Richard Feynman Read online

  Richard

  Feynman

  A Life in Science

  John Gribbin and Mary Gribbin

  I wonder why. I wonder why.

  I wonder why I wonder.

  I wonder why I wonder why

  I wonder why I wonder!

  RICHARD FEYNMAN

  Contents

  Title Page

  Epigraph

  Acknowledgements

  Prologue: ‘We love you Dick’

  1 A fascination with physics

  2 Physics before Feynman

  3 College boy

  4 Early works

  5 From Los Alamos to Cornell

  6 The masterwork

  7 The legend of Richard Feynman

  8 Supercool science

  9 Fame and (some) fortune

  10 Beyond the Nobel Prize

  11 Father figure

  12 The last challenge

  13 The final years

  14 Feynman after Feynman

  Epilogue: In search of Feynman’s van

  Bibliography

  Index

  About the Authors

  Copyright

  Acknowledgements

  Many people gave up time to talk to us about their personal and professional memories of Richard Feynman. Others took the trouble to answer specific queries by mail, e-mail or telephone. Without them, this book could not have been an accurate portrayal of the best-loved scientist of our times. We thank especially Joan Feynman, Carl Feynman, Michelle Feynman and Jacqueline Shaw from Feynman’s immediate family circle; James Bjorken, Norman Dombey, David Goodstein, James Hartle, Robert Jastrow, Daniel Kevles, Hagen Kleinert, Igor Novikov, Kip Thorne and Nick Watkins from the world of physics; Feynman’s former secretary, Helen Tuck; and Ralph Leighton, who knew Feynman as well as anybody did in the last decade of his life. Even where these people have not been quoted directly, their contributions have helped to shape the image of Richard Feynman in our minds, which we hope comes through in this book.

  We have also drawn on published accounts of Feynman’s life and work, cited in the text and referred to in full in the Bibliography. Where possible, we have checked important stories about Feynman with their sources; but, of course, we have had to rely on the secondary sources in cases where the originators of the stories are no longer alive, or were otherwise unavailable.

  Michael Shermer went to enormous trouble to arrange many interviews for us on a visit to Caltech, and Jagdish Mehra, who was the last person to interview Feynman formally about his life and work, gave permission for us to quote from his own book The Beat of a Different Drum, which remains the definitive technical account of the life and science of Richard Feynman, at a more academic level than the present book.

  Benjamin Gribbin spent many hours transcribing recordings of interviews with scrupulous accuracy and unfailing good humour, and Jonathan Gribbin prepared the diagrams with speed and skill. The archivists at Princeton University and Caltech, respectively Ben Primer and Charlotte Erwin, helped us to find source material, as did Karl Berkelman at Cornell University, Helen Samuels at MIT, and Roger Meade at the Los Alamos National Laboratory.

  Prologue: ‘We love you Dick’

  Does the world really need another book about Richard Feynman? We think so, or we wouldn’t have written it. And this is why. Richard Feynman was the best-loved scientist of modern times, perhaps of all times, and that is something that simply does not come across in any of the other books about the man and his work. There have been books about Feynman the character, a wise-cracking entertainer who imparted not a little worldly wisdom along with his anecdotes; there have been books about Feynman the scientist, putting his work in the perspective of physics in the second half of the twentieth century; there has even been a picture book, combining the illustrations with reminiscences about Feynman by his family and friends. But nobody has captured the essence of Feynman’s science and the essence of Feynman’s persona in one book. This is especially odd because, of all the scientists of modern times, Feynman seems to have been the one who had the best ‘feel’ for science, who understood physics not simply in terms of lines of equations written on a blackboard, but in some deep, inner sense which enabled him to see to the heart of the subject.

  This doesn’t mean that Feynman lived his life ‘like a scientist’, in the stereotypical sense of being a cold-blooded logician in everyday life. Far from it. The point is that he did physics ‘like a human being’, carrying into the world of science his inbuilt sense of fun, his irreverence, and his liking of adventure and the unexpected. The way Feynman did his physics depended on the kind of person he was, far more than in the case of any other physicist we know. It is impossible to understand Feynman’s science properly without understanding what kind of a person he was, and nobody put more life into science than he did.

