LIGO Opens New Window on the Universe with Observation of Gravitational Waves from Colliding Black Holes
For the first time, scientists have observed ripples in the fabric of spacetime called gravitational waves, arriving at the 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 September 14, 2015 at 5:51 a.m. Eastern Daylight Time (9:51 a.m.
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.
LIGO research is carried out by the LIGO Scientific Collaboration (LSC), a group of more than 1000 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.
Virgo research is carried out by the Virgo Collaboration, consisting of more than 250 physicists and engineers
belonging to 19 different European research groups: 6 from Centre National de la Recherche Scientifique
(CNRS) in France; 8 from the Istituto Nazionale di Fisica Nucleare (INFN) in Italy; 2 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.
Virgo was born thanks to the visionary ideas of Alain Brillet and Adalberto Giazotto. The detector was designed
based on innovative technologies expanding the sensitivity to the low frequency range. The construction started
in 1994 and it has been funded by CNRS and INFN; since 2007 Virgo and LIGO have shared and jointly
analysed the data taken by all the interferometers of the international network. After the start of the LIGO
upgrade, Virgo took data until 2011.
The Advanced Virgo project, funded by CNRS, INFN and Nikhef, was then launched: the new detector will be
in operation before the end of the year. In addition several institutes and universities of the five European nations
of the Virgo Collaboration contribute both to the Advanced Virgo upgrade and to the discovery effort.
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.
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 US 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 of New York, and Louisiana State University.
The Virgo collaboration
Contact:
Fulvio Ricci
Virgo spokesperson
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