"Grav" wrote in message oups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message ups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message oups.com...


[snip]

Bottomline is. The fabric of spacetime must be a real
entity enough to cause all this gravity trick.

Yet the GR gurus would likely say that its just geometry.
But there must be something that cause my entire body
to be attracted to earth. Remember when I'm in deep
space. I'm only moving in time. When the earth and
ladder say suddenly materialize in front of me. I got stuck
to the ladder. So there should be something in space that
can do all this.

If you'd say no. Pls. enlighten me using intuitive words how
come no and why not.

If you say there should be something in space that can do all
this, that doesn't imply there *is* something that can do all this.
Nature doesn't care about what you think it should do.
Physicists deal with the model of gravity. Not with the cause.
If you really want to know the real cause, turn to religion or
new-age or intelligent design or whatever you fancy.

Dirk Vdm

If we are dealing with knowing the properties of some particle
inside the atom. It's understandable that a model without
physical cause can suffice. But we are dealing with something
as concrete as gravity. When you fall from the bed to the floor.
This is something solid.

Come on, guys, there must be something. I described in
the geometry aspect. Now what's physically causing my body
to be stucked to this chair typing this.

We don't know.
Try a non-science newsgroup. I'm sure they know.

Dirk Vdm


We should extend science to explaining why too. Who
knows. When we know why. We may even learn how
to shield gravity and take the monopoly out of Boieng.

Grav

Maybe only you don't know.

Scientists don't know.

Dirk Vdm

"Grav" wrote in message
oups.com...
|
| Let's say I'm floating stationary in deep space light years from any
| massive bodies like galaxies or planets. Since I'm not moving in
| the 3 dimensions (judging by the unidirectional accelerator
| sensor reading zero).

You need three unidirectional accelerometers.

http://www.xbow.com/Products/productsdetails.aspx?sid=2

A three axis accelerometer is about the size of a golfball. Why would
you care about one of its unidirectional sensors?


| Space is steady but time is moving
| forward so there is a straight line in the Minkowski 4D graph.

Space is nothing.


| Straight line in the "world line" because I'm only going foward in
| the time direction.
|
| Right?
|
| Ok. Second scene. Let's say I'm now sitting on top of a 6 foot
| ladder on the ground on earth.


Sounds uncomfortable. Would you like a stool instead?


| What happens to my worldline is
| there is no longer a straight line in the 4D Minkowski graph
| because the earth is curving spacetime in my vicinity and I'm
| now curving in the graph.


I'd say the Earth was revolving around the sun and rotating
on its own axis. The worldline is a year long sinusoid with
a sidereal day sinusoid imposed.

| Then I jumped from the top of the ladder to the floor. Riemann
| wise. What happens is that I'm moving thru a geodesic which
| made me feel acceleration which I attribute to gravity.


You've got that backwards. You are weightless when you jump
and "feel" nothing. You'll feel your feet being accelerated upwards
when they reach the floor. Try it from a 30ft ladder and the upward
acceleration will break your legs. That is when you'll feel acceleration.
Why have you switched from unidirectional accelerator sensors
to how we feel?
Androcles.


|
| In the 4D spacetime Non-Euclidean Riemannian geometry, the
| earth is curving spacetime, and since I'm in the vicinity of
| the earth. I'm moving along with the curve too (remember
| time is always moving forward). Only when I'm in free
| fall like jumping from the top of the ladder do I take a
| geodesic and feeling the fall.
|
| Now when I sit atop the ladder. How come I don't float up. It's
| because the earth mass stress energy is registering on
| the Riemann's curvature tensor making the fabric of
| spacetime curve in certain way and affecting my
| mass-energy.
|
| Now. Visualizing it physically. When I sit atop the ladder.
| How come again I don't float up. My mass-energy is
| being affected by the fabric of spacetime. So this
| fabric must be super strong to affect my entire mass
| to curve with it. What is the fabric. Where is the fabric?
| The fabric must be real enough to affect my body mass.
| Don't say the fabric is just a mathematical creation or
| imagination. There must be something which guides my
| entire body to the earth making me feel gravity.
|
| Bottomline is. The fabric of spacetime must be a real
| entity enough to cause all this gravity trick.
|
| Yet the GR gurus would likely say that its just geometry.
| But there must be something that cause my entire body
| to be attracted to earth. Remember when I'm in deep
| space. I'm only moving in time. When the earth and
| ladder say suddenly materialize in front of me. I got stuck
| to the ladder. So there should be something in space that
| can do all this.
|
| If you'd say no. Pls. enlighten me using intuitive words how
| come no and why not.
|
| This message is only for those who can convey insight to
| others clearly and distinctly like Gregory and Bilge. Not
| Bill Hoopa who doesn't know how to explain intuitively.
|
| Tnx.
|
| Grav
|

