Feynman's working style. They are sometimes carefully organized into notebooks that were rigorously dated, such as the binders dated between 1966 and 1987 at the beginning of Group 2, Series 7. Unfortunately for researchers, these are the exception. The great mass of Feynman's working notes are scattered on miscellaneous sheets of papers, envelopes, placemats, and seemingly whatever else was at hand when thoughts struck him. Feynman occasionally took time to organize these into a system for files, although only a small fraction of his notes found their way into such a system. The great majority was left in a scattered condition and grouped during the processing of the papers as well as possible by subject matter. Many miscellaneous papers remain. Work of Others: Feynman officially maintained neutrality on the work of his contemporaries, but informal commentaries in the form of notes and marginal glosses on the work of others abound in his papers. A small segment of such materials can be found in Group 1, Series 5. A large amount of work by others, both with and without Feynman's commentary, forms Group 2's Series 8. A preponderance of material on computers dictated an arrangement in which computer-related projects are categorized separately. Individuals whose work is strongly represented—largely Caltech colleagues, students, or collaborators—are listed singly; otherwise materials have been listed by subject.

Immediate Source of Acquisition

The Richard Phillips Feynman Papers were given to Caltech by Richard Feynman and Gweneth Feynman in two main installments. The first group of papers, now boxes 1-20 of the collection, was donated by Richard Feynman himself beginning in 1968, with additions later. It contains materials dating from about 1933 to 1970. The second group occupies boxes 21-90. It was given to Caltech by Feynman's widow Gweneth early in 1989. Group 2 contains papers primarily from the 1970s and 1980s, although some older material is present. Supplements since 1994 occupy three boxes and have come from various donors outside the Feynman family.

Related Materials

Researchers should also consult the Caltech Archives' Historical Files, which contain much miscellaneous material on Richard Feynman acquired from many sources. Similarly the Photo Archives offer a selection of images, obtained in a similar way. The audio and video collections contain substantial Feynman material; researchers should consult the specific index. Manuscript collections at Caltech which contain materials of particular relevance to Feynman include the Robert Leighton Papers and course lecture notes by Bruce H. Morgan.

Processing Information

The initial processing of this collection was completed on July 1, 1993.

• Challenger (Space shuttle)
• Gravitation--Research
• Particles (Nuclear physics)
• Physics--Study and teaching
• Quantum chromodynamics
• Quantum electrodynamics
• Quantum theory
• Space shuttles--Accidents--Investigation--United States

Finding Aid & Administrative Information

Repository details.

Part of the California Institute of Technology Archives and Special Collections Repository

Collection organization

Richard P. Feynman Papers, FeynmanRP2. California Institute of Technology Archives and Special Collections.

Cite Item Description

Richard P. Feynman Papers, FeynmanRP2. California Institute of Technology Archives and Special Collections. https://collections.archives.caltech.edu/repositories/2/resources/168 Accessed May 01, 2024.

Richard Feynman on the Universal Responsibility of Scientists

By maria popova.

In The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman ( public library ) — the anthology that gave us The Great Explainer’s insights on the role of scientific culture in modern society , titled after the famous film of the same name — Richard Feynman adds to history’s famous definitions of science and considers the responsibility of the scientist as just about the polar opposite: to be continuously informed and shaped by life, free of the despotism of opinion and the addiction to rectitude.

Speaking to the notion that “every child is a scientist,” Feynman champions the true responsibility of science education — a responsibility and purpose sadly belied by the current education system — and argues:

When we read about this in the newspaper, it says, ‘The scientist says that this discovery may have importance in the cure of cancer.’ The paper is only interested in the use of the idea, not the idea itself. Hardly anyone can understand the importance of an idea, it is so remarkable. Except that, possibly, some children catch on. And when a child catches on to an idea like that, we have a scientist. These ideas do filter down (in spite of all the conversation about TV replacing thinking), and lots of kids get the spirit — and when they have the spirit you have a scientist. It’s too late for them to get the spirit when they are in our universities, so we must attempt to explain these ideas to children.

He then moves on to the broader role of science as a cultural force. The idea that ignorance is central to science — as well as film , media , and design — is an enduring theme, but Feynman lives up to his reputation and articulates it more beautifully and eloquently than anyone:

The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn’t know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty darn sure of what the result is going to be, he is in some doubt. We have found it of paramount importance that in order to progress we must recognize the ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty– some most unsure, some nearly sure, none absolutely certain.

Echoing Rilke’s counsel to “live the questions,” Feynman traces the roots of science to the vital anti-authoritarianism of brave minds like Galileo and reminds us:

Now, we scientists … take it for granted that it is perfectly consistent to be unsure — that it is possible to live and not know. But I don’t know whether everyone realizes that this is true. Our freedom to doubt was born of a struggle against authority in the early days of science. It was a very deep and strong struggle. Permit us to question — to doubt, that’s all — not to be sure. And I think it is important that we do not forget the importance of this struggle and thus perhaps lose what we have gained. Here lies a responsibility to society.

With his signature blend of graceful language and uncompromising conviction, Feynman echoes Bertrand Russell’s contention that “without science, democracy is impossible” and aims at the bullseye of the scientist’s responsibility:

We are at the very beginning of time for the human race. It is not unreasonable that we grapple with problems. There are tens of thousands of years in the future. Our responsibility is to do what we can, learn what we can, improve the solutions and pass them on. It is our responsibility to leave the men of the future a free hand. In the impetuous youth of humanity, we can make grave errors that can stunt our growth for a long time. This we will do if we say we have the answers now, so young and ignorant; if we suppress all discussion, all criticism, saying, ‘This is it, boys, man is saved!’ and thus doom man for a long time to the chains of authority, confined to the limits of our present imagination. It has been done so many times before. It is our responsibility as scientists, knowing the great progress and great value of a satisfactory philosophy of ignorance, the great progress that is the fruit of freedom of thought, to proclaim the value of this freedom, to teach how doubt is not to be feared but welcomed and discussed, and to demand this freedom as our duty to all coming generations.

Pair with Feynman’s timeless commencement address on integrity and Stuart Firestein’s fantastic Ignorance: How It Drives Science , one of the best science books of 2012 .

— Published March 6, 2013 — https://www.themarginalian.org/2013/03/06/richard-feynman-responsibility-of-scientists/ —

