Gravity waves and the aether

[Mike Smith Cosmos]

It used to be a common idea that a wave has to wave 'something', i.e. it needs a medium.

However the model we use, relativity, doesn't require a medium.

It also demands that there is no absolute reference frame.

And since the medium would provide an absolute reference frame against which motion could be judged, a medium is not only not required, but actually forbidden.

 

We'd have to get rid of relativity to make you happy, Mike.

And, although we all like you, that's not gonna happen.

.

 

Yes but you could always lower me down over the edge on a long coil of copper wire , and I could shout back what I see

 

" but it's all so beautiful " !

 

Then you could just let go

Edited June 20, 2016 by Mike Smith Cosmos

[Strange]

Yes , but surely rockets DO need a medium otherwise they would just drop over the edge of the void , where space ran out , and there was absolutely nothing there , over the edge , nothing !

 

I thought Frank Willczek and Ed Whitton , had both come up with the ideas that there was something there , rather than nothing ?

 

Perhaps it's this 'nothing' that I can not come to terms with ?

 

Mike

 

 

Space is NOT completely empty, so you don't need to worry about that. There is gas, dust, virtual particles and fields (such as the electromagnetic field).

 

Rockets would work just as well if space were completely empty. And light would propagate if space were completely empty apart from the electromagnetic field.

[StringJunky]

 

 

Space is NOT completely empty, so you don't need to worry about that. There is gas, dust, virtual particles and fields (such as the electromagnetic field).

 

Rockets would work just as well if space were completely empty. And light would propagate if space were completely empty apart from the electromagnetic field.

I wasn't actually implying space was completely empty, just devoid of a medium that was required for rockets and photons to work.

[Strange]

I wasn't actually implying space was completely empty, just devoid of a medium that was required for rockets and photons to work.

 

 

Indeed. I just wanted to make it completely explicit for Mike.

[Mike Smith Cosmos]

Indeed. I just wanted to make it completely explicit for Mike.

Why can I not call what you have listed and agree is there , namely " There is gas, dust, virtual particles and fields (such as the electromagnetic field)."

 

Why can I not call that ' a medium ' ?

 

And I still ask ( where did/does this electromagnetic field come from ? What is generating it ? )

 

Mike

Edited June 20, 2016 by Mike Smith Cosmos

[Strange]

Why can I not call what you have listed and agree is there , namely " There is gas, dust, virtual particles and fields (such as the electromagnetic field)."

 

Why can I not call that ' a medium ' ?

 

Mike

 

 

You can. It is called the interstellar medium or the intergalactic medium.

 

But it is not required for light to propagate or for rockets to work.

[Mike Smith Cosmos]

You can. It is called the interstellar medium or the intergalactic medium.

 

But it is not required for light to propagate or for rockets to work.

But how do you know , it's not required.? Maybe it is required , and if it was not there, possibly the EM waves would not propagate ?

 

And I repeat . And I still ask ( where did/does this electromagnetic field come from ? What is generating it ? )

 

Mike

Edited June 20, 2016 by Mike Smith Cosmos

[ajb]

Why can I not call that ' a medium ' ?

You could ... but it is not the 'mechanical medium' for the propagation of light or gravitational waves.

 

If you have a wave, then it has to be a wave in something. But this does not mean a 'mechanical medium' as originally thought.

 

Light (classically) is a wave in the electromagnetic field. In this sense the electromagnetic field is the 'medium'.

 

Graviational waves are waves in the local geometry of space-time, which may be described by a metric tensor. This metric can be thought of as the gravitational field. In this sense the metric is the 'medium'.

 

But these objects are all types of 'geometric objects' on space-time. They are not mechanical in the usual sense.

 

 

But how do you know , it's not required.? Maybe it is required , and if it was not there, possibly the EM waves would not propagate ?

 

Light seems to 'work' in vacuum that we have created here on Earth.

[Mike Smith Cosmos]

You could ... but it is not the 'mechanical medium' for the propagation of light or gravitational waves.If you have a wave, then it has to be a wave in something. But this does not mean a 'mechanical medium' as originally thought.Light (classically) is a wave in the electromagnetic field. In this sense the electromagnetic field is the 'medium'.Graviational waves are waves in the local geometry of space-time, which may be described by a metric tensor. This metric can be thought of as the gravitational field. In this sense the metric is the 'medium'.But these objects are all types of 'geometric objects' on space-time. They are not mechanical in the usual sense.Light seems to 'work' in vacuum that we have created here on Earth.

.

But I keep asking ....Where does this electro magnetic field come from?

 

If I want to set up an electro magnetic field , as a minimum I would need two plates of metal a few inches apart .and some magnetism field from permanent magnets. And apply a large voltage between the plates .

 

 

Also if you create a vacuum on earth , presumably you haven't sucked out " the electromagnetic field , " with the pumps, so it will still be there , but the question remains " where does this electro magnetic field come from ?

 

Mike ( who was last seen being taken away in a white van to the nearest lunatic asylum ..muttering .." Where did the electro magnetic field come from ? Da! Da! Da! )

Edited June 20, 2016 by Mike Smith Cosmos

[ajb]

But I keep asking ....Where does this electro magnetic field come from?

It is just part of the Universe that is everywhere. This is also how we think of all the other fields, they fill the Universe.

