University of Mississippi
Seventy miles from New Orleans is a central site of a huge international science collaboration, the Nobel-Prize-winning Laser Interferometer Gravitational-Wave Observatory (LIGO), which garnered immense public interest in 2015 with the world's first direct detection of gravitational waves. Interferometers (instruments utilizing light interference for precision measurements) are a fundamental technology across the sciences, including biomedicine, oceanography, fiber optics, and holography. Dwarfing all is the long-developing plan to create a giant interferometer in space, the Laser Interferometer Space Antenna (LISA). Scholars in this session examine astrophysical cases of interferometry that engage major issues across the history of science and technology: public policy debates about disparate space missions competing for funding, about international collaboration and competition, and about the nature of trust-building between the scientists and funding agencies to scale-up technologies. The papers ask: what is the nature of scaling up in size (from prototypes to four-kilometer big-science sites, to five-million-kilometer space detectors) and in time (from short tests, to years-long noise identification and reduction measurements, to decades-long struggles for funding and development of space missions, to longue durée understanding of light-as-instrument). Connemara Doran analyzes precision interferometry from Fizeau and Michelson to the cosmic first light. Tiffany Nichols analyzes the unexplored history of early MIT interferometer prototypes for LIGO, showing how prototypes have been used beyond modeling and teaching norms. Daniel Kennefick analyzes the struggles of scientists to overcome political and historical changes in the multi-decade gestation of LISA. David Kaiser will comment, assessing how focusing on one technique (interferometry) can provide cross-field methodologies for understanding the movement of ideas between theory and viable instrumentation.
Precision Interferometry from Fizeau and Michelson to the Cosmic First Light
Until very recently, light (visible or invisible to the eye) has been the sole instrument and messenger in observations of the cosmos. As 19th-century astronomers were opening up the spectrum to interrogation and classification, a number of scientists experimented with novel instruments to elicit information from the interference of electromagnetic waves, creating the first interferometers. Both Fizeau and Michelson designed their interferometers to make precision differential measurements, seeking to detect the effect of a moving medium on the speed of light. Theoretical, material, and technological advances compelled 20th-century physicists to interrogate a dynamic universe expanding from an initial singularity (associated with the big bang) and filled with gravitational singularities in space-time (black holes). The Laser Interferometer Gravitational-Wave Observatory (LIGO) became the most famous "multi-messenger" astronomical experiment in 2015, measuring the long-predicted gravitational waves in space-time itself. Yet, while gravitational waves within space-time are bearers of the message, light is still the detecting instrument in the interferometer. What is the epistemic role of light itself within interferometric measurements of light, heat, and gravity in astrophysical and cosmological systems? I will explore and compare the interplay of light and shadow, instrumentation and theory, and geometry and physics in several interferometric studies of the cosmos in the 19th-21st centuries, including in balloon and spacecraft observations of the very first light in the universe, the Cosmic Microwave Background radiation (CMB) leftover from the big bang.
More Than Models: Prototypes as Historical Records of the Evolving Epistemic Understandings of the Future Object of Study
Since the first direct detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015, there has been much focus on the two large-scale laser interferometers located at the Hanford, Washington and Livingston, Louisiana sites. Yet, there is minimal scholarship on the role of the prototypes constructed in this endeavor. What scholarship that does exist can be found in Harry Collins's work which explored how tacit knowledge of a model becomes routinized through use of the 40-meter prototype built at the California Institute of Technology. Through focusing on the 1.5-meter interferometer prototype built during the 1970s and 1980s at the Massachusetts Institute of Technology as a precursor to the large-scale laser interferometers used today, this talk will show that prototypes are not merely simplistic models but can also function to show feasibility of an experimental design to test a theory, reveal the need for supportive technologies from ancillary fields, build trust between the scientists and the funding agency to scale-up technologies, and provide a historical record of the epistemic understandings of the very aspects of focus for the future experimental tools including evolving noise profiles that may be encoded within the output signal of a future experimental apparatus, theorization of the forms that the future signals to be detected may take, and the conceptualization of environmental constraints needed for the envisioned future laboratory environment.
Lasers in Space: A Preliminary Focus on the History of LISA, the Proposed Space-Based Gravitational Wave Detector
University of Arkansas
The history of a project like LISA (the Laser Interferometer Space Antenna) raises many questions about scientists' motivations and their ability to engage with political forces. Fundamental science experiments done in space are projects which are so prone to delays and mishaps that their gestation frequently takes decades. How is such a project to be fitted within the confines of the typical scientific career? The idea for LISA originated in the 1970s and the project, currently in the most favorable circumstances in which it has ever found itself, is slated to fly in 2034, more than half a century later. This talk will examine the struggles of scientists to overcome political and historical changes. Issues include the hazards or benefits of international cooperation (LISA has been of interest to both the American and European space agencies, NASA and ESA), the competition for resources between science missions compared to manned space exploration, and the need to secure allies amongst scientists in related disciplines such as astronomy. The effects of a changing scientific and technological environment over several decades of planning by mission scientists will be charted in outline.
Massachusetts Institute of Technology