Gravitational wave effects on different materials

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Discussion Overview

The discussion centers on the effects of gravitational waves on different materials, particularly focusing on how these waves may induce differential strains in soft versus stiff materials. Participants explore the implications for gravitational wave detectors like LIGO and whether their sensitivity could be enhanced by altering their mounting systems.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants propose that gravitational waves may distort soft materials, such as ripe tomatoes, more than rigid materials like iron balls, raising questions about the differential effects on various earthly items.
  • It is suggested that the response of materials to gravitational waves will depend on their internal forces and stiffness, indicating a complex interaction between the waves and material properties.
  • Participants note that gravitational wave detectors like LIGO are designed to have free-to-move mirrors, which ideally do not have rigidity, and that the design aims to suppress noise from Earth vibrations rather than directly measuring gravitational wave effects.
  • There is a mention of proposals for space-based gravitational wave detectors, where mirrors would be mounted on separate satellites, potentially avoiding ground-related perturbations.
  • A summary reiterates the initial question about whether gravitational waves squash soft materials more than stiff ones, linking back to the effects of Earth's gravity as a comparative example.

Areas of Agreement / Disagreement

Participants express varying views on the effects of gravitational waves on different materials, with no consensus reached on the implications for detector sensitivity or the nature of material response.

Contextual Notes

The discussion highlights assumptions regarding material properties and the operational principles of gravitational wave detectors, but these aspects remain unresolved.

Andy DS
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TL;DR
Do gravitational waves squash soft materials more than stiff ones?
Given that the Earth's gravity will distort, say, a soft fruit like a ripe tomato more than an iron ball, can we say gravitational waves from space have the same differential effects on these and other common earthly items.
Does LIGO experience the effects of gravitational waves due to the distortion of the planet, if so could it be made more sensitive by mounting it on a soft more conformable base.
 
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The gravitational wave will induce strains in the object, and its internal forces will dictate how it responds. So the result will depend on material stiffness, yes.

Gravitational wave detectors are essentially free-to-move mirrors and a device that measures the distance between them. They have zero rigidity, ideally. Earth-based detectors need extremely rigid casings and very carefully designed mirror mounts to avoid transmitting vibration from the Earth to the detector. That's not really about detection of gravitational waves, though, just about suppressing noise.

I believe rigid-bar detectors were once suggested, but the LIGO type is more sensitive.
 
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OK, so the mirrors aren't rigidly mounted and their position will be perturbed relative to the ground by the passing waves.
 
The mirrors move relative to each other (or at least, the distance between them changes). The ground is (ideally) not relevant to the operation of the detector. In fact, there are proposals for space-based sensors where the mirrors are on separate satellites.

https://en.wikipedia.org/wiki/Laser_Interferometer_Space_Antenna
 
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Andy DS said:
TL;DR Summary: Do gravitational waves squash soft materials more than stiff ones?

Given that the Earth's gravity will distort, say, a soft fruit like a ripe tomato more than an iron ball, can we say gravitational waves from space have the same differential effects on these and other common earthly items.
Does LIGO experience the effects of gravitational waves due to the distortion of the planet, if so could it be made more sensitive by mounting it on a soft more conformable base.
https://www.ligo.caltech.edu/page/ligo-technology
 
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