Gravity's Ghost and Big Dog: Scientific Discovery and Social Analysis in the Twenty-first Century

  • Harry Collins
University of Chicago Press: 2013. 9780226052298 | ISBN: 978-0-2260-5229-8

In Gravity's Ghost and Big Dog, British sociologist Harry Collins documents the astrophysical search for the elusive gravitational wave. In part an account of sociological fieldwork among scientists in the field and part astronomy-history mystery, Collins's book is a terrific read informed by almost 40 years of research.

The book homes in on two sudden energy surges, thought to be the first truly significant detections of gravitational-wave signals, that got the astrophysics community in a stir: the Equinox Event in 2007 and Big Dog in 2010. The book's first part was previously published in 2010 as Gravity's Ghost (University of Chicago Press), a stand-alone account of the Equinox Event. The new, second part documents the frenzy over Big Dog — so named because the signal was bigger than the 2007 surge and seemed to come from the constellation Canis Major — when the stakes were higher and the future of the field hung in the balance. As an 'embedded' observer, participant, apprentice and analyst working among the astrophysicists, Collins reports on meetings, telephone conferences, e-mail discussions and social events. By conversing with and analysing scientists at research facilities, scientific conferences and home institutions, he offers a glimpse of the ways in which knowledge is made in this esoteric field.

Researchers working at the Laser Interferometer Gravitational-Wave Observatory. Credit: LIGO LABORATORY

Predicted by Albert Einstein's general theory of relativity, first published in 1915, gravitational waves are formed when the mass of an imploding star disappears, causing ripples in space time. Ground-based interferometers built to detect them have been in use for decades, but Collins focuses on the Laser Interferometer Gravitational-Wave Observatory (LIGO), which has sites at Hanford, Washington, and Livingston, Louisiana.

Two questions drive the narrative: are the signals real? And do they prove that gravitational waves exist? Collins lets us in on the conversations among the scientists. At times, they focus on the rigour of statistical margins by asking at which margin error can be ruled out; at others, they discuss the semantics of knowing, pondering whether they are confronted with observation, evidence or fact. He intersperses these exchanges with historical information and his own sociological analysis of gravitational-wave research. As the astrophysicists debate the two detection events, it emerges that deciding whether a gravitational wave exists is not just a matter of observation, calibration and learning to understand LIGO's idiosyncrasies. It also involves semantics, political considerations and attending to expectations from funders, media and the public.

A debate among key collaborators about how to announce Big Dog is a case in point. The degree of certainty with which a finding is announced sets expectations, and these find their way into the rationales for retooling or building new instruments. The validity of past research, the promise embedded in future instruments and scientific reputations are all explicitly at stake in the exchanges among the collaborators. Collins has turned the minutiae of these conversations into an exciting detective story.

Collins learns so much science that he becomes a force to be reckoned with.

Collins finds himself immersed, learning so much science that he becomes a force to be reckoned with. His queries are pertinent to the research and, by his own account, that gets the scientists to rethink strategies or interpretations of their findings. Collins even tries his hand at physics, and suggests an alternative strategy for some of the calculations for Big Dog. Flirting with the science, he begins to think not only about the astrophysicists, but with them. With Collins, we begin to wonder what it takes to be an expert in the field.

In social science, going native in this way is a tricky business. In an effort not to alienate his subjects, the sociologist may end up relying too much on the group's own interpretations of their actions, leading to less insightful renderings of their world. If, by contrast, he lacks credibility with the group, his presumption to reveal something new may offend. Collins walks a tight line deftly; although his interlocutors are somewhat incredulous at his efforts to do physics, the group does engage with them.

That does not make Collins an expert within their culture — only about it. And here, in trying to justify his calculations by asserting that they are not far off, he violates a golden rule of the sociology of science. Understanding the process of knowledge-making is not predicated on whether the knowledge in question is right or wrong. At the same time, Collins defies a best practice of anthropology — to examine one's motifs and motivations. He is not the first researcher in the sociology of science whose observation of scientific expertise turns into the desire to possess it. This interesting feature of the analysis of science remains unexamined in Collins's book.

That said, Collins's respect for science compels him to make a lovely observation: that there is something admirable about the modes of science — its aspiration to honesty, persistence and truth-seeking — and that this should serve as a moral and epistemological model for how to behave. And if, as US anthropologist Stefan Helmreich suggests in his book Silicon Second Nature (UC Press, 1998), social analysis of science enables participants to “recognize something new of themselves”, Collins's serial monograph is on point. It tells of scientists who are well aware of their own practices — perhaps not least as a result of having a sociologist in their midst.