Bill Hobba wrote:
"Grav" wrote in message
ups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message
oups.com...


[snip]

Bottomline is. The fabric of spacetime must be a real
entity enough to cause all this gravity trick.

Yet the GR gurus would likely say that its just geometry.
But there must be something that cause my entire body
to be attracted to earth. Remember when I'm in deep
space. I'm only moving in time. When the earth and
ladder say suddenly materialize in front of me. I got stuck
to the ladder. So there should be something in space that
can do all this.

If you'd say no. Pls. enlighten me using intuitive words how
come no and why not.

If you say there should be something in space that can do all
this, that doesn't imply there *is* something that can do all this.
Nature doesn't care about what you think it should do.
Physicists deal with the model of gravity. Not with the cause.
If you really want to know the real cause, turn to religion or
new-age or intelligent design or whatever you fancy.

Dirk Vdm

If we are dealing with knowing the properties of some particle
inside the atom. It's understandable that a model without
physical cause can suffice. But we are dealing with something
as concrete as gravity. When you fall from the bed to the floor.
This is something solid.

Come on, guys, there must be something. I described in
the geometry aspect. Now what's physically causing my body
to be stucked to this chair typing this.

What physically causes right triangles to obey Pythagoras?

As I said in the other message, Geometry.



We should extend science to explaining why too.


It already does. But every explanation, every single one, assumes some
things from which others follow. What is assumed can never be explained
within the theory that assumes them.

Who knows. When we know why.

We already know why within the paradigm of our best theory - GR. The why is
no prior geometry.

Pls elaborate what exactly you mean by "no prior geometry".
Are you referring to the Equivalence Principle which Einstein
intuited as the guiding principle in General Relativity?


We may even learn how
to shield gravity and take the monopoly out of Boieng.

Misunderstanding what science is about will not help.

Well. If GR is just a model. What if there would come a
better model that can even be capable of shielding
gravity? GR model is such that there is no exotic
mass-energy than can cause negative curvature so
anti-gravity is not possible (although I have heard
of Casimir negative energy but that's for time alteration).
But GR is just a model. What if the model is causing
a limitation of the possibilities. I'm not an anti-gravity
nut. Just mentioning it for the sake of pointing how
GR model may be limiting some possibilities. While
it can explain black holes, gravitational lensing,
frame dragging, gravitatational waves, etc. As long
as we don't know how space exactly pull those stunts
physically (we only know EFE can correctly model
the dynamics of objects and mass-energy, curvature) .
We can't say that GR is the last word. Agree?
Therefore since it's not the last word. You can't conclude
that shielding gravity is impossible, because the model
may be limiting the possibilities. Again I'm not an
anti-gravity nut or interested in it, just pointing it as
an example.

Grav



Bill



Grav

Dirk Van de moortel wrote:
"Grav" wrote in message oups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message ups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message oups.com...


[snip]

Bottomline is. The fabric of spacetime must be a real
entity enough to cause all this gravity trick.

Yet the GR gurus would likely say that its just geometry.
But there must be something that cause my entire body
to be attracted to earth. Remember when I'm in deep
space. I'm only moving in time. When the earth and
ladder say suddenly materialize in front of me. I got stuck
to the ladder. So there should be something in space that
can do all this.

If you'd say no. Pls. enlighten me using intuitive words how
come no and why not.

