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May 3, 2006 -- Nobel Laureate Frank Wilczek and Betsy Devine.
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Steve: Welcome to Science Talk, the podcast of Scientific American for the seven days starting May 3rd. I am Steve Mirsky. This week on a special edition of the podcast, we'll talk with Nobel Prize-winning M.I.T. physicist, Frank Wilczek, and his wife, Betsy Devine, and then we'll squeeze in a quick round of our science quiz. Frank Wilczek shared the 2004 Physics Nobel with David Gross and David Politzer for their work explaining the strong force that holds atomic nuclei together. It was a key step in the search for a grand unified theory of everything. Frank has a new book out, which Betsy contributed to. I caught up with them at a party celebrating the publication of the book at their editor's house in Brooklyn. We retreated to a fairly quiet room, but you'll still get a taste of New York life in the background—helicopters, sirens, cell phones and some kitchen clattering. In this first part of the interview, we talked about the book and what it's like to get a call from Stockholm at 5:30 in the morning.
Steve: Frank Wilczek and Betsy Devine, thank you very much for talking to me today. I am tempted to begin the interview this way. Why are all electrons the same?
Wilczek: (laughs) Well, that's the most profound thing we learn from quantum field theory; that's something you can't understand without combining the special relativity and quantum mechanics and the only way we know how to do [it] is something called quantum field theory, so it's really something that [has] only been understood properly in the last part of the twentieth century.
Steve: And the reason I asked that is it's in your book. You have a new book out called Fantastic Realities: 49 Mind Journeys and a Trip to Stockholm; and Betsy Devine is your wife.
Steve: Frank Wilczek's wife and I took your advice. In the introduction, you said, read Betsy's section of the book first
, by words, so I did. So let me start with you at this point.
Steve: I would like you to tell the story of what happened on that October day in 2004 at five-thirty in the morning, when the call came in from Stockholm—where you were, and where he was, and (laughs) what you did.
Devine: Okay, sure. Well that was a very—that morning is certainly etched up in my memory. So what happened is, the ordinary thing is that at five in the morning, everyone's
is asleep in our house, but this morning Frank was restless; he'd gotten up, he was in the shower; and I had registered that but I was still asleep. And then the phone rang, and I thought the kinds of thoughts you think when your phone rings at five in the morning; but then I thought, wait a minute, this is the morning they announce the Nobel Prizes, (laughs) so [I] went and I answered the phone and it was a woman. In a minute, I was in the bathroom saying to Frank, "Frank there's a woman on the phone who wants to talk to you."
Steve: Because he was in the shower.
Devine: He was in the shower; and that she has a beautiful Swedish accent. (laughs) She has a Swedish accent. He stepped out of the shower and (laughs) we were both in shower. I put the cell phone into his dripping hand and he put it to his ear and he is saying, "Yes, (laughs) yes; and then he gave me the thumbs-up with his hands, as you can see—so that was really funny—meaning thumbs-up, we know, it's good news.
Steve: Right! They have called to tell you, you've won the Nobel Prize in Physics.
Devine: Exactly, exactly.
Steve: Now he's dripping wet.
Steve: So a little time goes by and finally…
Devine: So, neither of us was probably picky at our finest at that point. I wanted to run into the kitchen and hear on the other phone, but—so I did that—but then after a few minutes, my conscience smote me and I thought, wait, Frank is in the bathroom with nothing on; he's completely wet and dripping. And I went running back to see if he picked up a towel, which he had not, so I grabbed his bathrobe, (laughs) tried to get it on to his shoulders.
Wilczek: I had thought it would be, hello, you've won the Nobel Prize, good bye, but it wasn't that way at all. It was a long series of people wanting to talk, friends from Sweden, dignitaries who all wanted to congratulate.
Steve: Not realizing that you might be standing there, just coming out of the shower.
Wilczek: Oh no, I don't think that entered into their considerations at all, but it didn't bother me at all. (laughs)
Devine: I am done.
Steve: You had waited a while for the Nobel Prize.
