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3
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2answers
42 views

Does shortening the path length of an excited etalon do work? What about LIGO?

Start with a high-Q etalon excited on-resonance with a laser for a time long enough that it has built up an essentially stable standing wave. There is a constant outwards-directed force on each mirror,...
0
votes
1answer
49 views

Can revolving movement also generate gravitational waves? [on hold]

If an object revolves around a circular path at the speed of light could it still generate gravitational waves and what would be the simulation in inner area?
2
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2answers
36 views

What cosmic event would have to occur for us to notice gravitational waves in everyday life? [duplicate]

I read that gravitational waves are so tiny that we need extremely precise equipment to detect them. I am no physicist, but GR really intrigues me and I was wondering about two things: How powerful ...
0
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0answers
44 views

Is there any primordial gravitational wave(form) that could explain dark energy?

First, I asked myself the question: Is there any gravitational waveform, however fantastical, that could explain dark energy. I suppose for a ubiquitous gravitational wave to be an explanation for ...
30
votes
3answers
2k views

How much mass can colliding black holes lose as gravitational waves?

Concerning the recent detection of gravitational waves produced by colliding black holes, it has been reported that a significant percentage of the combined mass was lost in the resulting production ...
4
votes
3answers
122 views

Does a planet/star itself lose mass when it 'emits' gravitational waves?

Orbiting planets and stars can create gravitational waves, as seen with the LIGO. But are they also losing mass-energy. Beside that, the kinetic energy associated with their orbital angular momentum ...
0
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0answers
17 views

What position are the BOSEMs in LIGO measuring?

As I understand it, the quadruple pendulum of LIGO is also actively positioned, in addition to the seismic damping of the ISI. What I don't understand is: relative to what are the BOSEM sensors ...
1
vote
1answer
55 views

How do gravitational waves transfer momentum?

In Electromagnetism I understand it in terms of the Lorentz force: the E-component of the field causes the charge to respond infinitesimally with a $\vec{v}$ in the E-direction such that the $\vec{v}\...
1
vote
1answer
45 views

Distortion of interference pattern at LIGO

Does the vibration due to the earthquakes distort the interference pattern of LIGO's interferometer?
1
vote
1answer
45 views

Determining the direction of origin for gravitational waves

For LIGO's first gravitational wave detection, GW150914, the signal first reached Livingston, LA and then about 7 ms later reached Hanford, WA. Based on the sequence it was stated that black-hole ...
3
votes
3answers
150 views

Transfer of energy from gravity back to other “more familiar” forms of energy?

In this question I've mentioned an account of the recently reported 2nd observation of gravitational waves, LIGO and Virgo Collaborations, Phys. Rev. Lett. 116, 241103, 15 June 2016, where 1 of the ...
5
votes
2answers
109 views

What is the uncertainty in the one solar mass radiated away as pure energy? (Gravitational waves)

edit: Thanks to the comment below - I learned that the PLR is available to read http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.116.241103. In it, ref. 5 links to this preprint dated June15, 2016: ...
3
votes
1answer
135 views

How to read numbers reported in this LIGO paper?

I am not sure how to read the numbers in this excerpt from the abstract of GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence: Are the +/- small ...
-7
votes
1answer
182 views

Why does Ligo's second detection of gravitational waves and a black hole merger look absolutely nothing like the first? [closed]

Why does Ligo's reported second detection of gravitational waves and a black hole merger look absolutely nothing like the first detection announced in Februaray? Here is the data from the first LIGO ...
25
votes
2answers
3k views

Why were the GW detections at Livingston and Hanford separated by 7 ms if the light travel time between them is 10 ms?

How did a gravitational wave travel from Livingston, Louisiana to Hanford, Washington in 7 milliseconds, when they are separated by 10 milli-light seconds (3002 km)?
2
votes
1answer
40 views

Can we repulse metter by specially crafted gravitational waves?

