Farewell to James Van Allen

Posted by jns on August 12, 2006

Physics^* tends to carry around all manner of homages to its creators and discoverers. Vast numbers of units of measure, constants, concepts, equations, effects, principles, and laws are named for famous scientists: Galilean Relativity, Newton’s Laws of Motion, Kepler’s Laws of Planetary Motion, Bernoulli’s Equation, Euler’s Equation, Laplace’s Equation, Boltzmann’s Constant, Planck’s Constant, Hubble’s Constant, the Compton Effect, the Zeeman Effect, Kelvins, Celsius degrees, Curies…. Obviously the list is not strictly endless, but it does go on quite a bit.

I’ve always found it a humanizing influence to acknowledge scientific pioneers this way, and a useful way for students of physics to learn some of its history as they go, which I also think is a good thing. I also find that it helps me remember which equation, constant, or effect is which — just imagine the mental chaos if all our equations and constants were simply numbered!

One thing that virtually all these nominal designations have in common is that the person after whom they are name is dead. There are a few exceptions, of course, for those that are associated with phenomena discovered more recently.

One such was the Van Allen radiation belts around the earth. They had been discovered in 1958 by James Van Allen. Van Allen and his team had built Explorer I, the first satellite launched by the US. The satellite carried only one instrument: a Geiger counter^#. The instrument’s readings led Van Allen to deduce the existence of regions of high-energy charged particles trapped by the Earth’s magnetic field. ^**

I went to college in Iowa (Cornell College, in Mt. Vernon, Iowa) in the late 70s. I knew about the Van Allen Belts, but hadn’t quite caught on to the fact that they had been discovered after I was born (albeit in my extreme youth: I was 2 years old). Thus, I thought of them as named for an historic scientist — if I thought of it at all back then.

Imagine my surprise then when I learned not only that Van Allen was a living, working physicist, but that he was also living and working at the University of Iowa, a mere 30-minute drive south through the corn fields from me! It was probably the only time I would be young enough and naive enough to react to something like that with such profound surprise — I had never imagined something like that! It seemed almost mystical at the time, since I was certainly still in awe of anyone who had something like that named for him. Since then I have met physicists with things named for them and they seemed like … people.^## It’s just as well, though, that I never met James Van Allen since, for me, he had mytical status and I’m sure I would have been embarrassingly tongue-tied.

James Van Allen died this past Thursday, news that seems surprising to me since — in my mind — he is immortal.

Here’s what Bob Park had to say in today’s “What’s New“:

JAMES VAN ALLEN: THE FIRST AMERICAN SPACE HERO, DEAD AT 91.

Almost nothing was known about conditions beyond the ionosphere when the US launched Explorer I on 31 Jan 58. The Cold War was at its peak, and the Soviets seemed to own space. Sputnik I, launched 4 Oct 57, carried no instruments. Sputnik II, a month later, could only send back Geiger counter readings taken when it was in sight of the ground station. In June, however, at a conference in the USSR, James Van Allen, a physics professor at the University of Iowa, announced that Explorer I had discovered the first of the two “Van Allen radiation belts.” Soviet space scientists were crushed; the “space age” was not a year old and already the U.S. had taken the lead in science. Two years ago I visited Prof Van Allen in his office at the U. Iowa. At 89 he was down to a 7-day work week. He showed me an op-ed he was sending to the NY Times in which he described human space flight as “obsolete” http://bobpark.physics.umd.edu/WN04/wn072304.html. I don’t believe they used it. Van Allen said using people to explore space is “a terribly old fashioned idea.”

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^*I’m sure this is true of many other fields, but I’m a physicist, so I’m talking about physics.

^#Named for Hans Geiger, one of its inventors in 1908.

^**Here are two pieces about the radiation belts: one more technical, one less technical; also, an article with lots of pretty pictures — be sure to scroll down past the section “Reading to be Informed Questions” to see them.

^##With maybe one exception (although we didn’t actually meet). The background is this: there was a famous textbook in quantum mechanics written by Eugen Merzbacher that was known to any physics student at the time; not surprisingly, given the familiarity of his name, Merzbacher also had a status that exceeded mere personhood. Once, when I was at a meeting of the American Physical Society, Merzbacher was there: I happened to stand in line next to him at a McDonald’s for breakfast. To this day it fascinates me to have heard someone of such exhalted status say: “I will have an Egg McMuffin, please.”