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CHAPTER ONE The Meaning of It All Thoughts of a Citizen Scientist By RICHARD P. FEYNMAN Addison-Wesley Read the Review The Uncertainty of Science I WANT TO ADDRESS myself directly to the impact of science on man's ideas in other fields, a subject Mr. John Danz particularly wanted to be discussed. In the first of these lectures I will talk about the nature of science and emphasize particularly the existence of doubt and uncertainty. In the second lecture I will discuss the impact of scientific views on political questions, in particular the question of national enemies, and on religious questions. And in the third lecture I will describe how society looks to me--I could say how society looks to a scientific man, but it is only how it looks to me--and what future scientific discoveries may produce in terms of social problems.     What do I know of religion and politics? Several friends in the physics departments here and in other places laughed and said, "I'd like to come and hear what you have to say. I never knew you were interested very much in those things." They mean, of course, I am interested, but I would not dare to talk about them.     In talking about the impact of ideas in one field on ideas in another field, one is always apt to make a fool of oneself. In these days of specialization there are too few people who have such a deep understanding of two departments of our knowledge that they do not make fools of themselves in one or the other.     The ideas I wish to describe are old ideas. There is practically nothing that I am going to say tonight that could not easily have been said by philosophers of the seventeenth century. Why repeat all this? Because there are new generations born every day. Because there are great ideas developed in the history of man, and these ideas do not last unless they are passed purposely and clearly from generation to generation.     Many old ideas have become such common knowledge that it is not necessary to talk about or explain them again. But the ideas associated with the problems of the development of science, as far as I can see by looking around me, are not of the kind that everyone appreciates. It is true that a large number of people do appreciate them. And in a university particularly most people appreciate them, and you may be the wrong audience for me.     New in this difficult business of talking about the impact of the ideas of one field on those of another, I shall start at the end that I know. I do know about science. I know its ideas and its methods, its attitudes toward knowledge, the sources of its progress, its mental discipline. And therefore, in this first lecture, I shall talk about the science that I know, and I shall leave the more ridiculous of my statements for the next two lectures, at which, I assume, the general law is that the audiences will be smaller.     What is science? The word is usually used to mean one of three things, or a mixture of them. I do not think we need to be precise--it is not always a good idea to be too precise. Science means, sometimes, a special method of finding things out. Sometimes it means the body of knowledge arising from the things found out. It may also mean the new things you can do when you have found something out, or the actual doing of new things. This last field is usually called technology--but if you look at the science section in Time magazine you will find it covers about 50 percent what new things are found out and about 50 percent what new things can be and are being done. And so the popular definition of science is partly technology, too.     I want to discuss these three aspects of science in reverse order. I will begin with the new things that you can do--that is, with technology. The most obvious characteristic of science is its application, the fact that as a consequence of science one has a power to do things. And the effect this power has had need hardly be mentioned. The whole industrial revolution would almost have been impossible without the development of science. The possibilities today of producing quantities of food adequate for such a large population, of controlling sickness--the very fact that there can be free men without the necessity of slavery for full production--are very likely the result of the development of scientific means of production.     Now this power to do things carries with it no instructions on how to use it, whether to use it for good or for evil. The product of this power is either good or evil, depending on how it is used. We like improved production, but we have problems with automation. We are happy with the development of medicine, and then we worry about the number of births and the fact that no one dies from the diseases we have eliminated. Or else, with the same knowledge of bacteria, we have hidden laboratories in which men are working as hard as they can to develop bacteria for which no one else will be able to find a cure. We are happy with the development of air transportation and are impressed by the great airplanes, but we are aware also of the severe horrors of air war. We are pleased by the ability to communicate between nations, and then we worry about the fact that we can be snooped upon so easily. We are excited by the fact that space can now be entered; well, we will undoubtedly have a difficulty there, too. The most famous of all these imbalances is the development of nuclear energy and its obvious problems.     Is science of any value?     I think a power to do something is of value. Whether the result is a good thing or a bad thing depends on how it is used, but the power is a value.     Once in Hawaii I was taken to see a Buddhist temple. In the temple a man said, "I am going to tell you something that you will never forget." And then he said, "To every man is given the key to the gates of heaven. The same key opens the gates of hell."     And so it is with science. In a way it is a key to the gates of heaven, and the same key opens the gates of hell, and we do not have any instructions as to which is which gate. Shall we throw away the key and never have a way to enter the gates of heaven? Or shall we struggle with the problem of which is the best way to use the key? That is, of course, a very serious question, but I think that we cannot deny the value of the key to the gates of heaven.     All the major problems of the relations between society and science lie in this same area. When the scientist is told that he must be more responsible for his effects on society, it is the applications of science that are referred to. If you work to develop nuclear energy you must realize also that it can be used harmfully. Therefore, you would expect that, in a discussion of this kind by a scientist, this would be the most important topic. But I will not talk about it further. I think that to say these are scientific problems is an exaggeration. They are far more humanitarian problems. The fact that how to work the power is clear, but how to control it is not, is something not so scientific and is not something that the scientist knows so much about.     Let me illustrate why I do not want to talk about this. Some time ago, in about 1949 or 1950, I went to Brazil to teach physics. There was a Point Four program in those days, which was very exciting--everyone was going to help the underdeveloped countries. What they needed, of course, was technical know-how.     In Brazil I lived in the city of Rio. In Rio there are hills on which are homes made with broken pieces of wood from old signs and so forth. The people are extremely poor. They have no sewers and no water. In order to get water they carry old gasoline cans on their heads down the hills. They go to a place where a new building is being built, because there they have water for mixing cement. The people fill their cans with water and carry them up the hills. And later you see the water dripping down the hill in dirty sewage. It is a pitiful thing.     Right next to these hills are the exciting buildings of the Copacabana beach, beautiful apartments, and so on.     And I said to my friends in the Point Four program, "Is this a problem of technical know-how? They don't know how to put a pipe up the hill? They don't know how to put a pipe to the top of the hill so that the people can at least walk uphill with the empty cans and downhill with the full cans?"     So it is not a problem of technical know-how. Certainly not, because in the neighboring apartment buildings there are pipes, and there are pumps. We realize that now. Now we think it is a problem of economic assistance, and we do not know whether that really works or not. And the question of how much it costs to put a pipe and a pump to the top of each of the hills is not one that seems worth discussing, to me.     Although we do not know how to solve the problem, I would like to point out that we tried two things, technical know-how and economic assistance. We are discouraged with them both, and we are trying something else. As you will see later, I find this encouraging. I think that to keep trying new solutions is the way to do everything.     Those, then are the practical aspects of science, the new things that you can do. They are so obvious that we do not need to speak about them further.     The next aspect of science is its contents, the things that have been found out. This is the yield. This is the gold. This is the excitement, the pay you get for all the disciplined thinking and hard work. The work is not done for the sake of an application. It is done for the excitement of what is found out. Perhaps most of you know this. But to those of you who do not know it, it is almost impossible for me to convey in a lecture this important aspect, this exciting part, the real reason for science. And without understanding this you miss the whole point. You cannot understand science and its relation to anything else unless you understand and appreciate the great adventure of our time. You do not live in your time unless you understand that this is a tremendous adventure and a wild and exciting thing.     Do you think it is dull? It isn't. It is most difficult to convey, but perhaps I can give some idea of it. Let me start anywhere, with any idea.     For instance, the ancients believed that the earth was the back of an elephant that stood on a tortoise that swam in a bottomless sea. Of course, what held up the sea was another question. They did not know the answer.     The belief of the ancients was the result of imagination. It was a poetic and beautiful idea. Look at the way we see it today. Is that a dull idea? The world is a spinning ball, and people are held on it on all sides, some of them upside down. And we turn like a spit in front of a great fire. We whirl around the sun. That is more romantic, more exciting. And what holds us? The force of gravitation, which is not only a thing of the earth but is the thing that makes the earth round in the first place, holds the sun together and keeps us running around the sun in our perpetual attempt to stay away. This gravity holds its sway not only on the stars but between the stars; it holds them in the great galaxies for miles and miles in all directions.     This universe has been described by many, but it just goes on, with its edge as unknown as the bottom of the bottomless sea of the other idea--just as mysterious, just as awe-inspiring, and just as incomplete as the poetic pictures that came before.     But see that the imagination of nature is far, far greater than the imagination of man. No one who did not have some inkling of this through observations could ever have imagined such a marvel as nature is.     Or the earth and time. Have you read anywhere, by any poet, anything about time that compares with real time, with the long, slow process of evolution? Nay, I went too quickly. First, there was the earth without anything alive on it. For billions of years this ball was spinning with its sunsets and its waves and the sea and the noises, and there was no thing alive to appreciate it. Can you conceive, can you appreciate or fit into your ideas what can be the meaning of a world without a living thing on it? We are so used to looking at the world from the point of view of living things that we cannot understand what it means not to be alive, and yet most of the time the world had nothing alive on it. And in most places in the universe today there probably is nothing alive.     Or life itself. The internal machinery of life, the chemistry of the parts, is something beautiful. And it turns out that all life is interconnected with all other life. There is a part of chlorophyll, an important chemical in the oxygen processes in plants, that has a kind of square pattern; it is a rather pretty ring called a benzine ring. And far removed from the plants are animals like ourselves, and in our oxygen-containing systems, in the blood, the hemoglobin, there are the same interesting and peculiar square rings. There is iron in the center of them instead of magnesium, so they are not green but red, but they are the same rings.     The proteins of bacteria and the proteins of humans are the same. In fact it has recently been found that the protein-making machinery in the bacteria can be given orders from material from the red cells to produce red cell proteins. So close is life to life. The universality of the deep chemistry of living things is indeed a fantastic and beautiful thing. And all the time we human beings have been too proud even to recognize our kinship with the animals.     Or there are the atoms. Beautiful--mile upon mile of one ball after another ball in some repeating pattern in a crystal. Things that look quiet and still, like a glass of water with a covered top that has been sitting for several days, are active all the time; the atoms are leaving the surface, bouncing around inside, and coming back. What looks still to our crude eyes is a wild and dynamic dance.     And, again, it has been discovered that all the world is made of the same atoms, that the stars are of the same stuff as ourselves. It then becomes a question of where our stuff came from. Not just where did life come from, or where did the earth come from, but where did the stuff of life and of the earth come from? It looks as if it was belched from some exploding star, much as some of the stars are exploding now. So this piece of dirt waits four and a half billion years and evolves and changes, and now a strange creature stands here with instruments and talks to the strange creatures in the audience. What a wonderful world!     Or take the physiology of human beings. It makes no difference what I talk about. If you look closely enough at anything, you will see that there is nothing more exciting than the truth, the pay dirt of the scientist, discovered by his painstaking efforts.     In physiology you can think of pumping blood, the exciting movements of a girl jumping a jump rope. What goes on inside? The blood pumping, the interconnecting nerves--how quickly the influences of the muscle nerves feed right back to the brain to say, "Now we have touched the ground, now increase the tension so I do not hurt the heels." And as the girl dances up and down, there is another set of muscles that is fed from another set of nerves that says, "One, two, three, O'Leary, one, two, ..." And while she does that, perhaps she smiles at the professor of physiology who is watching her. That is involved, too!     And then electricity. The forces of attraction, of plus and minus, are so strong that in any normal substance all the plusses and minuses are carefully balanced out, everything pulled together with everything else. For a long time no one even noticed the phenomenon of electricity, except once in a while when they rubbed a piece of amber and it attracted a piece of paper. And yet today we find, by playing with these things, that we have a tremendous amount of machinery inside. Yet science is still not thoroughly appreciated.     To give an example, I read Faraday's Chemical History of a Candle, a set of six Christmas lectures for children. The point of Faraday's lectures was that no matter what you look at, if you look at it closely enough, you are involved in the entire universe. And so he got, by looking at every feature of the candle, into combustion, chemistry, etc. But the introduction of the book, in describing Faraday's life and some of his discoveries, explained that he had discovered that the amount of electricity necessary to do performic electrolysis of chemical substances is proportional to the number of atoms which are separated divided by the valence. It further explained that the principles he discovered are used today in chrome plating and the anodic coloring of aluminum, as well as in dozens of other industrial applications. I do not like that statement. Here is what Faraday said about his own discovery: "The atoms of matter are in some ways endowed or associated with electrical powers, to which they owe their most striking qualities, amongst them their mutual chemical affinity." He had discovered that the thing that determined how the atoms went together, the thing that determined the combinations of iron and oxygen which make iron oxide is that some of them are electrically plus and some of them are electrically minus, and they attract each other in definite proportions. He also discovered that electricity comes in units, in atoms. Both were important discoveries, but most exciting was that this was one of the most dramatic moments in the history of science, one of those rare moments when two great fields come together and are unified. He suddenly found that two apparently different things were different aspects of the same thing. Electricity was being studied, and chemistry was being studied. Suddenly they were two aspects of the same thing--chemical changes with the results of electrical forces. And they are still understood that way. So to say merely that the principles are used in chrome plating is inexcusable.     And the newspapers, as you know, have a standard fine for every discovery made in physiology today: "The discoverer said that the discovery may have uses in the cure of cancer." But they cannot explain the value of the thing itself.     Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen. The quantum mechanical and the relativity ideas are examples of this.     The third aspect of my subject is that of science as a method of finding things out. This method is based on the principle that observation is the judge of whether something is so or not. All other aspects and characteristics of science can be understood directly when we understand that observation is the ultimate and final judge of the truth of an idea. But "prove" used in this way really means "test," in the same way that a hundred-proof alcohol is a test of the alcohol, and for people today the idea really should be translated as, "The exception tests the rule." Or, put another way, "The exception proves that the rule is wrong." That is the principle of science. If there is an exception to any rule, and if it can be proved by observation, that rule is wrong.     