Assuming we could generate arbitrary gravitational wave patterns (somewhat like we can do with electromagnetic radiation now), what effects would we be able to achieve? In particular, would it be ...
0
votes
0answers
22 views

High Amplitude, Low Frequency Gravitational Waves

Theoretically, how would a Gravitational Wave with a Sufficiently High Amplitude/Intensity such that it were easily measurable or larger, and a frequency low enough such that the wavelengths were ...
0
votes
1answer
41 views

Gruchestein Effect?

I overheard that name in a conversation, but not very clearly. I can't find anything on Google, probably because of my spelling is completely wrong. Does anybody knows about an effect with a similar ...
0
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0answers
21 views

Need a mass to accelerate to create gravitational waves?

For a charged particles which travels through an electric field it only emits photons when it is accelerated. It undergoes a change of momentum, and the law of conservation of momentum requires some ...
1
vote
1answer
35 views

Can an electron make quadrupole gravitational waves?

A gravitational wave is a quadrupole wave. Now when an electron is accelerated it usually emits a photon. But can an electron also emits an gravitational wave? If so how does it 'make' an quadrupole ...
-4
votes
1answer
66 views

Gravitational waves (linearized gravity) [closed]

Even in the Schwarzschild metric we can write $g_{uv}=\eta_{uv}+h_{uv}$ where $h_{uv}$ is very small. So after some coordinate transformation (using gauge freedom) we can simplify the Einstein ...
2
votes
3answers
89 views

Why do we say gravitational waves are analogous to sound?

In every popsci discussion of gravitational waves, the waves are said to be like "sound", and that gravitational waves allow us to "hear" the universe. Despite this, I have no idea how gravitational ...
2
votes
1answer
77 views

Will the speed of gravity and the speed of light always be the same?

I have been considering the following though experiment: If the entire sun were to disappear at once, would we feel it first due to the sudden drop in gravity or see it first? The answer I have come ...
0
votes
1answer
45 views

Why do LIGO use a quarter wavelength for detecting gravitational waves?

I have already researched into this and I am left slightly confused still. I have gathered that the use of a quarter wavelength is to turn a linearly polarised wave into a circularly polarised wave. ...
1
vote
1answer
56 views

Could gravitational waves have a large entropy in quantum gravity?

The question is broad, and we still don't know what is quantum gravity. But let me be more specific. In the question (on this site, see below) on whether gravitational waves have entropy the answers ...
6
votes
1answer
131 views

Gravitational wave and string theory

I'm new to physics and have been reading about fundamental and textbook physics text, which is the Young & Freedman University Physics (good book). I'm little skeptical towards string theory as ...
8
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2answers
185 views

Do gravitational waves have entropy?

We know, according the current understanding of black holes and General Relativity, as well as quantum fields in General Relativity, that black holes have an entropy proportional to the area of the ...
0
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0answers
21 views

LIGO Gravitational Wave Discovery and Gravitons [duplicate]

Now that gravitational waves have been detected, how hard will it be to detect a graviton? Will the equipment have to be more sensitive or are the difficulties more complicated than that?
2
votes
1answer
66 views

Do gravitational waves radiate isotropically?

Do gravitational waves radiate equally in all directions? If so, is this an inherent property of all gravitational waves or is it just due to how they are normally produced? In other words, in a ...
2
votes
1answer
31 views

Does an object creates gravitational waves when only accelerating in one direction?

I know from reading about the gravitational waves detected by Ligo, that when an object has angular acceleration, it produces gravitational waves. I'm wondering if an object creates gravitational ...
1
vote
1answer
77 views

At what rate do gravitational waves lose energy and amplitude?

