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From: Just Me on 11 Jan 2010 14:12
On Jan 10, 6:34 pm, Just Me <jpd...(a)gmail.com> wrote:

> ETHER AND THE THEORY OF RELATIVITY :An Address delivered on May 5th,
> 1920, in the University of Leyden by none other than Albert Einstein,
> himself.  Upon a first cursory scanning of the paper, it would appear
> that you are not in opposition to Einstein's understanding of the
> ether theory, that it would be seen, as you've insisted, for a
> "solid". Here is the link to that paper . . .
>
> http://www.gutenberg.org/dirs/etext05/slrtv10.txt
>
> I am going to give it a thorough reading over the next few days, in
> order that I might better know what I've supposed myself to be talking
> about.

Here is the final paragraph of that lecture, in which, once again it
would appear that there is no argument between Mr. Banerjee and Dr.
Einstein, at least so far as any understanding of the ether goes . . .

Recapitulating, we may say that according to the general theory of
relativity space is endowed with physical qualities; in this sense,
therefore, there exists an ether. According to the general theory
of relativity space without ether is unthinkable; for in such space
there not only would be no propagation of light, but also no
possibility
of existence for standards of space and time (measuring-rods and
clocks), nor therefore any space-time intervals in the physical
sense. But this ether may not be thought of as endowed with the
quality characteristic of ponderable media, as consisting of parts
which may be tracked through time. The idea of motion may not be
applied to it.
From: spudnik on 11 Jan 2010 18:09
is it a mistake,
to take Einstien's 1920 comprehension of aether,
to be the end-all & be-all?

I really have a problem with the analogy
of "the earthen riverbank & the water," since
they are taken as analogous to their opposites; eh?

--l'OEuvre!
http://w;ym.com
From: Surfer on 11 Jan 2010 19:27
On Mon, 11 Jan 2010 11:12:28 -0800 (PST), Just Me <jpdm45(a)gmail.com>
wrote:

>On Jan 10, 6:34�pm, Just Me <jpd...(a)gmail.com> wrote:
>
>> ETHER AND THE THEORY OF RELATIVITY :An Address delivered on May 5th,
>> 1920, in the University of Leyden by none other than Albert Einstein,
>> himself. �Upon a first cursory scanning of the paper, it would appear
>> that you are not in opposition to Einstein's understanding of the
>> ether theory, that it would be seen, as you've insisted, for a
>> "solid". Here is the link to that paper . . .
>>
>> http://www.gutenberg.org/dirs/etext05/slrtv10.txt
>>
>> I am going to give it a thorough reading over the next few days, in
>> order that I might better know what I've supposed myself to be talking
>> about.
>
>Here is the final paragraph of that lecture, in which, once again it
>would appear that there is no argument between Mr. Banerjee and Dr.
>Einstein, at least so far as any understanding of the ether goes . . .
>
>Recapitulating, we may say that according to the general theory of
>relativity space is endowed with physical qualities; in this sense,
>therefore, there exists an ether. According to the general theory
>of relativity space without ether is unthinkable; for in such space
>there not only would be no propagation of light, but also no
>possibility of existence for standards of space and time (measuring-rods and
>clocks), nor therefore any space-time intervals in the physical
>sense. But this ether may not be thought of as endowed with the
>quality characteristic of ponderable media, as consisting of parts
>which may be tracked through time. The idea of motion may not be
>applied to it.
>

It is interesting though, that in GR it can sometimes be useful to
model space as a substance in motion. Eg.

The river model of black holes
Am.J.Phys.76:519-532,2008
http://arxiv.org/abs/gr-qc/0411060

".......In the river model, space itself flows like a river through a
flat background, while objects move through the river according to the
rules of special relativity. In a spherical black hole, the river of
space falls into the black hole at the Newtonian escape velocity,
hitting the speed of light at the horizon. Inside the horizon, the
river flows inward faster than light, carrying everything with
it....."

Conversely, after supposing that space could be a substance in motion,
it is possible to derive basic features of GR. Eg.

Deriving the General Relativity Formalism: Understanding its Successes
and Failures
http://arxiv.org/abs/physics/0611002

".....From the generalised Dirac equation we show that the spacetime
formalism is derivable, but as merely a mathematical construct whose
geodesics arise from the trajectories of quantum wavepackets in the
3-space......"

There is a difference in that:

".....the metric of this spacetime is shown not to satisfy the
Hilbert-Einstein equations, except in the special case of the
Schwarzschild metric....."

But this difference is useful in that it allows the new theory to make
the same predictions as GR for situations for which GR is currently
accepted as correct, but to make better predictions for situations
where GR is currently being questioned.

Eg the new theory can:

1) Model the rotation rates of spiral galaxies without the use of dark
matter.
2) Model the expansion of the universe without the use of dark energy.

