Tomorrow, the people behind the LIGO detector are holding multiple press conferences in which they're expected to announce the first detection of gravitational waves. These are ripples in the fabric of space-time, caused by extremely energetic gravitational systems, like two black holes orbiting closely. They are a prediction of Einstein's theory of general relativity, but have never been detected before.
We've had indirect evidence they existed. For example, we've watched two neutron stars in a close orbit, and saw that they were spiraling closer together, with the energy they were losing matching with predictions of relativity to many decimal places. Relativity indicates the energy takes the form of tiny distortions in space time that radiate out from the system, but we've been unable to detect them.
Until now. LIGO (Sponsored by the US' National Science Foundation) went through an upgrade over the past several years that increased its sensitivity. LIGO works by sending lasers back-and-forth down a 4km tube multiple times, and looks for minuscule differences in the timing of their travel. Many of these are local sources of vibration, which need to be tracked. There are two of them at significant distances apart (Washington and Louisiana) in order to eliminate chance events, as well. If both detectors "see" the same events, and other sources are eliminated, then the cause of the distortion is likely to be a gravity wave passing through the space occupied by the photons in the laser.
This is a big deal, as big as the discovery of the Higgs boson. Step back and appreciate the fact that you're alive to see it.
We've had indirect evidence they existed. For example, we've watched two neutron stars in a close orbit, and saw that they were spiraling closer together, with the energy they were losing matching with predictions of relativity to many decimal places. Relativity indicates the energy takes the form of tiny distortions in space time that radiate out from the system, but we've been unable to detect them.
Until now. LIGO (Sponsored by the US' National Science Foundation) went through an upgrade over the past several years that increased its sensitivity. LIGO works by sending lasers back-and-forth down a 4km tube multiple times, and looks for minuscule differences in the timing of their travel. Many of these are local sources of vibration, which need to be tracked. There are two of them at significant distances apart (Washington and Louisiana) in order to eliminate chance events, as well. If both detectors "see" the same events, and other sources are eliminated, then the cause of the distortion is likely to be a gravity wave passing through the space occupied by the photons in the laser.
This is a big deal, as big as the discovery of the Higgs boson. Step back and appreciate the fact that you're alive to see it.
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