Professor K. Tabetha Hole '94: Teaching Physics and Studying Stellar Winds
Karen Tabetha Hole (’94) is an Assistant Professor of Physics at Norwich University. She earned her BA in Physics from Oberlin College and an MS and PhD in Astronomy from the University of Wisconsin-Madison. Previously, she was part of the calibration team for the Chandra X-ray Observatory and as worked as a postdoctoral fellow at East Tennessee State University. At Norwich, she splits her time between teaching physics to undergraduate students at all levels, and astrophysics research in supernova ejecta and stellar winds. Dr. Hole talks to Xinyi Zhou (’10) about her Magnet memories, her career trajectory towards a tenure-track faculty position, and her teaching and research.
In college, one of my professors asked if I wanted to work on a project related to radio observations of pulsars, using analysis of their timing and frequency, basically using them as background sources that were being scintillated ("twinkled") by the interstellar medium (ISM) between us and them, to study the ISM.
When was your first research experience?
Tell us a little about your Magnet experience -- what classes and teachers do you remember?
I remember physics, taking that my first semester with Mr. Bunday; as you might guess, that made a lasting impression. I fell in love with astronomy in Earth Science. I remember learning about the phases of the moon, and when it finally clicked for me. From the surface of the earth it's a pretty complicated pattern that changes over 28 days: when the moon rises, when it sets, whether it's crescent -- you can memorize all that. Or, if you can sort of visualize the system as the Sun, Earth, Moon, you can recreate it all from that model. For example, the full moon is on the opposite site of the Sun from us because the lit face is facing the Sun, so of course it’s highest overhead at midnight. When that finally clicked for me – that’s a classic thing I call back to when people ask me why I'm an astronomer or physicist. It's something that on the surface looks really complicated, but if you can switch your view of it, it becomes incredibly simple and elegant.
So when did you decide you wanted to go to grad school/become a professor?
I'd loved physics since I took it with Mr. Bunday. But I also felt like I might not be able to do it. And I also took an astronomy class at the Magnet, decided that I loved that, but again I wasn't sure that I wanted to spend all my life doing math -- or that I would be good enough. But I do remember deciding when I went to college that I was going to try it and see. I've always wanted to understand things so I sort of had in the back in the mind that I wanted to be a teacher or a professor. And I really enjoy teaching; I think that to really work with someone and help them figure out what they need to go from not understanding to understanding, especially something that is hard and deep like physics, that can be a really amazing connection with another person.
At the end of college I didn't go directly to grad school. I worked for a business for a year doing web development and tech support, then I went to work at the Chandra X-ray Observatory. It had just launched, and there I was, surrounded by ~400 people with PhDs and ~900 astronomers total. It was just an amazing place to be, not just in the physics sense but the way people were living their lives and their engagement and desire to do outreach... it just seemed like a community that I would want to be a part of, in addition to wanting to do astronomy. That's when I decided to do grad school. I had decided I wanted to do research and my goal was eventually to find a position in which I would be doing both research and teaching, but the majority of the time would be teaching.
And you made it!
I did. I've been very lucky a couple of times. I mean, I had the freedom and ability to move across the country a couple of times, and that's definitely not available to everybody. But yeah, I have. It's kind of a weird feeling. I'm sure you know this feeling too, where when you've reached something, it doesn’t seem as big a deal as it used to. Back when you were in high school, these college students seem to know so much, and then in college you're like these professors know so much. It's just getting used to it and learning where it comes from.
What do you think is the value of a PhD, and is a PhD valuable for students in your field who aren't interested in academia?
It's a good question. I think there is a value to it, you learn a lot of skills that are very useful. In astronomy, not to mention physics, you learn a whole lot about data processing and analysis including image analysis and computing, rigorousness, and perseverance. But at some level a PhD is job training, so if it's not a job you want it's probably not the most efficient way to get those skills. I don’t mean it’s just for people who want to be professors though; there are a lot of people in industry using the instrumentation skills they learned, or working at NASA.
But the hesitancy comes from me feeling there are a lot of problems with the PhD structure. It emphasizes self-sacrifice, and it makes you very dependent on a few people. Those people have not been selected for their ability to mentor -- the way you get that job is by publishing and maybe some teaching. But you don't get the job by showing that you're good at mentoring a young person. There are great advisors, I don't want to say that there aren't, but if you don't actively select for people who can handle a 25 year old when their experiment isn't working and they're not sure whether they'll get funding next semester, then you don’t necessarily get people who can help them handle it. I think there's greater recognition of that now, and there are people who are really trying to build out support so there are other people [besides the advisor] who can give the student feedback and advice. But it's still... I have now sent a couple of my undergrad students to grad school, very good students, one who got an NSF-GRFP fellowship... and he had a really toxic mentoring relationship with his advisor, and ended up having to switch labs. It shouldn't have to be a significant risk of going to grad school, that you might end up with a toxic advisor that materially affects your mental health and your career.