Unravelling the Dark Matter - Dark Energy Paradigm
http://arxiv.org/abs/0901.4140


It can also resolve,
A Bitter Pill: The Primordial Lithium Problem Worsens
Richard H. Cyburt, Brian D. Fields, Keith A. Olive
JCAP 0811:012,2008
http://arxiv.org/abs/0808.2818


as described here,
Dynamical 3-Space Predicts Hotter Early Universe: Resolves CMB-BBN Li7
and He4 Abundance Anomalies
Reginald T. Cahill
Progress in Physics, vol 1, 67-71, 2010.
http://arxiv.org/abs/0911.0960




From: Surfer on 12 Jan 2010 20:26
On Mon, 11 Jan 2010 23:20:10 -0800 (PST), Just Me <jpdm45(a)gmail.com>
wrote:

Quoting Einstein,
>
>"It also seemed to be a necessary consequence of the fact that light
>is capable of polarisation that this medium, the ether, must be of the
>nature of a solid body, because transverse waves are not possible in a
>fluid, but only in a solid."
>
>As I am not a physicist, I have no idea what that means. When I look
>at breakers coming ashore at the seaside, I see what I take to be a
>transverse wave -- what am I missing? What am I seeing instead?
>
The surfaces of bodies of water on earth can support vertical waves.
That is because under the influence of gravity, water tends to find
its own level, and the surface of the water can oscillate above and
below that level.

Such waves are transverse, but they are only possible at the surface.
We don't observe such waves deep under water, and we don't observe
horizontal transverse waves either on the surface of water or deep
underwater.

However it is easy to create transverse waves in a jelly by making it
wobble, or in a rope.
http://en.wikipedia.org/wiki/Transverse_wave

>
>But now look again at Einstein's stated reason as to why
>theoretically, no motion may be attributed to the ether . . .
>
>> > this ether may not be thought of as endowed with the
>> >quality characteristic of ponderable media, as consisting of parts
>> >which may be tracked through time. The idea of motion may not be
>> >applied to it.
>

There are two sentences here. You have interpreted the first as
providing a reason for the second. But my interpretation is that both
sentences essentially say the same thing, with no particular reason
given.

So, the two quotes say,

1) The ether must be of the nature of a solid body, but,
2) the idea of motion may not be applied to it.

If both were true we would have a contradiction.

Since a good reason is given for 1) but not for 2), it would seem more
reasonable than not, to reject 2).

>
> It is not so much that Einstein has here determined a dynamical
> ether as absolutely impossible, but simply impossible of detection
>*as motion*--
>

That's a reasonable position, but if the motion existed, it would be
premature to assume it could never be detected.


Surfer




From: mpc755 on 12 Jan 2010 20:56
On Jan 12, 8:26 pm, Surfer <n...(a)spam.net> wrote:
> On Mon, 11 Jan 2010 23:20:10 -0800 (PST), Just Me <jpd...(a)gmail.com>
> wrote:
>
> Quoting Einstein,
>
> >"It also seemed to be a necessary consequence of the fact that light
> >is capable of polarisation that this medium, the ether, must be of the
> >nature of a solid body, because transverse waves are not possible in a
> >fluid, but only in a solid."
>
> >As I am not a physicist, I have no idea what that means.  When I look
> >at breakers coming ashore at the seaside, I see what I take to be a
> >transverse wave -- what am I missing? What am I seeing instead?
>
> The surfaces of bodies of water on earth can support vertical waves.
> That is because under the influence of gravity, water tends to find
> its own level, and the surface of the water can oscillate above and
> below that level.
>
> Such waves are transverse, but they are only possible at the surface.
> We don't observe such waves deep under water, and we don't observe
> horizontal transverse waves either on the surface of water or deep
> underwater.
>
> However it is easy to create transverse waves in a jelly by making it
> wobble, or in a rope.http://en.wikipedia.org/wiki/Transverse_wave
>
>
>
> >But now look again at Einstein's stated reason as to why
> >theoretically, no motion may be attributed to the ether . . .
>
> >> > this ether may not be thought of as endowed with the
> >> >quality characteristic of ponderable media, as consisting of parts
> >> >which may be tracked through time. The idea of motion may not be
> >> >applied to it.
>
> There are two sentences here. You have interpreted the first as
> providing a reason for the second. But my interpretation is that both
> sentences essentially say the same thing, with no particular reason
> given.
>
> So, the two quotes say,
>
> 1) The ether must be of the nature of a solid body, but,
> 2) the idea of motion may not be applied to it.
>
> If both were true we would have a contradiction.
>
> Since a good reason is given for 1) but not for 2), it would seem more
> reasonable than not, to reject 2).
>
>
>
> > It is not so much that Einstein has here determined a dynamical
> > ether as absolutely impossible, but simply impossible of detection
> >*as motion*--
>
> That's a reasonable position, but if the motion existed, it would be
> premature to assume it could never be detected.
>
> Surfer

Einstein's definition of motion is, "[extended physical objects to
which the idea of motion cannot be applied] may not be thought of as
consisting of particles which allow themselves to be separately
tracked through time".

Einstein is not saying the aether consists of particle, or not.
Einstein is also not specifically saying the aether cannot be in
motion. What Einstein is specifically saying is the aether does not
consist of particles which allow themselves to be separately tracked
through time.

Einstein also says, "if, in fact nothing else whatever were observable
than the shape of the space occupied by the water as it varies in
time, we should have no ground for the assumption that water consists
of movable particles. But all the same we could characterise it as a
medium."

and

"the state of the [ether] is at every place determined by connections
with the matter and the state of the ether in neighbouring places"

The shape of the space occupied by the aether as it varies in time as
determined by its connections with the matter, is the aether's state
of displacement.
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