The Grid we live in
Posted: Wednesday, September 24, 2008 8:05 PM by Alan Boyle
Justin Knight Photography
Nobel-winning physicist Frank Wilczek says reality at its most basic level is best
described as the interplay of energy fields in "empty" space.
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What is the Matrix? It might be more than a cult movie classic, if you side with Nobel-winning physicist Frank Wilczek. In his new book, "The Lightness of Being," Wilczek sets forth the concept that at its most basic level, our universe exists as a vibrant energy field he calls "the Grid." (He says he might have considered calling it the Matrix, "but the sequels tarnished that candidate.")
The way Wilczek sees it, interactions in virtually empty space give rise to the substance of subatomic particles and complex molecules, of everyday objects and distant galaxy clusters. But you shouldn't just take his word for it: He says experiments at the Large Hadron Collider, the particle-smasher that is now under repair far beneath the French-Swiss border, could unlock some of the Grid's biggest mysteries.
Wilczek, a 57-year-old professor at the Massachusetts Institute of Technology, is quite familiar with mysteries. He won a share of the 2004 Nobel Prize in physics for explaining why the basic constituents of matter known as quarks and gluons are so hard to pull apart. And he promises that his next book is going to be an honest-to-goodness mystery novel, about a dark-matter discovery big enough to kill somebody over.
Right now, however, the Grid and the LHC are uppermost in Wilczek's mind. His book takes readers on a guided tour of the frontiers of physics - including the rugged terrain of quantum chromodynamics. The payoff is that you come away with at least an inkling of how gravity could be unified with nature's other fundamental forces, and why physicists are so anxious to find the Higgs boson (a.k.a. the God Particle).
In Wilczek's view, mass arises because the Grid is permeated with a not-yet-understood property that "slows down" some of the interactions in the field, just as electrons are slowed down in a superconducting medium. In the medium known as the Grid, we perceive that slowed-down quality as mass.
"It's as if we're very intelligent fish, or super-dolphins, who have figured out after careful scientific study that we are not living in empty space but that we live in water," Wilczek said during a book-tour stopover in Seattle. "We’re used to it, but we should understand this material – and we haven’t yet figured out what this material is made of. That’s really a close analogy to what’s going on with finding the Higgs particle."
The LHC could help scientists look behind the curtain and study the "water" in which we live: the very fabric of the Grid. If that sounds mysterious, it is. Here's an edited Q&A that dives into the depths of the Grid concept - and, by the way, also touches on the personal threats that were made against Wilczek in the days before the LHC's startup:
Wilczek: In our theories, to properly understand the world we have to imagine that we're living in a medium that changes the properties of things - that slows particles down and distorts them. Those equations really seem to work extremely well, but we don't know what this medium is made out of.
Cosmic Log: And is that the Grid?
Wilczek: Well, that’s one aspect of the Grid. The Grid is my term for what we normally perceive as empty space. It’s a medium in many senses. It has spontaneous activity. It also has a constant material component, and this is one of the constant material components in the field. It’s usually called the Higgs field. We don’t know what it’s made of. We know it’s not made of any of the known forms of matter; they don’t have the right properties. So the simplest possibility, logically, is that it’s made out of one new thing, and those would be Higgs particles. But I think you get a nicer theory by embedding it in a larger framework, where it’s made out of several things.
Q: How do people react to hearing about the Grid?
A: People react in different ways. Some people get very excited, because they really resonate with the idea that we live inside a medium and that we’re all connected. It sounds almost New Age-y. Other people just scratch their heads and say, "What does that have to do with the world I know?" And in fact, that’s a deep puzzle, because the concepts that we use to understand the physical world at the most basic level seem to be very removed from the world we experience.
But that’s part of the message: There’s much more to the world than meets the eye. There’s much more to the world than what our sensory apparatus has evolved to react to.
The reaction I hope for – and I get it sometimes – is that people are dazzled at first, and then think and let it enrich their concept of what the world is all about.
Q: A lot of people do wonder, “What’s in it for us?” That’s the classic question that all physicists usually face. Do you have a good answer?
A: Well, I don’t know if it’s a good answer, but I’ve been thinking about that more and more. I think the deepest answer I’ve come to is the following: When people ask, “What’s in it for us,” what are they really asking? There are certain drives that people have that came out of the way we evolved. So when you tell people you’re going to feed them better, or that you’re going to give them better shelter, or give them more prestige, they don’t have to ask, “What’s in it for us?” These primitive drives are just there.
This kind of stuff appeals to something a little more … evolved. It’s not so primitive. It really has to do with our higher brain function and learned behavior. If you are intrigued by ultimate questions, such as what the universe is made of, or what’s my place in it - questions that animals and probably primitive humans barely thought about - then this is the answer. These are the best answers we’re coming up with, at least from the point of view of studying the physical world. And they’re very informative answers, in the sense of conveying new information.
