American Scientist

THE DISORDERED COSMOS: A Journey into Dark Matter, Spacetime, and Dreams Deferred. Chanda Prescod-Weinstein. 320 pp. Bold Type Books, 2021. $28.

Chanda Prescod-Weinstein is a particle cosmologist who studies dark matter and the interface between particle physics and gravity—or as she puts it in her new book, “I use math to figure out the history of spacetime.” The Disordered Cosmos: A Journey into Dark Matter, Spacetime, and Dreams Deferred occupies a unique place in the thriving field of popular physics books by elite academics, because Prescod-Weinstein is the first Black woman to hold a tenure-track position in theoretical cosmology, and trenchant reflections on race and gender are a central component of the book. She describes having had to absorb “a hard lesson” in “rarified academic settings,” the lesson “that learning about the mathematics of the universe could never be an escape from the earthly phenomena of racism and sexism.” Physics and math classrooms, she says, come “complete with all of the problems that follow society wherever it goes.”

Hers is a twofold tale about embarking on the scientific quest to comprehend the evolution of the cosmos, and about doing so as a Black girl who grew up dreaming of being part of that quest in a society that historically has treated dark-skinned people cruelly and considered them to be intellectually inferior. The book’s narrative illuminates both the physics itself and the structural racism that continues to impede Black people who wish to participate fully in science as a knowledge-making endeavor. Prescod-Weinstein refers to herself as a “griot of the universe,” comparing herself to tribal African storytellers. She takes the term cosmology to mean not only the conditions of the physical world, but also the social matrix within which any articulation of the physical unfolds.

Prescod-Weinstein’s doctoral research focused on the very early universe just after its inflationary phase, when theorists believe a rapid reheating put the “bang” into the Big Bang. Understanding this heating is crucial to understanding how particles such as quarks and hadrons came into being out of what had previously been empty space. “This is a question of general interest to cosmologists, as well as people working on technical issues in quantum field theory in curved spacetimes,” she writes. “I happen to fall into both categories, so this is fun for me.” In cosmic acceleration (the speeding up of the expansion of the universe), she says, we glimpse “perhaps one of our first hints at quantum gravity.” That physicists can make pronouncements about such a distant exotic time is based on “a faith in the universality of mathematical equations”—a faith she celebrates.

Prescod-Weinstein writes with both a deep knowledge of physics and a psychic vulnerability that is a too rarely witnessed facet of the scientific persona. 

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When she is describing her research, Prescod-Weinstein’s prose lights up with joy as she speaks of the thrill of exploration and the magic of insights won from wrangling with equations. Yet after praising the power of a mathematical approach to the formation of the universe, she pivots to a more somber mode, noting that “What goes undiscussed is that it is not the only way to understand the origins of the world”; Indigenous people have their own cosmologies and knowledges. The knowledge used by Western science, and the cosmological work that Prescod-Weinstein herself does, are allied to “settler colonialism.” As a practicing scientist, how does one deal with such a bifurcation of consciousness? This tension is at the heart of the book, which calls on us, as readers and admirers of science ourselves, to take a deep look at both the stunning epistemological successes of science and its equally arresting institutional failures.

This duality is brilliantly captured in a chapter about the physics of melanin, which gives skin its color. Although race is a social construction, the melanin determining skin color is physical, and Black skin is a material phenomenon. “What is it in my skin,” Prescod-Weinstein asks, “that absorbs and emits light such that I am this color, this shade of brown that is on a spectrum of racialized Blackness?” Astounded that she has never wondered about the physics of skin color before, she digs into the scientific research. It turns out that melanin is a fascinating molecule now of interest to biophysicists and materials technologists, in part because it could be useful in understanding potential superconductors.

Not thinking about the physics of skin has consequences. In 2017, a Nigerian employee at Facebook posted a video on social media of an automatic soap dispenser failing to recognize a Black hand because the darker skin was absorbing rather than reflecting light. “The dark skin was invisible,” Prescod-Weinstein writes, “not because it wasn’t there, but because the detector hadn’t been designed with dark skin in mind. . . . [Likewise] Black people disappear from view when new, life-improving technologies are being developed.”

Realizing that she could use her scientific skills to understand her own Blackness was part of Prescod-Weinstein’s awakening as a Black scientist. (It was harsh, she says, to realize that she had been conditioned by “artificial social structures” not to ask basic questions.) Her examination of the history of what scientists have learned about melanin leads her to reflect upon the ways in which science and society have “co-constructed” one another.

In colonial and Enlightenment Europe, where the idea of darker-skinned “inferiority” was used to establish empires, scientists who should have confronted that view skeptically looked instead for ways of confirming it, thereby “consecrating” bias. Today, when scientists in the United States talk about the importance of diversity in science, too often the discussion is framed in terms of people of color being a “resource” for replenishing the STEM workforce. “In other words,” Prescod-Weinstein says, “like my enslaved ancestors, Black people—and other so-called minorities—in science are constructed as a commodity for nation-building. . . . None of this is about what society can do for people of color so much as what service people of color can provide to the national establishment.” Scientists should instead be thinking about “the ways that Black scientists can shape actual science.” What she most wants is for us to understand that “Black thoughts, like Black lives, matter.”

