Dark Side of the Room
It’s called the theory journal club, but think of it as a place to become fluent in the language of the far-out. Meeting most Thursday afternoons in a small lecture room on the Carleton University campus are about a dozen physics graduate students and a few professors scattered among them. The unshaven look prevails: I see some flowing Ted Nugent locks, a Brothers Karamazov beard. The room is saved from drabness by the vivid prints on the wall — those of the Russian abstract painter Wassily Kandinsky, whose lines and circles and planes are as alive as darting swallows or croaking frogs. Looking at the Kandinsky prints, with their bright abstractions, I think about how fitting they are as background decorations for this club. Kandinsky once said that his art “places a new world, which on the surface has nothing to do with ‘reality,’ next to the ‘real’ world.” Modern physics seems to do something very similar.
I take a seat at the back, unobtrusively, because the talk has already started.
A master’s student in physics, Hassan Easa, is presenting a paper with the intriguing title “Z’-portal right-handed neutrino dark matter in the minimal U(1)x extended Standard Model.” His listeners are respectfully absorbed. Here, graduate students choose a recently published paper from a theoretical physics journal and present it to a small audience of profs and peers.
“It’s a way to keep on top of interesting stuff in the field,” Carleton physics professor Heather Logan told me beforehand, “and it’s good for students to present. Nobody’s born with that as an innate skill — you have to learn it. The club is very friendly.” Friendly, yes, but technical. Blisteringly technical. Hassan is taking us through the Z-portal right-handed thing, moving from podium to blackboard, chalking down formulas, glancing at the journal paper in his hand. He chose this paper because it offered “a simple model” (his words) to explain dark matter, one of the thorniest puzzles of astrophysics. Dark matter, the invisible matter that pervades the universe, can’t be seen, but physicists know it’s there because of gravitational effects. What exactly is it? The paper he chose proposes that dark matter is composed of certain particles called neutrinos — actually, a new kind of neutrino. (A neutrino is a subatomic particle, or as one of its discoverers, Frederick Reines, called it, “... the most tiny quantity of reality ever imagined by a human being.”)
I’m jotting down as many of Hassan’s phrases as I can — “charge assignment,” ”symmetry breaking,” “Z-prime” — in the vain hope that maybe I can flesh out the rather weak summary I just gave.
This is Hassan’s first time presenting to the club. He’s 24 years old and, unlike most in this room, clean-shaven. When he arrived in Canada from Afghanistan in 2009, he spoke little English. Amazingly, he finished high school in two years and then entered the Carleton undergraduate physics program, in the theory stream. His goal, like that of many in the audience, is to get a PhD and go into research — the kind that’s being discussed here: big-horizon research.
Big-horizon research thrives at Carleton. They have their own research program in dark matter: the “Dark Matter Experiment with Argon Pulse shape discrimination” (DEAP). There is also the ATLAS Research Group, which works on data from the ATLAS detector at the biggest particle accelerator in the world, the Large Hadron Collider, located at Europe’s CERN research centre. The ATLAS work is not just theoretical: in Carleton’s basement labs, they are constructing components for the detector. Is this a golden age in physics? It certainly is a golden age in collaboration. ATLAS research, for example, involves 5,000 scientists from 180 institutes in 38 countries. Understanding the universe requires a lot of data and money, and collaboration is essential. And collaboration begins right here, with the theory journal club.
And why would somebody devote a life to pursuing these exotic worlds? As a career path, it has to be one of the toughest going. Very few budding physicists land a job right out of grad school. Even post-doc positions are coveted prizes.
The talk over, the club members applaud Hassan and disperse to their own corners of the universe. “I was a bit nervous,” Hassan says, “but I thought it went well.” When I ask him why he got into physics, he gives me a straightforward answer: “It gives an explanation in reasoning about how nature is. It’s very elegant.”
The ancient Jewish esoteric writers known as the Kabbalists had a wonderful metaphor for Holy Scripture: it was a great house filled with numberless rooms, all of which were locked. Outside each door was a key — but it was not the key to that particular door. Maybe the universe is like that: numberless doors, numberless keys. Some doors have been opened by physicists, but they led to other locked doors that nobody knew were there. A physicist might discover a big brass key on the ground floor and find that it, unexpectedly, opens the tiny little door to the attic. Maybe that’s why these folks want to be physicists: all those strange-looking keys dangling from your belt, all those strangelooking doors to open.