Wilczek: Well I had thought there were significant chances for about 20 years because the work was clearly important and …
Steve: This was way back in the '70s.
Wilczek: Yeah! The big breakthrough was in the early '70s, and by the early '80s, I'd say the evidence was pretty solid, so it was a possibility; and on the other hand there was our work was based in part on preceding theoretical work, especially by Horst and Laughlin, so I thought probably that would be the order. They would get it first and they got it in 1998, I believe; so once that happened I really thought it was imminent.
Steve: Let me ask you—in the book something you wrote—you're talking about reading Einstein's general relativity in 1915.
Wilczek: Well no! I didn't read it in 1915.
Steve: Well you didn't read it in 1915. He wrote it in 1915 and you were talking about being impressed, and I was expecting by Einstein's intellect by his findings. No? You were impressed by his style.
Wilczek: Yes. (laughs)
Steve: Talk about that for a minute.
Wilczek: Well I was really impressed by his style. I read that first in a fairly serious way when I was in college and this great paper of 1915 starts with a long—well the whole paper is fairly short, first of all—but it starts with about—out of the paper that's maybe fifteen text pages long—five pages of just words, sort of philosophical discussion about relative motion and the impossibility of defining relative motion, and if this thought experiment that if you had a ball over here and another one over there and nothing else and one was rotating, the rotating one would feel a centrifugal force according to the, you see, the laws of physics that would get to stored in, but that's ridiculous because you could have considered the other one to be rotating. And okay, so then the philosophical discussion stops (laughs), then there is another five pages, which is sort of exposition of the mathematics of curved spaces and remaining in geometry and tensors. And then the last five pages, he writes down general relativity, writes down as we know it and the classic tests. So I was just amazed at and I didn't understand things very well at that point, I didn't see the connections between the philosophical discussion and what came afterwards, but I was really blown away because I thought by these philosophical considerations, sort of as a bagatelle; he was just able to write down this most beautiful and maybe most profound of physical theories.
Steve: Great stuff.
Wilczek: But later (laughs) when I did understand that I learned that the first part is actually contradicted by the later parts. (laughs)
Steve: I know what you would have thought.
Wilczek: Well, that's a real genius.
Steve: More with Frank Wilczek right after this.
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Steve: Back to the interview. In this segment, we talk about his Nobel Prize winning research and the future of physics.
Steve: Let's talk about the work a little bit, for our general listeners, you know.
Wilczek: There are four fundamental forces of nature that we use in current theories of physics. There is gravity and electromagnetism, which have been known for a long time and we have beautiful theories of those; general relativity for gravity and what's called quantum electrodynamics for electromagnetism. With both have very beautiful equations and deep, profound theoretical principles behind them. Then early in the twentieth century, when physicists started to study interiors of atoms, they found that two new kinds of forces were needed. One is called the weak force, and that's responsible for various kinds of radioactivity; the other is called the strong force. The strong force is the basic force that holds atomic nuclei together, and the atomic nucleus of course contains protons and neutrons and electric forces that would want to blow it apart.
Steve: The protons are the one who repel each other.
Wilczek: The protons are [the] one[s] who repel each other. The neutrons don't care, they are neutral; and yet there had to be something that's holding them together, and this was just called the strong force, but not understood. Then by a long series of difficult and ingenious investigations, various facts were learned about the strong force—this whole subject of nuclear physics is about the strong force—but there was no beautiful theory or complete theory of where they are standing besides general relativity or Maxwell's theory of electromagnetism and its descendants of quantum theory; so that's what we found. We found the basic theory of the strong interaction using the notion of quarks, but also a very specific notion of the glue that holds them together—the so-called gluons—so we really provided a concrete picture—no, well, it's the concrete equations for what the gluons are and how they interact, and the answer was much more than we could have expected, in the sense because it turns out that, that theory is mathematically, in its concepts, a grand generalization of electrodynamics. It's based on so-called gate symmetry, which suggests ways to unify different interactions; also this fundamental property of asymptotic freedom, which was the key to unlocking the secret of the strong interaction. It says that the interactions get simpler, interactions between quarks and gluons get simpler at high energies; and that's like a gift because if you want to study fundamental physics at higher energies or cosmology, it means things simplify and we can see through it. So it opened a new window into both unification and the early universe as well as telling us what the fundamental force holding together on the nuclei is.
