On a September evening in Kingston, the lights of the 566-seat Performance Hall at Queen's University's Isabel Bader Centre for the Performing Arts will go down not over a symphony or a play, but over a question that has occupied physicists for a century: what is the universe made of, and why are most of its ingredients invisible to us? The speaker is Marcela Carena, one of the world's most influential particle physicists and, since November 2024, the executive director of the Perimeter Institute for Theoretical Physics in Waterloo. For two hours, free and open to the public, she will walk anyone who wanders in through the strange, shadowy architecture of reality — the Higgs field, dark matter, and the ghostly neutrinos that drift through us by the trillions without leaving a mark.
The talk, hosted by the Queen's physics department, is billed as "The Invisible Universe: Higgs, dark matter, neutrinos and the origin of mass and matter." Carena's framing is disarmingly personal: most of the universe is invisible, she argues, and yet the invisibles decide everything about our ordinary days. There is an invisible energy field — related to the Higgs boson, the elementary particle confirmed in 2012 at CERN's Large Hadron Collider near Geneva — that provides mass to all the matter we can touch. There is dark matter, an unknown substance that outweighs everything we have ever seen and whose gravitational pull holds our galaxy together, yet which has never been detected in any laboratory. And there are neutrinos, particles so shy they barely interact with anything at all, who nonetheless have rearranged our understanding of physics and of cosmic history.
For a Kingston audience, no part of Carena's story will land closer to home than the neutrinos. The proof that these particles have mass came, in part, from an experiment two kilometers beneath a working nickel mine near Sudbury, Ontario. There, in a detector filled with heavy water, the Sudbury Neutrino Observatory showed that neutrinos change identity as they travel — that they oscillate — and therefore must carry mass. The discovery earned the 2015 Nobel Prize in Physics for Arthur B. McDonald, a physicist who spent much of his career on the faculty at Queen's University in Kingston itself. The invisible universe, in other words, has deep roots in the very city where Carena will speak. And the search continues beneath the same northern ground: the successor laboratory SNOLAB, also deep under Sudbury, now hunts for the identity of dark matter and for the secrets neutrinos still guard.
Carena's own journey to this podium is as global as the physics she describes. Born in Argentina, she earned her doctorate from the University of Hamburg in Germany and held research positions in the United States, Germany, and Switzerland before joining Fermilab — the principal centre for particle physics in the United States, near Chicago — in 1996. There she rose to become head of the Theory Division while holding a part-time professorship at the University of Chicago, where she was a member of both the Enrico Fermi Institute and the Kavli Institute for Cosmological Physics. Her research has advanced understanding of the Higgs boson, supersymmetry, and electroweak baryogenesis — the quest to explain why the universe contains matter rather than nothing — and, more recently, of quantum simulation for particle physics. She has served as chair of the Division of Particles and Fields of the American Physical Society, and at Fermilab she originated a visitor program that brings graduate students from Latin America to pursue research alongside the lab's theoretical physicists, an initiative animated by her own origins.
Her return to Canada as head of Perimeter Institute made history in its own right. Carena is the first woman to lead the institute, which was established nearly 25 years ago by Mike Lazaridis, co-founder of Research in Motion (the company behind BlackBerry), and which celebrated its silver anniversary in 2025. Its founding mission is to pursue fundamental questions about the nature of reality in a uniquely unconstrained setting. Carena is no stranger to Perimeter: she previously held its Distinguished Visiting Research Chair — the same position once occupied by Stephen Hawking — and has served as chair of its Scientific Advisory Committee since 2022. In the announcement of her appointment, she emphasized the institute's role as a training ground for young scientists, pointing to the flagship Perimeter Scholars International master's program, which draws a highly competitive international cohort each year and has become a well-regarded pipeline of theoretical talent. "It's the people that make all the difference," she said.
The venue for the Kingston lecture is itself a layered piece of local history. The Isabel Bader Centre, designed by the celebrated architecture firm Snøhetta and built of wood, glass, and steel, stands on the shore of Lake Ontario inside the courtyard of what was once Morton's Brewery. One warship of the Royal Navy, the 112-gun HMS St. Lawrence, was even moored there during the War of 1812 and eventually sank in the lake, now a popular dive site. That a talk on the invisible universe unfolds within sight of a sunken warship is a pleasing accident of place — an 80,000-square-foot building where, on this night, the performance is pure idea.
Carena steps onto that stage at a moment of uncertainty in her field. Since the Higgs boson's confirmation more than a decade ago, the Large Hadron Collider has produced no unambiguous next discovery to point theorists toward a unified picture. Yet Carena's lecture is a reminder that the field's unfinished business is precisely what makes it thrilling. The collider may yet produce signals of dark matter, or of new forces of nature, or of "cousins" of the Higgs boson. Deep-underground facilities like SNOLAB are combing through the dark for weakly interacting particles that could make up the bulk of the universe's matter. Meanwhile the neutrinos, once dismissed as trivial, have become key players in cosmic history — and a Canadian mine helped reveal it.
The deepest thread of her argument is philosophical as much as physical. Why is there matter rather than nothing? Why do we exist? The invisible universe, Carena suggests, may hold the answer. If scientists can pull together a coherent picture of the dark — of the field that imparts mass, of the substance that binds galaxies, of the particles that change face as they travel — they may begin to explain the very fact of our being. That is a grand claim, and it is the kind of claim she will make to a roomful of strangers who simply walked in off King Street on a Wednesday night.
For the residents of Kingston, the lecture is a rare and generous sort of intellectual spectacle: no ticket platform, no reserved seat, no paywall. Just a renowned physicist, a two-hour talk, and a question as old as humanity, delivered in a beautiful hall overlooking the lake. On September 16, 2026, the invisible universe becomes, for one evening, completely visible — to anyone willing to look.