The book calls on us to take a deep look at both the stunning epistemological successes of science and its equally arresting institutional failures.

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Prescod-Weinstein discusses at some length some recent attempts to draw analogies between Black people and dark matter. The original idea behind the comparison, she explains, “was specifically to highlight the ways in which Black people and our contributions are erased from cultural discourses.” But as she goes on to point out, the analogy “has also taken flight as a way of identifying with Black as a positive,” as something “special and unique.” She doesn’t like to discourage this impulse of Black culture to embrace science, because so many Black people have been disenfranchised from positive engagement with it. “The analogy draws on their experiences as Black people to give the phrase [dark matter] meaning,” she says—but unfortunately, “this is not the meaning that dark matter should have as a scientific concept.” She delivers a scathing indictment of the analogy, noting that Black bodies aren’t invisible because they don’t intersect with light, they’re invisibilized by social systems designed not to see them. A more apt analogy, she maintains, would be one between weak gravitational lensing and systemic racism: Weak cosmological lensing requires a sophisticated capacity for pattern detection, as does the recognition of racist microaggressions.

Prescod-Weinstein describes herself as “a Black child from a biracial family growing up in Latinx eastern Los Angeles.” Her father is an Ashkenazi Jew and her mother, born in Barbados, is Margaret Prescod, a beloved Los Angeles activist and radical radio host. In part, the daughter has written this book to explain her research to her mother. It is a story lyrically told, one that entwines cutting-edge physics with personal memoir—a genre that also includes Janna Levin’s How the Universe Got Its Spots. Levin and Prescod-Weinstein write with both a deep knowledge of physics and a psychic vulnerability that is a too rarely witnessed facet of the scientific persona. It’s no coincidence that both are women. Their weaving of an assertive subjectivity into the supposed objectivities of physics heralds an exciting phase-shift in science writing.

Prescod-Weinstein’s book deals explicitly with gender. She deplores the paucity of women in 20th-century cosmology. Throughout her career, she says, she has “clung to Henrietta Swan Leavitt and Cecilia Payne-Gaposchkin as two of the only women greats in the history of cosmology,” but aside from those two and her mentor Vera Rubin, the field has largely been “a tale of great white men.” Rectifying this skew will involve acknowledging not just the achievements of the women in physics but those of the nonwhite men—for example, Elmer Imes, who in 1918 became only the second Black American man to earn a doctorate in physics, and whose spectroscopic research helped affirm the correctness of quantum mechanics.

Women, sadly, are not always able to count on other women for support, and Prescod-Weinstein’s descriptions of unacknowledged racism on the part of white female colleagues are distressing to read. As someone with a degree in physics who has been writing about gender and science since the 1990s, I can attest to how lonely it can feel to be working at the interface of science and social justice, only rarely encountering other women physicists with an ethos of solidarity.

It takes courage to write a book as complex, community-exposing, and self-revealing as The Disordered Cosmos, and doing so exacts an emotional price. Being one of the few Black women in physics is also taxing. Prescod-Weinstein describes the intense pressure she experiences to serve as an advisor and counselor to a stream of Black students and young Black scientists all over the country who write to her, email her, phone her, and come knocking at her door. Her moral fiber compels her to oblige.

But as she notes, scant credit is given for meeting these sorts of demands—for doing what she, echoing other feminists, calls the “housework” of science—when decisions are made regarding tenure and promotions. In the cutthroat world of academic science, all focus is on publications and research. I found myself moved to tears by her frustration with this blindness. Like many other women in science, at times Prescod-Weinstein would like to have the option of just getting on with her science. But she is too committed to forging a future in which Black people can contribute to science and have science contribute to their well-being in return.

Late in the book, like a bolt from the blue comes a chapter recounting the devastating effects on Prescod-Weinstein of having been raped at a science conference by a more senior scientist while she was in graduate school. She immediately signals her ambivalence about including the chapter, worrying that her book (and herself by association) will be defined by this horrendous event. But rape, she says, is part of her “disordered cosmos,” a now-irredeemable aspect of her relationship to science. Wrestling with its aftermath, she reflects on power and the ways in which “Science has become a practice of control.”

The violation still intrudes on her consciousness daily, more than a decade later, during myriad moments that accumulate into so much lost time. It’s “hard to stay deeply connected to science when a scientist violates you so intimately,” she writes. And the personal becomes political, for this rape took place in the larger framework of science, a framework in which some voices have always been heard and others suppressed. “Whose observations are taken seriously?” she asks. “Who is deemed to be a competent observer?” These are questions that ring through the annals of science.

To love science deeply and also to feel compelled to call out its systemic failings is a hard dichotomy to bear. Science is a set of conceptual enchantments to be celebrated and shared, yet it is also a culturally embedded activity with social and communal consequences, some of which should be occasions for shame and urgent targets for reform. Those of us who admire science are called on not just to convey what is wonderful about it but to lay bare its problems. Prescod-Weinstein does both with consummate grace. Her book ought to be mandatory reading for every student of science.