by John Gribbin
Even then, it wasn’t all plain sailing. Recovering from his third major operation took time, and Feynman would go on increasingly long walks with Leighton to build up his strength in readiness for the trip to Tuva. Meanwhile, the proposed filming trip seemed to be falling through. The proposal for the Tuva expedition was passed from the Soviet Academy of Sciences to the Ministry of Culture, which had no stake in the exhibition coming to America. As the negotiations with Sovinfilm dragged on through the summer, Feynman’s best chance to reach Tuva slipped away.
In September 1987, a Soviet delegation came to Los Angeles to coordinate the planning of the exhibition. It was headed by Andrei Kapitsa, the person in charge of exhibitions for the Soviet Academy of Sciences. Kapitsa provided a direct link with one of Feynman’s major contributions to science – he was the son of Pyotr Kapitsa, who had won the Nobel Prize in 1978 for his work in the 1930s and 1940s on low-temperature physics with liquid helium II. It was Pyotr Kapitsa who had actually coined the term ‘superfluid’ to describe the behaviour of liquid helium at very low temperatures. Richard and Gweneth entertained the delegation of three at their home, and Feynman and Andrei Kapitsa got on well, even though Feynman was uncomfortable at the prospect of linking an official visit to Moscow with his cherished trip to Tuva.
The exhibition planners (including the Feynmans) spent one day on a visit to Catalina Island, 25 miles from Los Angeles. A longer trip to Yosemite National Park was next on the agenda, but Feynman, tired after the outing to Catalina (which involved a boat ride lasting an hour and a half each way, through choppy seas) decided not to go, and Gweneth stayed with him.
It turned out that it wasn’t just the fatigue of the boat trip and the busy schedule of events surrounding the workshop that had got to Feynman. His cancer had struck again, and in October 1987, just a year after his previous operation, he was back at the UCLA Medical Center being operated on for the fourth time for this problem. After this operation, literally almost half of Feynman’s insides had been removed. Astonishingly (and partly due to having an epidural anaesthetic to aid his recovery), within weeks Feynman was back teaching a graduate course in quantum chromodynamics at Caltech, and although now often tired and clearly in pain, he again started the daily walks to build up his strength for the trip to Tuva.
By now, the scientific establishment in Moscow had got wind of Feynman’s proposed trip, from Andrei Kapitsa, and was eager to have him visit them while he was in the Soviet Union. This came close to being an invitation of the very kind that he had wanted to avoid, a trip for Feynman the physicist with Tannu Tuva thrown in as a sweetener, not a trip for Feynman the finder of international exhibitions. But still, even if the Soviet Academy of Sciences did finally want to get involved, the deal had been initiated through the museum connections, and Feynman must have been well aware that it would be his last chance to make the journey. So the ‘three musketeers’ agreed to take up the offer from the Academy of Sciences, if it ever materialized, and work towards a trip to Tuva in May or June of 1988.
In November, Feynman made his last public appearance, which has been movingly described by the physicist John Rigden, in Most of the Good Stuff. Feynman had agreed to serve on a panel discussing ‘What High School Physics Should Include’ at a public meeting in Los Angeles on 14 November. In October, it looked as if he would be too ill to make it, and Rigden was asked if he would be willing to ‘fill in for Feynman’ and agreed to join the panel. On 12 November, he heard that Feynman now felt well enough to participate. Rigden offered to step down, but the organizers said there was no need, and they would simply have both of them on the panel.