  Equally, it is impossible to understand what kind of man Feynman was without understanding at least something of the science that was so important to him. A fun-loving, adventurous character like Feynman was attracted to physics because physics is fun, and offers opportunity for adventure. You may find that hard to believe. But what’s wrong with the public image of physics is not so much the science itself as the way that the science is taught and portrayed. Perhaps Feynman’s greatest achievement was as a teacher, conveying the fun of science, and entertainer, providing an image of science that cut right across the stereotypes. Ralph Leighton describes Feynman as a ‘shaman of physics’. Feynman talked of nature as ‘She’ or ‘Her’, and seemed to have a contact with the way the world works that few people have. When he gave lectures, he brought his audience into contact with nature in ways that they could not achieve on their own, allowing them to see nature differently, in a transforming experience, so much so that often when he explained some subtle point in a way that they could understand the audience would break out into spontaneous applause, even laughter. The physicist Freeman Dyson has commented,1 ‘I never saw him give a lecture that did not make the audience laugh’, but the laughter stemmed as much from the pleasure of finding things out as from the jokes that Feynman cracked.

  After this experience, people would often have a memory of understanding something, but couldn’t always quite reconstruct how it was they had understood – Feynman would raise people to a level of understanding that they had never before achieved, but then they couldn’t quite remember how he had done it. Even fellow scientists sometimes felt this way about a Feynman lecture – Leighton recalls his own father, one of Feynman’s colleagues at Caltech, remarking on this almost transcendental experience. People who attended Feynman’s lectures say that they seemed like magic, almost literally spellbinding, while people who met him report the same sort of feeling, an awareness of being in the presence of something special, even when they can’t quite put their finger on why. They just felt changed by the experience. And people who never met Feynman still write to Leighton to say that they have been inspired by Feynman’s example. It may well be that he will be remembered more in this way, as a ‘wise man’, rather than for the specific aspects of the science that he was involved with.

  This would be appropriate, and perhaps what Feynman himself would have wanted. To Feynman, love was more important than science; but it just happened that, as well as loving people, he loved physics.

  And people, including physicists, loved him. In an obituary published in Nature on 14 April 1988 (volume 332, page 588), Hans Bethe, who had been Feynman’s boss both at Los Alamos and at Cornell, said ‘more than other scientists, he was loved by his colleagues and his students’. The day Feynman died, the students at Caltech hung a banner across the eleven-storey library building on the campus. The message on the banner read: ‘WE LOVE YOU DICK’. Around the world, many pe
ople who hadn’t even met Feynman felt a sense of personal loss when he died. Neither of us ever met him; but the physicist half of the partnership (JG) was exactly the right age to be among the first undergraduates to benefit from Feynman’s Lectures on Physics while at university. The clarity of those lectures helped to shape his career, and reinforced his own feeling that science, even at research level, could still be fun. Reading books and papers by Feynman over the years, and seeing him on TV, reinforced that belief, and made Feynman seem like an old friend.

  But to many people who felt the same way, Feynman was, more than any other great scientist of modern times, ‘famous for being famous’. The name of Stephen Hawking is inextricably linked with black holes; Albert Einstein’s with relativity theory; Charles Darwin’s with evolution. But Feynman? To many non-scientists, he was just ‘a scientist’. This is ironic, because Feynman’s greatest work was actually in the area of quantum theory, a subject of enormous fascination to non-scientists today. We want to explain why this work was so important, and how it lies at the heart of investigations of the quantum mysteries today; but we also want to share with you our understanding of the kind of man who carried out that work.

  Even today, writing seven years after Feynman died in 1988, it is far too soon to produce a definitive account of the historical importance of the man and his work. We don’t claim that this is more than a personal view of our subject, but it is one we have arrived at through a long (if one-sided) association with his works, and through recent discussions with Feynman’s family and friends.

