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In GR what is a “source-frame mass”?

In the recent LIGO paper, they refer to the masses in some models as: "... a nearly equal mass black-hole binary system of source-frame masses $36^{+5}_{−4} M_{\odot}$ and $29^{+4}_{−4} M_{\odot}$ ...
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1answer
18 views

Do Gravitational waves travel faster than light?

Today, a newspaper article read (with the discovery of Gravitational waves, we will be able to) Track Supernovas hours before they're visible to any telescope because the waves arrive Earth long ...
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6 views

How much force is required to produce a noticeable gravitational wave?

By noticeable, I do not mean noticeable from half way across the galaxy to our observatories, but noticeable as in, if there were an object with enough mass and energy within say, the distance of our ...
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2answers
44 views

Redshift of merging black holes

How did they found that the gravitational waves where emitted at redshift $z=0.09$? I understand the measurement of redshift for an electromagnetic wave where we have measured in a lab various ...
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1answer
1k views

What is the difference between gravitons and gravitational waves?

What is the difference between gravitons and gravitational waves? So as I understand, gravitational waves are predicted by and part of the theory of general relativity, whereas gravitons are predicted ...
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9 views

Is there a connection between Space-Time Vortex and Gravitational Waves?

Is there a connection between Space-Time Vortex and gravitational waves ? Space-Time Vortex
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30 views

How does LIGO account for curvature of Earth?

Using a earth curvature calculator I found that a distance of 4km (length of LIGO) causes more 1.26m to be hidden. When constructing LIGO, did they account for the curvature to allow the beam to ...
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1answer
48 views

Why are Gravitational Waves so small?

I'm sure you've all seen the diagrams and/or 3D visualizations of gravity; the ball sitting on a piece of fabric which makes it sink down. They've also started using it in the videos that explain ...
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1answer
60 views

Does the existence (now proved) of gravitational waves imply the existence of Gravitons?

I studied the theoretical part about the Gravitational waves in General Relativity (linearization of gravity and small perturbations of the metric and so on). But I was wondering about: since ...
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1answer
76 views

How gravitational waves are exactly produced?

I was thinking about gravitational waves, and I found out that I may have a doubt about their production. Assuming the whole calculations find a wave-like solution to be understood, I was wondering ...
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2answers
981 views

How strong were the gravitational waves that LIGO detected at the source?

Congrats to the LIGO team on the announcement of their discovery of gravity waves! The articles I've read say that the distortion we see here is much smaller than a proton. What about at the source? ...
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1answer
33 views

If the solar system is a sensitive chaotic system, can gravity waves make orbits unpredictable?

Scott Tremaine says here ..for practical purposes the positions of the planets are unpredictable further than about a hundred million years in the future because of their extreme sensitivity to ...
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3answers
2k views

Why is the detection of gravitational waves so significant?

Since there is to be an announcement about this today, I was wondering what the significance was of detecting gravitational waves. I know it is another confirmation of GR, but I thought we had already ...
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31 views

What would it look like if the earth were suddenly put on the anti-node of a gravitational standing wave with a huge amplitude?

What would it look like if the earth were suddenly put on the anti-node of a gravitational standing wave with a huge amplitude? Can gravitational standing waves even exist? Say if there were two ...
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0answers
40 views

In what shape do gravitational waves radiate?

The recent detection of gravitational waves made me wonder how the amplitude of the waves fell off with distance. My first naive thought was that it was probably by the cube of the distance. ...
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32 views
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2answers
65 views

At which point are gravitational waves generated when two black holes merge?

I was reading today's announcement of the gravitational waves and was wondering about this situation where there are two orbiting black holes. Did the wave come from the final merging or was it from ...
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43 views

How is it that gravitational waves can be detected by measuring distances?

If gravitational waves stretch space itself, how can they have an effect on the interference of two laser beams? According to my understanding, compression or dilation of space itself (as opposed to ...
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1answer
57 views

Are there waves of time?

If I understand correctly, gravitational waves are ripples in the fabric of space-time itself created by the movement of mass. Moreover, space and time are just dimensions of the same space-time ...
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1answer
42 views

How did LIGO detect the source location of the black holes mentioned to be the cause of today's announcement?

Today LIGO announced discovery of Gravitational waves. What method was used to determine the source location of the waves?
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1answer
79 views

So Black Holes Actually Merge! In 1/5th of a Second - How?

I've read a lot of conflicting answers in these forums. However, today saw the awesome announcement of gravitational waves. Two black holes merged: ...
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2answers
97 views

What will be the role of gravitational waves in future physics? [on hold]

What does this discovery mean for us? Can it lead to a better understanding of the cosmos?
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1answer
225 views

Can LIGO measure anything?

LIGO, Laser Interferometer Gravitational-Wave Observatory, is a large-scale physics experiment aiming to directly detect gravitational waves. The device measures the phase shift laser beams. If I ...
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0answers
28 views

Why do we assert Hulse–Taylor binary system's orbital decay to gravitational waves and not radiation?

From https://en.wikipedia.org/wiki/PSR_B1913%2B16#Star_system The Hulse–Taylor system's orbit has decayed since the binary system was initially discovered, in precise agreement with the loss of ...
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79 views

What is a good PhD Thesis Topic in General Relativity? [on hold]

For many reasons I am very uncertain whether I should agree to a particular topic for my PhD thesis. The thesis topic would be about "gravitational lensing". There are two main concerns: i) My ...
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2answers
140 views

Why are nonrelativistic methods used in binary pulsar systems (gravitational waves)?

