[1123581321]

I was wondering, like sound waves are vibrational waves of particles. How exactly are gravitational waves related. So are they vibrations of atoms ? and if so are they transverse or longitudinal vibrations ?

[ajb]

They are vibrations of space-time, or really in the curvature of or the metric on space-time.

[csmyth3025]

1123581321, on 19 July 2011 - 02:00 PM, said:

I was wondering, like sound waves are vibrational waves of particles. How exactly are gravitational waves related. So are they vibrations of atoms ? and if so are they transverse or longitudinal vibrations ?

http://upload.wikime...olarization.gif

The above link is an animation of how a gravitational wave would effect a ring of particles. The animation is taken from the Wikipedia article on Gravitational Waves here:

http://en.wikipedia....vitational_wave

Chris

[Mystery111]

Gravitational waves are none trivial in Einsteins Theory, meaning that you can have a curvature of spacetime but not the presense of matter. This is of course the presence of gravitational waves. Gravitational waves would be the curvature itself.

[guenter]

Mystery111, on 21 September 2011 - 10:52 AM, said:

Gravitational waves are none trivial in Einsteins Theory, meaning that you can have a curvature of spacetime but not the presense of matter. This is of course the presence of gravitational waves. Gravitational waves would be the curvature itself.

While Ricci curvature vanishes in the absence of matter (flat space) there is still Weyl curvature propagating with gravitational waves. To my understanding the Weyl tensor is responsible for tidal effects (stretching, shrinking) in the x-y-plane (the wave propagates in z-direction). This is only true for small fields (plan wave solution). But I wonder whatelse the Weyl curvature is responisble for. Is the x-y-plane flat like Minkowski-spacetime? If not, are triangles in this plane oszillating from concave to convex or whatelse would characterize this curvature? I have seen something like this but wasn't sure about the meaning and will search for it.

It would be great, if you could clarify this question.

[guenter]

I have posted my question in the sub forum "Relativity".

[Mystery111]

1123581321, on 19 July 2011 - 02:00 PM, said:

I was wondering, like sound waves are vibrational waves of particles. How exactly are gravitational waves related. So are they vibrations of atoms ? and if so are they transverse or longitudinal vibrations ?

They are the distortions carried when matter will radiate. Needless to say, a large amount of time is required before matter will radiate away in the form of gravitational waves.

[guenter]

Mystery111, on 30 November 2011 - 02:21 PM, said:

Quote

1123581321, on 19 July 2011 - 03:00 PM, said:I was wondering, like sound waves are vibrational waves of particles. How exactly are gravitational waves related. So are they vibrations of atoms ? and if so are they transverse or longitudinal vibrations ?

They are the distortions carried when matter will radiate. Needless to say, a large amount of time is required before matter will radiate away in the form of gravitational waves.

Gravitational waves are transverse waves like electromagnetic waves (and water waves).

Matter will not be radiated away. A binary neutron star e.g. looses gravitational binding energy while emitting gravitational waves, which results in an orbital decay of the system. Finally the stars are coalescing due to the loss of angular momentum.

This post has been edited by guenter: 2 December 2011 - 04:38 PM

[questionposter]

Can you surf on gravitational waves?

[Mystery111]

Of course matter will eventually radiate away in the form of gravitational waves. This is what Dyson worked out from his calculations. I will give you three examples of solutions to what will happen, there are more and will recite them all if you want.

Within the central region of the Galaxy may be expected to collapse into a Black Hole while stars in the outer region are detached from it.

After years, steller orbits around the Galaxy will decay into gravitational waves

After years, all ordinary matter will have fissioned or fusioned to iron through radioactive processes.


Please don't contradict me, I know what I am talking about. I knew this about his equations many years before today.

That was to guenter, sorry^^

This post has been edited by Mystery111: 5 December 2011 - 09:37 PM

[imatfaal]

How does static matter get radiated away as gravitational waves?

if after 10^19 years the centre has collapsed to a black hole and the outer region are no longer gravitationally bound then where do the gravitational waves come from?

10^1500 years - iron, seriously ? we will be in a warm radiation dominated universe by then - ie heat death, the big boring, dullsville tennessee .

[swansont]

Mystery111, on 5 December 2011 - 09:37 PM, said:

Of course matter will eventually radiate away in the form of gravitational waves.

