Are We Alone?

Particle physicist Prof. Jean-Sebastien Gagnon on alien life and other mysteries of the universe


This fall, researchers announced the discovery of phosphine gas in the atmosphere of Venus. On Earth, phosphine is associated with swamps and sewage. Produced by microbes in the lower intestinal tracts of humans, phosphine is linked with life.

It’s light-years too early to suggest that Venus harbors life, even the microscopic variety. But the notion that extraterrestrial life exists somewhere in the universe isn’t so far-fetched, says Assistant Prof. of Physics Jean-Sebastien Gagnon.

By life, Gagnon doesn’t mean humanoid aliens. But microbes or plants? The possibility isn’t outlandish. “It’s like the one-million-dollar question.” Gagnon points to data gathered by NASA’s Kepler space telescope, which suggests there are some 100 billion planets in our galaxy. Of those, 10 billion are rocky, Earth-like exoplanets orbiting Sun-like stars. “That’s a lot of environments in which life could potentially develop,” Gagnon says.

Before he joined the Norwich faculty in 2019, Gagnon served as a post-doc at Harvard, where he was part of the Origins of Life Initiative, among other projects. Trained in theoretical, high energy particle physics, Gagnon helped the team better understand the effect of fluctuations and noise in models of chemical systems that mimic life.

Now that he’s teaching at Norwich, the Canadian-born theoretical physicist continues to collaborate with his Harvard colleagues and independently contemplate other big questions. Among them, why is there more matter than anti-matter in the universe? And how does dark energy explain the increasing rate at which the universe is expanding?

The French-Canadian has a seriously unserious side, too. A science fiction and Star Wars fan (as a kid, he memorized the entire film, in French), Gagnon has applied his knowledge of particle physics to consider such weighty matters as, are light sabers possible? His answer: “I did not disprove it. Technically speaking, you could say that it’s … possible,” he says. “[But] you need so much energy for that to happen, that [it] is very, very impractical.”

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