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Don't these gravitational wave detectors usually come in pairs?
by ginko 5y ago
Don't these gravitational wave detectors usually come in pairs?
- brnt 5y agoThat would be the European thing to do, true.
- ncallaway 5y agoNot just a European thing, but also an important science thing. LIGO, which made the first gravitational wave detections, is located in the US and also has a pair of detectors (one in Hanford Washington; the other in Livingston, Louisiana). The reason to build in pairs is because the detectors need to be _extremely_ sensitive in order to detect gravitation waves. Such sensitive detectors can easily pick up all kinds of noise from local phenomena (such as a truck driving nearby), so having two sites separated by a good distance helps rule out local noise. Only signals that are replicated across both sites need to be evaluated. There are other benefits to have multiple detectors, too. Having two detectors gives us some ability to determine the direction the wave is coming from. More detectors will allow us to determine the direction even more precisely.
- Bombthecat 5y agoWouldn't 3 better than? For quorum?
- petschge 5y agoThey would. But it is harder to get funding for three than it is to get funding for two...
- ncallaway 5y agoIf you had infinite resources, sure! It’s a cost benefit analysis (and one I’m not remotely equipped to make). My guess is they went with two sites because that was the smallest number they could get away with while still being able to make detections.
- deleted 5y ago[deleted]
- emiliobumachar 5y agoGreat explanation, thanks. I'd like to add that the cost for two would be much less than twice the cost for one, due to the design reuse of all the custom equipment.
- magicalhippo 5y agoIt should be noted that while LIGO has one detector per site in an L shape, the Einsten Telescope (ET) will have three, each one in the corner of an equilateral triangle[1]. The idea is that this provides enough of a cross-check to rule out local sources and glitches. [1]: https://en.wikipedia.org/wiki/Einstein_Telescope#Current_design https://en.wikipedia.org/wiki/Einstein_Telescope#Current_des...