When you study it carefully, the world turns out to be a much bigger and richer place, a place that’s different from what it appears to be. To me, that adds a whole new dimension to life.
In the long run, of course, understanding things better might enable you to control things better, too. At this point, we know so much about how matter behaves under all kinds of conditions that we have to study the really, really extreme conditions of the early universe in particle accelerators in order to look for new surprises. It’s hard to see how those are going to feed back into new technologies directly. But the tools we develop in the search very much feed into technology. Historically, the World Wide Web was first hatched at CERN as a tool to facilitate information exchange in particle physics. Now, people are developing new technologies for building powerful magnets - the same kinds of magnets that are used in medicine. They’re working on the next level of the Internet. They’re working on faster electronics for analyzing data. All these things are of technological importance.
We don’t know exactly what’s going to come out of all this - but in the past, efforts of this kind with particle accelerators have really paid off, even if you look at them as a hard-headed investment.
Q: I have to ask about the risk: People hear scientists say that they don’t know exactly what will come of these experiments, and then they ask whether it’s worth the risk that something catastrophic might happen - like the creation of black holes and so on…
A: We’ve had to think about that. And we want to think about it. There are thousands of people who work at CERN, and other thousands who understand the issues involved. Many of them have families. Many of them have lives that they value. So we want to uncover any possible danger. There have been many careful studies, and people have tried to come up with worst-case scenarios. I personally served on one of these panels and spent considerable time trying to think of things that might happen. The conclusion of everyone competent to judge is that there’s really no danger. There’s just no remotely plausible scenario that suggests that there’s a way to make big trouble.
Q: And the question that usually comes back is, “Are you absolutely sure?”
A: Well, at some philosophical level, if we read our Hume, we’re not sure that the sun is going to rise tomorrow. There are levels of sureness. But I would say that I’m as certain that the LHC is safe as I am that the sun will rise tomorrow.
Q: There were reports that you had received some death threats over all this. What more can you say about that?
A: I don’t want to say too much, because I don’t want to irritate the situation. There was a disturbed individual who somehow glommed onto the idea that I was cavalier about endangering the whole world, and that I was a “mad scientist.” I didn’t go to the press with it. I discussed it with a colleague, who unfortunately mentioned it to a press person, and then it got blown up.
I’m not a brave hero here. The real heroes are the people who are building the machine and will do the experiments and participate in the science.
Q: But the important thing is that in terms of your personal situation …
A: It’s all under control.
Q: Are there particular clues that you’re going to be looking for in what the LHC will produce?
A: I’m very much invested in this idea that there’s a whole new world of particles that basically mirror all the particles we know about. They have the same charges and colors and other funny detailed properties, but different spins. This is called low-energy supersymmetry. It enables us to beautify the fundamental equations of physics in profound ways, which I describe in detail in the book. What’s exciting is that these ideas tell you the masses of these particles can’t be so heavy that they’ll escape being made at the LHC. So it’s make or break time.
Q: One of the things that I appreciated about your book was that you came up with some new ways to explain the pioneering concepts of particle physics. When you read books of this type, you come across a lot of the same examples, but you seem to have found some new ways to do the same old thing.
A: Well, some of it is different, or at least presented in such a different way that it might as well be different. The core of the book, as I see it, is the explanation of the story of mass. It used to be the defining property of matter, but now it’s something that’s kind of secondary. We explain it more deeply in terms of energy and properties of interaction. We’ve really delivered on the promise of E=mc2, and can explain the “m” in terms of the “E.”
In modern physics, energy and space are much more fundamental than mass. That’s part of the message. The traditional idea that there are stable, static bodies that are massive and hard to push around has been replaced by a much more fluid concept. Fields are more basic than particles. Empty space isn’t really empty. That’s the circle of ideas that hangs around this explanation of mass in terms of energy.
The whole barrier between light and matter - which is at the heart of the metaphorical contrast between “celestial” and “earthy,” or “free” and “heavy” - all that has fallen. The underlying reality is much closer to the traditional concept of light than the traditional concept of matter.
This revelation about matter is not only satisfying, but it also opens new doors. Once we know that mass is not fundamental, we can ask why gravity - which responds to mass - appears to be as feeble as it is. Once we understand why gravity is so feeble, and so different from the other fundamental forces, we can ask about unifying all those forces together. Not only can we ask these questions, but we have some promising candidates for the answers - which, remarkably, are going to be tested in the near future.
So it’s an exciting time to be a physicist. And you don’t have to be a physicist in the technical sense, in command of all the equations and so forth, to start to realize what the stakes are. Every thinking person can participate in the adventure.