 

We also have sources and sinks, but that is not really what you are asking about.

[Mike Smith Cosmos]

It is just part of the Universe that is everywhere. This is also how we think of all the other fields, they fill the Universe.We also have sources and sinks, but that is not really what you are asking about.

Ok . That's fine . " they fill the Universe " great .

 

A medium of electro magnetic fields , that fill the universe as being part of this universal ' medium ' . Probably with a few other bits and bobs .

 

I am happy now , because yes a light or Electro magnetic photon wave can propagate across such a medium . ( Space )

 

Where did/does this ' universal medium ' come from ? And you can not just say " because it is there "

 

Mike

Edited June 20, 2016 by Mike Smith Cosmos

[ajb]

Where did/does this ' universal medium ' come from ?

Who knows? It is taken to be part of the Universe. Part of the basic blocks that make up everything.

[Mike Smith Cosmos]

Who knows? It is taken to be part of the Universe. Part of the basic blocks that make up everything.

?

It is ' taken' to be part of the universe !

 

I am standing by this great black ' Obalisc ' and I just say who knows where that came from ?

 

Link :- Obalisc :- https://en.m.wikipedia.org/wiki/Interpretations_of_2001:_A_Space_Odyssey

 

 

Mike

Edited June 20, 2016 by Mike Smith Cosmos

[ajb]

I am standing by this great black ' Obalisc ' and I just say who knows where that came from ?

 

That is not the right question ... where did the fundamental particles that make up that obalisc come from?

[Strange]

But how do you know , it's not required.? Maybe it is required , and if it was not there, possibly the EM waves would not propagate ?

 

Because theories work perfectly well without it.

[Mike Smith Cosmos]

That is not the right question ... where did the fundamental particles that make up that obalisc come from?

.

 

Yes , but that is the second question .

 

My first question would be , where did that just come from ? Who put that there ? ( it looks totally out of place !)

Then I might start chipping at it , to see roughly what it was made of , and your question ( where did the fundamental particles that make up this ( strange, and out of place , massive , Obalisc, where did its particles come from ? ....)

 

Mike

[swansont]

.

But I keep asking ....Where does this electro magnetic field come from?

 

 

 

Charges. Electric charges create electric fields. Moving charges also create magnetic fields.

 

There are also field created via electromagnetic interactions, such as an atom's electron changing state, or a particle/antiparticle pair annihilating.

[Mike Smith Cosmos]

Because theories work perfectly well without it.

I am not convinced that, that would be the case . My guess is , that if that electro magnetic field type medium was NOT there . Then the EM waves would have no medium , to send waves through , and so would not work !

 

Mike

[ajb]

Well, I could always ask where the light bulb in my room came from ... but it is not directly realted to the fundamental nature of the light and the electromagnetric field. Asking what a light bulb is made of and how does it work is a better.

[Mike Smith Cosmos]

Charges. Electric charges create electric fields. Moving charges also create magnetic fields.

 

There are also field created via electromagnetic interactions, such as an atom's electron changing state, or a particle/antiparticle pair annihilating.

O.k. That is fine. IF there is SPACE , all nicely sprinkled with atoms , charges, charges moving creating magnetism , atoms changing state and particle changing state to antiparticles or annihilation one another.

 

Fine , a nice soup of all this ' stuff' , all generating a nice background electro magnetic field . Great !

 

A Medium , necessary for EM propagation. --------- No medium , no propagation . -----------

 

Mike

Edited June 20, 2016 by Mike Smith Cosmos

[Strange]

I am not convinced that, that would be the case . My guess is , that if that electro magnetic field type medium was NOT there .

 

The theory DOES require the electromagnetic field. In fact, the theory is the only reason we think such fields exist.

 

But the field doesn't require gas, dust, etc. to exist. (And the virtual particles are a consequence of the field being quantised.)

[swansont]

O.k. That is fine. IF there is SPACE , all nicely sprinkled with atoms , charges, charges moving creating magnetism , atoms changing state and particle changing state to antiparticles or annihilation one another.

 

Fine , a nice soup of all this ' stuff' , all generating a nice background electro magnetic field . Great !

 

A Medium , necessary for EM propagation. No medium , no propagation .

 

Mike

 

 

No, Mike. The fields are infinite in extent. You have them even when you aren't near any atoms. These are the sources and sinks ajb mentioned. If one used your example and applied it to sound, you would be arguing that someone's vocal chords are the medium for sound, and that's silly.

[Mike Smith Cosmos]

The theory DOES require the electromagnetic field. In fact, the theory is the only reason we think such fields exist.

 

But the field doesn't require gas, dust, etc. to exist. (And the virtual particles are a consequence of the field being quantised.)

So we still have a loose end !

 

---- What is generating the Field . -----

 

Mike

[Strange]

So we still have a loose end !

 

---- What is generating the Field . -----

 

Mike

 

Nothing. It is just part of nature.

[Mike Smith Cosmos]

No, Mike. The fields are infinite in extent. You have them even when you aren't near any atoms. These are the sources and sinks ajb mentioned. If one used your example and applied it to sound, you would be arguing that someone's vocal chords are the medium for sound, and that's silly.

But What is Generating or Causing the Fields to exist ?