The Space Around Our Planet
One of Dartmouth's most impressive research centers is the Radiophysics Laboratory, which is interested in
NATHAN SMITH HALL, an "Old World institute" type of building that has stood inconspicuously just north of the Wilder Physics Laboratory since 1908, has new Space Age tenants. Since 1964 this former outpost of the Medical School has been home to a cluster of radiophysicists and their graduate students and staff assistants who comprise the Dartmouth Radiophysics Laboratory.
In this ancient building, some of the most exciting research and teaching at the College is. going on. The Laboratory's director, Prof. Millett G. Morgan, and his colleagues, Profs. Leif Owren, Thomas Laaspere, Bengt U.ö. Sonnerup, and John Strohbehn, eight graduate students, and a staff of nine, are investigating the space that surrounds our planet. Simultaneously, these five faculty members are teaching courses at both the undergraduate and graduate level in the curricula of the Thayer School of Engineering and the Departments of Engineering Sciences and of Physics and Astronomy.
How did a Radiophysics Laboratory come into being at Dartmouth and how is it relevant to the aims of liberal education? To understand is to comprehend many of the forces that are shaping higher education today and to know something of how the national interest and academic pursuits can blend.
It began when Professor Morgan returned to his native Hanover in 1947 as a young assistant professor at the Thayer School. He had a Cornell B.A. with honors in physics and a Stanford Ph.D. in electrical engineering. Professor Morgan is one of those rare "Hanoverians" who have returned to their home town to join the College faculty. Another choice which he made soon after that one has had a profound effect on his career. As he explains it:
"Because so many scientific organizations compete for the attention of the young man in science, he must decide to ignore them all, pay lip-service to several, or become seriously involved with one. I felt that there were mutual benefits to the last course and began to participate in URSI, the International Scientific Radio Union."
As a consequence, in 1952 he was appointed by the National Academy of Sciences to the United States Delegation to a General Assembly of URSI to be held in Sydney, Australia. In those days before generous government and foundation travel grants, he sought and received support from a variety of sources to attend this triennial meeting of URSI which had never before been held outside of Europe or the United States. But it was not enough for the long trip. Finally, the late Luther S. Oakes '99, a Thayer School Overseer, offered to underwrite the remaining expenses for the trip. Professor Morgan says, "As it turned out, it wasn't necessary to accept Mr. Oakes's offer, but for me it was a wonderful vote of confidence from a wonderful man."
At the meetings Professor Morgan heard a paper describing the work of a young Cambridge University graduate student on naturally occurring, very-low-frequency radio signals which were believed to be caused by lightning. The author, L. R. O. Storey, theorized that these remarkable low-frequency signals, descriptively called "whistlers," follow the lines of magnetic force and bounce back and forth between the northern and southern hemispheres along these lines.
Storey's work touched off a spate of investigations into whistlers and related ionosphere physics by Professor Morgan and others. The International Geophysical Year of 1957-58 (the IGY) was ideally suited to the study of this global phenomenon and gave it great impetus in preparation for the exciting breakthroughs by direct measurements in space which are now being made.
Professor Morgan became chairman of the United States IGY Committee's Panel on lonospheric Physics which allocated $l3 million of the special funds appropriated by the Congress for the IGY program. He headed "Whistlers-East," a program in which Dartmouth observed the occurrence of "whistlers" at 14 stations in an Arctic to Antarctic chain along the W 70° meridian.
The Thayer School soon bulged with radio-tape recordings of these phenomena, and other investigators became involved. One of these was Thomas Laaspere, a native of Estonia who had come to the University of Vermont as a "displaced person," was graduated cum laude in electrical engineering, and had gone on to earn a Ph.D. at Cornell in 1960. Professor Laaspere, coming to Dartmouth in 1961, began teaching courses in electronics, electromagnetic theory and radiowave propagation in the ionosphere and has collaborated closely with Professor Morgan in much of his research.
Together they worked to prepare an experiment that went aboard the first polar-orbiting OGO (Orbiting Geophysical Observatory) in 1965 to observe whistlers above the ionosphere while simultaneously observing them on the ground.
"We've collected a frightful amount of data," Professor Morgan says, and he and Professor Laaspere and their associates and students are analyzing it, preparing articles for publication and readying new experiments - for example, for OGO-F which will be launched next year.
While this was going on, the Thayer School organized its programs into separate professional and research tracks leading to the Doctor of Engineering and Ph.D. degrees respectively, and the Physics Department had its proposal for doctoral work approved. These graduate programs spelled expansion of staff and facilities for this viable group. Space in the Thayer School's Cummings Hall was growing scarce just when the radiophysicists' work was demanding more room.
Dean Myron Tribus first suggested that one wing or one floor at Cummings be set aside for the radiophysicists, but Professor Morgan got his eye on Nathan Smith Hall which had stood idle since the Medical School was "refounded" at a new site. He saw great potential in the solidly constructed old building and especial attraction in a site close to the Physics Department. He procured a grant from the National Science Foundation to renovate and remodel the old building and Dean Tribus supplied the necessary "matching funds" from the $1 million grant which he had obtained from the Sloan Foundation. Together, these amounted to $97,000.