The meeting took place in the auditorium of La Cañada High School, where Rigden met Feynman for the first time since 1983. He was shocked by Feynman’s frail appearance, but impressed by his thoughtful responses to the questions posed for the panellists. But the most telling aspect of Rigden’s memoir is his description of what happened after the formal part of the meeting, when people crowded around Feynman asking him questions:
As I watched, I realized I was witnessing something extraordinary. Feynman’s energies grew as he responded to question after question. The outside corners of his eyes were creased by the smiles that played over his face as he talked about physics. His hands and arms cut through the air with increasing vigor as their motions served to complement, even demonstrate, his explanations … It was the enjoyment he exuded as he stood there talking physics with an eager, receptive group of physics teachers that moved me. It was an enjoyment I could feel. When the session ended and Feynman, along with David Goodstein, walked out of the La Cañada High School Auditorium, I had the feeling that I was standing on holy ground.
This was Feynman the showman physicist in his element. And the same phenomenon, of a failing body being lit up from within by the enthusiasm of the man, was seen again a couple of months later, at the end of January 1988, when Christopher Sykes came to Pasadena to interview Feynman for a BBC TV programme about Tannu Tuva. As anyone who has seen that programme will know, the enthusiasm for physics, for adventure and for life was still there.
Just before that interview was recorded, Feynman had received another visitor eager to talk to him about his life and science. Jagdish Mehra is a physicist who became fascinated with the history of his subject, especially the birth of quantum mechanics, and has written several scholarly books on the theme. He had got to know Feynman in 1962, and as early as 1980 he had asked Richard’s permission to write a serious scientific biography of him. They had met intermittently since then, with Mehra asking questions about various aspects of Feynman’s life and scientific work. In December 1987, he called Feynman and suggested another visit, to finish his preparations for the book. Feynman’s initial response was ‘I don’t think I want to go over the past again; I am too tired and depressed.’18 But on 23 December Feynman called back, in a more cheerful mood, to say that Mehra was welcome to come and talk. ‘Thanks very much for calling me’, Mehra replied. ‘I was thinking of coming early in March, would that be all right?’ Feynman said, ‘I don’t know. It might be too late then.’
Worried by this comment, Mehra (who was based in Houston) changed his schedule, and went out to Pasadena on 9 January. The next day, he met up with Feynman, who agreed to take part in taped conversations with Mehra every morning at 10am, except for Tuesdays and Thursdays, when he was teaching his class on quantum chromodynamics. In exchange, Mehra had to entertain Feynman with stories over lunch. Like Ralph Leighton a decade earlier, Mehra was in the right place at the right time, when Feynman, aware now that he hadn’t long to live, wanted to talk about his life and work to a wide audience. Although often obviously in pain, thin and weak, according to Mehra Feynman clearly enjoyed their discussions, and was in top storytelling form. The interviews continued until 27 January. As well as discussing science, covering the ground we have also covered in this book (and which he had covered in earlier interviews, most notably with Charles Weiner, of MIT, for the American Institute of Physics Archive), Feynman talked about life, the quest for Tannu Tuva, love and the happiness of his marriage to Gweneth and his delight in his two children. After the last interview, Mehra drove Feynman back to his house, and made his farewells. As Mehra left, he knew that he had seen the last of ‘a great physicist and a most extraordinary man’.
On 1 February, Christopher Sykes completed filming what was to be Feynman’s last interview, which took place just after Feynman gave what turned out to be his last quantum chromodynamics class. Two days later, new tests were carried out on Feynman’s failing body: his remaining kidney was failing, and the cancer was back. His life could have been prolonged by dialysis, but the returning cancer would have brought a painful death in a matter of weeks or months. Feynman preferred to accept the inevitable at once, provided the people closest to him could take it. He told Gweneth, who spoke to Joan on the phone, telling her, ‘Richard says he wants to die, and that it’s your decision.’19 The two women agreed that it would be
senseless to prolong Richard’s suffering, and went to visit him together, at the UCLA Medical Center.
When I came in he was lying there and he said: ‘Decision?’ Because he couldn’t talk very well. I said: ‘Yes, you’re going to die.’ And his whole body just relaxed.