The exceptions to any rule are most interesting in themselves, for they show us that the old rule is wrong. And it is most exciting, then, to find out what the right rule, if any, is. The exception is studied, along with other conditions that produce similar effects. The scientist tries to find more exceptions and to determine the characteristics of the exceptions, a process that is continually exciting as it develops. He does not try to avoid showing that the rules are wrong; there is progress and excitement in the exact opposite. He tries to prove himself wrong as quickly as possible.     The principle that observation is the judge imposes a severe limitation to the kind of questions that can be answered. They are limited to questions that you can put this way: "if I do this, what will happen?" There are ways to try it and see. Questions like, "should I do this?" and "what is the value of this?" are not of the same kind.     But if a thing is not scientific, if it cannot be subjected to the test of observation, this does not mean that it is dead, or wrong, or stupid. We are not trying to argue that science is somehow good and other things are somehow not good. Scientists take all those things that can be analyzed by observation, and thus the things called science are found out. But there are some things left out, for which the method does not work. This does not mean that those things are unimportant. They are, in fact, in many ways the most important. In any decision for action, when you have to make up your mind what to do, there is always a "should" involved, and this cannot be worked out from "if I do this, what will happen?" alone. You say, "Sure, you see what will happen, and then you decide whether you want it to happen or not." But that is the step the scientist cannot take. You can figure out what is going to happen, but then you have to decide whether you like it that way or not.     There are in science a number of technical consequences that follow from the principle of observation as judge. For example, the observation cannot be rough. You have to be very careful. There may have been a piece of dirt in the apparatus that made the color change; it was not what you thought. You have to check the observations very carefully, and then recheck them, to be sure that you understand what all the conditions are and that you did not misinterpret what you did.     It is interesting that this thoroughness, which is a virtue, is often misunderstood. When someone says a thing has been done scientifically, often all he means is that it has been done thoroughly. I have heard people talk of the "scientific" extermination of the Jews in Germany. There was nothing scientific about it. It was only thorough. There was no question of making observations and then checking them in order to determine something. In that sense, there were "scientific" exterminations of people in Roman times and in other periods when science was not so far developed as it is today and not much attention was paid to observation. In such cases, people should say "thorough" or "thoroughgoing," instead of "scientific."     There are a number of special techniques associated with the game of making observations, and much of what is called the philosophy of science is concerned with a discussion of these techniques. The interpretation of a result is an example. To take a trivial instance, there is a famous joke about a man who complains to a friend of a mysterious phenomenon. The white horses on his farm eat more than the black horses. He worries about this and cannot understand it, until his friend suggests that maybe he has more white horses than black ones.     It sounds ridiculous, but think how many times similar mistakes are made in judgments of various kinds. You say, "My sister had a cold, and in two weeks ..." It is one of those cases, if you think about it, in which there were more white horses. Scientific reasoning requires a certain discipline, and we should try to teach this discipline, because even on the lowest level such errors are unnecessary today.     Another important characteristic of science is its objectivity. It is necessary to look at the results of observation objectively, because you, the experimenter, might like one result better than another. You perform the experiment several times, and because of irregularities, like pieces of dirt falling in, the result varies from time to time. You do not have everything under control. You like the result to be a certain way, so the times it comes out that way, you say, "See, it comes out this particular way." The next time you do the experiment it comes out different. Maybe there was a piece of dirt in it the first time, but you ignore it.     These things seem obvious, but people do not pay enough attention to them in deciding scientific questions or questions on the periphery of science. There could be a certain amount of sense, for example, in the way you analyze the question of whether stocks went up or down because of what the President said or did not say.     Another very important technical point is that the more specific a rule is, the more interesting it is. The more definite the statement, the more interesting it is to test. If someone were to propose that the planets go around the sun because all planet matter has a kind of tendency for movement, a kind of motility, let us call it an "oomph," this theory could explain a number of other phenomena as well. So this is a good theory, is it not? No. It is nowhere near as good as a proposition that the planets move around the sun under the influence of a central force which varies exactly inversely as the square of the distance from the center. The second theory is better because it is so specific; it is so obviously unlikely to be the result of chance. It is so definite that the barest error in the movement can show that it is wrong; but the planets could wobble all over the place, and, according to the first theory, you could say, "Well, that is the funny behavior of the `oomph.'"     So the more specific the rule, the more powerful it is, the more liable it is to exceptions, and the more interesting and valuable it is to check.     Words can be meaningless. If they are used in such a way that no sharp conclusions can be drawn, as in my example of "oomph," then the proposition they state is almost meaningless, because you can explain almost anything by the assertion that things have a tendency to motility. A great deal has been made of this by philosophers, who say that words must be defined extremely precisely. Actually, I disagree somewhat with this; I think that extreme precision of definition is often not worthwhile, and sometimes it is not possible--in fact mostly it is not possible, but I will not get into that argument here.     Most of what many philosophers say about science is really on the technical aspects involved in trying to make sure the method works pretty well. Whether these technical points would be useful in a field in which observation is not the judge I have no idea. I am not going to say that everything has to be done the same way when a method of testing different from observation is used. In a different field perhaps it is not so important to be careful of the meaning of words or that the rules be specific, and so on. I do not know.     In all of this I have left out something very important. I said that observation is the judge of the truth of an idea. But where does the idea come from? The rapid progress and development of science requires that human beings invent something to test.     It was thought in the Middle Ages that people simply make many observations, and the observations themselves suggest the laws. But it does not work that way. It takes much more imagination than that. So the next thing we have to talk about is where the new ideas come from. Actually, it does not make any difference, as long as they come. We have a way of checking whether an idea is correct or not that has nothing to do with where it came from. We simply test it against observation. So in science we are not interested in where an idea comes from.     There is no authority who decides what is a good idea. We have lost the need to go to an authority to find out whether an idea is true or not. We can read an authority and let him suggest something; we can try it out and find out if it is true or not. If it is not true, so much the worse--so the "authorities" lose some of their "authority."     The relations among scientists were at first very argumentative, as they are among most people. This was true in the early days of physics, for example. But in physics today the relations are extremely good. A scientific argument is likely to involve a great deal of laughter and uncertainty on both sides, with both sides thinking up experiments and offering to bet on the outcome. In physics there are so many accumulated observations that it is almost impossible to think of a new idea which is different from all the ideas that have been thought of before and yet that agrees with all the observations that have already been made. And so if you get anything new from anyone, anywhere, you welcome it, and you do not argue about why the other person says it is so.     Many sciences have not developed this far, and the situation is the way it was in the early days of physics, when there was a lot of arguing because there were not so many observations. I bring this up because it is interesting that human relationships, if there is an independent way of judging truth, can become unargumentative.     Most people find it surprising that in science there is no interest in the background of the author of an idea or in his motive in expounding it. You listen, and if it sounds like a thing worth trying, a thing that could be tried, is different, and is not obviously contrary to something observed before, it gets exciting and worthwhile. You do not have to worry about how long he has studied or why he wants you to listen to him. In that sense it makes no difference where the ideas come from. Their real origin is unknown; we call it the imagination of the human brain, the creative imagination--it is known; it is just one of those "oomphs."     It is surprising that people do not believe that there is imagination in science. It is a very interesting kind of imagination, unlike that of the artist. The great difficulty is in trying to imagine something that you have never seen, that is consistent in every detail with what has already been seen, and that is different from what has been thought of; furthermore, it must be definite and not a vague proposition. That is indeed difficult.     Incidentally, the fact that there are rules at all to be checked is a kind of miracle; that it is possible to find a rule, like the inverse square law of gravitation, is some sort of miracle. It is not understood at all, but it leads to the possibility of prediction--that means it tells you what you would expect to happen in an experiment you have not yet done.     It is interesting, and absolutely essential, that the various rules of science be mutually consistent. Since the observations are all the same observations, one rule cannot give one prediction and another rule another prediction. Thus, science is not a specialist business; it is completely universal. I talked about the atoms in physiology; I talked about the atoms in astronomy, electricity, chemistry. They are universal; they must be mutually consistent. You cannot just start off with a new thing that cannot be made of atoms.     It is interesting that reason works in guessing at the rules, and the rules, at least in physics, become reduced. I gave an example of the beautiful reduction of the rules in chemistry and electricity into one rule, but there are many more examples.     The rules that describe nature seem to be mathematical. This is not a result of the fact that observation is the judge, and it is not a characteristic necessity of science that it be mathematical. It just turns out that you can state mathematical laws, in physics at least, which work to make powerful predictions. Why nature is mathematical is, again, a mystery.     I come now to an important point. The old laws may be wrong. How can an observation be incorrect? If it has been carefully checked, how can it be wrong? Why are physicists always having to change the laws? The answer is, first, that the laws are not the observations and, second, that experiments are always inaccurate. The laws are guessed laws, extrapolations, not something that the observations insist upon. They are just good guesses that have gone through the sieve so far. And it turns out later that the sieve now has smaller holes than the sieves that were used before, and this time the law is caught. So the laws are guessed; they are extrapolations into the unknown. You do not know what is going to happen, so you take a guess.     For example, it was believed--it was discovered--that motion does not affect the weight of a thing--that if you spin a top and weigh it, and then weigh it when it has stopped, it weighs the same. That is the result of an observation. But you cannot weigh something to the infinitesimal number of decimal places, parts in a billion. But we now understand that a spinning top weighs more than a top which is not spinning by a few parts in less than a billion. If the top spins fast enough so that the speed of the edges approaches 186,000 miles a second, the weight increase is appreciable--but not until then. The first experiments were performed with tops that spun at speeds much lower than 186,000 miles a second. It seemed then that the mass of the top spinning and not spinning was exactly the same, and someone made a guess that the mass never changes.     How foolish! What a fool! It is only a guessed law, an extrapolation. Why did he do something so unscientific? There was nothing unscientific about it; it was only uncertain. It would have been unscientific not to guess. It has to be done because the extrapolations are the only things that have any real value. It is only the principle of what you think will happen in a case you have not tried that is worth knowing about. Knowledge is of no real value if all you can tell me is what happened yesterday. It is necessary to tell what will happen tomorrow if you do something--not necessary, but fun. Only you must be willing to stick your neck out.     Every scientific law, every scientific principle, every statement of the results of an observation is some kind of a summary which leaves out details, because nothing can be stated precisely. The man simply forgot--he should have stated the law "The mass doesn't change much when the speed isn't too high." The game is to make a specific rule and then see if it will go through the sieve. So the specific guess was that the mass never changes at all. Exciting possibility! It does no harm that it turned out not to be the case. It was only uncertain, and there is no harm in being uncertain. It is better to say something and not be sure than not to say anything at all.     It is necessary and true that all of the things we say in science, all of the conclusions, are uncertain, because they are only conclusions. They are guesses as to what is going to happen, and you cannot know what will happen, because you have not made the most complete experiments.     It is curious that the effect on the mass of a spinning top is so small you may say, "Oh, it doesn't make any difference." But to get a law that is right, or at least one that keeps going through the successive sieves, that goes on for many more observations, requires a tremendous intelligence and imagination and a complete revamping of our philosophy, our understanding of space and time. I am referring to the relativity theory. It turns out that the tiny effects that turn up always require the most revolutionary modifications of ideas.     Scientists, therefore, are used to dealing with doubt and uncertainty. All scientific knowledge is uncertain. This experience with doubt and uncertainty is important. I believe that it is of very great value, and one that extends beyond the sciences. I believe that to solve any problem that has never been solved before, you have to leave the door to the unknown ajar. You have to permit the possibility that you do not have it exactly right. Otherwise, if you have made up your mind already, you might not solve it.     When the scientist tells you he does not know the answer, he is an ignorant man. When he tells you he has a hunch about how it is going to work, he is uncertain about it. When he is pretty sure of how it is going to work, and he tells you, "This is the way it's going to work, I'll bet," he still is in some doubt. And it is of paramount importance, in order to make progress, that we recognize this ignorance and this doubt. Because we have the doubt, we then propose looking in new directions for new ideas. The rate of the development of science is not the rate at which you make observations alone but, much more important, the rate at which you create new things to test.     If we were not able or did not desire to look in any new direction, if we did not have a doubt or recognize ignorance, we would not get any new ideas. There would be nothing worth checking, because we would know what is true. So what we call scientific knowledge today is a body of statements of varying degrees of certainty. Some of them are most unsure; some of them are nearly sure; but none is absolutely certain. Scientists are used to this. We know that it is consistent to be able to live and not know. Some people say, "How can you live without knowing?" I do not know what they mean. I always live without knowing. That is easy. How you get to know is what I want to know.     This freedom to doubt is an important matter in the sciences and, I believe, in other fields. It was born of a struggle. It was a struggle to be permitted to doubt, to be unsure. And I do not want us to forget the importance of the struggle and, by default, to let the thing fall away. I feel a responsibility as a scientist who knows the great value of a satisfactory philosophy of ignorance, and the progress made possible by such a philosophy, progress which is the fruit of freedom of thought. I feel a responsibility to proclaim the value of this freedom and to teach that doubt is not to be feared, but that it is, to be welcomed as the possibility of a new potential for human beings. If you know that you are not sure, you have a chance to improve the situation. I want to demand this freedom for future generations.     Doubt is clearly a value in the sciences. Whether it is in other fields is an open question and an uncertain matter. I expect in the next lectures to discuss that very point and to try to demonstrate that it is important to doubt and that doubt is not a fearful thing, but a thing of very great value. (C) 1998 Michelle Feynman and Carl Feynman All rights reserved. ISBN: 0-201-36080-2

