Public Thinker: Chanda Prescod-Weinstein on Dark Matter and White Empiricism

Thinking in public demands knowledge, eloquence, and courage. In this interview series, we hear from public scholars about how they found their path and how they communicate to a wide audience.
Dr. Chanda Prescod-Weinstein is one of fewer than a hundred Black American women ...

Dr. Chanda Prescod-Weinstein is one of fewer than a hundred Black American women to earn a PhD from a department of physics. Being part of an all too rare group has given her a glimpse into the way the world of physics works—through not just equations and experiments but also human social interactions. The child of grassroots political organizers, Prescod-Weinstein is a theoretical physicist and a self-taught Black feminist philosopher and scholar of science, technology, and society studies. She is also vocal about social problems within science and the way science contributes to problems in the larger world. I caught up with Dr. Chanda, as she is known to many on Twitter (@IBJIYONGI), via Skype, and what follows is a discussion that goes from dark matter to how whiteness operates in physics.

Lawrence Ware (LW): Can I ask you to explain to me, almost like I’m an eight-year-old, what you do?


Chanda Prescod-Weinstein (CP): I think about the origin of spacetime and the origin of everything inside of spacetime. It’s the question of how we get from the beginning of the universe to us sitting in the rooms that we are sitting in now. How do we get from point A to point B? And does the universe even have a beginning? What happened at the very beginning?


LW: But I am still very confused about what you do. Help me understand.


CP: I just do math all day.


LW: You do?


CP: That’s actually the meat of my work. I’m what you call a pen-and-paper theorist. On every desk that I have, I have a ream of blank white paper and several pens, and I do math all day.


LW: How do you bring your interest in race and gender into conversation with what you do with physics, then?


CP: When I was 10 years old, I began getting really excited about theoretical physics. And I was really excited about doing theoretical physics specifically because I thought it would get me away from human problems. My parents were both activists; I spent my entire childhood hearing about the ways the world is messed up. I think I saw theoretical physics as an exit from having to worry about the human condition.

Then, when I was in high school, I became aware that I might stand out in my classes, because my background was a little bit different from that of the typical physicist. I was aware that there weren’t a lot of Black women in physics. I had never heard of one. This generation might have a very different experience now, because of Hidden Figures, but there was nothing like that when I was in high school.

So I thought I would just stand out, but I didn’t really think much of it. I had no intention to go into college thinking about race or gender or anything like that. And then I started experiencing racism and sexism in physics environments and started trying to make sense of it. That was how it started to come together.


16 Books and Movies That Make You Want...

By Jenn Stroud Rossmann

LW: You got into theoretical physics when you were 10 years old?


CP: Yeah.


LW: How did that happen?


CP: I had been pretty obsessive about things like my times tables and long division all through elementary school. So my mom knew that I liked math.

Then, when I was in fifth grade, when I was 10, we started doing some physical science in school. I got really obsessed with things like photosynthesis, how plants use light and convert it to energy. Then we learned about how planes fly: how we have to balance the pressure under and over the wing so that planes can take off and stay up in the air.

By now, my mom had picked up on the fact that I was really into this stuff. She heard that there was this documentary by Errol Morris called A Brief History of Time, about a scientist named Stephen Hawking. She drove us all the way from East LA to West LA at 10:00 in the morning—because all she could afford was a matinee—and just said, “We’re going to see this documentary.” As a 10-year-old, I was totally horrified by this, because documentaries were boring. That was my take on things.

And I whined the whole way there, I whined the whole way in, and then halfway through the movie, Stephen Hawking is talking about the singularity at the center of a black hole: our current physical theories have no capacity to describe spacetime at the center of a black hole. Even Einstein hadn’t been able to figure it out.

In that moment, I put together that this guy was getting paid to figure out things that Einstein hadn’t figured out. I thought: You can get paid to do this? That was it for me. I walked out of the theater and just said, “Mom, you have to find me his book, you have to find me his book.”


LW: And so you started reading his book?


CP: My mom actually refused to get the book for me, because she thought I would get intimidated and then lose my interest. So my uncle went behind her back and bought it for me for my 11th birthday. I started reading the book. I found [Hawking’s] e-mail address on the internet very early on.


