Laser Interferometer Gravitational-Wave Observatory (LIGO) Opens New Window on the Universe with Observation of Gravitational Waves from Colliding Black Holes
PRESCOTT, Ariz. – For the first time, scientists have observed ripples in the fabric of space-time called gravitational waves, arriving at Earth from a cataclysmic event in the distant universe. This confirms a major prediction of Albert Einstein’s 1915 general theory of relativity and opens an unprecedented new window onto the cosmos.
Gravitational waves carry information about their dramatic origins and about the nature of gravity that cannot otherwise be obtained. Physicists have concluded that the detected gravitational waves were produced during the final fraction of a second of the merger of two black holes to produce a single, more massive spinning black hole. This collision of two black holes had been predicted but never observed.
The gravitational waves were detected on Sept. 14, 2015, at 5:51 a.m. Eastern Daylight Time (9:51 UTC) by both of the twin Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA. The LIGO Observatories are funded by the National Science Foundation (NSF), and were conceived, built, and are operated by Caltech and MIT.
The discovery, accepted for publication in the journal Physical Review Letters, was made by the LIGO Scientific Collaboration (which includes the GEO Collaboration and the Australian Consortium for Interferometric Gravitational Astronomy) and the Virgo Collaboration using data from the two LIGO detectors.
The Embry-Riddle Prescott group has been deeply involved in the design and construction of the LIGO interferometers, monitoring the instrument behavior, analyzing the data, and interpreting the results of the analyses. The Embry-Riddle gravitational wave astrophysics group is the only LIGO group in Arizona. It was established in 2005, and has been continuously supported by the National Science Foundation since 2006.
Dr. Michele Zanolin joined the LIGO Scientific Collaboration in 2004. He is one of the developers and users of the algorithm that first observed the event, a few minutes after the data were collected. Dr. Zanolin is the Principal Investigator of the Embry-Riddle LIGO group. He also coordinates the supernova subgroup of the LIGO and Virgo collaborations, which focuses on detecting gravitational waves from core collapse supernovae and extracting astrophysical information from them.
Dr. Andri Gretarsson has been a member of the LSC since 1996. As an instrumentalist, he helped design and characterize the mirrors that formed the heart of the LIGO detectors. From 2002 to 2005 he worked on commissioning the initial LIGO interferometers. After joining Embry-Riddle in 2005, Dr. Gretarsson conducted NSF-funded optics research in support of LIGO. Dr. Gretarsson is also the founder of the Embry-Riddle group.
Dr. Brennan Hughey has been an active member of the LIGO Scientific Collaboration for nearly a decade. As part of the LIGO teams that search for unmodeled transient gravitational waves and characterize detector behavior, Dr. Hughey was involved in several aspects of vetting and analyzing the gravitational wave signal. Dr. Hughey will present a colloquium on the first direct observation of gravitational waves this Friday, Feb. 12, at noon in Academic Complex 1, Room 107, on Embry-Riddle’s Prescott Campus.
The group also currently includes Ph.D. student Marek Szczepanczyk, plus undergraduate students Kiranjyot Gill, Marina Koepke, James Pratt and Sophia Schwalbe.
LIGO research is carried out by the LIGO Scientific Collaboration (LSC), a group of more than 1,000 scientists from universities around the United States and in 14 other countries. More than 90 universities and research institutes in the LSC develop detector technology and analyze data; approximately 250 students are strong contributing members of the collaboration. The LSC detector network includes the LIGO interferometers and the GEO600 detector. The GEO team includes scientists at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI), Leibniz Universität Hannover, along with partners at the University of Glasgow, Cardiff University, the University of Birmingham, other universities in the United Kingdom, and the University of the Balearic Islands in Spain.
LIGO was originally proposed as a means of detecting these gravitational waves in the 1980s by Rainer Weiss, professor of physics, emeritus, from MIT; Kip Thorne, Caltech’s Richard P. Feynman Professor of Theoretical Physics, emeritus; and Ronald Drever, professor of physics, emeritus, also from Caltech.
Virgo research is carried out by the Virgo Collaboration, consisting of more than 250 physicists and engineers belonging to 19 European research groups: six from Centre National de la Recherche Scientifique (CNRS) in France; eight from the Istituto Nazionale di Fisica Nucleare (INFN) in Italy; two in The Netherlands with Nikhef; the Wigner RCP in Hungary; the POLGRAW group in Poland and the European Gravitational Observatory (EGO), the laboratory hosting the Virgo detector near Pisa in Italy.
The discovery was made possible by the enhanced capabilities of Advanced LIGO, a major upgrade that increases the sensitivity of the instruments compared to the first generation LIGO detectors, enabling a large increase in the volume of the universe probed—and the discovery of gravitational waves during its first observation run. The U.S. National Science Foundation leads in financial support for Advanced LIGO.
Funding organizations in Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council, STFC) and Australia (Australian Research Council) also have made significant commitments to the project. Several of the key technologies that made Advanced LIGO so much more sensitive have been developed and tested by the German UK GEO collaboration. Significant computer resources have been contributed by the AEI Hannover Atlas Cluster, the LIGO Laboratory, Syracuse University, and the University of Wisconsin-Milwaukee. Several universities designed, built, and tested key components for Advanced LIGO: The Australian National University, the University of Adelaide, the University of Florida, Stanford University, Columbia University in the City of New York, and Louisiana State University.
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