What is Science?

Presented at the fifteenth annual meeting of the National Science Teachers Association, 1966 in New York City, and reprinted from The Physics Teacher Vol. 7, issue 6, 1969, pp. 313-320 by permission of the editor and the author. [Words and symbols in brackets added by Ralph Leighton.]

I thank Mr. DeRose for the opportunity to join you science teachers. I also am a science teacher. I have much experience only in teaching graduate students in physics, and as a result of the experience I know that I don’t know how to teach.

I am sure that you who are real teachers working at the bottom level of this hierarchy of teachers, instructors of teachers, experts on curricula, also are sure that you, too, don’t know how to do it; otherwise you wouldn’t bother to come to the convention.

The subject “What Is Science” is not my choice. It was Mr. DeRose’s subject. But I would like to say that I think that “what is science” is not at all equivalent to “how to teach science,” and I must call that to your attention for two reasons. In the first place, from the way that I am preparing to give this lecture, it may seem that I am trying to tell you how to teach science–I am not at all in any way, because I don’t know anything about small children. I have one, so I know that I don’t know. The other is I think that most of you (because there is so much talk and so many papers and so many experts in the field) have some kind of a feeling of lack of self-confidence. In some way you are always being lectured on how things are not going too well and how you should learn to teach better. I am not going to berate you for the bad work you are doing and indicate how it can definitely be improved; that is not my intention.

As a matter of fact, we have very good students coming into Caltech, and during the years we found them getting better and better. Now how it is done, I don’t know. I wonder if you know. I don’t want to interfere with the system; it is very good.

Only two days ago we had a conference in which we decided that we don’t have to teach a course in elementary quantum mechanics in the graduate school any more. When I was a student, they didn’t even have a course in quantum mechanics in the graduate school; it was considered too difficult a subject. When I first started to teach, we had one. Now we teach it to undergraduates. We discover now that we don’t have to have elementary quantum mechanics for graduates from other schools. Why is it getting pushed down? Because we are able to teach better in the university, and that is because the students coming up are better trained.

