Four British schoolboys had just been called from class. They were ten days away from their A-level exams, the ones that determine the direction the rest of their lives would take, but they’d been interrupted from their studies to discuss the deepest secrets of the universe—their work hunting for the magnetic monopole at the Large Hadron Collider.
Clearly, they would much rather be studying than be interviewed. The disinterested troop sat around a table in the back of a large high school science room outside of Canterbury in the United Kingdom. The teens, none older than 16, who could have been the early Beatles in matching school uniforms, were discussing graduate-level physics.
“Monopoles themselves are very ionizing,” 16-year-old Andrew Nicoll told me. “4,700 times more than a proton. They’ll lose energy very quickly. Our chips are designed to detect very short lived monopoles.”
The monopole is exactly what it sounds like: A magnet with one pole. Take any magnet, and you’ll notice it has a north and a south pole. Chop it in half, and you’ll have two magnets, each with a north and south pole. Keep chopping, and each piece will always have two poles. But the monopole, if it existed, would only have one pole. Magnetic field lines, rather than connecting the north and south, would shoot off into infinity.
The basic equations for electromagnetism, the famous Maxwell equations, have an obvious blank that a monopole could fill. The equations with a magnetic charge (a monopole) would be symmetric with each magnetic term looking like the corresponding electric term. In other words, the equations would just look nicer.
In 1894, Marie Curie’s husband Pierre called for physicists to search for that charge. Paul Dirac showed that the existence of the monopole was consistent with the rules of quantum mechanics, the physical theory governing the smallest bits of matter. And lots of the grandest theories of the universe, theories you’ve probably heard of including string theory, M theory, and the grand unified theory (GUT) that unites the electromagnetic with the weak and strong nuclear forces at high energies all require a monopole. Some theories say there should be lots of them.
So far, we haven’t found any.
These four boys are among the Simon Langton Grammar School for Boys’ latest recruits to join the Large Hadron Collider’s hundred-person MoEDAL (Monopole and Exotics Detector at the LHC, pronounced ‘meddle’) collaboration in Geneva, Switzerland, a new attempt to find the monopole and maybe other exotic particles.
Given the collaboration’s small size, James Pinfold, the experiment’s spokesperson, and Dr. Becky Parker, director of the Institute for Research in Schools in the United Kingdom, thought it was the perfect chance to get high schoolers involved in high-energy physics experiments. Parker wants nothing more than to get her students’ names on a physics paper.
“The students don’t just want to be on the collaboration,” she said. “We want to show that young people can make contributions.”
They’d be contributing to the latest in a long history of unsuccessful attempts to find a fundamental particle that some deem the next discovery in line after CERN’s Higgs Boson announcement in 2012. But physicists have been hunting for the monopole for a very long time.
One team looked for a signature electric current in moon rocks in the 1970s. Physicist Buford Price noticed some high-energy particle from space etched a track through 33 sheets of plastic attached to a balloon and claimed it was evidence for a monopole in 1975. He walked back that conclusion in 1978, some say due to pressure from competing teams. Blas Cabrera thought he spotted one in his detector, a superconducting ring, but didn’t see any other events to confirm the first wasn’t a fluke. Others have hunted for the monopole at CERN at the Large Electron-Positron collider and its successor, the currently-operating Large Hadron Collider.
Lots of people think and hope it exists, but that doesn’t mean it has to take a form scientists will ever detect. Maybe right after the Big Bang, the universe’s inflation spread out the monopoles so sparsely that they became undetectable. Maybe their mass is too high to be produced by the Large Hadron Collider. If the monopole existed in those too-massive ranges, “we’d never be able to produce enough energy on Earth to create them,” said University of Alberta physicist Richard Soluk, MoEDAL’s technical coordinator. “Let’s hope they’re not there,” in those too-heavy-to-create ranges, he said.
Pinfold, physicist at the University of Alberta, is the MoEDAL collaboration’s spokesperson. The eager professor wore his white hair combed back and his shirt’s top buttons unbuttoned when I visited him at the CERN cafeteria. I would have bought the experiment had he tried to sell it, but one sort of has to be a salesperson when they’re running a hundred-person collaboration for a several million dollar experiment, compared to the thousands of people running the several hundred million dollar ATLAS or CMS experiments. “Our cost is at least a factor of 100 cheaper than other LHC experiments,” he said. “If we did discover the monopole it would be a real David versus Goliath configuration.”
