The Earth As a Gravitational Wave Detector 70
b30w0lf writes "Gravitational wave detection — i.e. the detection of propagating ripples in spacetime — is a hot subject these days, with ground-based interferometer experiments like LIGO active, and hopes for a space interferometer like LISA. However, physicist Freeman Dyson proposed back in 1969 that the earth itself could be used as a gravitational wave detector. The idea is behind the approach is that gravitational waves impact the earth's crust, causing potentially detectable seismic waves. Using Dyson's approach, Physicists at Harvard and NINP, Florence were able to put an upper limit on the intensity of gravitational background radiation based on a year of observational seismic data (abstract, full pre-print). The upper limit they found improved currently laboratory upper limits by 9 orders of magnitude."
Re:45 year old story (Score:3, Insightful)
Upper Limit on a Stochastic Background of Gravitational Waves from Seismic Measurements in the Range 0.05–1 Hz
Michael Coughlin and Jan Harms
Phys. Rev. Lett. 112, 101102 (2014)
Published March 13, 2014
LIGO is a money pit (Score:4, Insightful)
They've sunk over a billion into the Hanford and Livingston observatories. The LIGO observatories from 2002 to 2010 were only operational for a very small fraction of the time, plagued by equipment problems, never acheived the design sensitivity, and NEVER detected anything useful. Most of their data was contaminated by local noise, including the highway a few miles away. They blindly collected terabytes of raw data that has never been fully analyzed and they have minimal local data analysis capability.
Now NSF is pouring even more money into it in the hopes they can improve the sensitivity and actually detect something? At best they might record a perturbance that is correlated between multiple sites (they also partner with an Australian site I believe), of which the value of that data is still debatable.
I wish the NSF would pull the plug on this waste of resources and invest in something more useful like cleaner nuclear power.