If you say there should be something in space that can do all
this, that doesn't imply there *is* something that can do all this.
Nature doesn't care about what you think it should do.
Physicists deal with the model of gravity. Not with the cause.
If you really want to know the real cause, turn to religion or
new-age or intelligent design or whatever you fancy.

Dirk Vdm

If we are dealing with knowing the properties of some particle
inside the atom. It's understandable that a model without
physical cause can suffice. But we are dealing with something
as concrete as gravity. When you fall from the bed to the floor.
This is something solid.

Come on, guys, there must be something. I described in
the geometry aspect. Now what's physically causing my body
to be stucked to this chair typing this.

We don't know.
Try a non-science newsgroup. I'm sure they know.

Dirk Vdm


We should extend science to explaining why too. Who
knows. When we know why. We may even learn how
to shield gravity and take the monopoly out of Boieng.

Grav

Maybe only you don't know.

Scientists don't know.

Dirk Vdm

It's understandable if that is so. But Bilge seems to have other
thought.
He resisted all alternative modelers like IIja as if GR model is the
complete answer. If Bilge would agree that scientists don't know
what actually happens in physical space when mass-stress energy
registers on the Riemann curvature tensor and how our say
physical bodies are physically guided to the ground. Then its
understandable. But it seems Bilge thinks he knows the physical
mechanism that you guys don't. This is why his words haunted me
day and night and I'm looking for the explanation which he may
know. Hope Bilge would tackle this point.

Grav
..

"Grav" wrote in message oups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message oups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message ups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message oups.com...


[snip]

Bottomline is. The fabric of spacetime must be a real
entity enough to cause all this gravity trick.

Yet the GR gurus would likely say that its just geometry.
But there must be something that cause my entire body
to be attracted to earth. Remember when I'm in deep
space. I'm only moving in time. When the earth and
ladder say suddenly materialize in front of me. I got stuck
to the ladder. So there should be something in space that
can do all this.

If you'd say no. Pls. enlighten me using intuitive words how
come no and why not.

If you say there should be something in space that can do all
this, that doesn't imply there *is* something that can do all this.
Nature doesn't care about what you think it should do.
Physicists deal with the model of gravity. Not with the cause.
If you really want to know the real cause, turn to religion or
new-age or intelligent design or whatever you fancy.

Dirk Vdm

If we are dealing with knowing the properties of some particle
inside the atom. It's understandable that a model without
physical cause can suffice. But we are dealing with something
as concrete as gravity. When you fall from the bed to the floor.
This is something solid.

Come on, guys, there must be something. I described in
the geometry aspect. Now what's physically causing my body
to be stucked to this chair typing this.

We don't know.
Try a non-science newsgroup. I'm sure they know.

Dirk Vdm


We should extend science to explaining why too. Who
knows. When we know why. We may even learn how
to shield gravity and take the monopoly out of Boieng.

Grav

Maybe only you don't know.

Scientists don't know.

Dirk Vdm

It's understandable if that is so. But Bilge seems to have other
thought.

Perhaps you don't properly understand what he thinks.
Ask him politely to explain politely.
Maybe that helps.

Dirk Vdm

"Grav" wrote in message
ups.com...

Bill Hobba wrote:
"Grav" wrote in message
oups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message
ups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message
oups.com...


[snip]

Bottomline is. The fabric of spacetime must be a real
entity enough to cause all this gravity trick.

Yet the GR gurus would likely say that its just geometry.
But there must be something that cause my entire body
to be attracted to earth. Remember when I'm in deep
space. I'm only moving in time. When the earth and
ladder say suddenly materialize in front of me. I got stuck
to the ladder. So there should be something in space that
can do all this.

If you'd say no. Pls. enlighten me using intuitive words how
come no and why not.

If you say there should be something in space that can do all
this, that doesn't imply there *is* something that can do all
this.
Nature doesn't care about what you think it should do.
Physicists deal with the model of gravity. Not with the cause.
If you really want to know the real cause, turn to religion or
new-age or intelligent design or whatever you fancy.