For the few days that remained, Feynman was watched over by Gweneth, Joan and his cousin Frances, who had shared the house in Far Rockaway. Before he slipped into the inevitable coma resulting from kidney failure he apologized to Dr Morton for dying on him. But even after he was in a coma, things happened that Joan is keen that people should know about:
In the coma, his hand was moving, and Gweneth said that the doctor had told her that the motion is automatic, and it doesn’t mean anything. So this man who’d been in a coma for a day and a half or something, and hadn’t moved, picks up his hands, and goes like this, like a magician, as if to say ‘Nothing up my sleeve,’ and then he put his hands behind his head. It was to tell us that when you’re in a coma you can hear, and you can think.20
The other message which Joan is sure Richard wanted communicated came soon after that incident. He came out of the coma briefly, and said, ‘This dying is boring.’ Then he went back into the coma. Those were his last words; Richard Feynman died at 10.34pm on 15 February 1988.
Early in March, a letter addressed to Feynman arrived from Moscow. Dated 19 February, it was the formal invitation to visit Tannu Tuva. When the Soviet Academy of Sciences learned of Feynman’s death, nothing more was heard from them about the possibility of the other ‘musketeers’ making the trip. Nothing daunted, Ralph and Phoebe Leighton managed to make their way to Novosibirsk, in the summer of 1988, as guests of Vladimir Lamin, a historian involved with the Silk Road exhibition. And through Lamin’s good efforts, they made it all the way to Kyzyl – not as hangers-on to a party riding on Feynman’s fame as a physicist, but in their capacity as finders of international exhibitions, just as Dick himself would have wished. The exhibition did indeed come to Los Angeles in February 1989. ‘It turns out’, Leighton (who is now an Honorary Consul of the Republic of Tuva) recalls with justified pride, ‘that we inadvertently brought over the largest exhibition of artefacts ever brought in to the USA, all through trying to get to Tuva.’ And, of course, through living life the way Feynman lived his life. In June 1989, Gweneth Feynman, Glen Cowan and others were invited to visit Tuva privately in 1990. But on 31 December 1989 Gweneth died of cancer.
Richard Feynman provided his own best epitaph, in a conversation he had with Danny Hillis when they were out walking in the hills behind Feynman’s house, not long after one of his operations. It was the moment when Hillis realized that the problem was really serious, and that Feynman was probably going to die soon. Noticing his subdued state, Feynman asked him what was the matter. Hillis told him that he was sad because Feynman was going to die – such straightforward honesty seemed natural in Feynman’s company:
Richard said, ‘Yeah, that bugs me too, sometimes.’
But then he said something which I wish I could remember exactly. It was to the effect of ‘Yeah, it bugs me, but it doesn’t bug me as much as you think it would, because I feel like I’ve told enough stories to other people, and enough of me is inside their minds. I’ve kind of spread me around all over the place. So I’m probably not going to go away completely when I’m dead!’21
There is indeed a little bit of Richard Feynman in all of us who have heard, or read, his stories; and we are all the better for it.
Notes
1. Ralph Leighton, Tuva or Bust! (hereafter referred to as Tuva).
2. Feynman’s mother, Lucille, died a few days before this second majorcancer operation. In the words of Ralph Leighton (letter to JG), ‘she died peacefully, in her favorite chair, after eating dinner’. She was 86 years old.
3. Joan Feynman, in No Ordinary Genius.
4. Ralph Leighton, interview with JG, April 1995.
5. Surely You’re Joking.
6. Tuva.
7. See note 4.
8. Richard Feynman, introduction to QED.
9. The obituary was simply signed ‘an old friend’. The old friend was Philip Morrison.
10. Dyson, From Eros to Gaia.
11. Leighton, interview with JG, April 1995.
12. Interview with JG, April 1995.
13. Leighton, interview with JG, April 1995; see also Gleick.
14. Gweneth Feynman, as told to Gleick.
15. Tuva.
16. Tuva.
17. Tuva.
18. This account of Mehra’s last encounter with Feynman is taken from the transcript (provided by Mehra) of a talk he gave at Cornell University on 24 February 1988, while the events were still fresh in his mind; the introduction to his book The Beat of a Different Drum is based on the same talk.