LW: Did you e-mail?


CP: I sent an e-mail to him and said, “How do you become a theoretical physicist?” And one of his graduate students replied and explained it.


LW: Wow.


CP: Yes.


LW: So you go from an 11-year-old Chanda who is interested in it, and then you go to college, then graduate school. Well, what was your experience of being a Black woman in the world of physics then, as you entered into the mature world of physics?


CP: Even my first week of college, I experienced … I had dreadlocks when I started college.


LW: Okay.


CP: Everybody was already talking about what they wanted to major in and stuff. I knew I was going to do physics, maybe a joint major with astrophysics. People would say, “What are you majoring in?” And I would say, “Oh, I’m going to do physics,” and people would say, “You don’t look like a physicist.”


LW: So implicit in that is that a physicist is a white male?


CP: A white guy, or at least like a white woman with straight hair. I heard this from women and from men.


LW: How did it feel hearing that from women?


CP: The worst part about hearing it from women was that I would ask, “Why would you say that to me? I think you’re saying it because of my race.”


LW: Right.


CP: People would say, “Oh, I think it’s just because you dress really well or differently.” And I would say, “I go to class in my pajamas like a lot of other students.”


LW: Right, right.


CP: It was a really early lesson in how gaslighting works. When you are trying to talk to people about microaggressions and racism, people will totally deny it.


Toxic Masculine Cosmology

By Chanda Prescod-Weinstein

LW: So now you’re in this world. You said that you dealt with racism, you dealt with sexism. Talk to me about what that experience was like.


CP: The list of things that I’ve had to deal with is so lengthy; at the same time, I’m so aware of the ways I had an easier path than a lot of other people. My grandmother likes to say about things that she is shocked but not surprised.


LW: That’s good.


CP: I am definitely moving into the mood of, when I now see something messed up happen, I think it’s shocking but not surprising. But I have to say that I spent a lot of my career being surprised at how awful people are, and also how thoughtless and insensitive people are.

Even when I got engaged to my ex-wife, I had professors in my graduate program who said, “Oh, so are you saying you don’t like men? Are you sure you don’t like men?” Why am I having this conversation with a professor? This is weird and creepy.


LW: Right.


CP: There are a lot of people who just never engage in proper adulting. It’s just totally lost on me; I don’t feel that I have the option to act like a child in professional environments. But I find that a lot of other physicists need to feel like they can, or they don’t understand that their behavior is what I would call childish.


LW: It sounds like you are advocating for a distance between any kind of personal talk and professional life.


CP: It’s complicated, right? Now that I have a graduate student, I don’t even ask him questions about his personal life. And yet, as a professor, a graduate student is part of your life for several years. Also, students have crises, and you are often the closest adult in their life.


LW: Right.


CP: I’m not saying students shouldn’t come to you. But I definitely think that you always have to be aware of the power dynamics that are in the room with you: you, as the professor, are the person who has more power. So if you are asking questions, they may not feel like they have the option of telling you, “I don’t want to answer that question.” You need to create a situation where they feel safe coming to you.

LW: You’ve thought a lot about how to do science, and now you are writing a book, right? So please explain to me what you are up to with this book.


CP: It’s probably going to be called “The Disordered Cosmos.” The book is going to be about my science and also about the context in which my science happens.

I’m also going to be writing about dark matter, because dark matter is probably the area of scientific research that I am best known for professionally. I actually was given a nickname by journalist Ryan F. Mandelbaum: the axion wrangler.


LW: I don’t know what that means, but keep going.


CP: I’m an expert on a hypothetical particle called the axion. This axion might be the particle that explains dark matter. It could compose all of the dark matter.


LW: So it is a hypothetical particle? It doesn’t exist? Are you an expert in stuff that exists or stuff that doesn’t exist?


CP: That’s an interesting question. My job is as a theoretical physicist. So I’m not someone who collects data, right?


LW: Wait, wait, wait, you don’t collect data?


CP: No. I don’t collect data out in the world. I collect data in my mind.


LW: Keep going, keep going, I’m listening.


CP: My job is real, okay?


LW: I know it’s real, I just don’t know what you study.