What is science? Of course you all must know, if you teach it. That’s common sense. What can I say? If you don’t know, every teacher’s edition of every textbook gives a complete discussion of the subject. There is some kind of distorted distillation and watered-down and mixed-up words of Francis Bacon from some centuries ago, words which then were supposed to be the deep philosophy of science. But one of the greatest experimental scientists of the time who was really doing something, William Harvey, said that what Bacon said science was, was the science that a lord-chancellor would do. He [Bacon] spoke of making observations, but omitted the vital factor of judgment about what to observe and what to pay attention to.

And so what science is, is not what the philosophers have said it is, and certainly not what the teacher editions say it is. What it is, is a problem which I set for myself after I said I would give this talk.

After some time, I was reminded of a little poem:

A centipede was happy quite, until a toad in fun Said, “Pray, which leg comes after which?” This raised his doubts to such a pitch He fell distracted in the ditch Not knowing how to run.

All my life, I have been doing science and known what it was, but what I have come to tell you–which foot comes after which–I am unable to do, and furthermore, I am worried by the analogy in the poem that when I go home I will no longer be able to do any research.

There have been a lot of attempts by the various press reporters to get some kind of a capsule of this talk; I prepared it only a little time ago, so it was impossible; but I can see them all rushing out now to write some sort of headline which says: “The Professor called the President of NSTA a toad.”

Under these circumstances of the difficulty of the subject, and my dislike of philosophical exposition, I will present it in a very unusual way. I am just going to tell you how I learned what science is.

That’s a little bit childish. I learned it as a child. I have had it in my blood from the beginning. And I would like to tell you how it got in.  This sounds as though I am trying to tell you how to teach, but that is not my intention. I’m going to tell you what science is like by how I learned what science is like.

My father did it to me. When my mother was carrying me, it is reported–I am not directly aware of the conversation–my father said that “if it’s a boy, he’ll be a scientist.” How did he do it? He never told me I should be a scientist. He was not a scientist; he was a businessman, a sales manager of a uniform company, but he read about science and loved it.

When I was very young–the earliest story I know–when I still ate in a high chair, my father would play a game with me after dinner.

He had brought a whole lot of old rectangular bathroom floor tiles from some place in Long Island City. We sat them up on end, one next to the other, and I was allowed to push the end one and watch the whole thing go down. So far, so good.

Next, the game improved. The tiles were different colors. I must put one white, two blues, one white, two blues, and another white and then two blues–I may want to put another blue, but it must be a white. You recognize already the usual insidious cleverness; first delight him in play, and then slowly inject material of educational value.

Well, my mother, who is a much more feeling woman, began to realize the insidiousness of his efforts and said, “Mel, please let the poor child put a blue tile if he wants to.” My father said, “No, I want him to pay attention to patterns. It is the only thing I can do that is mathematics at this earliest level.” If I were giving a talk on “what is mathematics,” I would already have answered you. Mathematics is looking for patterns. (The fact is that this education had some effect. We had a direct experimental test, at the time I got to kindergarten. We had weaving in those days. They’ve taken it out; it’s too difficult for children. We used to weave colored paper through vertical strips and make patterns. The kindergarten teacher was so amazed that she sent a special letter home to report that this child was very unusual, because he seemed to be able to figure out ahead of time what pattern he was going to get, and made amazingly intricate patterns. So the tile game did do something to me.)

I would like to report other evidence that mathematics is only patterns.  When I was at Cornell, I was rather fascinated by the student body, which seems to me was a dilute mixture of some sensible people in a big mass of dumb people studying home economics, etc. including lots of girls. I used to sit in the cafeteria with the students and eat and try to overhear their conversations and see if there was one intelligent word coming out.  You can imagine my surprise when I discovered a tremendous thing, it seemed to me.

I listened to a conversation between two girls, and one was explaining that if you want to make a straight line, you see, you go over a certain number to the right for each row you go up–that is, if you go over each time the same amount when you go up a row, you make a straight line–a deep principle of analytic geometry! It went on. I was rather amazed. I didn’t realize the female mind was capable of understanding analytic geometry.

She went on and said, “Suppose you have another line coming in from the other side, and you want to figure out where they are going to intersect.  Suppose on one line you go over two to the right for every one you go up, and the other line goes over three to the right for every one that it goes up, and they start twenty steps apart,” etc.–I was flabbergasted.  She figured out where the intersection was. It turned out that one girl was explaining to the other how to knit argyle socks. I, therefore, did learn a lesson: The female mind is capable of understanding analytic geometry. Those people who have for years been insisting (in the face of all obvious evidence to the contrary) that the male and female are equally capable of rational thought may have something. The difficulty may just be that we have never yet discovered a way to communicate with the female mind. If it is done in the right way, you may be able to get something out of it.

Now I will go on with my own experience as a youngster in mathematics.  Another thing that my father told me–and I can’t quite explain it, because it “was more an emotion than a telling–was that the ratio of the circumference to the diameter of all circles was always the same, no matter what the size. That didn’t seem to me too unobvious, but the ratio had some marvelous property. That was a wonderful number, a deep number, pi. There was a mystery about this number that I didn’t quite understand as a youth, but this was a great thing, and the result was that I looked for pi everywhere.

When I was learning later in school how to make the decimals for fractions, and how to make 3 1/8, 1 wrote 3.125 and, thinking I recognized a friend, wrote that it equals pi, the ratio of circumference to diameter of a circle. The teacher corrected it to 3.1416.

I illustrate these things to show an influence. The idea that there is a mystery, that there is a wonder about the number was important to me–not what the number was. Very much later, when I was doing experiments in the laboratory–I mean my own home laboratory, fiddling around–no, excuse me, I didn’t do experiments, I never did; I just fiddled around.  Gradually, through books and manuals, I began to discover there were formulas applicable to electricity in relating the current and resistance, and so on. One day, looking at the formulas in some book or other, I discovered a formula for the frequency of a resonant circuit.  There was a mystery about this number that I didn’t understand as a youth, but this was a great thing, and the result as that I looked for pi everywhere.

[?Something missing here] which was f = 1/2 pi LC, where L is the inductance and C the capacitance of the circle? You laugh, but I was very serious then. Pi was a thing with circles, and here is pi coming out of an electric circuit. Where was the circle? Do those of you who laughed know how that comes about?

I have to love the thing. I have to look for it. I have to think about it. And then I realized, of course, that the coils are made in circles.  About a half year later, I found another book which gave the inductance of round coils and square coils, and there were other pi’s in those formulas. I began to think about it again, and I realized that the pi did not come from the circular coils. I understand it better now; but in my heart I still don’t know where that circle is, where that pi comes from.

When I was still pretty young–I don’t know how old exactly–I had a ball in a wagon I was pulling, and I noticed something, so I ran up to my father to say that “When I pull the wagon, the ball runs to the back, and when I am running with the wagon and stop, the ball runs to the front.  Why?”

How would you answer?

He said, “That, nobody knows.” He said, “It’s very general, though, it happens all the time to anything; anything that is moving tends to keep moving; anything standing still tries to maintain that condition. If you look close you will see the ball does not run to the back of the wagon where you start from standing still. It moves forward a bit too, but not as fast as the wagon. The back of the wagon catches up with the ball, which has trouble getting started moving. It’s called inertia, that principle.” I did run back to check, and sure enough, the ball didn’t go backwards. He put the difference between what we know and what we call it very distinctly.

Regarding this business about names and words, I would tell you another story. ‘We used to go up to the Catskill Mountains for vacations. In New York, you go the Catskill Mountains for vacations. The poor husbands had to go to work during the week, but they would come rushing out for weekends and stay with their families. On the weekends, my father would take me for walks in the woods. He often took me for walks, and we learned all about nature, and so an, in the process. But the other children, friends of mine also wanted to go, and tried to get my father to take them. He didn’t want to, because he said I was more advanced. I’m not trying to tell you how to teach, because what my father was doing was with a class of just one student; if he had a class of more than one, he was incapable of doing it.

So we went alone for our walk in the woods. But mothers were very powerful in those day’s as they are now, and they convinced the other fathers that they had to take their own sons out for walks in the woods.  So all fathers took all sons out for walks in the woods one Sunday afternoon. The next day, Monday, we were playing in the fields and this boy said to me, “See that bird standing on the stump there? What’s the name of it?”

I said, “I haven’t got the slightest idea.”

He said, ‘It’s a brown-throated thrush. Your father doesn’t teach you much about science.”

I smiled to myself, because my father had already taught me that [the name] doesn’t tell me anything about the bird. He taught me “See that bird? It’s a brown-throated thrush, but in Germany it’s called a halsenflugel, and in Chinese they call it a chung ling and even if you know all those names for it, you still know nothing about the bird–you only know something about people; what they call that bird. Now that thrush sings, and teaches its young to fly, and flies so many miles away during the summer across the country, and nobody knows how it finds its way,” and so forth. There is a difference between the name of the thing and what goes on.