But still, grad school is an amazing opportunity. It's hard not to think of it as one of those luxury problems. I was getting paid to go to grad school and do research, which was my dream. It’s hard to complain about that. It's such a contradiction because in many ways it's the best thing in the world. And in other ways, it's really hard.
Could you talk about your teaching at Norwich?
This is my fourth year here so I teach a combo of service courses and upper level major courses. I continually enjoy teaching the intro sequence, it always has challenges. I think the ideas in the first year of physics can change the way we think about the world and allow us distinguish between sci fi and sci fact, and it's a way to hook students who are smart to think more deeply about the world.
I've also taught an upper level electricity and magnetism class, which I think is one of the hardest classes that physics students take in undergrad. It's a transition further away from your intuition, and understanding this elegant interplay between the math and the physics and how you can solve problems using tools that are really surprising. For example, it turns out that there is this thing [in electromagnetism] called the Uniqueness Theorem. If you find one solution that works for the equations, it has to be the solution, because there can't be two different solutions. And if it gives the right values at the boundary conditions it's the one right solution. So you can just make up charges and put them in various places – as long as it works, it’s right. So much of training as a scientist is learning to be willing to put aside what you thought was true when it's confronted with [experimental evidence]. And that's not something that humans do easily. Things like time not being universal -- that's a thing we have measured and that is as true as the fact that gravity is going to pull you down. That's mind blowing to students, but that also takes them to another level of understanding of the process of science.
What's your research on?
Unlike Magnet students, a lot of people don't get exposed to science when they're young. They don't think of science as a potential future, they think of science as thing that's done by some alien group of people in a lab somewhere. And I don't think of science that way; I think of it as something that's all around us. When I watch a leaf fall, I'm thinking about the shape and aerodynamics. When I'm walking around the house and I see a rainbow on the wall, I'm looking for what refraction causes that.
Young kids are still looking at the world with less of a filter than we get as we get older. I think by the time you're an adult a lot of your thinking… if you want to talk about “thinking fast and thinking slow,” the fast thinking is heuristic thinking, and it runs along the shortcuts that almost always work, but it doesn't let you always see things and think about them as deeply. Adults tend to do [heuristic thinking]. There's this whole field of pedagogy of physics, and as a physics professor I believe in demos and I love them, but there's research that demos can actually do harm to learning. If you are going to use demos, you have to make students predict what they expect will happen first, because otherwise students who see demos actually do worse than those that don't! They literally remember what they expected to see, not what they saw, unless you force them at that moment to see that’s not what happened.
But kids are different -- they are still building those heuristics. Getting them excited about something, like showing them that they can see Jupiter's moons through the telescope, and to see what's possible, before they get the idea that science is boring or math is hard, before they get the idea of what a scientist is from somewhere else... I love doing that.
You've done a lot of science outreach work -- could you talk a little about that?
My thesis research was on modelling supernovas, or actually their ejecta -- what the structure of the stuff that supernovas throw out into space is like. I've done a little bit of that recently but most of my recent work has been on stellar winds. Partly looking at X-ray observations of some binary stars, looking to try and see if we can characterize the winds. And with theoretical modelling, trying to understand the charged particles that are coming off the star. These stars are so bright that the light from them at the surface is enough to accelerate the particles out into the space. Massive stars lose a significant amount of mass over their lifetime; depending on who you ask, the most massive stars can lose half their mass to this process. We want to understand what they're doing and how they lose the mass at what rate.
Dr. Hole's Publications
R. Ignace, Z. Damrau, K. T. Hole, and W. L. Waldron, Variability in X-ray line ratios in helium-like ions of massive stars: The wind-driven case (Astronomy & Astrophysics 2019)
M.F. Corcoran, et al., Variability in X-ray line ratios in helium-like ions of massive stars: the radiation-driven case (The Astrophysical Journal 2015)
K. T. Hole and R. Ignace, Variability in X-ray line ratios in helium-like ions of massive stars: the radiation-driven case (Astronomy & Astrophysics 2012)
K. T. Hole, D. Kasen, and K. H. Nordsieck, Spectropolarimetric Signatures of Clumpy Supernova Ejecta (The Astrophysical Journal 2010)
K. Tabetha Hole, et al., WIYN Open Cluster Study. XXIV. Stellar Radial-Velocity Measurements in NGC 6819 (The Astronomical Journal 2009)