A Dark Matter Detective

February 21, 2024
Sarah Williams

Hertz Fellow Katelin Schutz thinks existing experimental data across many fields of physics and cosmology can be re-analyzed through a “dark matter lens.” 

Much of the universe is composed of a mysterious, invisible form of matter that is difficult to directly observe. Called dark matter, it doesn’t absorb, reflect or emit light but it is imprinted in the way galaxies form, how acoustic oscillations change across cosmic time, and the behavior of the oldest remnants of the universe. 

Schutz has made it her mission to understand this enigmatic substance. She thinks, thanks to the omnipresent nature and far-reaching effects of dark matter, it can be studied in numerous ways – including by analyzing experiments that scientists carried out in the past for other reasons. 

“My specialty is taking experimental data that already exists and reinterpreting it through a dark matter lens,” she says. “It turns out we can get a lot of new information out of observations that have already occurred.”

Schutz, a self-described extrovert who loves scientific dialogue and collaboration, was first drawn to studying physics as an undergraduate at the Massachusetts Institute of Technology (MIT) after she found mathematics too isolating. Then, as a Hertz Fellow at the University of California, Berkeley, she bounced around between research groups while deciding what topic to pursue longer-term. 

“It wouldn’t have been possible for me to really explore my interests in this very open way without the Hertz fellowship,” says Schutz. “Because I had the financial support from Hertz, I wasn’t tied to one person’s research. I could try working with different advisors and collaborators and then pursue a project that was really my own.”

Over time, she became enamored with the study of dark matter, which presented many open questions. The field felt new, young and exciting. Schutz began probing new ways of detecting dark matter, by homing in on its measurable effects on visible matter. 

Katelin Schutz

“Because I had the financial support from Hertz I could try working with different advisors and collaborators and then pursue a project that was really my own.”

Katelin Schutz Arrow Right
2014 Hertz Fellow

Assistant Professor, McGill University

Now, as an assistant professor of physics at McGill University in Canada, Schutz is still coming up with ways to push the boundaries of what scientists know about dark matter. In 2021, she and collaborators at MIT — where Schutz had been a NASA Einstein postdoctoral fellow — described how the detectable remnants of supernovas could be used to deduce the presence of dark matter. But her other research has pulled data from things as disparate as tabletop experiments, the Large Hadron Collider, and space-based telescopes. And even when her experiments are designed to study dark matter, they have implications in developing tools for areas of applied physics. The same ultra-sensitive sensors designed to detect dark matter, for instance, could be used to improve the sensors used in medical imaging technologies. 

“One of the things I really love about the field of dark matter research right now is just how creative you can be,” says Schutz. “You can mix and match: let me test this model with this system, or let me see how a different system can help model dark matter. I like making all the puzzle pieces fit together.”

In each instance, Schutz and her collaborators ask how dark matter is leaving its footprints on the universe in different environments and across many orders of magnitude in time and length. Schutz says that the book is still completely open on what, exactly, dark matter is. 

“I think, arguably, we’re more confused about dark matter than we were twenty years ago,” she says. “We know a lot more about what dark matter is not than we know about what it is.”

While many physicists view the search for answers about dark matter to be a race to the finish, Schutz has a controversial take: “Honestly, I hope we don’t find out everything about dark matter anytime soon,” she says. 

That’s because, for Schutz, the journey is the destination. She says the quest to understand dark matter — and other parts of cosmology that aren’t explained by the Standard Model of Physics — has already led to the development of new types of sensors and applications that extend beyond physics into medicine. 

“There’s also a lot of cool stuff we’re learning about fundamental science that we might never have thought to ask in the absence of this big question about dark matter,” she says. “When you’re driven by this kind of question you end up learning things you never would have expected.”

In 2023, Schutz was been named a Canada Research Chair, a prestigious title that comes with funding to support a scientists’ salary and research. She is now focusing on growing her lab, with the goal of bringing together diverse minds to tackle the question of dark matter.   

“We need all hands on deck and as many different perspectives on this question as we can get,” she says. “It’s one of those situations where I think the more people are working together, the better it is for the science.”

Schutz also brings that mindset to her collaborations, seeking out scientists from fields that do not typically study dark matter to help her develop new strategies for discovering dark matter. She firmly believes that clues about dark matter can be found in unexpected places. 

“I think scientists in other fields should be really excited about dark matter because maybe it is part of their field and they just don’t realize it yet,” she says. “I think we’re at a time where almost anything, if you view it the right way, could be construed as a dark matter experiment. So if you’re a scientist and someone comes knocking at your door talking about dark matter, take them seriously and keep an open mind because it could lead to really unexpected collaborations.”

As she launches such collaborations herself, mentors her students, and watches each person bring different expertise to the table, Schutz is confident she has found the field she was first seeking as an undergraduate. 

“It’s the excitement and the community that keep me going,” she says.