Despite MoEDAL’s fancy acronym, it’s nothing like ATLAS or CMS, the LHC’s famous, mansion-sized particle-detecting metal monsters. It seems like the perfect detector to staff with monopole-hunting teens.
The experiment lives in a warehouse behind a McDonald’s, beside grassy fields and the wide Jura mountains. Its elevator has only two floors, 0 and -1, into a 300 foot pit. At the bottom, past the giant blue cylindrical corpse of a scrapped particle detector and beyond several yards of white concrete shielding is a vast, yellow-lit cavern, dominated by the LHCb experiment. That detector is a striped, 60-by-30 foot sideways pyramid to the left side of the particle collision point. On the right, up some metal stairs in a studio apartment-sized nook surrounding the point, the first thing you notice is a tiny blue LED on a circuit board connected to cables. That’s when you realize that the walls are tiled with flat rectangles of thick, translucent plastic bordered by aluminum bars. Each plastic sheet is labeled: MoEDAL.
That’s it. A few walls covered in aluminum-lined plastic attached to a tiny silicon detector are tasked with discovering the magnetic monopole. The CERN press officer was as surprised to see it as I—no journalist had planned a trip to see it in person before.
The detector is simple because it does all it needs to do and no more. A monopole created from the energy of a pair of colliding protons might leave a visible trail in MoEDAL’s plastic “nuclear track detectors.” If you remember from high school physics, a regular two-poled magnet passing through a coiled wire will send a current through the wire one way, then the other way. A monopole passing through the aluminum bars should show a signature as if the current moved in one direction, but never moved back. As for the silicon pixel chip, the constant stream of debris resulting from the collisions can fog the plastic. The state-of-the-art TimePix particle detector helps scientists best understand what background particles did the fogging so it’s easier to shield against them in the future.
That makes it the perfect experiment to draft high schoolers onto, given the simplicity. “Not as publicity,” said Pinfold. “They can actually do things.”
The students are part of the Institute for Research in Schools (IRIS) program, letting high schoolers take part in real science experiments, like those at CERN, the European Space Agency and NASA. Ever-cheerful Parker runs it with a curiosity, enthusiasm and excitability you could only wish every high schooler possessed. After visiting the Langton during our driving tour of Canterbury, she pulled the car just to appreciate the blooming bluebells at the side of the road. She jogs the two steps from the door of her parked car to the parking meter.
Today, her students focus on that teeny TimePix chip, which takes snapshots of the collisions, many photos per second, recording the particles that hit it. A barrage of background particles appear on the output as dots (high-energy light particles) little circles (alpha particles) and straight or curly lines (muons or electrons). Training a computer to identify these particles can be difficult. But people can identify them with just a bit of practice. “It was incredible,” said Pinfold. “The students all identified the main features, essentially perfectly.”
Their role quickly grew from identifying particles. Anna Evans has since graduated Langton and now attends the University of Manchester, but was on the MoEDAL team a few years ago. She and her team helped developed a citizen program for other lay-people to help identify what the monopole might look like in the plastic. Her classmates soon became experts on the TimePix chip. They identified anomalies due to dead pixels. They wrote proposals to get more of the chips into the detector. They’d skype into MoEDAL collaboration meetings.
But Evans and her classmates’ young ages could get in the way when working with the collaboration. “People wouldn’t acknowledge that we did what we were talking about,” she said.
Today, the Langton Students are still poring over the TimePix data. And it’s immediately clear that these kids are far more than human computer algorithms. The four boys I chatted with forego playing video games to hang out after school trying to identify which particles have struck its teeny surface. One project manages, one crafts theories about their data and what the monopole might look like. One pores over research trying to understand the mounds of theoretical physics required to comprehend their particle. They dissect papers from the arXiv, the physics paper preprint server that offers free PDFs.
“It’s not about finding it,” said Nicoll. “It’s about improving the actual method of finding it, and learning how to use these chips and implement ideas.”
Doubts about the student’s work dissipate when they open their mouths, said Evans. Sure, “a lot of the stuff went over our heads,” said Evans. But they’re real contributors. “When we spoke about the TimePix stuff, we spent so much time dedicated to it that they’d stop to listen and say, ‘Oh wow. This is impressive.’”
