Interview with Professor Murray Gell-Mann by Joanna Rose, science writer, 9 December 2001.
Professor Gell-Mann tells of how being awarded the Nobel Prize increases the number of stories people make up about you, describes the origins of the term ‘quark’, (2:10), explains his studies of complexity (3:46) and talks about his engagement in environmental issues in order to preserve the heritage of biological diversity (9:41).
Transcript of the interview
Welcome to this interview, Professor Murray Gell-Mann.
Murray Gell-Mann: Well, thank you.
Actually I don’t know, maybe I could speak Swedish to you, because the story goes that when you got the news about the Nobel Prize in 1969, in October, you prepared your speech in Swedish for the December date when the ceremony was. Is it true?
Murray Gell-Mann: Well, one thing about winning this award is that it increases the number of stories that people make up about you.
Yes? This is one more, yes?
Murray Gell-Mann: This is one more. No, what happened was that when I talked at the banquet, after the awards ceremony, one paragraph was in Swedish.
But you speak lots of languages. How many languages can you speak?
Murray Gell-Mann: Well, that’s not actually true. That’s another story they make up about me. I’m very interested in languages and I know something about the relations among languages, about the entomologies, about sound changes from one language to another and so on and so forth. Very interested in that, and even in helping a little bit to work on it. But as to speaking languages, any European waiter could do much better than I.
OK. You are a physicist.
Murray Gell-Mann: I’m a physicist, and I speak my native language fairly well, American English. I can speak French moderately well, like [INAUDIBLE] and so on, but I do make mistakes now and then. And Spanish, Italian, much weaker, especially the vocabulary. Danish I can speak a little bit. But when I’m in Sweden I try to convert it to Swedish with sometimes with some success and sometimes with much less success.
But you’re interested in languages, I would say …
Murray Gell-Mann: But I can read these, I can read these languages moderately well.
You have found that one word that has got the fame, I would say, and also was named in another prize, and that is quark and quarks. What does that come from?
Murray Gell-Mann: Well, let’s see. In the citation for the award, it was barely mentioned. But I did propose that the neutron and proton and the related barions were composed, roughly speaking, of three quarks each, and that the quarks were the fundamental entities, they are analogous to the electron, and that the neutron, proton and so on were not elementary. The word I had first as a sound, quark. It might have been spelled K W O R K, for example. But then I thought it was the right sound for the fundamental constituents of nuclei. Sounds, sounds good.
Murray Gell-Mann: Quark. But then I discovered the Word quark, in Finnegan’s Wake.
Oh, James Joyce, yeah.
Murray Gell-Mann: Right, and with the number three also, and there are roughly speaking three Quarks to a nucleon, or barion, and I thought well, perhaps I could use the spelling there, Q U A R K. So there it is.
Yeah. So we haven’t lived with the Quarks for more than 30 years now, but you have moved your interest from theoretical physicist to broader interest of complexity.
Murray Gell-Mann: Simplicity and complexity, regularities and randomness.
Murray Gell-Mann: Yes. And this subject, which I call plectics, the study of the simple and the complex. Includes a good deal that has to do with physics, plectics comes from the common root of the word simple, the word simplicity and the word complexity, without distinguishing, without specifying whether you’re talking about the simple or the complex. I used to work on the simple only. That is the fundamental laws of nature which we believe are fundamentally simple.
Quarks are simple.
Murray Gell-Mann: Right. We see around us a great deal of individuality. We see around us adaptive evolution, as in biological evolution, for example. But also cultural evolution, evolution of ideas and so on and so forth. A great deal of individuality. These are not things that one finds directly in the fundamental laws of physics where, for example, every electron is exactly with every other electron in the universe, and where we believe, at least, that the laws don’t change with time, the fundamental laws are immutable. In fact, some people now have claimed just in the last few months that they have found some evidence that some of the supposed constants of nature are actually changing very slowly, but that’s a, if true, that would be a very slow cosmological effect. But in the world around us we see lots of individuality, and a great deal, a great many kinds of evolution and so on and so forth, and we see a lot of complexity. So where does that come from? And in my book, Quarken och Jaguaren, The Quark and the Jaguar, I discussed this question, but the point is the fundamental laws are simple but they are not deterministic.