The result of this is that I cannot remember anybody’s name, and when people discuss physics with me they often are exasperated when they say “the Fitz-Cronin effect,” and I ask “What is the effect?” and I can’t remember the name.

I would like to say a word or two–may I interrupt my little tale–about words and definitions, because it is necessary to learn the words.

It is not science. That doesn’t mean, just because it is not science, that we don’t have to teach the words. We are not talking about what to teach; we are talking about what science is. It is not science to know how to change Centigrade to Fahrenheit. It’s necessary, but it is not exactly science. In the same sense, if you were discussing what art is, you wouldn’t say art is the knowledge of the fact that a 3-B pencil is softer than a 2-H pencil. It’s a distinct difference. That doesn’t mean an art teacher shouldn’t teach that, or that an artist gets along very well if he doesn’t know that. (Actually, you can find out in a minute by trying it; but that’s a scientific way that art teachers may not think of explaining.)

In order to talk to each other, we have to have words, and that’s all right. It’s a good idea to try to see the difference, and it’s a good idea to know when we are teaching the tools of science, such as words, and when we are teaching science itself.

To make my point still clearer, I shall pick out a certain science book to criticize unfavorably, which is unfair, because I am sure that with little ingenuity, I can find equally unfavorable things to say about others. There is a first grade science book which, in the first lesson of the first grade, begins in an unfortunate manner to teach science, because it starts off an the wrong idea of what science is. There is a picture of a dog–a windable toy dog–and a hand comes to the winder, and then the dog is able to move. Under the last picture, it says “What makes it move?” Later on, there is a picture of a real dog and the question, “What makes it move?” Then there is a picture of a motorbike and the question, “What makes it move?” and so on.

I thought at first they were getting ready to tell what science was going to be about–physics, biology, chemistry–but that wasn’t it. The answer was in the teacher’s edition of the book: the answer I was trying to learn is that “energy makes it move.”

Now, energy is a very subtle concept. It is very, very difficult to get right. What I meant is that it is not easy to understand energy well enough to use it right, so that you can deduce something correctly using the energy idea–it is beyond the first grade. It would be equally well to say that “God makes it move,” or “spirit makes it move,” or “movability makes it move.” (In fact, one could equally well say “energy makes it stop.”)

Look at it this way: that’s only the definition of energy; it should be reversed. We might say when something can move that it has energy in it, but not what makes it move is energy. This is a very subtle difference.  It’s the same with this inertia proposition.

Perhaps I can make the difference a little clearer this way: If you ask a child what makes the toy dog move, you should think about what an ordinary human being would answer. The answer is that you wound up the spring; it tries to unwind and pushes the gear around.

What a good way to begin a science course! Take apart the toy; see how it works. See the cleverness of the gears; see the ratchets. Learn something about the toy, the way the toy is put together, the ingenuity of people devising the ratchets and other things. That’s good. The question is fine. The answer is a little unfortunate, because what they were trying to do is teach a definition of what is energy. But nothing whatever is learned.

Suppose a student would say, “I don’t think energy makes it move.” Where does the discussion go from there?

I finally figured out a way to test whether you have taught an idea or you have only taught a definition.

Test it this way: you say, “Without using the new word which you have just learned, try to rephrase what you have just learned in your own language.” Without using the word “energy,” tell me what you know now about the dog’s motion.” You cannot. So you learned nothing about science. That may be all right. You may not want to learn something about science right away. You have to learn definitions. But for the very first lesson, is that not possibly destructive?

I think for lesson number one, to learn a mystic formula for answering questions is very bad. The book has some others: “gravity makes it fall;” “the soles of your shoes wear out because of friction.” Shoe leather wears out because it rubs against the sidewalk and the little notches and bumps on the sidewalk grab pieces and pull them off. To simply say it is because of friction, is sad, because it’s not science.

My father dealt a little bit with energy and used the term after I got a little bit of the idea about it. What he would have done I know, because he did in fact essentially the same thing–though not the same example of the toy dog. He would say, “It moves because the sun is shining,” if he wanted to give the same lesson.

I would say, “No. What has that to do with the sun shining? It moved because I wound up the springs.”

“And why, my friend, are you able to move to wind up the spring?”

“I eat.”

“What, my friend, do you eat?”

“I eat plants.”

“And how do they grow?”

“They grow because the sun is shining.”

And it is the same with the [real] dog.

What about gasoline? Accumulated energy of the sun, which is captured by plants and preserved in the ground. Other examples all end with the sun.  And so the same idea about the world that our textbook is driving at is phrased in a very exciting way.

All the things that we see that are moving, are moving because the sun is shining. It does explain the relationship of one source of energy to another, and it can be denied by the child. He could say, “I don’t think it is on account of the sun shining,” and you can start a discussion. So there is a difference. (Later I could challenge him with the tides, and what makes the earth turn, and have my hand on mystery again.)

That is just an example of the difference between definitions (which are necessary) and science. The only objection in this particular case was that it was the first lesson. It must certainly come in later, telling you what energy is, but not to such a simple question as “What makes a [toy] dog move?” A child should be given a child’s answer. “Open it up; let’s look at it.”

During those walks in the woods, I learned a great deal. In the case of birds, for example, I already mentioned migration, but I will give you another example of birds in the woods. Instead of naming them, my father would say, “Look, notice that the bird is always pecking in its feathers.  It pecks a lot in its feathers. Why do you think it pecks the feathers?”

I guessed it’s because the feathers are ruffled, and he’s trying to straighten them out. He said, “Okay, when would the feathers get ruffled, or how would they get ruffled?”

“When he flies. When he walks around, it’s okay; but when he flies it ruffles the feathers.”

Then he would say, “You would guess then when the bird just landed he would have to peck more at his feathers than after he has straightened them out and has just been walking around the ground for a while. Okay, let’s look.”

So we would look, and we would watch, and it turned out, as far as I could make out, that the bird pecked about as much and as often no matter how long he was walking an the ground and not just directly after flight.

So my guess was wrong, and I couldn’t guess the right reason. My father revealed the reason.

It is that the birds have lice. There is a little flake that comes off the feather, my father taught me, stuff that can be eaten, and the louse eats it. And then an the loose, there is a little bit of wax in the joints between the sections of the leg that oases out, and there is a mite that lives in there that can eat that wax. Now the mite has such a good source of food that it doesn’t digest it too well, so from the rear end there comes a liquid that has too much sugar, and in that sugar lives a tiny creature, etc.

The facts are not correct; the spirit is correct. First, I learned about parasitism, one on the other, on the other, on the other. Second, he went on to say that in the world whenever there is any source of something that could be eaten to make life go, some form of life finds a way to make use of that source; and that each little bit of left over stuff is eaten by something.

Now the point of this is that the result of observation, even if I were unable to come to the ultimate conclusion, was a wonderful piece of gold, with marvelous results. It was something marvelous.

Suppose I were told to observe, to make a list, to write down, to do this, to look, and when I wrote my list down, it was filed with 130 other lists in the back of a notebook. I would learn that the result of observation is relatively dull, that nothing much comes of it.

I think it is very important–at least it was to me–that if you are going to teach people to make observations, you should show that something wonderful can come from them. I learned then what science was about: it was patience. If you looked, and you watched, and you paid attention, you got a great reward from it–although possibly not every time. As a result, when I became a more mature man, I would painstakingly, hour after hour, for years, work on problems–sometimes many years, sometimes shorter times; many of them failing, lots of stuff going into the wastebasket–but every once in a while there was the gold of a new understanding that I had learned to expect when I was a kid, the result of observation. For I did not learn that observation was not worthwhile.

Incidentally, in the forest we learned other things. We would go for walks and see all the regular things, and talk about many things: about the growing plants, the struggle of the trees for light, how they try to get as high as they can, and to solve the problem of getting water higher than 35 or 40 feet, the little plants on the ground that look for the little bits of light that come through all that growth, and so forth.

One day, after we had seen all this, my father took me to the forest again and said, “In all this time we have been looking at the forest we have only seen half of what is going on, exactly half.”

I said, “What do you mean?”

He said, “We have been looking at how all these things grow; but for each bit of growth, there must be the same amount of decay–otherwise, the materials would be consumed forever: dead trees would lie there, having used up all the stuff from the air and the ground, and it wouldn’t get back into the ground or the air, so nothing else could grow because there is no material available. There must be for each bit of growth exactly the same amount of decay.”

There then followed many walks in the woods during which we broke up old stumps, saw frizzy bags and funguses growing; he couldn’t show me bacteria, but we saw the softening effects, and so on. [Thus] I saw the forest as a process of the constant turning of materials.