Dirk Vdm

If we are dealing with knowing the properties of some particle
inside the atom. It's understandable that a model without
physical cause can suffice. But we are dealing with something
as concrete as gravity. When you fall from the bed to the floor.
This is something solid.

Come on, guys, there must be something. I described in
the geometry aspect. Now what's physically causing my body
to be stucked to this chair typing this.

We don't know.
Try a non-science newsgroup. I'm sure they know.

Dirk Vdm


We should extend science to explaining why too. Who
knows. When we know why. We may even learn how
to shield gravity and take the monopoly out of Boieng.

Grav

Maybe only you don't know. It seems Bill and Bilge knew.
They stated that by understanding the geometry, the answer
would come out and one can understand why it correlates
to reality.

That is not what I said. I said you will be able to understand GR (which
is
a theory) if you understood math better. Why theories exist that have
experimental support is a deep mystery. But the mystery not only applies
to
GR - it apples to good old Euclidian geometry as well. When faced with
such issues simply think back to it and ask how it solves the issue.

So I spent the whole evening in library reviewing
for all the available books about GR and the above is what
I came up. At the end of the day. I learned Einstein himself
believe in the so called "Gravitational Ether". Don't you guys
believe in this too? Bilge?

Einstein himself said:

"[...] we will not be able to do without the ether in theoretical
physics, i.e., a continuum which is equipped with physical
properties; for the general theory, whose basic points
of view physicists surely will always maintain, excludes
direct distant action. But every contiguous action theory
presumes continuous fields, and there also the existence
of an "ether"."

"We may still use the word ether but only to express the
physical properties of space. The word ether has changed
its meaning many times in the development of science.
At the moment, it is no longer stands for a medium built
up of particles. It's story, by no means finished, is
continued by the relativity theory."

"With regards to the general theory of relativity, space cannot
be imagined without ether".

Note Einstein only disbelieved in the aether from 1905-1917.
After that. He believe it and interchanging the word
ether with spacetime many times.

So Einstein himself believed in the Relativistic or
Gravitational Ether.

Not correct -
http://math.ucr.edu/home/baez/RelWWW/wrong.html#aether
'Albert Einstein, in his essay On the Aether (1924), made some
injudicious
comments to the effect that relativity theory could be said to ascribe
physical properties to spacetime itself, and in that sense, to involve a
kind of "aether". He clearly did not mean the kind of "aether" which had
been envisioned by Maxwell and others in the nineteenth century, but his
remarks have been seized upon ever since, by various cranks and other
ill-informed persons, as evidence that "gtr is an aether theory". Here's
a
typical claim of this sort: 'the aether is restored in General Relativity
see Einstein's 1924 essay "On the Aether". Einstein recanted on his 1905
rejection of the aether since the mutable curved space-geometry is a
dynamical object (with shift and lapse fields in ADM formulation), hence
an
aether. This claim is misleading, to say the least. What Einstein really
meant was that the aether which had been overthrown by str (and thus was
incompatible with gtr, which incorporates str) involved a a specific
"preferred frame of reference" in the classical field theory, whereas the
field equation of gtr involves no "prior geometry" (such as the euclidean
geometry of "space" which has assumed by Maxwell and his contemporaries),
much less any "preferred frame". Nonetheless, gtr does not quite say
there
is "nothing" in "empty space"; in general there will be gravitational
waves
running about, and these carry (very tiny) amounts of energy, which
gravitate. So in this sense, a very different kind of "aether" in the
very
weak sense of there being "something there" in a vacuum (namely
nonlocalizable gravitational field energy, metric properties of "space"
in a
3+1 decomposition, etc.), could be said to enter into gtr. In modern
quantum
field theories, of course, there are still more "things which are there"
in
a vacuum, but again these do not constitute an "aether" in the nineteenth
century sense in which this word was used as a technical term. Einstein
was
criticizing people who claimed, in effect, that the classical notion of
the
aether was such nonsense that people like Maxwell should have known
better.
He was saying that the problem with the classical aether was not
ontological, merely that it is inconsistent with observation and
experiment;
hence the need for str'