By moving into Nathan Smith, the Radiophysicists made a considerable block of urgently needed space available in Cummings Hall but, much more importantly, demonstrated far greater strengths than had been apparent while they were spread from attic to basement of Cummings. Still firmly a part of the Thayer School and the Department of Engineering Sciences, they serve by virtue of their interests and their location as a true bridge between physics and engineering at Dartmouth.
The work of the Radiophysics Laboratory has brought considerable prestige to the College and the Thayer School. Among other things, it resulted in the United States National Committee of the International Scientific Radio Union, of which Professor Morgan is chairman, holding its annual fall scientific meetings at Dartmouth in 1965. About 400 radiophysicists attended and 90 scientific papers were presented.
Soon these exciting activities at Dartmouth began to attract other radiophysicists. In late 1964 Prof. Leif Owren joined the faculty. He had studied and worked in his native Norway's Institute of Astrophysics, at Cornell where he earned his Ph.D., and at the University of Alaska. He began teaching mathematical physics and radio astronomy and pursuing his research on the effects of solar particle streams, especially in the lower ionosphere near the geomagnetic poles.
He has been working with the Russians in Antarctica, and with the Danes in Greenland, to carry out observations of these phenomena. His work is supported by the Office of Antarctic Programs of the National Science Foundation and is an example of the international cooperation that was spurred by the International Geophysical Year.
"One great handicap of the radiophysicist," Professor Owren explained recently, "is that he can't simulate these phenomena in a laboratory under controlled conditions. We can assume that many of the phenomena are a thousand times more intense beyond the ionosphere but the data are extremely hard to get."
The ionosphere, fortunately for man, captures much of the potentially harmful radiation from space. But, unfortunately for the radiophysicist, it also obscures the phenomena that occur above it and within it.
"It's like watching the sun through a fog or at twilight," Professor Owren explained. "It appears red because the atmosphere scatters and filters out the short-wave light, violets and blues, while the long-wave light waves, the reds, penetrate."
In order to study the effects of solar particle streams upon the farthest reaches of the earth's atmosphere, another of the Laboratory's faculty members, Associate Professor Bengt U. ö. Sonnerup, is analyzing data taken with spacecraft which cross the thin boundary region 50,000 miles or so from the earth that separates the terrestrial magnetosphere from interplanetary solar system space.
Professor Sonnerup is a native of Sweden. His special interest in "Magnetoplasmas" was turned to the magnetosphere by Prof. Thomas Gold at Cornell. Leaving Cornell in 1962, he returned to Sweden to work on the outer boundary region between the earth's magnetic field and the solar wind with Prof. Hannes Alfven at the Royal Technical Institute in Stockholm. In this "far-out" region, some 10 to 12 earth radii from the earth, the ionized gases of the "solar wind" encounter the geomagnetic field and shock waves are set up.
Professor Sonnerup, mechanical engineer turned solar system theoretician, came to the Laboratory in 1964 where his research is supported by National Aeronautics and Space Administration grants. He teaches courses in electromagnetic theory, fluid mechanics, and solar-system physics.
The work of the fifth faculty member in the Radiophysics Laboratory, Assistant Professor John W. Strohbehn, is, if you'll pardon the expression, more "down to earth." His principal research interests lie in the non-ionized atmosphere and the propagation of radiowaves through it, and in the application of communication theory to the reduction of geophysical data. This young Stanford Ph.D. is currently on leave as a visiting scientist at the Institute of Atmospheric Physics in Moscow on the exchange program of the U. S.-USSR Academies of Sciences. In Moscow he is working with two world leaders in his field, Professors V. I. Tatarski and A. M. Obukhov. Professor Strohbehn has just published in the December issue of the Journal of Geophysical Research a very interesting paper entitled: "The feasibility of laser experiments for measuring atmospheric turbulence parameters."
Looking ahead, Professor Morgan foresees a modest but steady growth of the facilities, students, and staff of the Laboratory. He expects participating faculty to increase to about eight and their graduate students to about 24. This, together with the steadily growing requirements for space in which to store data obtained with orbiting spacecraft, will require an expansion of facilities.
The Laboratory's annual research budget is currently about $365,000 and derives mainly from NASA, the National Science Foundation, and the Air Force.
This, then, is an outline of the Radiophysics Laboratory's origins and development and its contributions to man's understanding of the phenomena which exist above the solid earth. How that understanding is growing is illustrated by the following encounter:
When interviewed for this article, Professor Sonnerup was poring over a massive computer printout of statistical data from an Explorer satellite. At his elbow was a slide rule, and the visitor, who some 25 years ago had taken some small pride in knowing how to use a couple of slide-rule scales, asked jokingly if Professor Sonnerup used his rule to double-check the computer calculations. The quick reply was:
"No, but it comes in handy when I want to draw a straight line!"
Radiophysics Laboratory director, Prof. Millett G. Morgan (left), confers with hiscolleague, Prof. Thomas Laaspere, who teaches courses in radiowave propagation.
Prof. Leif Owren (left), who is researching the effects of solar particle streams, shownwith Prof. Bengt Sonnerup, who has been analyzing spacecraft data.