19. Joan Feynman, in No Ordinary Genius.
20. See note 19.
21. Hillis, in No Ordinary Genius.
14 Feynman after Feynman
There is no clear distinction between physics after Feynman and physics before Feynman, not least because Feynman’s own methods and way of thinking have become an integral part of research at the cutting edge in modern physics. Indeed, as we shall see, some of the most intriguing new developments in theoretical physics have come, not from any breakthrough into new territory beyond the scope of Feynman’s work, but rather from taking old ideas of his that were far ahead of their time and incorporating them into modern physics in a new way.
The most striking example of this link between what Feynman was doing decades ago and what young researchers are doing today comes from the aspect of his work that was least sung during his lifetime, the study of gravity. As we saw earlier, this culminated in a course of graduate lectures that he gave at Caltech in 1962–3, alongside the second year of the famous undergraduate lectures. During that remarkable year, Feynman gave his first sophomore lecture every Monday morning, a gravity lecture Monday afternoon, and followed these up later in the week with his second sophomore lecture and his regular talk at Hughes. At most, fifteen people attended each of the gravity lectures – but they included two students, James Bardeen and James Hartle, who went on to make major contributions to the development of the theory of gravity. This highlights the way in which Feynman, as a teacher, provided an inspiring influence on students who were one step distanced from him, even if his compulsion to solve every problem he came across himself made him sometimes a less than ideal thesis supervisor. Since Bardeen actually was one of Feynman’s PhD students, however, it is certainly far from true that none of the students Feynman supervised directly ever achieved much in physics.
Hartle remembers the lectures as being, like all Feynman lectures, brilliant and memorable, giving the students a feel for physics at the cutting edge of research. His own career was particularly influenced by Gell-Mann, John Wheeler and others, and would, he says, probably have followed the same path even without the Feynman lectures on gravity. But the major idea which Feynman introduced into thinking about gravity at around that time was the perturbation technique that had previously been developed in the context of QED. It was another example of Feynman coming up with the right tool for the job from his extensive kit of mathematical techniques.1
Two of the other students who attended those classes, Fernando Morinigo and William Wagner, made notes which were edited and reproduced for sale in the Caltech bookstore, where they have been purchased by generations of students ever since. Thirty years later, they were turned into a book by Brian Hatfield.2 You might think that this is a piece of cynical exploitation of the ‘Feynman industry’ that has sprung up since he died, like the repackaging of old recordings by dead rock stars. But you would be wrong. Although the work is extremely technical in parts, it is also more than ever of relevance to serious students of gravity; Feynman Lectures on Gravitation also contains a strong flavour of Feynman the teacher at work, and some astonishingly prescient insights.
For those serious students, perhaps the
most important feature of the book is the way in which Feynman develops the theory of gravity from scratch, using the standard techniques of quantum physics. We saw before how he had found that the entire classical theory of electromagnetism, including Maxwell’s equations, could be derived starting out from a quantum description of interactions between particles that have charge, involving the exchange of photons, which are regarded as massless particles with one unit of quantum ‘spin’. In the first part of his lecture course, Feynman showed that the entire classical theory of gravity, including Einstein’s equations of the General Theory of Relativity, could be derived starting out from a quantum description of interactions between particles that have mass, involving the exchange of gravitons, which are regarded as massless particles with two units of quantum spin. The situation is more complicated than in QED because the gravitons can interact with each other, as well as with massive particles, so renormalization doesn’t work. The other difference is that with gravity, unlike the case in electromagnetism (where like charges repel and unlike charges attract), like gravitational ‘charges’ (that is, masses) attract one another. But the philosophical approach is just the same, and provides yet another example of the way in which fundamental truths in physics can usually be described in more than one mathematical formalism.