In which sense does the Universe make sense?

In the sense you sense a sense.

—Victor Weisskopf

It’s the sort of nonsense punchline that might run through a physicist’s mind past bedtime while grappling with a maddening problem. Victor Weisskopf, late professor of physics at the Massachusetts Institute of Technology, learned early that he wouldn’t survive without cracking a few jokes. For decades, Weisskopf packed folders with poems about physics, limericks, and scripts of skits making fun of his peers. The sense of humor he cultivated helped him become a community leader among physicists, giving him a platform to advocate for ethical science.

Weisskopf, a Jewish-Austrian theoretical physicist, said he chose science in rebellion “against an extremely humanistic family” that loved art and music. After earning his doctorate at the University of Gottingen, he worked under Erwin Schrödinger. Weisskopf found him dull, “not at all inspiring,” and distant from his colleagues. Imagine Weisskopf’s surprise when he transferred to the Niels Bohr Institute in Copenhagen, where Bohr’s closest associates pulled pranks and teased him for his habit of thinking aloud. And Bohr didn’t hold himself above his assistants. He invited them to amusement parks and movies. He was a particular fan of Czech actress Anny Ondra and insisted on seeing every one of her shows.

Weisskopf was initially so bothered by the silliness that he brought it up with Bohr on a walk. Bohr asked how he liked the institute. Weisskopf replied he liked the work and all the people—except for one thing.

“I expect scientists to be more serious,” the young Weisskopf declared.

“There are some things that are so serious you can only joke about them,” Bohr answered.

To explain his approach to the nature of reality, Bohr used not a scientific figure but a Cubist painting on the wall in his house. He explained to his students that to fully understand something, you have to see it from many different perspectives that might first appear to contradict each other—just as a Cubist painter depicts a figure from multiple angles at the same time.

Bohr’s attitude toward humor and the arts won over Weisskopf, drawing him back to the cultural life he once fled. He proved his conversion when he took the stage—as the Dalai Lama—in a satirical adaptation of Jules Verne’s Around the World in Eighty Days after Bohr returned from a long trip.

While working to uncover the quantum behavior of electric fields, he wrote parody science articles for the institute’s Journal of Jocular Physics. In one, “The Complementary Philosophy of Jokes,” he applies a quantum concept to humor. Complementarity was Bohr’s way of explaining how an electron behaves as both a wave and a particle. According to science historian Paul Halpern, Weisskopf’s article claimed that jokes also have a complementary nature—while apparently unreal, jokes actually hold up fun-house mirrors to reality and can reveal a way to the truth.

A humorless force swept Weisskopf away from Bohr’s lab. By 1936, the threat of Nazi invasion loomed, and as a Jew, he had to escape. Bohr helped Weisskopf land a teaching job in the U.S. Seven years later, J. Robert Oppenheimer asked Weisskopf to lead the theoretical physics division of the Manhattan Project in Los Alamos, New Mexico. Their goal was to beat Nazi Germany to building an atomic bomb.

Weisskopf’s charisma led colleagues to ask him to run for chairman of the Los Alamos city council. He served one term as chairman and three terms as town councilor. The physicist-turned-politician hashed out issues concerning playgrounds, milk shortages, and sidewalks.

Weisskopf recalled one such discussion in his memoir, The Joy of Insight. Residents first complained to the council that the post office was charging rates above legal ceiling prices. Next, a woman alleged that she suspected prostitutes were operating in Los Alamos. A man who Weisskopf described as “adept at seeing the connections between things” declared that he “had nothing against prostitution as long as the ceiling prices were kept.” The complaint was later dropped.

But nothing prepared Weisskopf for the ultimate consequence of modern physics—the detonation of atomic bombs in Japan. “For many of us who had hoped that the bomb would be used in a bloodless demonstration…the news was horrifying,” Weisskopf wrote. In a speech, a shaken Oppenheimer urged the international “fraternity of scientists” to cooperate to control nuclear weapons.

For the rest of his career at MIT, Weisskopf put his community-building skills to use by gathering people to fight against the spread of nuclear weapons. He co-founded the Union of Concerned Scientists with MIT physicists and met with Soviet scientists to convince them to join the cause. But while striving for nuclear control, he also kept playing piano. His favorite composer was Mozart. His sense of fun let him live “a happy life in a dreadful century,” as he put it. He showed fellow scientists that even theoretical physicists don’t live in a vacuum.