I was born November 28, 1950 in New York City, the son of Alan and Betty Joan Hulse. My parents tell me that I quickly showed an unusual level of curiosity about the world around me as a child, and that this transformed itself into an interest in science at a very early age. For my part, I certainly recall that science was a defining part of my approach to life for as far back as I can remember. My parents fostered and supported this interest, and I thank them very much for being my first and, by far, most uncritically supportive funding agency. I ran through a seemingly endless series of interests involving chemistry sets, mechanical engineering construction sets, biology dissection kits, butterfly collecting, photography, telescopes, electronics and many other things over the years.
The door to a whole range of new experiences opened for me when my father started building a summer house on land given to us by my Aunt Helen in Cuddebackville, New York, about two hours northwest of the city. Eventually, this became a year-round house for my grandparents when they retired and it is where my parents live now that they are retired. I remember spending weekends and summers helping my father put in place walls, rafters, siding and everything else that goes into a house. Among other things, it produced an early familiarity with tools and a do-it-yourself approach which has stood me in good stead over the years. My parents’ friends and relatives were apparently not too sure that I should have been given such freedom to work with power tools at an early age, but fortunately I came through the experience with all of my fingers intact. Cuddebackville was also important to me as a place where a city kid could see nature, and as a practical place to work on my bigger projects.
My parents not only supported my interests at home but also suffered along with me (and, most likely, much more than me) when some of my first experiences with school proved to be less than positive. Though I had some elementary school teachers with whom I got along well, there were some real problems with others who found me and my intense interest in science difficult to understand and deal with.
Entering the Bronx High School of Science in 1963 was thus very important to me as it was there that I found myself in a school environment which explicitly emphasized what I found most interesting in life. Yet, as in the years before and after, while schoolwork was an important job to be done my interests in science tended to be expressed most clearly by my home projects. My biggest home project while at Bronx Science was building an amateur radio telescope up at my parents’ house in Cuddebackville. I particularly enjoyed building antennas of various types, relying on an amateur radio antenna design book as a guide. The electronics were an odd mix of old television parts, military surplus power supplies, receivers and the like combined with other components I built myself. Unfortunately, the telescope never did work particularly well in terms of detecting radio sources (a little outside technical advice probably would have made a big difference in there somewhere), but I did enjoy myself and I learned a lot in the process.
At the end of high school, I had my first big career decision to make. While I had by then begun to focus more on physics and astronomy amongst the sciences, I also enjoyed designing and building electronic equipment. This lead me to consider electrical engineering as well but, in the end, I decided that a degree in physics was probably the best fit to my interests.
My college choices were limited by the fact that paying for college would have placed an inordinate financial burden on my parents. Fortunately, I was admitted to Cooper Union, a tuition-free college in lower Manhattan. From 1966 to 1970, I lived at home in the Bronx with my parents and commuted to Cooper each day on the New York subway system. Along, with the usual course work, Cooper provided me with my first experience with a new interest, computers. Cooper had an IBM 1620 available for the students to use and, while there were no courses on programming it, there were the instruction manuals. The first project that I selected by way of teaching myself FORTRAN was to use the computer to do orbit simulations, perhaps an early omen of things to come.
After receiving my bachelor’s degree in physics from Cooper Union in 1970, I started graduate school at The University of Massachusetts in Amherst. While I knew that I eventually wanted to do my thesis research in astronomy, preferably radio astronomy, I once again leaned towards a broader background and decided to get my doctorate in physics rather than astronomy. I went to UMass not only because its graduate program offered this type of flexibility, but also because it was located not too far from New York in a rather beautiful part of rural western Massachusetts.
The five years I spent in Amherst are some of those which I remember most clearly from my past. Graduate school was an entirely new environment, with new experiences and challenges. The demands were such that, for the first time, I focused almost exclusively on my academic career, with my other outside interests tempered by the demands of the moment.
After passing my Ph.D. qualifying examinations, I turned to finding a thesis project. This represented at long last a convergence of my outside and career interests, as I finally started working in radio astronomy again, now as a career rather than as a hobby. The rest of that story is told in my Nobel lecture.
After completing my Ph.D. in 1975, I had a post-doctoral appointment at the National Radio Astronomy Observatory in Charlottesville, Virginia from 1975 to 1977. While I still enjoyed doing pulsar radio astronomy, from the moment I arrived at NRAO I was increasingly preoccupied with the lack of long-term career prospects in astronomy. While I had some confidence that I could find another position of some sort after NRAO, it was not at all clear to me when, where, and how I would be able to settle down with some reasonable expectation of stability in my career. I certainly knew of astronomers who had been obliged to roam from place to place for many years and the potential for such repeated major dislocations in my personal life was more than I could quite tolerate. In particular, I had the classic problem of how a two-career couple could stay in reasonable geographical proximity, since my friend, Jeanne Kuhlman, was then doing her graduate work at the University of Pennsylvania. I therefore decided to try falling back on my broader interests and my physics Ph.D., exercising the option which I had left myself when I started at UMass.
