1. B. R. Abbott, R. Abbott, et al., “Observation of Gravitational Waves from a Binary Black Hole Merger,” Physical Review Letters 116 (2016), 061102-1–16. In this case, the LIGO collaboration is applying the 5 σ criterion for an observation. In high energy physics, this is a requirement for the use of “observation,” which is synonymous with “discovery.”
2. Russell Hulse and Joseph Taylor, “Discovery of a Pulsar in a Binary System,” The Astrophysical Journal 195 (1975), L51–L53.
3. Joel Weisberg and Joseph Taylor, “Gravitational Radiation from an Orbiting Pulsar,” General Relativity and Gravitation 13 (1981), 1–6.
4. Ibid., 1.
5. Harry Collins, Gravity’s Kiss (Cambridge, MA: MIT Press, 2017).