Gravitational waves are not matter.

[Mystery111]

swansont, on 6 December 2011 - 04:51 PM, said:

Gravitational waves are not matter.

Given enough time, matter will radiate away, and all that will be left is graviational waves. Gravitational waves are non-trivial, they are a presence of curvature in the universe even when matter is not present.

The fact matter is predicted to radiate gravitational waves is an aspect predicted by dyson and his equations.

imatfaal, on 6 December 2011 - 04:07 PM, said:

10^1500 years - iron, seriously ? we will be in a warm radiation dominated universe by then - ie heat death, the big boring, dullsville tennessee .

Actually I agree with this statement. This is what Dyson predicted.

stationary mass does not radiate wave's however. Only an acceletating mass will. I should have mentioned that.

Gravitational waves basically carry energy away from their sources.

''and in more detail in a 1918 paper, Einstein showed that when a mass accelerates – in other words, changes its state of motion – it can't help but give rise to time-varying gravitational fields that travel away from the source at light-speed as undulations in the surface of spacetime.''

http://www.daviddarl...G/gravwave.html

Imaatfal

I think you have the concept of heat death wrong. It does not imply a warm radiated universe.

It means that the universe will cool down.

[swansont]

Mystery111, on 7 December 2011 - 05:10 PM, said:

Given enough time, matter will radiate away, and all that will be left is graviational waves. Gravitational waves are non-trivial, they are a presence of curvature in the universe even when matter is not present.

The fact matter is predicted to radiate gravitational waves is an aspect predicted by dyson and his equations.

"Matter radiates gravitational waves" is not the same as "matter will radiate away as gravitational waves" Where does the matter go? I have a bunch of quarks (in some form) and possibly leptons. And suddenly they aren't there?

[Mystery111]

swansont, on 7 December 2011 - 09:28 PM, said:

"Matter radiates gravitational waves" is not the same as "matter will radiate away as gravitational waves" Where does the matter go? I have a bunch of quarks (in some form) and possibly leptons. And suddenly they aren't there?

stop being pedantic. It is clear what I meant!

This reminds me of the time you corrected someone on the difference between mass and matter.

There is no need for it.

[DrRocket]

Mystery111, on 8 December 2011 - 12:04 AM, said:

stop being pedantic. It is clear what I meant!

This reminds me of the time you corrected someone on the difference between mass and matter.

There is no need for it.

The only thing that is clear is your propensity to pontificate on subjects about which you know absolutely nothing. In fact you know less than nothing as what you say is often wrong, but couched in buzz words designed to bamboozle neophytes.

Matter most certainly will not always radiate away as gravity waves. Were that the case there would be no such thing as a stable particle.

[swansont]

Mystery111, on 8 December 2011 - 12:04 AM, said:

stop being pedantic. It is clear what I meant!

This reminds me of the time you corrected someone on the difference between mass and matter.

There is no need for it.

No, it wasn't clear to me what you meant (you don't get to decide if it was clear to me, only I can decide that), and there is absolutely a need for it.

[Mystery111]

DrRocket, on 8 December 2011 - 12:11 AM, said:

The only thing that is clear is your propensity to pontificate on subjects about which you know absolutely nothing. In fact you know less than nothing as what you say is often wrong, but couched in buzz words designed to bamboozle neophytes.

Matter most certainly will not always radiate away as gravity waves. Were that the case there would be no such thing as a stable particle.

is that really true?

I mean, I did actually say I should have mentioned it was for accelerating objects, well before this post.

So if anyone is misrepresenting facts, it is you!

swansont, on 8 December 2011 - 12:58 AM, said:

No, it wasn't clear to me what you meant (you don't get to decide if it was clear to me, only I can decide that), and there is absolutely a need for it.

Well, ... ok?

[DrRocket]

Mystery111, on 8 December 2011 - 01:02 AM, said:

is that really true?

I mean, I did actually say I should have mentioned it was for accelerating objects, well before this post.

So if anyone is misrepresenting facts, it is you!

Wrong,

[guenter]

DrRocket, on 8 December 2011 - 12:11 AM, said:

Matter most certainly will not always radiate away as gravity waves. Were that the case there would be no such thing as a stable particle.

In deed, the masses of the elementary particles are considered as physical constants.

This post has been edited by guenter: 8 December 2011 - 04:44 PM