How does Quadruple Pendulum isolate LIGO from Seismic Vibrations?

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nvikas
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On 28 November 2018, a lecture was given by Dr. Rainer Weiss (2017 Nobel Prize Winner for Physics) at the Ontario Science Centre, Toronto. The lecture was about his work with the Laser Interferometer Gravitational-Wave Observatory (LIGO).

In his lecture talked about quadruple pendulums or four pendulums vertically stacked one below the other. LIGO uses such pendulums to isolate its mirrors from seismic vibrations. Gravitational Waves and Seismic Vibrations have overlaps in frequencies.

He encouraged the audience to make a quadruple pendulum using washers and strings to see for themselves how they worked. We took up this challenge and planned an experiment around it. The best way to learn science is by doing an experiment.

We made a quadruple pendulum and added accelerometers to it, to get change in motion data at each stage. After the experiment, it became clear to us how the quadruple pendulum works and why it is used in LIGO.

Check our experiment and data:
https://hotpoprobot.com/2019/04/07/ligo/

 
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Orodruin said:
Very nice home experiment. Do you also have some video showing the pendulum in action? I can only see still images from your homepage.
Thanks. At this moment, we do not have any videos. But we will record them once we run this experiment again.
 
On 22 May 2019, we gave a presentation on our project:
How does Quadruple Pendulum isolate LIGO from Seismic Vibrations? at the meeting of the Royal Astronomical Society of Canada -Toronto at the Ontario Science Centre.

The video of the presentation: which show the pendulum in action, and live data being gathered is available at:

Complete details about the project are available at:
https://hotpoprobot.com/2019/04/07/ligo/
 
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Orodruin said:
Very nice home experiment. Do you also have some video showing the pendulum in action? I can only see still images from your homepage.

Thanks. We now have the video available based on the presentation we gave at the Ontario Science Centre. It can be viewed at:
 
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