Part 1: How do gravitational waves decay with distance? My Newtonian instincts tell me that gravitational waves would likely decay in the same way that Newtonian gravity decays, but at this point I'...
1
vote
1answer
26 views

scaling law of gravitational waves and consequences

With which power law of distance is decreasing the amplitude of the distortion caused by a gravitational wave ? $r^{-1}$ ? $r^{-2}$ ? something else ? -> The coalescence between 2 black holes about a ...
0
votes
2answers
76 views

Speed of gravitational waves and light

We all know that speed of gravitational waves (GW) and that of light in space are exactly the same (= $c$). We also know that space is medium for GW. Does that mean space is also the medium for ...
2
votes
1answer
65 views

Gravitational waves and it's interaction with matter

I have been reading an article on gravitational waves here. There, it is written that the gravitational wave, unlike the electromagnetic waves, interact very weakly with matter. The principle of LIGO ...
0
votes
0answers
31 views

Gravitational waves' Amplitude

Gravitational waves are disturbances in gravitational field which in turn is the curvature of space-time. So my question is it possible to somehow measure the amplitude of a gravitational wave and if ...
5
votes
3answers
176 views

Do gravitational waves propagate backwards in time?

Gravitational waves are spacetime waves, which stretch and squeeze both space and time. Since relativity puts space and time (almost) on an equal footing, it seems to me that since gravitational waves ...
0
votes
0answers
40 views

How does one derive Christodoulou Memory Effect?

There is a non-linear effect associated to the permanent displacement of test masses when a gravitational wave interact with them. This is called the Christodoulou memory effect. How does one obtain ...
8
votes
3answers
671 views

Speed of gravitational waves vs speed of light

I own an educational YouTube channel on physics and astronomy. I am currently working on a gravitational waves video extension to my "How Fast Is It" video book on relativity theory. I have a question ...
3
votes
1answer
76 views

Is there high ring-down frequencies in LIGO's recent discovery?

This question is from Physics overflow: question in physicsoverflow. I am reading LIGO's new discovery of gravitational waves by black hole merger. During the merger, two phases are not hard to ...
0
votes
1answer
45 views

Can gravitational waves interfere polarize or show any other properties of stndard waves

Is it possible for gravitational waves to be able to produce phenomenon such as interference and polarization etc. which are observed in standard waves. Also is it possible for gravitational waves to ...
3
votes
2answers
80 views

Why are they building eLISA and what implications would it have?

I understand that the next step after LIGO is to plan and build eLISA, I understand that out in space there are a lot less interferences compared to Earth which makes it a good way to detect things we ...
3
votes
0answers
98 views

Gravity vs Gravitational Waves

I thought I had a reasonable understanding of relativity, the speed of light speed limit, and how this stuff related to gravity. Then I read through all the answers/comments for this question: How ...
1
vote
1answer
62 views

Gravitational wave equations worked out

Is there a website where gravitational wave equations are worked out numerically? I would like to experiment with mass configurations but can't find examples.
0
votes
0answers
27 views

Non equilibrium black hole radiating away energy and angular momentum, with total energy and angular momentum conserved

The question refers to whether mass (i.e., energy) and angular momentum can be considered to have been carried away by the gravitational radiation in the hole settling down. And whether those entities ...
4
votes
1answer
103 views

Gravitational waves from neutron star - neutron star merger

How is neutron star-neutron star merger different from Black Hole-Black Hole merger and what information can be extracted from gravitational waves emitted by these processes?
1
vote
2answers
122 views

A spin zero graviton?

Why can the graviton not be a spin 0 particle? On a similar note why can it not be a spin 4, spin 6 particle?
27
votes
10answers
11k views

How does Zumberge's 1981 gravitational measurements relate to gravitational waves?

Gravitational waves were discovered 35 years ago without fanfare in 1981/2 by Zumberge, R L Rinker and J E Faller, then completely ignored. See: "A Portable Apparatus for Absolute Measurements of ...
3
votes
2answers
600 views

Producing gravitational waves in labs

Can gravitational waves be created on very small region of vacuum with quadruple movement of atom or subatomic particles?
0
votes
0answers
18 views

Why is graviton not found yet? [duplicate]

Why is graviton not found yet? Newton said gravity pulls us, Einstein said space is bent and it pushes us, hawking predicts the existence of graviton and 'hawking radiation'. How far are we from ...
0
votes
1answer
102 views

Do Gravitational Waves disprove superluminal Alcubierre drive?

I am not a physicist. But... does the rate at which gravitational waves travel set an upper limit to the "speed" of a ship propelled with Alcubierre drive? Or does it present a relativistic trick (...