As Nuno F.G. Loureiro’s colleagues mourn his shocking death at the hands of a former classmate, many are reflecting on the MIT physics professor’s legacy of scientific contributions and leadership.
Loureiro’s specialty, plasma physics, deals with the dynamics of the ionized gas known as the “fourth state of matter.” Though somewhat esoteric, it is a field with broad applications, from the safety of astronauts to the fast-growing fusion energy industry — and one that Loureiro made strides to advance, his associates say.
Loureiro, who for the past year served as director of MIT’s Plasma Science and Fusion Center, one of the institute’s biggest labs, earned a reputation for being a jack of all trades.
“In plasma physics, I think he was definitely known as someone who understood a lot,” said Hari Krovi, a senior research staff member with IBM Research in Cambridge who worked with Loureiro for years.
Officials believe 47-year-old Loureiro was fatally shot on Monday by Claudio Manuel Neves Valente, who was also linked to the shooting at Brown University last Saturday that killed two students and injured nine, setting off a six-day manhunt. Both natives of Portugal, Neves Valente and Loureiro studied physics together at the Instituto Superior Técnico in Lisbon in the mid-to-late 1990s.
In the 2023-24 academic year, US institutions granted 1,945 Ph.D. degrees in physics, down 1.5 percent from the previous year, according to data from the American Institute of Physics. Twenty-four of these doctoral degrees were from MIT, according to the data, while six came from Brown University. (One study published last year said that the retention rate for physics Ph.D. students is about 50 percent, suggesting that the programs can be long and grueling.)
Neves Valente was enrolled at Brown from fall 2000 to spring 2001, pursuing a physics Ph.D., before going on a leave of absence and eventually dropping out.
“We know that graduate school can be very stressful and mental health needs to be better addressed. But I don’t think there’s a coordinated effort worldwide,” said Rogerio Jorge, an assistant professor in the physics department at the University of Wisconsin–Madison who studied under Loureiro for his master’s and Ph.D. at Instituto Superior Técnico.
William Daughton, a scientist in plasma physics, knew Loureiro for about 15 years, and worked with him regularly, he said. In 2023, Loureiro was named a Stanislaw M. Ulam Distinguished Scholar, a prestigious award at the Los Alamos National Laboratory, where Daughton works, and spent a semester at the New Mexico institution on sabbatical, Daughton said.
Daughton said he got the impression that Loureiro was interested most in “the basic science of it all.” Broadly speaking, Daughton said, the field is a collaborative one, but full of human ambitions.
“Certainly all of physics is competitive,“ he said, “trying to push your ideas forward.”
For Loureiro, many of those ideas focused on plasma — superheated gases turned into a soup of electrons and ions. Humans almost never encounter plasmas, but they are said to make up about 99 percent of all the matter in the universe, according to Jorge.
In Portugal, Loureiro transformed plasma physics research and raised the field’s profile in his home country, Jorge said. Specializing in magnetic reconnection — how magnetic field lines break and reconnect to drive solar flares — Loureiro struggled to secure European funding for that work. He shifted his focus to fast particles in fusion reactors and built a research group more than a decade ago that remains active today, Jorge said. (Commonwealth Fusion Systems, a Massachusetts company spun out of MIT that has raised billions of dollars to bring fusion energy to market, has collaborated with the Plasma Science and Fusion Center.)
Loureiro was not required to teach in Portugal, Jorge said, but chose to do so anyway. In class, he emphasized fundamentals and refused to assume what students already knew.
Jorge recalled his plasma physics course with Loureiro. The professor began by asking whether students could define a plasma. Half could not. “‘OK. Let’s start there,’” Loureiro said, according to Jorge.
As complicated as the field is, Loureiro had a knack for breaking down its nuances, said Krovi, who specializes in quantum computing. “He would write equations, but still explain it in a simple enough way that I would understand,” he said.
During his near-decade at MIT, Loureiro grew more well-known in the field. When he was named director at MIT’s Plasma Science and Fusion Center, Krovi said it didn’t seem like anyone was surprised. “I felt like it was considered a natural progression in his career,” said Krovi.
Loureiro would take summer trips to Portugal and would travel elsewhere in Europe to give talks, Krovi said. “He was very much an academic,” he said. “You could see that in almost everything he did.”
Robert Langer, the prolific inventor and biomedical engineering professor at MIT who helped found Cambridge-based Moderna, said he didn’t know Loureiro personally, but that his killing ranks among the worst crimes in the school’s history.
“It’s just a terrible thing,” said Langer, who has spent 55 years at MIT as a graduate student and then a professor.
Although the sequence of events was shocking, it was not the first time an MIT employee was threatened or targeted by a killer.
In 1995, Phillip Sharp, a Nobel Prize-winning geneticist at MIT, received a letter from Ted Kaczynski suggesting that he would become a target of the so-called Unabomber because of his research in genetics. (Kaczynski’s attacks killed three and injured many others, including scientists, but Sharp was not harmed.)
In 2013, Sean A. Collier, an MIT police officer, was shot and killed by Tamerlan and Dzhokhar Tsarnaev, days after the brothers perpetrated the Boston Marathon bombings, which killed three people and injured hundreds.
In the wake of this week’s tragedy, many who worked with Loureiro are left with questions and memories. MIT graduate student Isaac Narrett remembers bringing a copy of a seminal textbook from 1958 about solar system plasma physics to Loureiro.
“We both shared a moment of awe,” Narrett wrote Friday in an email. “Nuno enjoyed the history of science.”
Narrett said he met Loureiro during his first year at MIT, and described him as an “amazingly eloquent speaker.” He credited him for incorporating lecture material relevant to Narrett’s specialty in solar system space sciences even though Loureiro and many of his students focus more on nuclear science and engineering. Narrett said he asked Loureiro to serve on his dissertation committee, and he agreed. He hopes to defend his thesis work in the spring to complete a Ph.D. in planetary science.
“It will be an extremely hard day when I defend, to not have him there,” Narrett wrote.
Dana Gerber can be reached at dana.gerber@globe.com. Follow her @danagerber6. Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her @lauracrimaldi. Hiawatha Bray can be reached at hiawatha.bray@globe.com. Follow him @GlobeTechLab. Jonathan Saltzman can be reached at jonathan.saltzman@globe.com.