While even with this broader view not many good career opportunities seemed available, I did discover from an advertisement in Physics Today that the Princeton University Plasma Physics Laboratory (PPPL) was hiring. Not only did controlled fusion seem an interesting and diverse field, but the lab was located in Princeton, not too far from Jeanne in Philadelphia.
After interviewing at PPPL, I was offered a position with the plasma modeling group, based on my physics and computer background. Starting at the lab in 1977, my first task was developing new computer codes modeling the behavior of impurity ions in the high temperature plasmas of the controlled thermonuclear fusion devices at PPPL. I had never really done computer modeling before and the art and science of computer modeling is one of the most valuable things which I have learned in the 16 years which I have now been at the lab.
The multi-species impurity transport code which ultimately grew out of this initial work at PPPL is still in use to this day. It models the behavior of the different charge states of an impurity element under the combined influences of atomic and transport processes in the plasma. I oriented my development of this code very much towards its practical use by spectroscopists and other experimentalists in interpreting their data and one of my greatest satisfactions has been that this code has become widely used over the years both at PPPL as well as at other fusion laboratories. My own research with this code included determining transport coefficients for impurity ions by modeling spectroscopic observations of their behavior following their injection into the plasma. In connection with modeling impurity behavior, I also worked on investigating the atomic processes themselves, for example, by helping to elucidate the importance of charge exchange reactions between neutral hydrogen and highly charged ions as an important recombination process for impurities in fusion plasmas. In a rather different sort of contribution, I more recently developed a computer data format which has been adopted by the International Atomic Energy Agency as a standard for the compilation and interchange of atomic data for fusion applications.
While I am still involved in supporting this impurity transport modeling code at PPPL, my more active area of work in the past few years has been modeling the transport of electrons in the plasma as revealed by pellet injection experiments. The pellets involved here are pellets of solid hydrogen, injected at high velocity into the plasma. The relaxation of the plasma electron density profile after a pellet has deposited its mass inside the plasma provides an important way of observing plasma transport in action. For this work, I wrote an electron particle transport code which focused on modeling the experimentally observed density profile evolutions using theoretically motivated, highly non-linear forms for the particle diffusion coefficients.
In another recent new direction, I have been working to establish a new effort at PPPL in advanced computer modeling environments. The objective of this research is the development of novel approaches to creating modular computer codes which will make it much easier to develop and apply computer models to an extended range of applications in research, industry and education. I have been pursuing this work in the context of cooperative research and development agreements with an industrial partner, taking advantage of this new type of collaborative arrangement recently made possible between government sponsored research laboratories and the private sector.
By now, it is surely clear that my interest in science has never been so much a matter of pursuing a career per se, but rather an expression of my personal fascination with knowing “How the World Works”, especially as it could be understood directly with hands-on experience. This central motivation has been expressed over the years not only in my career but also in a wide range of hobbies. Notable amongst these “hobbies” have always been interests in various areas of science beyond whatever I was professionally employed in at any given time. For example, I have most recently been considering that much of what I have found so interesting about both the natural and man-made world has involved how individual, often autonomous, elements combine to make a functioning whole, either by design or by self-organization. I have thus started to be interested in various aspects of the new so-called “sciences of complexity”, especially as they can be explored using computer modeling.
My list of more traditional hobbies and recreational activities has also changed over time. Many activities which I formerly enjoyed, such as amateur radio and woodworking, have been eventually dropped simply because I realized that I did not have enough time and energy to pursue everything I might enjoy doing. A current list of my activities would include nature photography, bird watching (and observing the beauty and drama of nature in general), target shooting, listening to music, canoeing, crosscountry skiing, and other outdoor activities.
I do not pretend to be anything like an accomplished expert in all of the many things that I have ever been or am presently involved in doing. My most fundamental urge has always been just to spend time on what I found the most interesting, trying of course to match this up somehow with the more practical demands of life and a career. In this sense I have come to realize that at times I must not have always been the easiest person to have had as a student, or as an employee, and I therefore appreciate the efforts of those who helped me to accommodate myself to these practical demands, or often, who worked to help accommodate the practical demands to me.
I would like to close on the thought that some of the most enjoyable moments of my life have always involved sharing my various interests with those others who understood them (and me) the best. Thus special thanks go to my parents, to Jeanne Kuhlman, and to all of the good friends that I have had over the years.
This autobiography/biography was written at the time of the award and later published in the book series Les Prix Nobel/ Nobel Lectures/The Nobel Prizes. The information is sometimes updated with an addendum submitted by the Laureate.