David Kaplan's documentary 'Particle Fever' shows the human side of physics

On September 10, 2008, scientists flipped the switch on the Large Hadron Collider, a 17-mile circular tunnel that resides nearly 600 feet below the border between France and Switzerland. The LHC was designed to begin answering questions that have puzzled physicists for the past half century about, well, how the entire universe works. LHC construction began in 1998, a collaborative effort that now involves more than 10,000 scientists from more than 100 countries and an obscene amount of computing power.

Image caption: David Kaplan

Image credit: Matt Roth

It has been widely heralded as humankind's most ambitious science experiment ever. For particle physicists, the expectation of LHC data has dwarfed the zeal of hardcore David Lynch fans eagerly awaiting the return of Twin Peaks. "Ever since I entered physics, people have been talking about this machine," David Kaplan says in a voiceover in Particle Fever, the documentary he produced about the LHC. The shared belief that this supercollider would tell scientists something new about the field of physics loomed large—though no one really knew what, exactly, that something might be. Revolutionary physics data happen so infrequently and come at such extraordinary costs that breakthroughs are rare. In between those revelations are theories and papers, the result of physicists developing highly specialized hypotheses based on what is known. That, and a lot of math.

Kaplan, a professor in the Krieger School of Arts and Sciences' Department of Physics and Astronomy, has been talking to friends and family about the LHC for years. "When the LHC turns on, we're going to find out if [certain theories] in theoretical physics are correct or not," he would tell them. Kaplan has the lanky frame and long limbs of an NBA power forward, the long hair pulled into a ponytail of a man who probably appreciates jazz, the few days' stubble of a guy who's letting nature warm him against the mid-December chill, and the easygoing demeanor of a physicist seasoned in speaking to nonphysicists. "A decision on the theories people have worked on since the late '70s has not been made because the data has not been there," he explains during an interview in his office. "So nobody active in the field has ever seen a discovery that's changed anything."

Kaplan began work on Fever, which debuts in theaters this March, in 2006. He had a film crew in Geneva the moment the LHC was first turned on. The doc captures the excitement of the day, with scores of international news teams on site. Reporters ask the supercollider's experimental physicists about the gigantic multibillion dollar machine. What's going to happen? Will it create a black hole? "It's not going to destroy the earth," a patient physicist politely reassures them.

Eventually teams assume their positions in control rooms. A booting sequence is started. Anticipation builds as people wait for something, anything, to happen. And, finally, there's proof that the LHC can accelerate a proton to close to the speed of light: a very quick bleep on a screen. Celebration ensues, and Fever's soundtrack echoes the scientists' moods with Beethoven's "Ode to Joy."

"It works!" Monica Dunford, an American postdoc working at the LHC, exclaims to the camera with a huge smile. "It just worked."

Champagne is poured and glasses clinked together. Handshakes exchanged. Backs slapped. All this demonstration proved was that the decade of construction and piles of money made a machine that turns on. But work it did.

Nine days later, it broke. And then took months to fix. Once it was re-operational, its researchers decided to conduct the first experiments at a much lower energy level than previously planned, which wouldn't produce the same kinds of findings as high-energy collisions.

"I thought I was stronger than this," Savas Dimopoulos says in a Fever interview. A distinguished man of full face and silver hair, the Stanford physicist formulates theories about the basic building blocks of physics, and he's visibly disappointed about the LHC's condition. He needs new findings to know whether his ideas are accurate. He's been waiting three decades to know if he's even on the right track. "Once you have curiosity, you can't control it," he says, unable to hide the pessimism in his voice. "Little did I know when I started that the experiments would take 30 years, and here I am not knowing. I really want to know the truth."

At least he still has some time to find out— as one of his colleagues reminds him. As Fever follows Dimopoulos around CERN (the European Organization for Nuclear Research, which operates the LHC), he wanders into a break room to get a cup of coffee. There, he runs into Riccardo Barbieri, a professor at Italy's Scuola Normale Superiore di Pisa. They discuss the LHC's current status, wondering if they'll ever see results that impact their work— or, worse, if the results that come out disprove their theories entirely. Barbieri, a decade older than Dimopoulos, says that he's retiring soon and worries that he's spent an entire career on nothing.

They refill their cups. "[Making] coffee is very serious in the life of a physicist," Dimopoulos confides. "You don't have to wait 30 years to find out if you're right."

"People [in physics] don't often talk like that," Kaplan says during the December interview in his office. "We brush things off. Savas' statement [in the coffee scene] that 'jumping from failure to failure with undiminished enthusiasm is the secret to success'—we live that. We are trained in some way that we come like that. You can work on a theory for a year and then you immediately see, 'Oh shit. We forgot that term, it's inconsistent. It's not true.' OK, you take maybe an hour to get over it. A year's work? Completely gone. And you have to respond quickly and strongly to these things when you know something is true."

