The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large observatories were built in the United States with the aim of detecting gravitational waves by laser interferometry. These observatories use mirrors spaced four kilometers apart which are capable of detecting a change of less than one ten-thousandth the charge diameter of a proton.
Kip Stephen Thorne is an American theoretical physicist known for his contributions in gravitational physics and astrophysics.
The Max Planck Institute for Gravitational Physics is a Max Planck Institute whose research is aimed at investigating Einstein's theory of relativity and beyond: Mathematics, quantum gravity, astrophysical relativity, and gravitational-wave astronomy. The institute was founded in 1995 and is located in the Potsdam Science Park in Golm, Potsdam and in Hannover where it closely collaborates with the Leibniz University Hannover. Both the Potsdam and the Hannover parts of the institute are organized in three research departments and host a number of independent research groups.
GEO600 is a gravitational wave detector located near Sarstedt, a town 20 km to the south of Hanover, Germany. It is designed and operated by scientists from the Max Planck Institute for Gravitational Physics, Max Planck Institute of Quantum Optics and the Leibniz Universität Hannover, along with University of Glasgow, University of Birmingham and Cardiff University in the United Kingdom, and is funded by the Max Planck Society and the Science and Technology Facilities Council (STFC). GEO600 is capable of detecting gravitational waves in the frequency range 50 Hz to 1.5 kHz, and is part of a worldwide network of gravitational wave detectors. This instrument, and its sister interferometric detectors, when operational, are some of the most sensitive gravitational wave detectors ever designed. They are designed to detect relative changes in distance of the order of 10−21, about the size of a single atom compared to the distance from the Sun to the Earth. Construction on the project began in 1995.
Ronald William Prest Drever was a Scottish experimental physicist. He was a professor emeritus at the California Institute of Technology, co-founded the LIGO project, and was a co-inventor of the Pound–Drever–Hall technique for laser stabilisation, as well as the Hughes–Drever experiment. This work was instrumental in the first detection of gravitational waves in September 2015.
Robert M. Wald is an American theoretical physicist and professor at the University of Chicago. He studies general relativity, black holes, and quantum gravity and has written textbooks on these subjects.
Gravitational waves are waves of the intensity of gravity that are generated by the accelerated masses of binary stars and other motions of gravitating masses, and propagate as waves outward from their source at the speed of light. They were first proposed by Oliver Heaviside in 1893 and then later by Henri Poincaré in 1905 as the gravitational equivalent of electromagnetic waves.
Gravitational-wave astronomy is an emerging field of science, concerning the observations of gravitational waves to collect relatively unique data and make inferences about objects such as neutron stars and black holes, events such as supernovae, and processes including those of the early universe shortly after the Big Bang.
Alessandra Buonanno is an Italian naturalized-American theoretical physicist and director at the Max Planck Institute for Gravitational Physics in Potsdam. She is the head of the "Astrophysical and Cosmological Relativity" department. She holds a research professorship at the University of Maryland, College Park, and honorary professorships at the Humboldt University in Berlin, and the University of Potsdam. She is a leading member of the LIGO Scientific Collaboration, which observed gravitational waves from a binary black-hole merger in 2015.
Barry Clark Barish is an American experimental physicist and Nobel Laureate. He is a Linde Professor of Physics, emeritus at California Institute of Technology and a leading expert on gravitational waves.
The first direct observation of gravitational waves was made on 14 September 2015 and was announced by the LIGO and Virgo collaborations on 11 February 2016. Previously, gravitational waves had been inferred only indirectly, via their effect on the timing of pulsars in binary star systems. The waveform, detected by both LIGO observatories, matched the predictions of general relativity for a gravitational wave emanating from the inward spiral and merger of a pair of black holes of around 36 and 29 solar masses and the subsequent "ringdown" of the single resulting black hole. The signal was named GW150914. It was also the first observation of a binary black hole merger, demonstrating both the existence of binary stellar-mass black hole systems and the fact that such mergers could occur within the current age of the universe.
GW151226 was a gravitational wave signal detected by the LIGO observatory on 25 December 2015 local time. On 15 June 2016, the LIGO and Virgo collaborations announced that they had verified the signal, making it the second such signal confirmed, after GW150914, which had been announced four months earlier the same year, and the third gravitational wave signal detected.
Marica Branchesi is an Italian astrophysicist. Her leadership and scientific work was pivotal for Virgo/LIGO's discovery of gravitational waves. She is vice president of International Astronomical Union Gravitational Wave Astrophysics Commission and member of the Gravitational Wave International Committee.
Chiara Mingarelli is an Italian-Canadian astrophysicist who researches gravitational waves. She is an assistant professor of physics at Yale University since 2023, and previously an assistant professor at the University of Connecticut (2020–2023). She is also a science writer and communicator.
Samaya Michiko Nissanke is an astrophysicist, associate professor in gravitational wave and multi-messenger astrophysics and the spokesperson for the GRAPPA Centre for Excellence in Gravitation and Astroparticle Physics at the University of Amsterdam. She works on gravitational-wave astrophysics and has played a founding role in the emerging field of multi-messenger astronomy. She played a leading role in the discovery paper of the first binary neutron star merger, GW170817, seen in gravitational waves and electromagnetic radiation.
GW 190814 was a gravitational wave (GW) signal observed by the LIGO and Virgo detectors on 14 August 2019 at 21:10:39 UTC, and having a signal-to-noise ratio of 25 in the three-detector network. The signal was associated with the astronomical superevent S190814bv, located 790 million light years away, in location area 18.5 deg2 towards Cetus or Sculptor. No optical counterpart was discovered despite an extensive search of the probability region.
Rana X. Adhikari is an American experimental physicist. He is a professor of physics at the California Institute of Technology (Caltech) and an associate faculty member of the International Centre for Theoretical Sciences of Tata Institute of Fundamental Research (ICTS-TIFR).
Deirdre Marie Shoemaker is an American astrophysicist whose research studies the mergers of binary black holes through both simulation and observation. She is a professor of physics at the University of Texas at Austin, where she directs the Center for Gravitational Physics and is affiliated with the Oden Institute for Computational Engineering and Sciences.
Laura Cadonati is an American physicist who specializes in gravitational waves.
Richard Alfred Matzner is an American physicist, working mostly in the field of general relativity and cosmology, including numerical relativity, kinetic theory, black hole physics, and gravitational radiation. He is Professor of Physics at the University of Texas at Austin where he directed the Center for Relativity. In 1993 he organized and was Lead Principal Investigator of an NSF/ARPA funded computational Grand Challenge program involving ten university teams seeking computational descriptions for the interaction of black holes as potential sources for observable gravitational radiation. His work leading what became known as the Binary Black Hole Grand Challenge Alliance featured in Kip Thorne's Nobel Prize lecture, including when Matzner and Alliance collaborators wagered Thorne that numerical relativity would produce a simulated waveform comparable to observation prior to the first LIGO detection. Matzner and colleagues eventually won, Thorne saying he "conceded the bet with great happiness."