There were many such things, descriptions of things, in odd ways. He often started to talk about things like this: “Suppose a man from Mars were to come down and look at the world.” For example, when I was playing with my electric trains, he told me that there is a great wheel being turned by water which is connected by filaments of copper, which spread out and spread out and spread out in all directions; and then there are little wheels, and all those little wheels turn when the big wheel turns.  The relation between them is only that there is copper and iron, nothing else–no moving parts. You turn one wheel here, and all the little wheels all over the place turn, and your train is one of them. It was a wonderful world my father told me about.

You might wonder what he got out of it all. I went to MIT. I went to Princeton. I came home, and he said, “Now you’ve got a science education.  I have always wanted to know something that I have never understood, and so, my son, I want you to explain it to me.”

I said yes.

He said, “I understand that they say that light is emitted from an atom when it goes from one state to another, from an excited state to a state of lower energy.

I said, “That’s right.”

“And light is a kind of particle, a photon, I think they call it.”

“Yes.”

“So if the photon comes out of the atom when it goes from the excited to the lower state, the photon must have been in the atom in the excited state.”

I said, “Well, no.”

He said, “Well, how do you look at it so you can think of a particle photon coming out without it having been in there in the excited state?”

I thought a few minutes, and I said, “I’m sorry; I don’t know. I can’t explain it to you.”

He was very disappointed after all these years and years of trying to teach me something, that it came out with such poor results.

What science is, I think, may be something like this: There was on this planet an evolution of life to a stage that there were evolved animals, which are intelligent. I don’t mean just human beings, but animals which play and which can learn something from experience–like cats. But at this stage each animal would have to learn from its own experience. They gradually develop, until some animal [primates?] could learn from experience more rapidly and could even learn from another’s experience by watching, or one could show the other, or he saw what the other one did.  So there came a possibility that all might learn it, but the transmission was inefficient and they would die, and maybe the one who learned it died, too, before he could pass it on to others.

The question is: is it possible to learn more rapidly what somebody learned from some accident than the rate at which the thing is being forgotten, either because of bad memory or because of the death of the learner or inventors?

So there came a time, perhaps, when for some species [humans?] the rate at which learning was increased, reached such a pitch that suddenly a completely new thing happened: things could be learned by one individual animal, passed on to another, and another fast enough that it was not lost to the race. Thus became possible an accumulation of knowledge of the race.

This has been called time-binding. I don’t know who first called it this.  At any rate, we have here [in this hall] some samples of those animals, sitting here trying to bind one experience to another, each one trying to learn from the other.

This phenomenon of having a memory for the race, of having an accumulated knowledge passable from one generation to another, was new in the world–but it had a disease in it: it was possible to pass on ideas which were not profitable for the race. The race has ideas, but they are not necessarily profitable.

So there came a time in which the ideas, although accumulated very slowly, were all accumulations not only of practical and useful things, but great accumulations of all types of prejudices, and strange and odd beliefs.

Then a way of avoiding the disease was discovered. This is to doubt that what is being passed from the past is in fact true, and to try to find out ab initio again from experience what the situation is, rather than trusting the experience of the past in the form in which it is passed down. And that is what science is: the result of the discovery that it is worthwhile rechecking by new direct experience, and not necessarily trusting the [human] race[‘s] experience from the past. I see it that way. That is my best definition.

I would like to remind you all of things that you know very well in order to give you a little enthusiasm. In religion, the moral lessons are taught, but they are not just taught once, you are inspired again and again, and I think it is necessary to inspire again and again, and to remember the value of science for children, for grown-ups, and everybody else, in several ways; not only [so] that we will become better citizens, more able to control nature and so on.

There are other things.

There is the value of the worldview created by science. There is the beauty and the wonder of the world that is discovered through the results of these new experiences. That is to say, the wonders of the content which I just reminded you of; that things move because the sun is shining. (Yet, not everything moves because the sun is shining. The earth rotates independent of the sun shining, and the nuclear reaction recently produced energy on the earth, a new source. Probably volcanoes are generally moved from a source different from the shining sun.)

The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in the flaming heat is released the flaming heat of the sun which was bound in to convert the air into tree, and in the ash is the small remnant of the part which did not come from air that came from the solid earth, instead. These are beautiful things, and the content of science is wonderfully full of them. They are very inspiring, and they can be used to inspire others.

Another of the qualities of science is that it teaches the value of rational thought as well as the importance of freedom of thought; the positive results that come from doubting that the lessons are all true.  You must here distinguish–especially in teaching–the science from the forms or procedures that are sometimes used in developing science. It is easy to say, “We write, experiment, and observe, and do this or that.” You can copy that form exactly. But great religions are dissipated by following form without remembering the direct content of the teaching of the great leaders. In the same way, it is possible to follow form and call it science, but that is pseudo-science. In this way, we all suffer from the kind of tyranny we have today in the many institutions that have come under the influence of pseudoscientific advisers.

We have many studies in teaching, for example, in which people make observations, make lists, do statistics, and so on, but these do not thereby become established science, established knowledge. They are merely an imitative form of science analogous to the South Sea Islanders’ airfields–radio towers, etc., made out of wood. The islanders expect a great airplane to arrive. They even build wooden airplanes of the same shape as they see in the foreigners’ airfields around them, but strangely enough, their wood planes do not fly. The result of this pseudoscientific imitation is to produce experts, which many of you are. [But] you teachers, who are really teaching children at the bottom of the heap, can maybe doubt the experts. As a matter of fact, I can also define science another way: Science is the belief in the ignorance of experts.

When someone says, “Science teaches such and such,” he is using the word incorrectly. Science doesn’t teach anything; experience teaches it. If they say to you, “Science has shown such and such,” you might ask, “How does science show it? How did the scientists find out? How? What? Where?”

It should not be “science has shown” but “this experiment, this effect, has shown.” And you have as much right as anyone else, upon hearing about the experiments–but be patient and listen to all the evidence–to judge whether a sensible conclusion has been arrived at.

In a field which is so complicated [as education] that true science is not yet able to get anywhere, we have to rely on a kind of old-fashioned wisdom, a kind of definite straightforwardness. I am trying to inspire the teacher at the bottom to have some hope and some self-confidence in common sense and natural intelligence. The experts who are leading you may be wrong.

I have probably ruined the system, and the students that are coming into Caltech no longer will be any good. I think we live in an unscientific age in which almost all the buffeting of communications and television–words, books, and so on–are unscientific. As a result, there is a considerable amount of intellectual tyranny in the name of science.

Finally, with regard to this time-binding, a man cannot live beyond the grave. Each generation that discovers something from its experience must pass that on, but it must pass that on with a delicate balance of respect and disrespect, so that the [human] race–now that it is aware of the disease to which it is liable–does not inflict its errors too rigidly on its youth, but it does pass on the accumulated wisdom, plus the wisdom that it may not be wisdom.

It is necessary to teach both to accept and to reject the past with a kind of balance that takes considerable skill. Science alone of all the subjects contains within itself the lesson of the danger of belief in the infallibility of the greatest teachers of the preceding generation.

So carry on. Thank you.

The value of science

• Richard P. Feynman
• Eng.Sci. 19 (1955) 13-15
• Published: Dec, 1955
• CBPF-CS-010/88
• KEK scanned document

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Philosophical Science

Richard feynman’s philosophy of science, ben trubody finds that philosophy-phobic physicist feynman is an unacknowledged philosopher of science..

Richard Feynman (1918-88) was one of the greatest physicists of the twentieth century, contributing, among other things, to Quantum Electro Dynamics (QED), for which he won a Nobel Prize. His popular portrayal is of a buffooning genius with a preference for no-nonsense thinking – the sort that by his reckoning seemed in short supply within philosophy. He is noted, and quoted, for his dislike of philosophy, and in particular of the philosophy of science. Any quick trawl of the Internet will bring up quotes attributed to him on the absurdities of philosophy, no doubt informed by his brief flirtation with it at Princeton. Feynman would parody what he saw as ‘dopey’ exercises in linguistic sophistry. As he remarks in a famous lecture series, “We can’t define anything precisely. If we attempt to, we get into that paralysis of thought that comes to philosophers… one saying to the other: you don’t know what you are talking about! The second one says: what do you mean by ‘talking’? What do you mean by ‘you’? What do you mean by ‘know’?” ( The Feynman Lectures on Physics , Vol.1, 1963).

Indeed, similar sentiments were also expressed by the philosopher of science Sir Karl Popper concerning the openness to either intractability (constantly adding new terms to define the old ones) or tautologies (statements true by definition) if one has to define all terms precisely before starting scientific investigation. The point I’m making is that Feynman, for all his perceived dislike of philosophy, is in fact an overlooked philosopher of science himself.

The Philosophy of Doing Science

One of the most famous quotes attributed to Feynman, often requoted with relish by the British science presenter Brian Cox, is that “The philosophy of science is as useful to scientists as ornithology is to birds.” But although this has become a standard put-down by some scientists to those philosophers brave enough to opine on science, maybe this phrase can be lit under a different light? Firstly, whilst Feynman did nay-say philosophy quite a bit, it’s not clear that he actually said those words. And the saying itself points to something quite prescient within the philosophy and sociology of science – that there’s a fundamental difference between speaking or writing about a subject, and living or doing the subject.

