Van Allen, at 90, Sifting Data, Writing Papers, and Enjoying Icon Status

If physicist James Van Allen wanted to look back over his career, all the way back to his first experimental research as an undergraduate at Iowa Wesleyan College in 1931, the task would be daunting. Although his papers are conveniently gathered at the main library of the University of Iowa, the school where Van Allen earned his physics PhD in 1939, the collection stretches across more than 210 feet of shelf space.

And Van Allen, who was honored by the university in early October on the occasion of his 90th birthday, continues to add to the collection. Five days a week, he goes to his office on the top floor of a building that bears his name and delves into the massive amount of data his Geiger Tube Telescopes gathered on their decades-long journeys through the solar system aboard the Pioneer 10 and 11 spacecraft. The last bit of the data came from Pioneer 10 in February 2003, when NASA finally shut down communications with the small spacecraft. “It was about 80 astronomical units away,” Van Allen said, and detecting its 8-watt signal across more than 11 billion kilometers of space was “terribly demanding. I had the only instrument on board still operating so I had a hard time justifying keeping going. So I didn’t kick on [the decision to abandon the spacecraft].”

Best known for his 1958 discovery of the Van Allen radiation belts surrounding Earth, Van Allen has spent much of his life in his native Iowa, including 53 years on the faculty at the University of Iowa. The Van Allen celebration, which included talks by some of his 80 graduate students, several of whom have already retired, was, in Van Allen’s words, “a delicious occasion.” With his birthday festivities over and the celebration of his 59th wedding anniversary with his wife, Abigail, just past, Van Allen took a deep breath and talked with Physics Today about his research and the changes he’s seen in physics.

PT: For several years you hoped one of the two Pioneer spacecraft would be the first to reach the heliopause, the edge of the Sun’s influence. When the craft were launched in the early 1970s, how far away did scientists believe the heliopause was?

VAN ALLEN: There were some preliminary indications that the heliopause would be at 5 or 6 astronomical units, just beyond the orbit of Jupiter. That was the prevailing expectation at the time we launched Pioneer 10. And it’s sort of been like a rabbit on a racetrack. It’s kept ahead of us all of these years.

PT: That must have significantly changed your thinking about the Sun’s influence in the solar system.

VAN ALLEN: It’s changed my acceptance of theoretical expectations. They [theoretical physicists] are a lot of fun, but you can’t take them too seriously.

PT: You’ve been involved in the US space program since the beginning, yet you’ve written that you don’t favor the manned space program. Why?

VAN ALLEN: I recently wrote an article for Issues in Science and Technology called, “Is Human Space Flight Obsolete?” I compare the history of human space flight with the history of manned ballooning. I have personal knowledge of that going back into the 1930s, when it was being advocated as a revolutionary new technique for doing scientific work with human crews carried aloft by balloons. That soon was recognized as a very poor way to do it, and that expectation faded away. But unmanned balloons remain valuable for scientific work. Manned ballooning has survived only as an adventurous sport.

From the perspective of 2004, I consider that human space flight has had a parallel history and is now best regarded as an adventurous sport, appropriate perhaps to the private sector but not to governmental support. Current human space flight makes minor contributions to scientific knowledge and virtually no contribution to the pervasive role of space technology in modern life. All of [the] great advances in science of the Earth and all of the planetary exploration have been done by unmanned spacecraft.

PT: You wrote several years ago that during your childhood in Iowa, your father read to you and your brothers every day and that your parents encouraged learning. How important was that to you?

VAN ALLEN: Both my father and my mother—my mother had been a schoolteacher before she was married—were fiercely dedicated to learning. The same was true of my grandfather. He was a scholarly type, very devoted to learning, and had a beautiful library and had read everything in it. So it was a family tradition and a very inspiring childhood.

PT: But it was unusual for kids from small, rural towns to go to college back then.

VAN ALLEN: Yes. Out of my high-school graduating class of about 60 kids, only 3 of us went to college.

PT: Your family expected you to attend college?

VAN ALLEN: Oh, it wasn’t even discussed. It was beyond discussion. The understanding was, You are going to college, young man. I had three brothers and that was true of all of us.

PT: Have you seen changes in the types or attitudes of physics students over the decades?

VAN ALLEN: I’ve been retired from the active faculty for 19 years, so I don’t have the kind of contact I once had, but the major change in our department is the number of women. We have 65 graduate students in physics and astronomy and 11 are women. That is a distinct change. It used to be a woman graduate student was rather uncommon. Of the 34 students who earned PhDs under my guidance, only two were women.

The other change is a very large proportion of the graduate students are now foreign students. I think the majority of our graduate-level students are now foreign.

PT: The body of knowledge in physics has increased dramatically during your career. How is that reflected in the work of your students?

VAN ALLEN: Our current PhD theses are far more sophisticated than anything I did when I was a graduate student. But I did almost everything with my own hands, and the current students have a lot of technical support, enormous computer support, and access to the literature and information on the internet. So I don’t know if they are any brighter or harder working, but they have access to enormously greater resources.

PT: Your career spans so many decades, going all the way back to developing proximity fuzes in World War II. How do you identify the landmarks?

VAN ALLEN: I think getting my PhD was the high point of my earlier life. And then I went to the Carnegie Institution in Washington, which was a turning point. I got acquainted with a much larger body of colleagues and associates there. In 1942, I was commissioned as an officer in the naval reserve and … spent 17 months in the South Pacific on combatant ships introducing radio proximity fuzes into effective use in the fleet. Then I founded the high-altitude group at the Applied Physics Lab at Johns Hopkins University using V-2 and Aerobee rockets to study cosmic rays and the upper atmosphere.

The other great break in my life was coming to the University of Iowa in 1951, returning to my alma mater as head of the physics department. Then I had great freedom and felicitous circumstances for pursuing my research interests. It has been a glorious experience. I love to teach. I taught big courses, big undergraduate courses. That was the great pleasure of it. I love to explain things.

PT: At this point in your career, how do you approach your work?

VAN ALLEN: I get up, stretch, and say, By George, I’m at it again.