Steve: The tough situation in which to try to reason things out is everyday existence—[it] is at the super-high energies when things get simpler.
Wilczek: That's right! (laughs) At low energies, the only way we know how to—for instance, we calculate the internal structure of protons based on the more fundamental description of quarks and gluons relies on massive numerical work to solve the equations. In fact it continues to push the frontiers of computer science with massively parallel computers. I like to say that these computers operate at teraflop
s speeds. So they do 10 to the twelfth the trillion multiplications of big numbers per second, operate for months at a time, so 10 to the seven[th] seconds, and they consist of about 10 to the thirtieth protons and neutrons; and what they are desperately trying to do with all that effort is compute what protons figure out every 10 to minus 24 seconds, every one of them, which is how to balance the quarks and gluons into a combined state. Our methods of calculation probably could use improvement (laughs), but the answer justifies the effort: We really do understand through these calculations what protons are and how their mass arises in terms of more basic notions.
Steve: Which is really exciting, because I am sure most of the people listening and for me the proton was one of the things we were given.
Steve: So, and then you work with them, but the work you've done explains why the proton is what it is.
Wilczek: As physicists in the very early times of when nuclear physics was young in the 1930s or so, people anticipated that protons and neutrons would be elementary particles, which means that they would obey simple equations. But as things were investigated more fully it was found that they don't. (laughs) The interactions between them are very, very complicated; and not only that but when you dump energy into a proton it tends to break apart into other new objects, other kind of particles. So it's not at all that [they] resemble protons; in fact a single proton, if you put energy into it, could break up into three protons and two antiprotons. So it became clear that it was wrong to think of protons as basic particles—they don't obey simple equations. And eventually it emerges that these quarks and gluons that obey simple equations and the quarks have properties parallel to properties of electrons. The gluons have properties parallel to the properties of photons, and that’s why they also make the hint of unification.
Steve: We have the Large Hadron Collider coming online soon.
Steve: And a lot of the people listening have probably have heard of string theory or superstring theory and that's got a lot of attention.
Steve: I know that you're a big fan of supersymmetry.
Steve: Rather than or in addition to string theory.
Steve: And one of the great things about the Large Hadron Collider, if I understand right, is that [we] will have energies high enough where we might see some of the predictions of supersymmetry.
Wilczek: Yes. Supersymmetry is not inconsistent with string theory, but it's really a separate idea, and I am a firm believer in Ockham's razor, that we should try to use the minimal hypothesis; or, in any case, it's a good strategy to check out your minimal hypothesis before building further hypothes
is[es]. So supersymmetry would be a big step in the understanding of nature, and the reason I am optimistic that the LHC will turn up supersymmetry is based on these unification ideas because many things about unification worked beautifully. If you try to make the strong and electromagnetic and weak interactions into a unified structure based on the color charges of the strong interaction being different versions of electric charges, if you like, and the photons really being different versions of gluons—I won't try to be precise about this—and a lot of things work out beautifully. You do find consistency with the charges and properties of the particles, we know, if you carry out this unification, and that's not at all automatic. It would explain things that we know that can't be explained otherwise. But superficially there appears to be a terrible problem with unification, which is that the strength of the coupling of photons is different from the strength of the coupling of the colored gluons. That is the reason why the strong interaction is called strong and the electromagnetic interaction isn't called strong; and that's the same reason why atomic nuclei which are held together by the gluons are much smaller and more compact than atoms which are held together by the photons, by the electromagnetic force. So that 's appears to be a terrible problem with unification. It sort of stops it right off the bat.
Steve: Can you explain unification real quick for everybody?