Although gravitational waves are a subject of the General Relativity, why do most books use Newtonian equations of motion for power radiated and rate of change of eccentricity calculations? In most ...
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1answer
330 views

Would warp bubbles emit gravitational Cerenkov radiation in general relativity?

Inspired by the gravtiomagnetic analogy, I would expect that just as a charged tachyon would emit normal (electromagetic) Cerenkov radiation, any mass-carrying warp drive would emit gravitational ...
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2answers
57 views

Space-time and gravitational fields

I am reading a book by Carlo Rovelli, Seven Brief Lessons On Physics, and would like to check if I have understood something. Apologies if my question is badly phrased, feel free to edit where ...
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0answers
82 views

Gravitational waves: novel or confirmatory? [duplicate]

If the rumors are true and gravitational waves have been detected, would we learn any new fundamental physics from them? Or is this simply an important confirmation of a prediction of general ...
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2answers
123 views

Gravitational waves, tides and the end of universe

Is tides proof of gravitational waves with low frequency? According to Wikipedia, In physics, gravitational waves are ripples in the curvature of space-time which propagate as waves, travelling ...
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2answers
241 views

Gravitational waves and time

Two questions. It is said that time can only go slower in gravity fields and if you move faster. I have heard that when a gravitational wave pass earth then the space/time vibrate and time change ...
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3answers
82 views

Could the recent evidence of a gravitational force orbiting the solar system indicate not the existance of a ninth planet, but rather a black hole?

In case you haven't heard already, researches at the California Institute of Technology discovered mathematical evidence of large object orbiting the sun at a distance about 20 times further than that ...
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55 views

Can gravitational waves produce “sonic boom”?

I've heard that a fast moving object such as a jet plane traveling much faster than speed of sound can produce shockwaves which is also known as sonic boom, also Cherenkov radiation is produce by ...
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0answers
49 views

Gravitational wave as a consequence of gravity being a field

I was reading an online article about gravitational wave detection and there is a sentence which says: The existence of gravitational wave is simply a consequence of the fact that gravity is a ...
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1answer
116 views

What are the benefits of Gravitational wave studies?

Gravitational waves were first predicted by Albert Einstein and later indirectly confirmed in an number of experiments. Recently leading physicists announced that they may have a 'solid' proof that ...
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2answers
198 views

The ADM Energy of Gravitational Waves?

I have been looking for books about this question for several days. However, almost all books use Landau–Lifshitz pseudotensor to calculate the energy of Gravitational Waves.And they said the result ...
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1answer
141 views

Isn't LIGO basically measuring the luminiferous aether?

I am bit confused about this one. I am not very acknowledgeable about gravitational waves and LIGO. But if it is basically a Michelson interferometer and can detect shifts in vacuum, doesn't this ...
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3answers
211 views

What would be the implications for current theories if gravitational waves are not detected?

Let's assume that scientists trying to detect gravitational waves get a huge raise in funding, design even better experiments, and run them for decades, but just can't find any gravitational waves ...
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1answer
357 views

Simple quadrupole field not yet in Lorenz gauge?

I'm having trouble reproducing some of the results regarding gravitational waves in the Wald's General Relativity. In section 4.4 of gravitational radiation, eq.4.4.49 shows the far-field generated ...
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1answer
181 views

Unbounded perturbed geometry due to analiticity

I have an interesting mystery for you, loosely inspired on work related with this question. I have a certain Ansatz for a gravitational wave perturbation of the metric $h_{\mu \nu}$ that is nonzero ...
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1answer
386 views

Are there weak force waves?

In the same way as there are electromagnetic and gravitational waves that update the information on their respective field, is there an analogue for the weak and strong forces?
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0answers
54 views

Transforming to the Transverse-Traceless gauge

I have a certain Ansatz for a gravitational wave perturbation of the metric $h_{\mu \nu}$ that is nonzero in a compact set of background flat Minkowski spacetime But the Ansatz field does not satisfy ...
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2answers
770 views

Do gravitational waves slow down as they pass through matter?

I've heard that gravitational waves travel at the speed of light, and have some parallels to electromagnetic waves. EM waves slow down as they pass through matter (speed of light in glass is slower ...
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1answer
680 views

The final parsec “problem”

Many and perhaps all galaxies seem to contain supermassive black holes of about $10^7 M_\odot$ at their centres. Determining their origins is of great astrophysical interest. In what I understand to ...
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3answers
605 views

Do gravitational waves cause time dilatation?

The effect of gravitational waves in transverse traceless gauge on matter is represented by the expansion and contraction of a ring of test particles in the direction of polarization of the wave. ...
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1answer
36 views

Why only binary star system produce ripples in space-time (gravitational waves)?

I saw a statement being made in a video, but it didn't explain why. It originally said, "stars orbiting each other does not create gravitational waves, binary system of two massive stars or black hole ...
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1answer
424 views

Are some gravitational wavelengths forbidden by causality?

Consider a gravitational wave in linearized gravity $d_{\mu \nu}(X_{\eta}) = D_{\mu \nu} e^{i X_{\eta} K^{\eta}}$ with $K^{\eta} = (-\omega t, \textbf{k})$. Let $d=| \textbf{D}|$ the scalar maximum ...
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1answer
108 views

Gravity amplifier

Just a hypothetical question. Is it possible to increase or amplify gravitational interactions between two or more bodies ( without changing the mass)? Will changing the graviton ...
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3answers
361 views

Do gravitational waves exist at the quantum level?

Do gravitational waves exist at quantum level produced by electrons or by atoms or by molecules? If yes, which particle produces them and how are they produced? Spacetime exists at a quantum level ...