A glimpse of the truth is what Kaplan is aiming for with Particle Fever. "From the beginning, I had extremely high goals for the film." Specifically? "Cultural transformation," he says. For Kaplan, this documentary can help make science as much a part of the everyday conversation as, say, religion.

"I thought a cultural transformation was in order, and [particle physics] was the perfect field to express it in because it's so pure. It doesn't have commercial applications or military applications. It really can't get you famous at the level of fame that we experience today. The only arbiters are data and mathematical consistency—which are such pure, independent-of-human-being things—that it would be great to show that world."

Of course, data and math don't do themselves. They require human beings, and in following those people, Particle Fever delivers a human drama as gripping as a thriller. What's at stake in Particle Fever isn't just new science but the careers of the people who pursue it. These are some of the most educated people in their fields who have spent their entire professional lives trying to figure out natural phenomena—gravity, mass, how the universe was created, where it might be heading—based on data from physical interactions they will never directly observe. The entire LHC enterprise simmers down to an existential personal ad: "Man's Biggest Machine ISO Universe's Tiniest Anything."

What's the LHC going to show us? Nobody knows. But as Kaplan says in Fever, "It could be nothing other than understanding everything."

In the beginning was the bang. Big, it was. The release of energy created a very hot environment, but as the universe cooled it created a field that, when things interacted with it, caused them to acquire a mass. Some things become particles like electrons, which have a mass, a charge, a spin, and a momentum. Others become quarks, which gather in groups of three to become protons and neutrons. Protons, neutrons, and electrons get together to form atoms. And atoms get together to make everything: wood, plastic, metal, rock, cheese, cars, iPhones, Hermès scarves, Legos.

Holding everything together as stuff are four fundamental forces that can't be reduced to anything more basic: gravitational (the interaction between physical matter), electromagnetic (the interactions between charged particle and conductors), strong nuclear (which holds atomic nuclei together), and weak nuclear (which is responsible for radioactive decay). At least, and very reductively, that's one idea about how energy becomes matter and, eventually, the stuff we see all around us. It's called the Standard Model, and since the 1970s it has become the leading theory to describe the relationships among the subatomic particles.

There are a few gaps in proving that the Standard Model is accurate—including a lack of (nonmathematical) evidence for the existence of the field required for mass. It was proposed by Scottish theoretical physicist Peter Higgs in a pair of papers published in 1964 and is now known as the Higgs field. (Other physicists theorized a field responsible for mass around the same time, but it is most commonly referred to as the Higgs.)

About 15 years later, Monica Dunford—that young American physicist working at the LHC— was born.

Dunford had no interest in physics when she entered college in the late 1990s. She intended to major in chemistry, maybe math, but under no circumstances physics. It's too theoretical: all thinking, no doing. But as the enthusiastic young woman recounts in Fever, as a freshman she was introduced to experimental physics. While theoretical physicists take what we know about the observable world and use math to try to explain everything, experimental physicists take that same information and make experiments to try to discover something new. In other words, experimental physicists do things.

After earning her PhD, Dunford started participating in particle physics experiments, eventually joining a team working on the biggest science experiment ever. In Fever, she recalls the awe she felt when she first visited the LHC in 2005. "People tell you, 'It's five stories tall,' and you go, 'Oh, five stories tall,'" she says, rolling her eyes. "And then you see five stories completely filled with microelectronics, custom-designed, hand-soldered. It's as if it's a five-story Swiss watch."

Dunford, who talks about particle physics like a sports fan recounting the glories of a favorite team, is Fever's breakout star. She came to CERN to work as part of ATLAS (A Toroidal LHC Apparatus), which was designed to detect new subatomic particles. When the LHC accelerates protons to near the speed of light and then smashes them together, the ATLAS detectors register the results: billions of bits of information resulting from about 40 million collisions per second. "You take two things and smash them together," she says in the film. "And you get a lot of stuff out of that collision and you try to understand that stuff."

Particle physicists hypothesized that one of the things that might come out of that stuff would be a previously undetected particle predicted by the Higgs field, called the Higgs boson. The Higgs field can't be observed, but scientists calculated that if the Standard Model was accurate, the Higgs boson would show up at some point shortly after the proton collision. If they could find that particle, they'd have evidence that the Higgs field itself exists.