CP: So I study theoretical stuff. My task is looking at problems that exist in the data. Perhaps we’re not able to explain the data, or there are things about the data that don’t quite make sense to us.

With dark matter, for example, the real issue is that when we take measurements of how much mass there is in a galaxy—how many stars there are, how many particles, how much mass there is in those stars, et cetera—and then we take measurements of how fast those stars are moving, there is a discrepancy. That is, the speed at which the stars are moving should tell you something about how much mass there is in the stars, and how much light the stars are emitting should also tell you about how much mass there is in the stars. But when we measure those two things and pair them up, they don’t actually match. In fact, what these measurements show is that there is “too much” mass. What’s left over, that missing remainder, that’s what we call dark matter.

This was a problem that people started thinking about in the late 19th century. But it wasn’t until Vera Rubin came along in the ’60s that the field became what it is today. She thought of a way to actually show that there was this mismatch. That was when people started taking the dark matter problem very seriously as a substantive problem in astrophysics.

What we call dark matter is actually transparent or clear matter. It’s something that does not interact with light. Light goes right through it. So as far as we know—and we hope this isn’t true—it only seems to interact gravitationally.

My task as a theoretical physicist is to try to explain what this dark matter is made of. What are the properties of the dark matter? If we can write down properties of the electron—which we know is real—what are the analogous properties for the dark matter particle?

I just think that the standard model of particle physics is fun, so I want to communicate to people why I think it’s fun. And at the same time, I wanted to talk about problems with the way physics works as a community. For example, sometimes physicists give things problematic names.


LW: What’s wrong with the names?


CP: Well, for example, there’s a whole area of physics that sometimes gets referred to in textbooks as “colored physics” or “colored dynamics.”


LW: Shut up, are you serious?


CP: Yes. Or a “colored charge.”


LW: Oh my.


CP: It’s a theory of the elementary particles that make up other particles, like the neutron and the proton. These constituent particles are called quarks, and quarks are described by a theory called quantum chromodynamics. In quantum chromodynamics, quarks can have these different color charges, or “colored charges,” as they are sometimes called.

People came up with this terminology in the ’60s. It is interesting that it happened in the ’60s, given what was happening in the United States, and that the name stuck. No one ever says, “Hey, maybe we shouldn’t refer to ‘colored’ things.”


Black Speculation, Black Freedom

By Petal Samuel

LW: It sounds like that is happening because there are probably not enough Black people in the discipline to raise their hands and say, “Wait a minute, let’s change that.”


CP: I think about this quite a bit. Occasionally there has been a Black person around: almost all of them have been men, but there have been a few Black women too. I have been going back and forth asking people about this, saying, “How did that sit with you when you first learned about quantum chromodynamics when you were taking quantum field theory?” or “How did that sit with you when it came up in your research?”

One of the ways that we survive in physics is by not rocking the boat. So raising your hand in class and saying, “Look, your terminology is offensive to me as a Black person or sits with me wrong as a Black person,” is a great way to be labeled as someone who can’t be chill.


LW: But that takes a psychological toll either way: to sit down quietly and accept that, but also to raise your hand and say that. How do you deal with the psychological toll that goes along with raising your hand and trying to change things from the inside out?


CP: The challenge of defending yourself versus not speaking up, it’s a very, very hard decision to make, because it is painful and difficult, regardless of which decision you’ve made. I’ve been on both sides. Very early on in my PhD program at the institute where I graduated, I had an incident where a postdoc made a “you Black people” comment to me. I chose not to actively challenge him on it. I was afraid that it would damage me professionally and create problems for my research career. I just announced that I was going home and left. I actually ended up going to my office and crying for two hours. Then the next day I had various postdocs, who were all senior to me, come up to me and say, “I heard you overreacted last night.” And none of them had seen me cry or anything. I hadn’t chewed the guy out, I hadn’t nailed him to a wall, none of the things that people might have expected me to do. And it ended up damaging my ability to do research in that field, and I basically had to switch dissertation topics because of it.

What I learned from that experience is that you have to make your own decisions about when you need to keep your mouth shut and when you open your mouth. But you have to understand that there will be consequences either way. What you are really making a decision about is which consequences are more livable for you.

