Featured Scientist - Catherine "Cat" James
From the Fall 1997 sciencelines
Cat, thanks for agreeing to participate in this interview. Please tell us about your position here at Fermilab.
I am an associate scientist at Fermilab, working as an experimental physicist, and have been here as a postdoc for six years previous to this position. The associate scientist position is analogous to an assistant professor position at a university and the postdoc is a standard "apprenticeship" one does in this field after your doctorate. The university analogy translates for tenure as well; my position is not a permanent position until after six years and a tenure review. I've been at the Lab even longer, though; I began here in 1982 as a graduate student.
I was at the University of Minnesota in Minneapolis, but I was the only student there on what became my thesis experiment. The facts of life in high-energy physics are that there are only a few places in the world where you can do this kind of science . . . at an accelerator laboratory, and that's where your experiment is, not on a university campus. You do have a choice once your experimental data is on tape; you can take all those tapes back to your university and do your analysis there, but all experiments are a collaborative effort. You are not doing the analysis alone, and you will get through school faster if you work with those other people on your experiment. It is usually best then to live where the people you collaborate with are.
I moved here after I passed the prelim exams. These prelim exams are a "filter" in graduate school. You are not officially a Ph.D. candidate until you have passed these exams, no matter what classes you have taken or what grades you received. The exams are generally designed to filter out about 50 percent of the students in the graduate physics programs. I failed these exams the first time around. Graduate schools usually give you two chances. I was a B student from a small liberal arts college. I had to work hard to pass those exams. To me, it only proves the point that you don't have to be brilliant to get where I am. Hard work counts too.
Please tell us about the project you are working on now.
I work on a very small high-energy physics collaboration measuring CP (charged parity) violations. The collaboration consists of no more than 30 experimenters including all the students, postdocs and professors. The experiment is designed to produce and detect billions of a particular kind of particle and their anti-particle. Then we sift through them using computers, looking for a special sort of deviant behavior that indicates this CP violation. The effect is expected to be small, and we may not have the statistics to see it all . . . we don't know yet. This has not been an easy experiment; we had to build new detectors that could take high rates of charge passing through them. That costs money. But, in comparison to other high-energy physics experiments, the cost as well as size of the collaboration was small scale. (For more information on CP violation, refer to the 1963 Nobel Prize awards in physics - Cronin and Fitch.)
Why are certain experiments chosen?
Well, in high-energy physics theorists make predictions based on prior experiments and comparison to the current models of how the universe works. The current model has been working so well and for so long now, we call it the Standard Model. But there are various gaps in this model that cannot be filled in purely by working out the math. There are several options, not all consistent. So often the motivation for doing an experiment is to look for a certain prediction or set of predictions. If you don't see the predicted effect, then that tells the model makers to make adjustments. Any experiment can be done to check that. And on and on. Not all predictions can be checked, however, because the effect may be beyond our tehcnology to measure. But that is, in part, what drives people to be clever and inventive. So theory drives experiments, and experiments drive theory.
What factors influenced you to go into a science career?
I was always interested in science, and had parents who instilled a belief that we can become whatever we really want to be. There are not many women in physics, and I think that is due to society at large still holding views about what tasks are for women and what tasks are for men. We are seeing this change of course, but it takes more than a generation. The beliefs of one's parents can have a strong effect. Parents tend to steer their children towards what is familiar to them, mostly unintentionally. Among some women scientists here at Fermilab, we've had an informal poll asking how many of us had a parent in a scientific or technical field. The rate was over 75 percent. And I'm one of those. My father has a doctorate in physics. At the time it was called nuclear physics, but his first postdoc was building a cyclotron at the University of British Columbia. That's early high-energy physics. Then he went to Bell Labs and worked as an engineer. But I never knew, and never asked about those details of his postdoc work until I was in graduate school.
My mother is an art historian and I am also very influenced by her family background. The women in her family began going to college back as far as the Civil War. They mostly attended Oberlin College in Ohio, since that is where that part of my family settled (moved there from New England around 1815). There is consequently a strong family connection with Oberlin College.
Where did you go to college and what were the things you remember most about it?
I went to Grinnell College in Iowa. It is a small liberal arts college, like Oberlin. There are many of these and they're all very good schools. I decided to do physics within my freshman year.
This decision was based back in high school. By the time I got to high school, I think I knew I wanted to do science. I began high school with biology. Even back then, I felt it was too much memorization and not enough of really figuring out how things work. Then I took chemistry and that was more interesting; now we were starting to figure out how things work. Then I took physics and it was really interesting. It was obvious that physics told you how chemistry works and chemistry told you how many things in biology work. And I was attracted to understanding how the world worked.