Fever's cameras were on hand to record the first LHC collision in 2010, nearly two years after it was first turned on, and Dunford practically vibrates when it happens. She walks around with her laptop open showing her colleagues lines and lines of information running up her screen. "We have data," she exclaims to nobody in particular. "It's unbelievable how fantastic this data is."

It's also unbelievable how confounding those data are. The ATLAS detectors can't "see" a Higgs particle because it decays almost immediately into four particles, two of which can be detected. Evidence of that decay is what the experiments were created to document. It's a bit like testing athletes for performance-enhancing drugs: You don't test for actual substance in the body but rather evidence of how the substance affected the body.

"This is where experimental physics becomes difficult," Dunford said of the search for the Higgs particle during a 2010 panel at the World Science Foundation in New York. "There are actually four distinct particles coming from the Higgs and a bunch of other particles coming from the rest of the proton collision that we don't care about. . . . So one of the things we have to do experimentally is try to get rid of all of that other stuff and then find those four other parts. So it's kind of like a double needle in the haystack. One is trying to find the Higgs particle out of those 40 million collisions per second. And the second is trying to find the products of the Higgs decay out of all the crap."

On the morning of July 4, 2012, ATLAS director Fabiola Gianotti presented the two years' worth of sorting through crap during a press conference at CERN. As Fever relates, physicists packed into an auditorium along with a gaggle of news media. The low hum of conversation calms down a bit when Peter Higgs enters the auditorium and takes a seat toward the front. Savas Dimopoulos arrives too late to get a seat in the main hall, so he, along with many others, finds a place to sit in the hallway, opens a laptop, and joins the global audience of physicists watching online. Imagine Hollywood on Oscar night, only with more anxiety.

Kaplan isn't in attendance, but Fever shows him in his car driving to Princeton, New Jersey, where a group of stateside physicists will be watching the announcement via live stream at 3 a.m. Judgment day has arrived.

Fever only shows bits and pieces of Gianotti's presentation of the findings, which were published in the journal Physics Letters B in an article called "Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC," by the ATLAS Collaboration, an author group whose attribution runs 10 pages in the report and includes Dunford. The article is highly technical and descriptive of what ATLAS measured, how it did so, the mathematical interpretation of the data, the statistical analysis of the data, and the conclusions that can be drawn from all that. It reads, in part: "These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. The signal strength parameter μ has the value 1.4 ± 0.3 at the fitted mass, which is consistent with the SM Higgs boson hypothesis μ = 1."

Or as CERN director Rolf-Dieter Heuer says when he takes the podium after Gianotti, "I think we have it."

The audience cheers. After the announcement, Fever's cameras catch the normally reserved Peter Higgs removing his glasses to wipe a few tears from his eyes. Nearly half a century after he theorized the presence of a field that might account for questions raised by the Standard Model, a team of physicists believes it has detected evidence of the particle that proves its existence. He stands and receives a rock star's ovation.

This human drama in the scientific discovery is what makes Particle Fever such an entertaining ride—and a key reason why the documentary is connecting with nonscientists. Variety called the film a "surefire crowd pleaser" when it screened at the Telluride Film Festival in October; the Hollywood Reporter added that it "humanizes the field in a way that will inspire practitioners and provoke the curiosity of nonspecialists." Fever—directed by Mark Levinson and edited by Walter Murch, A&S '65—made its world premiere at the Sheffield Doc/Fest last summer, where it shared the Audience Award with The Act of Killing, a 2014 Academy Award nominee for Best Documentary feature.

"I think the thing that's always been missing in [science programming] on the Discovery Channel [and] most science documentaries is that people don't get the real emotional experience of being the scientist," Kaplan says, adding that he wasn't going to be happy with the film until the LHC had new discoveries to present. "Only when the Higgs was truly discovered was I happy with the ending. [That] had an impact on the theorists."

Particle Fever does an impressive job of parsing the abstract physics involving the Higgs particle—the ATLAS results yield a mass for it that opens up new questions about the Standard Model—but even more affecting is the way it dramatizes what this new sliver of information means for physicists: new challenges and theories to explore that might get us a fraction closer to understanding how we're here.

"The LHC was guaranteed to make a statement, and the entire field was waiting for it—we just didn't know what the result would be," Kaplan says. "Whatever it was, hopefully we understood enough about the field that it was compelling [to the layperson]. That was always the risk I was taking: that it may be hard to explain."

Less hard to explain is what drives scientists'—and our own—curiosity. Toward the movie's end Dimopoulos wonders aloud about why people pursue science. "Why do art?" he replies. "The things that seem like the least important for our survival are the very things that make us human."

Correction: An earlier version of this story misstated the date of the Higgs discovery announcement. The correct date is July 4, 2012.