The standard portrayal of science in textbooks, documentaries and traditional philosophy of science is that science is its methodology : science is a method for discerning (approximately) true and false statements about the world. Specifically, scientists make hypotheses they then test with observation or experiment. Hypotheses which are disproved by observation are then discarded. This is sometimes called the hypothetico-deductive model . However, this is a way of talking about science, as ornithology is a way of talking about birds. Neither is actual science or the bird itself. Science itself is simply what scientists do. Putting this another way, all the description and formalizing in the world will not tell you what it is like to be a bird, or more to the point, just what it is to do science.

In 1966, Feynman addressed America’s National Science Teachers Association with a talk entitled ‘What is Science?’ At the opening of this address, Feynman states that in textbooks on science, “There is some kind of distorted distillation and watered-down and mixed-up words of Francis Bacon” ( The Pleasure of Finding Things Out , 2001, pp.172-3). The Baconian method was to build up universal laws from single observations via inductive reasoning – a typical example being ‘This swan is white; that swan is white; and so on – from which we can draw the conclusion that all swans are white’. Feynman rebukes the Baconian concept of science, saying one cannot merely observe nature – a judgement is involved about what to pay attention to.

Here Feynman comes across as making a distinction between explicitly knowing things (a bit of data, say) and seeking understanding (a deeper and more intuitive appreciation of how nature works). As he disliked philosophical exposition, he does not use these terms, but he makes it clear that the practice of science is dependent upon more than just explicitly knowing things, applying principles, or copying a format or method. He takes the Baconian approach to be an example of where philosophers have sought a methodological description of science and failed. But he says this failure equally applies to deductive models utilizing Popper’s ‘principle of falsification’. From all this Feynman says: “And so what science is, is not what the philosophers have said it is, and certainly not what the teacher editions [science textbooks] say it is.” ( Ibid .)

Feynman also states that learning the meaning of scientific concepts is not science. That is, the learning of what words and concepts mean is part of teaching science, but not of doing science. It is a necessary but not a sufficient condition of science. Concepts and words are the tools of science, but not science itself, since learning the meaning of words and concepts will only teach you about the limits of people’s imaginations when naming or trying to describe things, and nothing about nature itself. To illustrate, he states that the scientific idea of energy is so difficult to get right that any everyday use of the term will derive incorrect inferences or deductions. We may for instance say that energy is ‘in’ a moving object. If we wind up a clockwork toy we may say that the energy in the spring makes it move, for example; yet it would be more accurate to say that it is the spring that makes the toy move. Feynman quips that you may as well say “God makes it move” as to say ‘energy’ makes it move (pp.178-79). The problem, he says, is that we use synonyms of ‘energy’ to describe what energy is. Feynman suggests that if you cannot re-describe the concept of energy without using the word ‘energy’, you are only learning definitions and have gained zero scientific knowledge. (He himself hints that science tells us about the relationships where energy is found, but not what energy is.)

Doing versus Receiving

‘Understanding’, for Feynman, is a much deeper relationship with the world than knowing what gets taught as ‘facts’ – I can understand something even when the evidence is pointing in the opposite direction. Feynman says that to be slavish to a received view or even to a method for discovering the facts means that we can never advance scientifically, for the old ‘facts’ may need to be overhauled in order to discover new ones, and how that may be done is, well, up for grabs. This flexible view breaks with the traditional view of science as a set procedure, methodology, or fact-checking system, and places Feynman alongside many contemporary historians of science.

To get at the spirit of what he’s saying about science, Feynman quotes a children’s poem about a toad asking a centipede how he runs. In trying to work out how he runs, the centipede falls over confused. Feynman likens the question ‘What is science?’ to this, in that any explication of what science is simply confuses the issue, for science is a lived activity and it has an inexpressible aspect. I can write down what it is for me to ride a bike – describe it terms of bio-mechanics or highway code rules – but none of this is how I do it, nor will it teach you how to do it. Science may well be a lot like this.

Feynman then offers up a theory of his own, going back to a hypothetical point to explain how science got started. His story is that our efficiency with language meant humans got to a stage where worldviews could be passed on without losing too much information. Mistaken ideas can be passed on too. So for Feynman the purpose of science is “to find out ab initio , again from experience, what the situation is, rather than trusting the experience of the past in the form in which it was passed down” (p.185).

This idea is more profound than it may seem. It not only echoes phenomenology in starting from experience as a first principle, it was also the driving idea behind some crucial developments in the philosophy of science. Thomas Kuhn’s motivation for writing The Structure of Scientific Revolutions (1962) was that his experience from the archives of historical science clashed with the received view of science being taught in textbooks. Similarily, in his published lectures about Quantum Electro Dynamics, Feynman points out the disparity between what science is taught to be and how it is: “What I have just outlined is what I call a ‘physicist’s history of physics’, which is never correct… a sort of conventionalized myth-story that the physicist tell to their students, and those students tell to their students, and it is not necessarily related to actual historical development, which I do not really know!” ( QED: The Strange Theory of Light and Matter , 1990, p.6).

Science As Constructive Scepticism

Towards the end of his talk to the National Science Teachers Association, Feynman noted from his own experience that science is neither its content nor form. To just copy or imitate the method of the past is indeed to not be doing science. Feynman says we learn from science that you must doubt the experts: “Science is the belief in the ignorance of experts. When someone says ‘science teaches such and such’, he is using the word incorrectly. Science doesn’t teach it; experience teaches it” ( The Pleasure of Finding Things Out , p.187).

Again this simple idea is more profound than it seems. As I mentioned, a view widely received today is that science is its method: scientists check predictions against the evidence from observation. But Feynman is suggesting that our very experience of nature is molded by the collective scientific knowledge of the past, and that the way we view the world is handed down to us, so that evidence and observations are both historically loaded. For example, Aristotelians experienced the world as geocentric (earth-centred) in a void; Newtonians saw the world as heliocentric (sun-centred) in an infinite space-time; Einsteinians see the world as centreless in a finite space-time geometry. Feynman reasons that established descriptions of reality are hijacked as science in the name of trusted experience. In response, Feynman calls for a “philosophy of ignorance.” This is more than just healthy scepticism; it requires professional judgement. Scepticism by itself – merely being distrustful of evidence or experience – is useless in science, as it does not itself tell us what we should be looking for or doing. Feynman describes judgement in science as the skill to “pass on the accumulated wisdom, plus the wisdom that it might not be wisdom… to teach both to accept and reject the past with a kind of balance that takes considerable skill. Science alone of all the subjects contains within itself the lesson of the danger of belief in the infallibility of the greatest teachers of the preceding generation” ( Ibid , p.188).

What Feynman calls ‘wisdom’ I would call ‘tacit understanding’. Under a conservative view it’s hard to accept that science is not its methodology or the knowledge it generates. These are certainly the by-products of doing science, but for Feynman they are not science itself. Science is not merely its form, method, past exemplars, or the beliefs and knowledge it generates, for these change when great discoveries are made.

© Ben Trubody 2016

Ben Trubody is a lecturer at the University of Gloucestershire and a tutor for the Workers’ Education Association. His research interests include the philosophy of expertise, the history of ideas, and phenomenology.

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Richard Feynman: What Is Science?

“I learned then what science was about: it was patience.”

Richard Feynman – brilliant scientist, fantastic teacher, bongo drummer extraordinaire, practical joker, and a perpetually curious mind – was also well known for articulating his love and passion for science ( Surely You’re Joking, Mr. Feynman! , The Pleasure of Finding Things Out ). His enthusiasm for the subject and for teaching was legendary, and infectious.

In this speech given at the at 15th annual meeting of the National Science Teacher’s Association in 1966, Feynman expounds on ‘What is science?’ , beautifully articulating his love and passion for the subject, as well as what drives his curiosity and his philosophy on teaching.

I think it is very important – at least it was to me – that if you are going to teach people to make observations, you should show that something wonderful can come from them. I learned then what science was about: it was patience. If you looked, and you watched, and you paid attention, you got a great reward from it – although possibly not every time. As a result, when I became a more mature man, I would painstakingly, hour after hour, for years, work on problems – sometimes many years, sometimes shorter times; many of them failing, lots of stuff going into the wastebasket – but every once in a while there was the gold of a new understanding that I had learned to expect when I was a kid, the result of observation. For I did not learn that observation was not worthwhile. […] When someone says, “Science teaches such and such,” he is using the word incorrectly. Science doesn’t teach anything; experience teaches it. If they say to you, “Science has shown such and such,” you might ask, “How does science show it? How did the scientists find out? How? What? Where?” […] It should not be “science has shown” but “this experiment, this effect, has shown.” And you have as much right as anyone else, upon hearing about the experiments–but be patient and listen to all the evidence–to judge whether a sensible conclusion has been arrived at.

Ruchita Bamane

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