LW: It seems like working through your understanding of these experiences affected your trajectory in academia. You have an appointment as a physicist, but you also have an appointment in gender studies, women’s studies?


CP: Yeah, I have a 100 percent tenure track in the University of New Hampshire Department of Physics and Astronomy. But I also have core faculty status in what was the women’s studies program and is now the Department of Women’s and Gender Studies.


LW: At this point, how are those two things in conversation with each other?


CP: Over the last five years, I’ve developed a secondary area of expertise in feminist science, technology, and society studies.

I started getting interested in trying to explain my own experiences with racism and sexism and homophobia in this world, so first I became kind of an amateur sociologist, particularly of Black women in physics.

There were studies being done about women in science, and they often would not ask about race. So there was really no way of understanding the intersectional forces that were at work in the lives of women of color, and in particular, of Black women. From there I got interested in thinking through new questions: Is physics shaped by the social forces that affect the people who are doing physics and that aren’t acted on by the people doing physics? How is whiteness in the room with us when we’re doing physics? How does white supremacy shape what we do and do not know about physics?

I got a grant to use intersectionality as an analytic framework for understanding race and gender in physics. What came out of this was a paper that would technically be considered to be social epistemology: a philosophy paper about how whiteness shapes empiricism. The paper was the finalist for the Catharine R. Stimpson prize from Signs journal, and it will be published in Signs, I think in the Winter 2020 issue. So now I have developed a concept called “white empiricism.”


Losing Their Religion

By Marah Gubar

LW: Explain to me what white empiricism is.


CP: Empiricism is the idea that we gather data through the human senses, right? And using that data, we develop models of how the world works. This is basically the operating principle behind the scientific method. So this is what all physicists are socialized into thinking: This is just lab data based on your senses.

One of the challenges that Black women—Black people in general, although I think Black women have distinct experiences—face is when we have experiences with racism. In response to what we experience, white people—our white colleagues—will tell us, “Oh, that wasn’t actually racism.” So your capacity for empirical analysis gets called into question constantly, even as you are supposedly training to become an expert empiricist. That’s one aspect of white empiricism.

The other thing is that questioning the value of data or the need for data is not something that is typically acceptable within the scientific community, except, apparently, when white men decide that it’s okay to question whether data are necessary. So in determining whether an incident is racist, a white person can just say to you, “Well, it doesn’t seem racist to me,” and then it doesn’t matter what kind of empirical data you have from your own lived experience.

So the case study that I use in the article is about string theory, which is a very interesting and exciting extension of particle physics. There has been a crisis recently about string theory. There are no empirical data backing up the theory, so the question now is: Does that mean that string theory is no longer a relevant model? Is it not a good model of the world? One way that people have responded is by saying that we need to move to a “postempiricist” framework. We shouldn’t require that data are needed to prove that something is real.

This is interesting. Because white people are willing to throw out some empirical evidence and at the same time say that empirical evidence isn’t necessary when it suits them. But when Black people say, “Look at the data,” that’s different. The data show that Black women experience these levels of discrimination and sexual harassment; women of color overall have higher rates of harassment in astronomy and planetary science than white women do. Taken together, this means that there is this double epistemic standard. That’s essentially white hubris.


LW: So how do you connect women and gender studies with your physics?


CP: I read a beautiful paper yesterday by a very talented Black woman undergraduate in material science who was actually thinking about analogies between mathematics and the impact of the transatlantic slave trade. There is also Karen Barad, another thinker connecting physics and women’s studies. Karen thinks about the foundations of quantum theory and uses analytic frameworks that come out of women’s studies to think of new ways to interpret quantum mechanics.

Others, like Barad and the undergraduate, are really actually taking this framework and putting them together, whereas I am much more focused on contextualizing. I’m doing this research about axions; I’m doing this research about dark matter; I’m asking how it’s shaped by the fact that I have had these racialized and gendered experiences. And I’m also asking: How do we make physics better? How do we make it easier for Black women to fulfill their potential and live their best lives as physicists?


This article was commissioned by Ben Platt. icon

Featured image: Chanda Prescod-Weinstein. Photograph by Lisa Longstaff