How Do Gravitational Waves Impact a Solid Sphere of Mass?

In summary: There's no evidence that black holes generate gravity waves, but they could potentially do so if they had the energy.
  • #1
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What effect would a train of gravitational waves have when it hits a solid sphere of mass?
We know about its expected effect on a dust sphere where it is ellipsed alternately in x and y direction. I would like to know how would an isolated solid sphere be affected when it is hit by a train of gravitational waves?

Would appreciate if the regular professionals respond - no speculating amateurs please!

Thanks.
 
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  • #2
Is there no one here who wants to tackle this?! (The previous caveat stands though).
 
  • #3
We know about its expected effect on a dust sphere
So you know what the wave tries to do with the sphere. Bonding forces will try to counteract the respective change in distance. Basically, you have a resonator: if the waves are of low frequency, bonding forces will keep the body in shape without noticeable effects. If the wave frequency coincides with a resonant frequency of the body, it will http://en.wikipedia.org/wiki/Gravitational_wave_detector#Weber_bars", as the counteracting force is out of phase then.
 
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  • #4
Ich said:
So you know what the wave tries to do with the sphere. Bonding forces will try to counteract the respective change in distance. Basically, you have a resonator: if the waves are of low frequency, bonding forces will keep the body in shape without noticeable effects. If the wave frequency coincides with a resonant frequency of the body, it will http://en.wikipedia.org/wiki/Gravitational_wave_detector#Weber_bars", as the counteracting force is out of phase then.

Thanks Ich for taking this on.
Is there any motion of the object along the direction of impact of the waves? In other words do they act like a repulsive force? Or is all energy of the waves dissipated in the perpendecular direction of the impact, and there is no net displacement of the body in any direction?
 
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  • #5
Are you sure? I thought gravitational waves worked by length contraction and time dilation.
 
  • #6
Is there any motion of the object along the direction of impact of the waves?
I don't think so, if you don't count that "ringing", which deforms the body also along the direction of impact. There should be no net motion, however.
But I read in a paper that a stochastic background of waves (in all directions) can act like a cosmological constant, very weakly repulsive.
 
  • #7
Ich said:
I don't think so, if you don't count that "ringing", which deforms the body also along the direction of impact. There should be no net motion, however.
But I read in a paper that a stochastic background of waves (in all directions) can act like a cosmological constant, very weakly repulsive.

Intriguing! Could you please post the link to that paper.
Do you know how that weak repulsion could be made consistent with the fact that the amplitude of gravity waves decays as the inverse of distance and therefore the energy of the waves decline. Will the repulsion decay with distance as well? If so, at what proportion to distance?

Thanks.
 
  • #8
http://arxiv.org/abs/0909.1922"
They're talking about waves that fill the whole universe, so it makes not much sense to introduce 1/r² here either. They decay over time.
 
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  • #9
Ich said:
http://arxiv.org/abs/0909.1922"
They're talking about waves that fill the whole universe, so it makes not much sense to introduce 1/r² here either. They decay over time.

Thanks for the link Ich.

Now slightly shifting the focus:

Do gravitational waves, i.e., real gravitons, have a gravitational field, like any normal particle has a gravitational field? Or are real gravitons gravitationally 'neutral'?
 
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  • #10
Do gravitational waves, i.e., real gravitons, have a gravitational field, like any normal particle has a gravitational field?
Hmpf. :confused:

Classically, gravity is nonlinear, i.e. creates gravity. I really have no idea how this translates to the quantum level.
<speculation>
Gravitons go at light speed, so they should gravitate like photons do.
Gravitons carry energy, so they are "charged" like gluons. That's responsible for accelerated expansion, the pioneer anomaly,and the financial crisis.
</speculation>
 
  • #11
Ich said:
Hmpf. :confused:

Classically, gravity is nonlinear, i.e. creates gravity. I really have no idea how this translates to the quantum level.
<speculation>
Gravitons go at light speed, so they should gravitate like photons do.
Gravitons carry energy, so they are "charged" like gluons. That's responsible for accelerated expansion, the pioneer anomaly,and the financial crisis.
</speculation>

Hmmm!:wink: Thanks for trying anyway.
 
  • #12
Gravitational waves do cause light and space to bend, in other words the GWs from a celestial object will cause this.
 
  • #13
Do black holes generate gravity waves?
 

Related to How Do Gravitational Waves Impact a Solid Sphere of Mass?

What are gravitational waves?

Gravitational waves are ripples in the fabric of space-time caused by the acceleration of massive objects. They were first predicted by Albert Einstein's theory of general relativity and were finally detected in 2015 by the LIGO experiment.

How are gravitational waves detected?

Gravitational waves are detected using highly sensitive instruments called interferometers. These instruments measure tiny changes in the distance between two points caused by the passing gravitational waves.

What is the importance of studying gravitational waves?

Studying gravitational waves allows us to gain a better understanding of the universe and its origins. It also helps us to test and refine theories of gravity, as well as potentially uncover new phenomena and sources of gravitational waves.

How do gravitational waves affect space-time?

Gravitational waves cause the fabric of space-time to stretch and compress as they pass through it. This stretching and compressing is what interferometers measure in order to detect the waves.

Can gravitational waves be harmful to humans?

No, gravitational waves are extremely weak and have no harmful effects on humans. They can only be detected by highly sensitive instruments and do not pose any danger to our health or environment.

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