I took introductory physics my first year in college and just stuck with it. In Grinnell a lot of students take introductory physics, but the people who sign up for the next level of physics, class size goes down to a dozen. The physics professors know that pool will become most of the physics majors. So, one day one of the physics professors was walking down the hall with a camera looking to take pictures of students who were the physics majors to post on the department bulletin board, and he asked me, "So you're going to declare a physics major, right?" And I said yeah, and got my picture added to the board. After a few weeks I got around to declaring physics as my major. Such are life-defining decisions made.
What was high school like for you?
I liked my high school physics teacher. He was not a scientist, but he did a good job of teaching high school physics. He taught us a basic strategy for solving typical introductory physics problems that helped me, at least, from feeling like it was some mysterious process only the smartest kids could comprehend (like, Step 1: draw a picture, Step 2: list the known and unknown quantities). He was a volunteer fireman and a lot of the physics problems were illustrated from his experiences, some very memorable, as a volunteer fireman.
One really good one was when a supermarket alarm system went off. The firemen arrived, right, and they don't see any flames. They don't really even see any smoke. So, they were about ready to open the doors when someone stopped them. He had noticed the bulletins on the inside of the windows had scorched edges. What became apparent was that there was a very slow-burning fire somewhere. The building was very well sealed, and the fire had used up a lot of the oxygen in the building. If they had opened up the doors, the whole place would have exploded! So they backed everything away from the building. They got this mortar and fired a shell to poke a hole into the roof of the building. The whole roof was lifted up in the air by the ensuing burst of oxygen-fed flame. So, a physics homework question that week was to calculate how much force was needed to lift the concrete roof up 50 feet. It was a real-life problem! He was really enthusiastic! That was Mr. Mitchell, my high school teacher in Rumson, New Jersey.
Did anything make science memorable for you when you were younger?
It is hard to make definite statements along these lines. Doesn't everything in one's childhood lead in one way or another to the person you grow up to be? My dad was the scientist, but his hobbies were not that influential on me. My grandfather, on the other hand, who was also an engineer, let us play around in his workshop - building stuff - taught me how to use tools. We moved to New Jersey from Maryland when I was in 7th grade, and I wanted to take wood shop like I had in the Maryland school. The New Jersey school was still in the old mode: boys took wood shop, girls took home economics. But my mom had already taught me to sew (and I still sew today), so I argued that home ec. wasn't going to teach me anything new. I lost the argument, of course. It was my first run-in with that sort of attitude, frankly, and given my age then, and in that time period (early seventies), it just radicalized my views towards "women's lib." Fortunately I had a mother who agreed with my point of view (my father was a bit oblivious to all of this I think.) This is not an example of making science part of my childhood, but learning to refuse to be pigeon-holed and standing up for what one wants to do. That is still an important lesson. But the lesson would never have taken place without backup from my family.
In the 60's when my dad worked for a subsidiary of Bell Labs whicH did contract work for NASA, we would get to go to the rocket launches on Cape Canaveral. The Saturn V launches were amazing! We also got to observe tests of the various proposed moon rover vehicles held in lava fields outside Flagstaff, AZ. This is where I see a large contribution during my childhood from science. We got to see and do neat stuff, and it's because of what my dad did for his career. I also have an uncle who is a geology professor, and who would tell us about fossil-hunting locations (a hobby I still enjoy, although I don't get to do it very often). That along with more typical activities like going to natural history museums and zoos, and participating in activities (classes, workshops) held at those places. I think this exposure was importan; I take my kids to the zoo and the aquarium and the museums (including the art museums) as often as I can. And they love it.
What do you see in your future?
I hope I can keep doing basic research at Fermilab. I recently joined an experiment which will try to measure if particles called neutrinos have mass. This is done in an indirect way which entails sending a beam of neutrinos from Fermilab, under Wisconsin, to a detector in an iron mine in northern Minnesota. If the numbers of the types of neutrinos detected at each end are different, it is evidence for neutrinos having mass. This has implications for understanding how the universe has evolved, as well as helping refine the Standard Model. I also enjoy making contributions to education. The Lab is not a university, so I don't teach. But I can do things like the Phriendly Physics workshop. I am also involved in making improvements to the "tourist" displays at the Lab. I think it is important for scientists to explain to the general public what they do, without jargon, and without "talking down" to them. Most people find science interesting even if they decide not be become scientists, and we have a responsibility to keep science interesting and accessible.