Wilczek: Yeah! So as I keep emphasizing that['s] the theory of strong force that we developed, [a] grand generalization of the theory of electromagnetism. So electromagnetism is based on the way photons sense and respond to a property called the electric charge, that's the central notion of electromagnetism. The theory of the strong force—quantum chromodynamics or QCD—involves three different kinds of charges, which we call colors,
by[but] they are not, of course, the color of anything. They are more like different charges, but they're not electric charges, intrinsically, [they are] new kinds of charge. Now the theory becomes much more complicated if there are three kinds of charges—you need eight kinds of gluons because now you can not only sense the different charges, but change some into others to make the good. So to make the theory mathematically perfect, you need eight gluons that have one photon. But the mathematical structure is very suggestive that they are different facets of the same bigger theory, which would involve all four kinds of charges and a unified description. So all of them would be on the same footing and weak interactions—I didn't talk about [that]— is[it's] also simpler, [it] is even more suggestive that there are two other kinds of colors associated with the weak interaction. So this is begging you to make a unified theory where all the charges are on the same footing.
Steve: How do you know the universe is that way?
Wilczek: Well we don't. (laughs) That's what we tried to check. We tried to find consequences of that idea and then see if they are true in the world. And Karl Popper was very fond of this idea that the goal of science was to falsify theories, and that's much too simple, I think. The way we operate is in a way closer to the opposite, but what we really try to do is "truthify" our theories, find ways to say, might be true; of course, one of the ways that's most convincing to show that your theory might be true is to show that it has consequences that could have been wrong, but happened to be right. So, that makes contact with falsifying. Truthifying, I think, is [a] much more important idea. Anyway, in this case, if you try it—so if you want to put these guys who are on the same footing with different charges, they should have the same power roughly, so the interaction strength should be the same; but it's not, as I said. However, we don't let that stop us. (laughs) So one of the lessons that you learn from asymptotic freedom—like the essence of asymptotic freedom—is that what we call empty space, what we see as empty space, is not at all an inert void. It contains quantum fluctuations of all kinds and those quantum fluctuations condition the properties of the particles we see. So if we look at a charge from a distance, we see it in a distorted way through this medium and if you look closer it might have a different power than what
it appear[s] when we look further away; and in the case of QCD, the asymptotic freedom mathematically is the statement that if you look closer and closer to a color charge it looks weaker and weaker, has less and less effect. You can do similar kinds of corrections for the dynamics of quantum fluctuations in the void and empty space for the weak and strong and electromagnetic interactions and see if when you strip away the effect of the distorting medium and go to the core, you know, the really small distances, whether they have the same strength; and it turns out that almost works, and if you use the particles we know about, almost works. So Popper would say, give up, you falsified the theory; but no, we tried to truthify the theory. (laughs)
Steve: And supersymmetry is a part of it?
Wilczek: If you want to implement this idea of supersymmetry, which is very attractive in many ways, it's another way of unifying [the] description of physics. The idea of unifying the charges kind of brings to provision the idea that photons and gluons are different aspects of the same reality, but it does not touch the other contrasts between electrons and photons or quarks and gluons and the others; it makes the electrons similar to the quarks and photons similar to the gluons, but it still leaves you with two separate things. Supersymmetry unifies things in the other direction. But it requires changing the equations from things we know about securely; and when you change the equations, you find out that if you want supersymmetry, we've to have extra particles. Those extra particles also have quantum fluctuations in empty space, and so they change the calculation, they change the medium, they change the corrections you have to make; and if you make those corrections, then it works, then they really do unify. So what I think, well what I hope (laughs) is that those particles really do exist that LHC will find them and then we'll have evidence for both kinds of unification. (laughs)
Steve: Sounds very exciting in the coming years.
Wilczek: Yeah! I think it—well, unless nature is playing a cruel joke on us—I think it's going to be exciting; because although that broad picture I outlined to you, I would be very disappointed if it's not verified and that would be very exciting. But I've been expecting that for 20 or more years. (laughs) But we'll also learn essentially new things because the details of how supersymmetry [works] is certainly not precisely exact in the world; it's not true that electrons have the same mass as photons and so forth, so, but there are lots of ideas. But how it might be broken, none of them looks really absolutely compelling, but they will tell us possibly about new aspects of gravity, possibly about extra dimensions, possibly about string theory, possibly about new kinds of colors and interactions; we just don't know what its going to be and so, we'll be opening a whole new world.