Parker thinks her students are good enough to do physics with their older collaboration counterparts. “They’ll be flying with ideas about how to develop MoEDAL, how to use the background radiation to make the chips better. I think so often you just assume that A- level students just learn exactly what they have to and don’t contribute at university until their third and fourth year,” said Parker. “These students have too much to offer to wait until then.”
The Langton’s students aren’t the only ones looking at the TimePix data, though. Stanislav Pospíšil leads a group at the Institute of Experimental and Applied Physics at the Czech Technical University in Prague that also takes part in the MoEDAL collaboration and also looks at the TimePix data. Their work is quite similar to the students’, said Pospíšil, analyzing the particles that strike it during a particle collision. But “the amount of data is so huge that it’s good if two independent groups are evaluating is,” he said.
Yet the TimePix analysis might not even appear in a MoEDAL paper. “It wouldn’t directly affect our conclusions or data analysis,” said Soluk. Though he did say it’s important. “If you know what [background] is there, you might be able to shield against it.”
MoEDAL is still more than just the TimePix chip. Once the LHC run finishes and the MoEDAL team can retrieve their plastic, they’ll have to analyze it. The plastic sheets head to a lab in Bologna where they’re treated with a potassium hydroxide or sodium hydroxide in alcohol solution, which would makes monopoles’ etchmarks visible under a microscope as cones in the plastic. The researchers can then do some form of automated scanning, or have citizen scientists, maybe the Langton students, look for the monopole. And if you gave them some time to prepare, there’s not really a limit to what sorts of tasks the kids can do.
And the IRIS program is flourishing beyond just MoEDAL. Parker has introduced the program to over 350 schools across the United Kingdom. Students are using data to optimize the Transport for London system. In fact, you might remember one British student, Miles Soloman who found an error in NASA data earlier this year—he was part of the IRIS program at his own school, working on the TimPix project using the TimePix chip to monitor radiation levels onboard the International Space Station. The MoEDAL research is getting recognition, too—students including Evans presented their work at the Royal Society Summer Exhibition back in 2015.
The students’ work hasn’t been published yet. MoEDAL released its first set of null results last year (they didn’t find anything, but the experiment works). “We were so close to the last paper, having all their names on,” said Parker. She had just returned from a phone call she had made in response to a dumb question I asked. I didn’t yet thoroughly understand how each of MoEDALs’ parts worked together, and asked whether the TimePix data was actually relevant. It made her literally run out of the café where she, Evans and I were sharing coffee. “They can be on the paper if they generally contributed,” she said when she returned. “A paper about all those classifications and analysis systems which they’ve been a part of, they can be on.”
I called Pinfold about the student’s work. There’s a place that their work could appear: “It’s likely to be a paper on our application of citizen science to the analysis,” he said. It’s not on the monopole specifically, but on the citizen science program the students developed versus machine learning as a means of analyzing data. “The students that worked on it were remembered,” he said. “We’re working on it actively.”
But students inevitably graduate while the MoEDAL collaboration is going to continue hunting for the monopole with a new batch of Langton students to help. It’s bittersweet for those who’ve moved on to University. “It’s odd having that exciting thing to do and feeling that you’re getting some recognition in the field you want to go into, then going to University,” said Evans. “When we get to university it feels like a step down because the stuff you’ve been doing is so exciting.” But many of the past graduates have gone into physics, and three of the four boys I spoke to planned on pursuing physics when for their A-level studies before going to University.
And at least the students I spoke to have developed a whole new appreciation for science and physics. It’s changed their whole perspective on who particle physicists are.
“I always thought of physicists old people separate from technology, doing theory hard maths,” said Patrick Abbott, one of the Langton boys. “I never thought of them as people working in teams—I thought it was one person working alone. And I never saw physics as a happy experience. Now I’ve realized how cool it is.”
Even after the paper comes out, it is still unlikely that anyone finds the monopole. That didn’t phase the Langton boys. “We’ve all accepted the fact that we’re not going to find it,” said Langton student Paul Holland. Said another student, Patrick Abbott: “If we only contribute slightly, even then we’ll be happy.”
The reporting for this article was partially supported by a grant from the National Science Foundation.