  The one thing that is clear above all else in Feynman’s character, from his own work and from conversations with people who knew him, is passion. His passion for physics, for drawing, for drumming, for life itself and for his jokes. Of course Feynman’s own anecdotes, gathered together by Ralph Leighton and published in two volumes, tend to portray Feynman as a larger than life, legendary scientific superman and scourge of established authority. Were those stories accurate? We asked Feynman’s sister, Joan, on a visit to Pasadena in April 1995. ‘It’s easy to tell which stories are accurate’, she replied. ‘How?’, we asked. ‘My brother didn’t lie.’

  Ralph Leighton, to whom the stories were told, agrees, but stresses that Feynman was a showman, who loved telling stories.2 The stories were all true, in that they were about real things that had happened to Feynman; but he used to try telling them in different ways, with different emphasis, until he found the way that worked best. They were not, after all, just anecdotes; in many cases, the stories became parables, and have a moral, telling you something about the right way to live and how to get on in the world, as well as offering amusement and entertainment.

  There is indeed a legend growing up around Richard Feynman; but there is truth behind the legend.3 In the classic western The Man Who Shot Liberty Valence, a reporter is faced with a choice between printing the truth about the early career of a great man, or the legend, and in a memorable moment decides to ‘print the legend’. We don’t intend to go that far, although we agree with the spirit of that decision. We offer you something of the legend of Richard Feynman, but also something of the man behind the legend; and we hope we can put across the importance of his scientific work in language that non-scientists can both understand and enjoy. That, after all, is what Feynman himself would have wanted.

  John Gribbin*

  Mary Gribbin

  March 1996

  Notes

  1. See Freeman Dyson, From Eros to Gaia (Pantheon, New York, 1992).

  2. Joan Feynman, interviewed by JG in April 1995, said that according to her mother ‘when Richard was very little he couldn’t decide whether he wanted to be a comedian or a scientist, so he combined the two options’.

  3. Interviewed by JG in April 1995, David Goodstein, who is Professor of Physics and Vice Provost at Caltech, said, ‘Feynman is a person of historic proportions; he deserves the kind of attention that he’s gotten, in my opinion.’

  * johngribbinscience.wordpress.com/

  1 A fascination with physics

  Family legend has it that when his wife Lucille became pregnant for the first time, Melville Feynman commented ‘if it’s a boy, he’ll be a scientist’.1 The baby was born on 11 May 1918 in Manhattan, and brought up in Far Rockaway, New York; he was named Richard Phillips Feynman,* and he grew up to be the greatest scientist of his generation. He not only won the Nobel Prize for Physics for his first major contribution to science, but carried out at least two other pieces of research that were worthy of the prize; he was one of the leaders of the team that worked on the Manhattan Project, to develop the atomic bomb; and he was, above all, a great teacher who encouraged generations of students to think about physics in a new way.

  Melville Feynman has to take some of the credit for this, because he deliberately set out to stimulate his son to think, from an early age, in a ‘scientific’ way. When the boy was sitting in his high chair, Melville would play games with him using a collection of coloured bathroom tiles. At first, the game mainly involved setting up a row of tiles on end, in any order, and toppling them, like dominoes; but soon they moved on to setting up patterns, maybe two white tiles followed by a blue one, then two more white and another blue, and so on. The young Feynman – called Ritty or Richy by his parents, family and friends – became very good at the game, which his father had started in a conscious attempt to get young Ritty to think about patterns and the basics of mathematical relations.2

  Melville encouraged his son’s interest in science in the obvious ways – buying a set of the Encyclopaedia Britannica, taking Ritty on trips to the American Museum of Natural History, and so on. But even the conventional sources of information were used by Melville as jumping-off points for extrapolations which made the dry material come alive, and which brought home to Richard the magical, mysterious aspects of science. When the Britannica mentioned that a long-extinct dinosaur had been ‘twenty-five feet high’ and had a head ‘six feet across’, Melville would stop reading and explain what that meant – that if the dinosaur stood in the front yard of the house in Far Rockaway, he would be able to look in through the second-floor window, but his head would be too big to fit through the window.