Steve: Five or six years from now physics could be a whole new bulb.
Wilczek: I think fundamental physics would be a much richer subject.
Steve: In closing, could you read something from the book?
Wilczek: Yeah! I would be happy to.
Steve: I was hoping you would read this section, right here.
Wilczek: Okay! This is the greatest lesson, which was the last part of my acceptance speech for the Nobel Prize.
Evidently asymptotic freedom, besides resolving the paradoxes that originally concerned us, provides a conceptual foundation for several major insights into nature's fundamental workings and a versatile instrument for further investigation. The greatest lesson however is a moral and philosophical one. It is truly awesome to discover by example that we humans can come to comprehend nature's deepest principles, even when they are hidden in remote and alien grounds. Our minds were not created for this task nor were appropriate tools ready at hand. Understanding was achieved through a vast international effort involving thousands of people working hard for decades, competing in the small, but cooperating in the large, abiding by rules of openness and honesty. Using these methods, which did not come to us effortlessly, that required
nuturant vigilance, we can accomplish wonders.
Steve: Frank Wilczek's book is called Fantastic Realities: 49 Mind Journeys and a Trip to Stockholm. It's from World Scientific Publishing, and Betsy Devine keeps a great blog of their adventures and it is amazingly easy to find, if you Google just her first name, Betsy. You'll find it probably as the fourth listing on page one. We'll be right back.
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Steve: Okay let us get in a quick round of TOTALL…….Y BOGUS. Here are four science stories, but only three are true. See if you know which story is TOTALL…….Y BOGUS.
Story number 1: At Frank Wilczek's M.I.T., students celebrate drop date, the last date to drop a class by dropping a piano off the top of a building.
Story number 2: From pianos to organs. A
story researcher claims that TV shows featuring a black market for body organs or doctor's prematurely declaring death to harvest organs are scaring people from donating organs.
Story number 3: From organs to Morgans. Genetic analysis at the University of Vermont has reveal[ed] that the breed of horse called the Morgan Horse is distinct from other horse breeds due to a gene duplication that provides the animal with unusually high levels of myoglobin which leads to super-oxygenated muscle tissue.
Story number 4: From horses to horseflies, kind [of]. Berkley researchers have created a device that mimics an insect's eye with about nine thousand individual tiny lenses providing a panoramic view.
Those are your four stories, and your time is up.
Story number 4 is true. Berkley researchers created an epoxy resin artificial compound-lens device. The panoramic view it offers could make it popular for hidden cameras or medical scopes in the future. You can read David Biello's story on the eye on our Web site, www.sciam.com.
Story number 1 is true. M.I.T. students revived an old tradition this year and dropped a piano off a seven-story building to celebrate the last day you could officially drop a class. As one commentator noted, they won't make you drink at M.I.T., but you can push a piano off a roof. (music)
There is video up at, baker.mit.edu/piano.
Story number 2 is true. A Purdue researcher says many people believe that what they see on TV is real and their plot lines involving organ thefts keep people from being donors. She wants writers and producers to stop such stories; or we could have an educated populace, say,
she[that] does not think everything on TV is real. Yeah! You better work on the writers and producers.
Which means that Story number 3, about the extra myoglobin genes in Morgan Horses, is TOTALL…….Y BOGUS. Although what is true is that myoglobin, which stores oxygen in muscles and hemoglobin, which carries oxygen in the blood, probably exists because of the duplication of some ancient globin gene. After the duplication, the two genes were free to mutate into their current roles.
We'll be right back.
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Well that's it for this edition of the Scientific American podcast. Our e-mail address is email@example.com; and also remember that science news is updated daily on the Scientific American Web site, www.sciam.com. For Science Talk, the podcast of Scientific American, I am Steve Mirsky. Thanks for clicking on us.