STEVE AHLEN: The fact is, from a physicist's point of view, from a philosopher's point of view, from an observational point of view, mass is actually quite mysterious.
DAVE WARK: In our best theory of matter, the Standard Model, all the really fundamental particles are like photons—the particles of light—in that they have no intrinsic mass.
But we know that objects in the real world have mass, and scientists know that particles like protons and electrons also have mass. So where does that mass come from?
PETER FISHER: Why do particles have different masses? And why do they have mass at all? Mass is not something that emerges naturally from a theory.
MEENAKSHI NARAIN: We basically do not understand why some particles got mass and others didn't. What happened? What gave mass?
DAVE WARK: The leading idea for explaining mass is something called the Higgs field, a field which we believe pervades all of space and which the fundamental particles interact with.
The Higgs field is like cosmic cotton candy; it sticks to everything. And, according to this idea, it's actually that stickiness that gives particles their mass.
If the Higgs field, along with a Higgs particle, really exists, then the Large Hadron Collider should find it. And that would be a triumph for the Standard Model.
But since the LHC will take the particle hunt to a whole new level, many physicists are hoping it will uncover types of matter we've never even dreamed of.
MEENAKSHI NARAIN: The best case, in my mind: we do not find the Higgs particle, and we find a whole new set of new particles.
STEVE AHLEN: I don't really care what we find. You know, I just want to go off there and look at something and see something no one's ever seen before. That's what motivates me.
PETER FISHER: It's just a voyage of discovery. It's looking out into the cosmos and trying to see where we fit in it.
NEIL DEGRASSE TYSON: Many people think that the laws of nature and the universe tell us that everything breaks down. Things fall apart, energy wanes, living things grow old and die. Yes, we have some good laws which explain all that, but what about the emergence of life? What about the complexity of life? Where do they come from? Are these rare, miraculous developments? Or is this kind of complexity inevitable, following natural laws we just haven't quite figured out yet?
Correspondent Carla Wohl went looking for the answer.
CARLA WOHL (Correspondent): It is mysterious how a flock of birds or a school of fish move as one, with such grace and coordination, as if there's one brain behind them all or an invisible force at play. An explanation may be found in emergence, a science that tries to explain complex patterns and behavior that arise in the world around us.
Some believe emergence may reveal more than just how birds and fish do this, but how we think and how life itself began in the first place.
But while many of science's mysteries long have been explained—gravity, we predict with Newton's laws of gravity, and magnetism, through Maxwell's laws—but things like this remain largely unpredictable.
JOHN HOLLAND: Emergence, when you first see it, seems mysterious. But then, if I go back and read the papers at the time of Maxwell, electromagnetism seemed very mysterious, too.
CARLA WOHL: Let's start with what we do know about emergence. It's an order we might not expect to see. Usually where there is order, there is a leader—a conductor of an orchestra or a general with his army—orders come from the top, and they go down.
JOHN HOLLAND: Yeah, and they go down.
KEITH STILL (Crowd Dynamics Limited): Top-down order, where you have one brain controlling the functions of the entire group.
CARLA WOHL: A leader at the top and many who follow down below: it's just how we expect things to be.
So who's in charge here? Him? No.
Him? Unh uh.
JOHN HOLLAND: There's no conductor; there's no general.
ROBERT HAZEN: There's no leader. There's no director that's telling every fish where to go.
CARLA WOHL: Well, then what about these birds?
KEITH STILL: There's no one in charge of the birds either.
CARLA WOHL: So if the order isn't coming from the top down, where is it coming from?
JOHN HOLLAND: The organization comes from the bottom up. So, at the bottom, we have these things that are following their own sets of rules, often fairly simple. One is to go in the same direction as the other guys. Another is "Don't get too close, but don't get too far from my neighbors."
CARLA WOHL: And perhaps the most important rule: if someone's coming after you, get out of the way.
From these simple rules, very complex patterns can spontaneously emerge.
JOHN HOLLAND: What we see is a pattern emerging from the bottom up.
CARLA WOHL: And so it came to be called "emergent complexity" or simply, "emergence."
Of course, different creatures have different rules, but whether ants or wildebeests or this slime mold...
JOHN HOLLAND: The behavior emerges from the actions that are controlled by the rules, and behavior of the whole is more than the sum of the parts. And that's the flag for emergence.
CARLA WOHL: And you might not have noticed it, but it's not just seen in animals.
KEITH STILL: Similarly, with crowds; there are no leaders within certain types of crowds.
CARLA WOHL: Crowds of people? We do it just like the birds and fish?
KEITH STILL: Movement is happening at a very much subconscious level. You don't think about how to walk, you just do it.
CARLA WOHL: Keith Still studies the emergent complexity in crowds. He says these people crossing the street have no idea they're part of a larger pattern.
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