  But the special nature of Richard’s relationship with his father, and the special nature of the way in which Melville encouraged the younger Feynman’s fascination with science, is highlighted by two of Richard Feynman’s favourite anecdotes about his father.

  The first dates back to summers spent in the Catskill Mountains, where families from New York would go to escape the heat of the city. Mothers and children would stay in the mountains for several weeks, but the fathers of the families still had to work in the city, only visiting their families at weekends. On long weekend walks in the woods, Melville introduced Richard to many of the wonders of nature – but with his typical sideways manner of looking at the world. So when one of the other children pointed out a bird to Richard and asked if he knew its name, he had to reply that he didn’t. Triumphantly, the other kid named the bird, sneering that ‘your father doesn’t teach you anything’. ‘But’, Feynman tells us,3 ‘it was the opposite.’ His father had already pointed out that kind of bird:

  ‘See that bird?’ he says. ‘It’s a Spencer’s warbler.’ (I knew he didn’t know the real name.) ‘Well, in Italian, it’s a Chutto Lapittida. In Portuguese, it’s a Bom da Peida. In Chinese it’s a Chung-long-tah, and in Japanese it’s a Katano Tekeda. You can know the name of that bird in all the languages of the world, but when you’re finished, you’ll know absolutely nothing whatever about the bird. You’ll only know about humans in different places, and what they call the bird. So let’s look at the bird and see what it’s doing – that’s what counts.’

  So Richard learned, at a very early age, the difference between knowing the name of something and knowing something. To such a person, it made perfect sense, years later when he was in graduate college, to ask a baffled librarian where he could find ‘the map of a c
at’, and to be equally baffled by her reaction to this simple request. The actual telling of this story, many years later, also gave a fundamental insight into Feynman’s childhood and upbringing. While going through that story with Feynman, not long before Feynman died, Ralph Leighton said to him, ‘there’s all this about your father, but what did your mother teach you?’ He replied, ‘My mother taught me that the highest forms of understanding that we can achieve are laughter, and human compassion.’4

  The second key anecdote from Richard’s early childhood concerns the occasion when he noticed the odd behaviour of a ball left lying in his little wagon when he pulled the wagon forward. The ball rolled to the back of the wagon, then, when the wagon stopped the ball rolled to the front. He asked his father why this happened, and got this reply:

  That, nobody knows. The general principle is that things which are moving tend to keep on moving, and things which are standing still tend to stand still, unless you push them hard. This tendency is called ‘inertia’, but nobody knows why it’s true.

  This represents a deep insight into the nature of physics and the nature of the world, and it was examples like this that encouraged Richard Feynman, in later years, to question everything, to search for underlying truths, and never to believe that just because some process had been labelled meant that it was understood.†

  But there is another aspect to this way Melville had of teaching his son, which has echoes in the way Feynman later used his own anecdotes to bring out highlights of his own life when he became a storyteller in his turn. The stories don’t have to be literally ‘true’, in every detail, in order to make a valid point. As Feynman himself said, he knew full well that the bird being described by Melville wasn’t really called a ‘Spencer’s warbler’, and that the foreign ‘names’ his father made up for the bird were just nonsense words. But he also knew that that didn’t matter – that, indeed, the whole point of this particular story was that names didn’t matter, so if Melville wanted to call the bird a Spencer’s warbler he was fully entitled to do so. Richard Feynman’s own stories should always be understood in this spirit – that as long as the underlying message is correct, the details and emphasis can be adjusted to improve the impact of the story. Joan Feynman’s brother didn’t lie, but as a great showman he presented his stories in the best possible light. As he said of his father’s stories, ‘I knew that they weren’t quite accurate, and yet they were utterly accurate, if you see what I mean, in the character of the story he was trying to tell me.’5 We could say the same about his own stories, especially when, for example, he quotes childhood conversations with his father verbatim, as if he had total recall, when in fact he was making up dialogue to match what he remembered of the occasion. The truth in Richard Feynman’s anecdotes is a much deeper truth than the trivia of exactly what words were said on a particular day in the 1920s.