John W. Moffat
- Published in print:
- 2020
- Published Online:
- June 2020
- ISBN:
- 9780190650728
- eISBN:
- 9780197517383
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780190650728.003.0007
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology
At a press conference on February 11, 2016, David Reitz, LIGO Executive Director, announced, “We did it!” They detected gravitational waves for the first time. Both LIGO sites, in Washington state ...
More
At a press conference on February 11, 2016, David Reitz, LIGO Executive Director, announced, “We did it!” They detected gravitational waves for the first time. Both LIGO sites, in Washington state and Louisiana, registered the incoming gravitational waves from two black holes colliding and merging far away. Over the following months, more mergers were detected. Gravitational waves are caused by the acceleration of a massive object, which stretches and compresses spacetime in a wave-like motion that is incredibly small and difficult to detect. Numerical relativity research over decades has produced over a quarter of a million template solutions of Einstein’s equations. The best template fit to the wave form data identifies the masses and spins of the two merging black holes. Much of this chapter describes the technology of the LIGO apparatus. On October 3, 2017, Barish, Thorne, and Weiss, the founders of LIGO, received the Nobel Prize for Physics.Less
At a press conference on February 11, 2016, David Reitz, LIGO Executive Director, announced, “We did it!” They detected gravitational waves for the first time. Both LIGO sites, in Washington state and Louisiana, registered the incoming gravitational waves from two black holes colliding and merging far away. Over the following months, more mergers were detected. Gravitational waves are caused by the acceleration of a massive object, which stretches and compresses spacetime in a wave-like motion that is incredibly small and difficult to detect. Numerical relativity research over decades has produced over a quarter of a million template solutions of Einstein’s equations. The best template fit to the wave form data identifies the masses and spins of the two merging black holes. Much of this chapter describes the technology of the LIGO apparatus. On October 3, 2017, Barish, Thorne, and Weiss, the founders of LIGO, received the Nobel Prize for Physics.
John W. Moffat
- Published in print:
- 2020
- Published Online:
- June 2020
- ISBN:
- 9780190650728
- eISBN:
- 9780197517383
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780190650728.003.0008
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology
On August 8, 2017, LIGO/Virgo detected the merging of two neutron stars 130 million light years away. Just 1.7 seconds later, the Fermi Gamma Ray Space Telescope received an optical signal—a short ...
More
On August 8, 2017, LIGO/Virgo detected the merging of two neutron stars 130 million light years away. Just 1.7 seconds later, the Fermi Gamma Ray Space Telescope received an optical signal—a short gamma ray burst (GRB). Thus began a new era of “multimessenger astronomy.” The GRBs are very energetic explosions observed in galaxies. The neutron star merger offers the first evidence that heavy metals such as gold, platinum, and uranium were created by the collision of neutron stars in a “kilonova.” The resulting gravitational waves offer a new way of measuring the Hubble constant, which determines the rate of expansion of the universe. An important result from the neutron star merger is an extremely accurate determination of the speed of gravitational waves; they move at the speed of light. This has significant ramifications for gravitational theory. It falsifies many proposed modified gravity models.Less
On August 8, 2017, LIGO/Virgo detected the merging of two neutron stars 130 million light years away. Just 1.7 seconds later, the Fermi Gamma Ray Space Telescope received an optical signal—a short gamma ray burst (GRB). Thus began a new era of “multimessenger astronomy.” The GRBs are very energetic explosions observed in galaxies. The neutron star merger offers the first evidence that heavy metals such as gold, platinum, and uranium were created by the collision of neutron stars in a “kilonova.” The resulting gravitational waves offer a new way of measuring the Hubble constant, which determines the rate of expansion of the universe. An important result from the neutron star merger is an extremely accurate determination of the speed of gravitational waves; they move at the speed of light. This has significant ramifications for gravitational theory. It falsifies many proposed modified gravity models.
John W. Moffat
- Published in print:
- 2020
- Published Online:
- June 2020
- ISBN:
- 9780190650728
- eISBN:
- 9780197517383
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780190650728.001.0001
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology
The author visits one of the two Laser Interferometer Gravitational- Wave Observatory (LIGO) sites in the United States, at Hanford, Washington. This is where scientists are detecting gravitational ...
More
The author visits one of the two Laser Interferometer Gravitational- Wave Observatory (LIGO) sites in the United States, at Hanford, Washington. This is where scientists are detecting gravitational waves generated by faraway merging black holes and neutron stars. He meets the people who work there and has discussions with some of them. The director gives him a tour of the LIGO experimental installation, describing the work, the technological details of the apparatus, and answers his questions. On the final day of the visit, the author gives a talk to the LIGO group on gravitational waves and on an alternative gravitational theory.Less
The author visits one of the two Laser Interferometer Gravitational- Wave Observatory (LIGO) sites in the United States, at Hanford, Washington. This is where scientists are detecting gravitational waves generated by faraway merging black holes and neutron stars. He meets the people who work there and has discussions with some of them. The director gives him a tour of the LIGO experimental installation, describing the work, the technological details of the apparatus, and answers his questions. On the final day of the visit, the author gives a talk to the LIGO group on gravitational waves and on an alternative gravitational theory.
