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Who is allowed to have wild ideas in physics?

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Dark matter, conceptual illustration.

The presence of dark matter (light spots, illustration) is inferred from its effects on visible matter.Credit: Mark Garlick/SPL

Fear of a Black Universe: An Outsider’s Guide to the Future of Physics Stephon Alexander Basic (2021)

Dark matter and dark energy are mysterious components of the cosmos that have thrown monkey wrenches into our understanding. In Fear of a Black Universe, Stephon Alexander writes of efforts to make sense of this “dark sector”. They have stalled, he posits, partly because researchers are wary of bold explanations for these unknowns. He offers a personal exploration of whether science is receptive to ideas that violate norms and expectations. And Alexander, a Black theoretical physicist, asks: is the search for answers in modern physics hindered by an establishment afraid to entertain the ideas of those it considers outsiders?

A physicist at Brown University in Providence, Rhode Island, Alexander had an epiphany while hiking in Trinidad and Tobago, his birthplace. Although brimming with ideas, he realized that he had been dodging research on seemingly controversial topics because of the risks to his professional standing. “Black persons in scientific circles are often met with skepticism about their intellectual capabilities,” he writes. “My exploratory, personal style of theorizing, when coupled with my race, often creates situations where my white colleagues become suspicious and devalue my speculations.” This book — his second — makes a poignant case for why everyone deserves equal opportunities to let their imagination soar.

Alexander discusses three fundamental principles of physics. The first is that of invariance — the laws of physics are unchanging for observers moving relative to each other at constant speeds. This principle underlies Isaac Newton’s laws of mechanics, and similar ideas allowed Albert Einstein to develop his special and general theories of relativity. Second, he focuses on superposition: the state of a quantum mechanical system is expressed as a combination of all the possible states that the system can be in. Third is the principle of emergence: “Systems with interacting elementary constituents can exhibit novel properties that are not possessed by the constituents themselves.” For example, superconductivity, the phenomenon in which electrical resistance disappears in certain materials under certain conditions, is an emergent property of some quantum-mechanical systems.

Riffs on the classics

This is a fresh way of introducing some basics, but Alexander’s brisk, brief forays demand a lot of his readers. An accomplished jazz musician, Alexander admits that his narrative and structure will proceed like an improvisation (his first book was The Jazz of Physics in 2016). Much as an untrained ear can find it hard to appreciate a complex solo, those unschooled in relativity, quantum mechanics, string theory and quantum gravity might struggle to keep up.

Alexander riffs through a host of grand ideas: the nature of the Big Bang and the questions it begets; the origin of life; the role of consciousness in quantum mechanics and the evolution of the Universe; theories that seek to reconcile general relativity with quantum mechanics; and more. Others have written tomes on each of these topics, and Alexander has no doubt thought deeply about them, but they’re hard to corral cogently into a couple of hundred pages of non-linear narrative.

Stephon Alexander writing on a blackboard.

Cosmologist Stephon Alexander also explored the importance of improvisation in his first book, The Jazz of Physics.Credit: John Sherman

Take the chapter ‘Dark ideas on alien life’. It’s an account of a wild thought experiment that Alexander dreamed up with his friend Jaron Lanier, a virtual-reality pioneer. What if, they ask, there are numerous alien civilizations running powerful quantum computers that tie topological knots in the fabric of space-time to do computations, using gravitational-wave detectors to read from and write information to the vacuum of space-time? It is speculation piled upon speculation — breathless stuff.

Alexander writes that this “bizarre notion” could explain why the observed amount of dark energy in the Universe is nearly 120 orders of magnitude smaller than expected from theoretical considerations: maybe “the aliens used dark energy as a resource to run their ultimate computers in much the same way we devour oil to run our cars and jets”. Why would they? To enjoy high-quality virtual reality, of course. Alexander’s leaps of imagination follow the strong tradition of thought experiments in physics, but their import might be accessible only to cognoscenti.

Case studies in diversity

Along the way, Alexander wants to convince the reader that the lack of diversity in science diminishes the quality of the research accomplished, as well as being a social-justice concern. Two of his stories exemplify the issues. One is about James Gates, an African American theorist, whose work on supersymmetry (an extension to the standard model of particle physics) in the 1990s with Hitoshi Nishino got little attention. According to Alexander, similar work more than a decade later, called the ABJM theory (after the last names of the researchers who developed it: Ofer Aharony, Oren Bergman, Daniel Jafferis and Juan Maldacena), was hailed as a landmark result. Alexander challenges us to reflect on why few researchers (himself included) noticed Gates and Nishino’s earlier work.

The other story is more personal. Alexander gives a harrowing account of being told by a white visiting colleague and friend that his fellow postdocs at Stanford University in California might be shunning him because “they feel that they had to work so hard to get to the top and you [Alexander] got in easily, through affirmative action”. It goes without saying that they had no idea how hard Alexander had had to work, or what barriers he’d had to vault, to make it in physics, coming from a poor family growing up in the Bronx, New York City, in the 1980s.

Stung, and realizing that he had to showcase his strengths independently, Alexander began working alone in a café, without help from colleagues. Here, he honed the outside-the-box thinking that led to a paper (with his mentor Michael Peskin) providing a new theory for why there is much more matter than antimatter in the Universe (S. H. S. Alexander et al. Phys. Rev. Lett. 96, 081301; 2006). His account offers powerful insight into the systemic forces that work against inclusion.

There’s no doubt that physics has a diversity problem in the United States — one of the biggest in all the sciences. According to the American Institute of Physics, in 2012, Black or African Americans, who comprise about 13.4% of the US population, made up only 2.1% of physics faculty members. In 2018, members of the American Physical Society’s inclusion team warned that although about one-third of university-age US citizens are African Americans, Hispanic Americans or Native Americans, less than 11% of bachelor’s degrees in physics are awarded to people from these groups. The figure is just 7% for PhDs — around 60–70 students each year (see T. Hodapp and E. Brown Nature 557, 629–632; 2018).

In addition to the impact of historical and structural racism on the gatekeeping of ideas, other sociological factors advantage some avenues of research over others. The community of string theorists is large and well funded and can out-compete other theories of quantum gravity, for instance — as is explored in books such as The Trouble With Physics (2006) by Lee Smolin. And many ideas are discarded simply because they are bad. Fear of a Black Universe might have been richer for a more searching look at the way these factors interact. Nevertheless, it’s a timely reminder of the need to hear a wider variety of voices in physics, as in all the sciences.

Competing Interests

The author declares no competing interests.

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