Meet: Dennis Gallagher

Who I Am
I am 46 years old, married with two children: although, they don't think they're children anymore (15 and 18 years old). I received my Ph.D. in Physics at the University of Iowa (UI). UI has a long history of space research lead by Professor James Van Allen, after whom the radiation belts were named. He is still an active researcher in the Physics and Astronomy Department there.

I did my graduate research in natural plasma waves. For example, I studied waves called Auroral Kilometric Radiation. There are called "kilometric" because the length of these radio waves is around one kilometer long. These natural radio waves are kind of exciting, because they are produced above the aurora in the north and south hemispheres with an average power of 10 million Watts.

Graduate school wasn't all research. Many of us built personal computers, in 1977, that ran the CP/M operating system using one of the first Intel microprocessor computer chips, the 8080. At that time the 2MHz processor speed seemed fast. Of course, the 64KB maximum memory size and 10MB hard disk drives also seemed pretty darn good. I even earned a little money selling a program I wrote; the program would take any other machine code program and convert it into assembly language, which you could then modify and recompile into a new running program. After graduate school I came to Huntsville, Alabama. For the first two years I worked for the University of Alabama in Huntsville in the Physics Department. Since that time I have worked for NASA Marshall Space Flight Center in the Space Plasma Physics Branch.

Since coming to Huntsville, I've worked with very low energy particles that are found near the Earth. These particles or low energy plasma greatly influence how energy is moved from one place to another near the Earth and how higher energy particles are lost into the Earth's atmosphere. Charge gas (a plasma) from our high altitude atmosphere is contently flowing away from the Earth, guided by the Earth's magnetic field. Some scientists are beginning to believe that these low energy particles flow in the direction away from the Sun where they are given energy and then drawn back toward the Earth where they cause at least some of the auroral lights we see at high latitudes. All of this happens in a region dominated by the Earth's magnetic field that is called the magnetosphere. The magnetosphere is shaped something like a bullet with a blunt nose pointing toward the Sun and a long tail leading away from the Sun.

What I do now
I am currently working on several exciting projects. One is the IMAGE mission. The Earth's magnetosphere has several populations of plasma, each being different because of its energy and the way it behaves. The IMAGE mission is the first where scientists will take pictures of these plasma populations. In the past we have only been able to make measurements where we could send spacecraft, without actually being able to see what we were studying. In another project I will be using a computer to simulate how cold plasma from the upper atmosphere accumulates near the Earth and interacts with higher energy particles along with electric and magnetic fields.

When we use computers to describe how real things behave in nature, we have the chance to test whether our ideas about how things work compare to what we see nature really doing. When our computer programs fail to look like the real world, we learn where we need to work harder to understand nature and improve our computer programs.

When I was a Child
As long as I can remember I have wanted to know how things worked. For my first 21 years or so I spent most of my effort taking things apart, trying to find out why they didn't work or why they did. I hardly ever got anything back together again! There was a period of time while I was in junior high school where I read lots of short books on subjects like neutrinos and other subatomic particles. I only tried to blow myself up once; only caused a stink once in the house when I burned sulfur in the basement using a chemistry set. That was called the "rotten egg" experiment in the manual for the chemistry set. We won't talk about that brief electrical fire in my college dorm.

The first time I was exposed to physics was as a senior in high school. During the next couple of years, as I took that course and went on to college, all physics and math seemed to easily make sense to me. Of course that ended. For me that was when I took differential equations and quantum mechanics in college. Intuition only goes so far. At some point you have to understand math well enough to depend on it to help you understand how things work. I didn't learn about the existence of "space physics" until after I graduated from college. This was the perfect match for my long background in electronics (by then I'd stopped blowing things up and starting fires), computers (hardware and software) and physics.

I see in reading the biographical sketch of another scientist, on this Web site, that he has been interested in science fiction for many years. That is probably pretty common among scientists and it's certainly true for me. Many of the best hardcore science fiction writers are also physicists. For me, watching or reading science fiction is a kind of challenge. Good science fiction authors take what we know about nature and picture what might follow. They don't really know how to make the things they imagine come true, however it's this kind of creativity that leads to new, real knowledge about nature. Several hundred years ago, a person came to be thought of as a scientist b ecause they were always interested in understanding how things worked. They would mix every day things together, just to find out what would happen. They would notice repeated patterns in the stars overhead at night and connect that to the seasons. By asking the right questions and experimenting, they would learn how things worked and how to use that knowledge to do something new.

You don't have to be a "book learned" scientist to wonder about the things around you. Why does makeup stick to your face, how is rubber elastic, why are there pot-holes in the street, why is it a bad idea to put metal in the microwave oven, or can water heated in solar panels on the roof give you a sun burn? Many questions will seem silly, but that's how we learn. That's why I enjoy what I do.

Personal
I've already told you that I'm married with two kids. I met the lady that became my wife in high school chemistry class and we will have been married 25 years this summer. Guess it's kind of nerdy, but I've never dated anyone else. I didn't get involved in sports while I was in school, so I'm making up for it now. I play racket ball, volleyball, soccer, and softball. I still can't chew gum and dribble a basket ball at the same time; can't win them all. I really enjoy backpacking and canoeing, when I can get out. So do my kids. As they've become older, we have shared many of the same sports.

My Two Cents Worth
I believe that what you do for others is the best you can bring to life; but family and science research are sure close behind!