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Laser Interferometer Gravitational-Wave Observatory

"LIGO's first Science Run (S1) was originally scheduled to begin on June 29, but accidental damage to H2, the 2-km interferometer here at Hanford, occurred just prior to the start leading to a frustrating postponement. The damage was triggered by a magnitude 7.2 earthquake that took place June 28 on the border of China and Russia. When the seismic waves reached Hanford around 15 minutes later, the ground vibration overwhelmed the control system for the interferometer."

".....Another key measure of performance is the depth of the search, namely the distance at which one could have detected a particular source. This varies by very large factors for different types of sources, often depending on details that we do not yet know. As a benchmark, we typically use the distance to which we could detect the inspiral of two 1.4-solar-mass neutron stars. The exact range for each interferometer has yet to be determined by a full analysis of the S1 data, which is ongoing. But preliminary estimates indicate that such a source would have been detectable throughout our galaxy....."

"The LIGO acronym stands for Laser Interferometer Gravitational-Wave Observatory, whose mission is to observe gravitational waves of cosmic origin. LIGO will search for gravitational waves created in the supernova collapse of stellar cores to form neutron stars or black holes, the collisions and coalescences of neutron stars or black holes, the wobbly rotation of neutron stars with deformed crusts and the remnants of gravitational radiation created by the birth of the universe. LIGO is a joint project of scientists at the California Institute of Technology (Caltech) and the Massachusetts Institute of Technology (MIT), sponsored by the National Science Foundation (NSF)..."

"Gravitational waves that originated hundreds of millions of lights years from earth are expected to distort the 4-kilometers mirror spacing by about a thousandth of a fermi, less than one tenth of a trillionth of the diameter of a human hair. These waves were first predicted by Einstein's Theory of General Relativity in 1916, but the technology to make their detection did not exist then..."

The Gravitation and Cosmology Research Group at MIT. Part of the Center for Space Research [] within the Physics Department at MIT. This page has links to LASTI- the LIGO Advanced System Test Interferometer at MIT, Quantum Measurement Group @ MIT and Thermal Noise Research.

LIGO: A New Window on the Universe   [New Window]
NCSA/Univ. of Illinois

Almost all our current information about the cosmos is based on our ability to sense, pinpoint and measure electromagnetic radiation -- which until the early 1940s meant only visible light. Since then, radio telescopes, infrared telescopes, and X-ray telescopes have dramatically broadened our "vision." An even more dramatic chang e will occur once we are able to "see" the gravitational waves predicted by Einstein's General Theory of Relativity.

This page will explain; Catching the Waves, How Does Laser Interferometry Work?, From Prototype to Full-Scale Detectors and Why Two U.S. Locations? Complete with images, photos, movies and sound files.

Some of the goals that the U.S. instruments are being designed to accomplish are:
  Prove by direct measurement that gravitational waves exist.
  Ascertain whether gravitational waves propagate at the speed of light, as postulated by Einstein.
  Verify that gravitational waves cause the predicted displacements in matter they travel through.
  Confirm the presence in the universe of black holes and study their dynamics and evolution.
  Observe cosmic cataclysms, from supernovae to coalescing black holes to the Big Bang.

The LIGO Scientific Collaboration (LSC) is a forum for organizing technical and scientific research in LIGO. Its mission is to insure equal scientific opportunity for individual participants and institutions by organizing research, publications, and all other scientific activities. It includes scientists from the LIGO Laboratory as well as collaborating institutions. It is a separate organization from the LIGO Laboratory, with its own leadership and governance, but reports to the Laboratory Directorate for final approval of its research program, technical projects, observational physics publications, and talks announcing new observations and physics results.

Penn State Center for Gravitational Physics and Geometry - "The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a facility dedicated to the detection of cosmic gravitational waves and the harnessing of these waves for scientific research. LIGO is a partner in iVDGL (International Virtual Data Grid Laboratory), which is tasked with establishing and utilizing an international laboratory of unprecedented scale and scope, comprising of heterogeneous computing and storage resources in the U.S., Europe and ultimately other regions linked by high-speed networks, and operated as a single system for the purposes of interdisciplinary experimentation in Grid-enabled, data-intensive scientific computing."

LIGO = Laser Interferometer Gravity-wave Observator is a successful attempt by several important people to sell the government outmoded technology to build what will be a phenomonally expensive observatory presently pegged at over one third of a billion (up from an intitial $192 million proposed cost of course). This monster will blight the funding prospects of a generation of young scientists, and didn't even profit the hopeful egos who pushed it through; they have largely been booted off the project now that it has a life of its own and demands competent managers.

Misner, Thorne, and Wheeler's "Gravitation" speculates widely on every possible way of detecting gravitational waves and doesn't even mention interferometers (ironically). The reason is that they are technically unpromising.