Jenn Does Science

Audacity of imagination

Month: September, 2014

What Is a Physicist?

Last Friday, I stumbled upon a paper on the arXiv called “Upper-Level Physics Students’ Perception of Physicists,” which investigates the question “what is a physicist?” from the perspective of undergraduate students pursuing a physics major. That evening, I listened while D tried to explain what he’d been doing that week to my mother. Now, my mom is a pretty savvy lady when it comes to what physicists do, but I realized while listening to the conversation that even she had a hard time understanding that the project that D was describing wasn’t even really his ultimate research goal, just a short-term task that, while important, wasn’t particularly interesting to him at the time.

These two things got me thinking about what physicists are and what they do. And how that’s not really the same thing much of the time. The paper asks for students to answer the aforementioned question and then sorted the responses according to four categories on a 2×2 grid. Responses could put either a high or low emphasis on the importance of research to identifying a physicist, and they could focus on internal mastery of physics concepts versus external performance that shows this mastery. The four categories were ranked such that physicists were perceived as anything from natural philosophers akin to Aristotle or Newton (“Physicists Are Researchers Who Answer the Unanswered Questions”) to simply a student who declares a physics major (“Physicists Are People Who Are Committed to Physics”), with varying degrees in between. In my view, it seemed like many engineers would certainly fall under some of these definitions of a physicist.

But that’s a good start. It addresses the important ideas about what it means to be “A Physicist,” versus just someone with an interest in physics. I’m not here to claim I have the answer to that. But it misses something important when discussing what a physicist does: physicists don’t always do physics all the time every day. When I was an undergraduate researcher, the post-docs were fixing some plumbing leak or other and we joked about how “physics” involved an awful lot of not-physics work. And one of the post-docs turned to the other and said, “God, I wonder what it’s like to be a theorist and actually do actual physics, like, all the time?” And then we all went quiet and thought about it for a moment, and then went back to mopping.

But it’s true: experimental physicists are often not physicists. We’re plumbers or electricians or mechanics. I was the resident plumbing “expert” in an old group because I was the only one who got a certain connection to not leak. And that’s what we tend to do on a daily basis. Then, there’s the weekly tasks. They’re actually physics experiments, but often they’re at the level of an advanced undergraduate lab: measure some constant or calibrate some equipment. It’s not at all new or groundbreaking, and no one is going to rise through the ranks, but just like making sure your plumbing connections don’t leak and your electronics don’t short-circuit, they’re necessary to advancing the interesting stuff. Heck, even the theorists, the ones that sit around all day thinking about “pure” science sometimes find themselves being computer programmers more than physicists.

And if someone were to go out for a drink or dinner during one of those weeks and asked “what did you do in the lab this week?” the answer would sound depressing and not very science-y. Or it might sound just science-y enough to be confusing because why aren’t you more excited about doing SCIENCE!? That’s where my mom was with D the other night when he was talking about how boring and uninteresting the task that’s been taking him all week is. She was confused because she thought this was his “thesis research.” And it is, inasmuch as it’s necessary to get to the good stuff on which his thesis will be based.

That’s something that I think it’s important to instill in young, aspiring physicists as much as the equations and concepts: being a physicist doesn’t always mean doing physics. But even the not-physics will ultimately advance knowledge in some, albeit indirect, way.

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The Culture of a Physics Group

One of the most striking things I’ve learned in the past couple of years of post-doctoral work has nothing to do with the lab. I’ve been learning about the cultural differences between different groups, as well as between different disciplines in physics. I spent seven years in graduate school, for most of which I was a research assistant in an atomic physics group. Then, I graduated and started a postdoc in a condensed matter group. And now, I’m back in atomic physics. And one of the major things I noticed was how different the scientific and investigative culture is between atomic and condensed matter. I’ve also had to adjust to specific differences particular to each group.

The first group I worked in was as a graduate student. The group was mostly graduate students with the advisor (a professor at the university) and an occasional handful of postdocs. I joined the group when the senior grad student had been there only for a few years, so we had several years together to bond as a group. We were a bit of a gang. We showed up to events at the department together, usually early so we were the first in line for food. We were generally social and outgoing. When we went to conferences, we were the ones bar-hopping and bringing beer back to someone’s room to play XBOX till the wee hours. And I don’t think it was just the students. When a new professor joined the group, I fielded a phone call from someone looking for my adviser because they were heading out to the bar. It calmed down a bit as certain key instigators left the group, but we always had an outgoing mindset in the group. We went out to lunch in a group (a herd of sorts) every Friday. We tried to institute a tradition in which when someone graduated, they had to go out to the bar after and have a drink for every year they spent in grad school.

After grad school, I slowly lost touch with a lot of the guys who had gotten out before I did. And then I joined another group. A quieter group. Culturally, we went out to lunch maybe once a year, usually to celebrate someone starting or leaving. When we went out to lunch on my first day, the other postdoc told me it was the first time he’d ever seen our boss eat out. We would occasionally go to a happy hour during a conference, but it was lower-key. And generally consisted of one drink each.

In my current position, I haven’t quite figured out the culture. Yes, we have a weekly group lunch, and I’ve already been invited to a social gathering in the first month of living there. But all the other postdocs have young children, so it seems unlikely we’ll be doing boilermakers or shotgunning beers.

Even more intriguing is the fact that atomic physicists and condensed matter physicists seem to approach physics differently. Moving from one to the other and back again showed me that. I spent the last two years in a very device-driven field. Conference talks and conversations tend to be about the current device, how you designed it, how you think you could do better. One group spent a year trying to replicate a particularly good device. Two groups square off against each other when one accuses the other of only showing data from “hero” devices — i.e., those that work the best — and ignoring the rest. While that is the general thrust of the field, to implement the best of a certain type of device, exploration of basic physics concepts seems to take a back seat to the product.

Then, a year and a half into this position, I started writing a proposal to get another postdoc in an atomic physics group. All of a sudden, I’m back to thinking about the Bloch sphere, and abstract concepts in quantum mechanics. It’s no longer just about the stuff you can do with your hands in the lab. The day-to-day involves a lot more conversations about fundamental concepts of quantum physics because that’s something atomic physicists aim to study. But apart from that, there’s a sense that you want to learn more than just what you do daily in the lab. You read papers about anything remotely related to quantum, not just papers about your specific project. It’s an attitude that I like a lot, which is why I returned.

But it was intimidating to realize that I’d have to go back to being as well-versed in the theory as the theorists. And that might give me a hangover more than all those Bud Lights at conferences.