Even at the fundamental level they are not deterministic, because of quantum mechanics, but besides that they fail to be deterministic because no observer anywhere in the universe can have access to all the necessary for predicting the future.
You mean deterministic in the …
Murray Gell-Mann: In other words, any observer sees only a coarse grained version of the universe, and the coarse grained state at a given time does not determine the coarse grain state of the next time. Only probabilistically. So we have to look at all the alternative possible histories of the universe as a branching tree of possibilities, with probabilities at the branchings. And the great writer, the Argentine writer, Jorge Luis Borges wrote a story about somebody who made a model of the branching alternative histories of, alternative possible histories of the universe, in the form of a garden of forking paths. El jardin de senderos que se bifurcan. And this, this idea of alternative possible histories of the universe, coarse grained, of course, form a branching tree, means that the history that is actually seen is co-determined by the simple fundamental laws, and by an inconceivably long sequence of accidents or chance events, which can come out in various ways and in advance one can predict only the probabilities of the different outcomes. So there, of course, is the source of complexity. Now, some of these accidents produce a great deal of regularity in the future. And those we can call frozen accidents. Things that at least locally in space and time create new regularities, in addition to the fundamental laws. Now, fundamental physics relates to the basic laws, but the rest of physics and chemistry, and especially other sciences like biology and geology and so on, and observational astronomy and so on, all of these depend a great deal on the accident, not just on the fundamental laws, but on the, all the rest of the information that contributes to the history of the universe.
So how can you make models or series of these histories that are based on accidents?
Murray Gell-Mann: Well, we, the fundamental laws give you the probabilities. But you have to adjoin to that information a lot of information about the accidents that have already occurred, and especially these important ones which we can call frozen accidents which create a great deal of regularity in the future. And by complexity, then, what I call effective complexity, we mean the length of a very concise description of the regularities of something.
If I change the subject for a while, you have travelled to the tropics, and you were also engaged in environmental issues?
Murray Gell-Mann: Yes, very much, in trying to preserve the heritage of biological diversity. I’m also somewhat interested in the preservation of cultural diversity, although that involves a great many more paradoxes and contradictions. But I’ve worked hard on trying to help with the preservation of biological diversity around the world, and of course on land the greatest diversity is found in the tropics, and also the tropics are full of poor and, in many cases, overpopulated countries.
So these are the main obstacles.
Murray Gell-Mann: So what is most important to preserve is in the tropics, at least, on land, and also the dangers are greatest in the tropics, so a lot of our work is concentrated on the tropics. I’ve worked mostly through the John D. and Catherine T. MacArthur Foundation, based in Chicago.
This was maybe not so bad for you to travel, because you are so interested in ornithology.
Murray Gell-Mann: Oh yes, and it was a very great field ornithologist, Ted Parker, who joined me in, over a camp fire, in Venezuela, when we invented the idea of the rapid assessment programme, which has been quite useful in nature conservation. The idea is if a certain tract of land is considered for possible preservation as a national park or whatever, how to evaluate the diversity that is present, and the quality of the environment, to what extent is this a natural area worth preserving. Now, the old fashioned way, of course, of looking at an area, was to have skilled botanists and skilled zoologists of various kinds spend many years cataloguing the various species and their interactions with one another and so on and so forth. The trouble is, by the time you do that the area may not exist any more. So what we did was to champion the notion of having certain very special field biologists, like Ted himself, form teams to go in and rather quickly and approximately to evaluate the diversity and the quality represented by the area.
I have one last question about the birds. What is your dream now that you would like to encounter?
Murray Gell-Mann: Oh, there are many species. I’ve seen less than 4,000 out of 9,600 or something like that. Almost 10,000 species that are recognised in the world. But there are a few special ones that it would be wonderful to see. The Congo peacock, for example.
Which lives in Congo?
Murray Gell-Mann: Yes.
Ah, I see.
Murray Gell-Mann: For a long time nobody could believe there was a peacock in Africa, and …
Nobody has seen it.
Murray Gell-Mann: No outsider, no European, had actually seen one alive until quite recently.
So I hope that you one day will see one.
Murray Gell-Mann: But I saw one in the Regent’s Park Zoo which is probably the only place in the world where you can see a Congo peacock in captivity. But it would be wonderful to see one in the wild.
I hope you will find it. Thank you very much for taking your time with us. Thank you.