That's not entirely accurate. I read Ludwik Kostro book
"Einstein and the Ether" in the libary in one sitting last
night. What Einstein is saying is that STR can't have
any ether of the maxwell kind to avoid a preferred frame
of reference that can violate the principle of relativity.
So the new ether he proposed can't have particles that
can be tracked in time and place. So the Einstein ether
is nothing but space-time itself which can give it a more
physical sounding nature. Again quoting Kostro (there
are more Einstein quotes in the book which I borrowed):

That is the point. The aether by definition is a real medium like a fluid
or gas. Einstein was basically talking about introducing a new concept of
the aether to replace its usual definition. As he says
http://www.tu-harburg.de/rzt/rzt/it/Ether.html
'As to the part which the new ether is to play in the physics of the future
we are not yet clear.'. That was written in 1920. We now know the answer -
up to this point none at all. Because of this the usage of aether in
physics has not changed and is not what Einstein proposed, so we can cay
with 100% certainty; and even by Einstein's own admission is not how the
term is used:
'But this ether may not be thought of as endowed with the quality
characteristic of ponderable inedia, as consisting of parts which may be
tracked through time. The idea of motion may not be applied to it.'


"When we use only the expression "space-time continuum",
its materiality is not indicated in any way. We therefore
need a special word to express it. The traditional word
"ether" is ideally suited to this purpose.

The expression "new ether" and "relativistic ether" are
particularly useful from the physical point of view because
they indicate immediately that in the Theory of Relativity,
space-time is of a material nature. It is well to recall the
reasons why Einstein attributed material properties to
the space-time continuum:

1. The space-time continuum participates, in a real and
active way, in physical becoming. E.g. the gravitational
potentials described mathematically by the Guv
components of the metrical tensor g determine the
inertio-gravitational behavior of test particles.

2. Space-time is a field, and there is no quantitative
difference between field and matter. Field is characterized
by a certain distribution of energy, and therefore,
materiality."


But I'm puzzled how come
physicists (such as Bilge) don't believed them nowadays.

Because it never has been detected and theories do not require it.

What if it is possible to program space itself which can
affect material properties? Some experiments can done
it.

I have no idea what you mean by 'program space itself'. Define precisely
what you mean by that and propose an experiment to test it.




When I'm sitting on top of the ladder, the Gravitational
Ether can interact with my mass-energy and guiding
its position in space.

Read the link above - current evidence does not require a gravitational
aether nor did Einstein believe it was required.

Because Einstein doesn't know of the extra evidence.

What extra evidence?

But let's talk of purely GR. An Einstein Ether is the
only one which can coordinate my mass energy body to
gravitate to earth with the Einstein Field Equations describing
how the Einstein Ether should behave interlinking the earth
and my body mass. Why not??

Because in the usual sense of the term no aether is required to explain
gravity. Stick to the definitions standard to physics. It is one thing for
a scientist of Einstein's stature to propose a new use of the term and for
time to prove it is a dead end - it is quite another for a person like
yourself; who, well to put it bluntly, does not understand the
technicalities of the theories he is talking about; to propose it and think
it provides physical insight - it doesn't - semantic word games is not
physics.

None of the above of course proves an aether does not exist - it simply, as
far as we can tell today, is not required, ie is superfluous, which his why
Einstein's conception never caught on. For an example of an aether theory
see
http://www.ilja-schmelzer.de/GET/

Bill


Grav



Bill


If Bilge will agree to it. I'll be
satisfied. I just want to gain that one crucial insight
on the physical mechanism of General Relativity.
Give me that and I'm outta here and you'd be happy.


Grav

In sci.physics.relativity Grav wrote:

Well. If GR is just a model. What if there would come a
better model that can even be capable of shielding
gravity?

What do you mean by a better model? If the model
predicts something that is impossible, then it
is not a good model.

GR model is such that there is no exotic
mass-energy than can cause negative curvature so
anti-gravity is not possible (although I have heard
of Casimir negative energy but that's for time alteration).
But GR is just a model. What if the model is causing
a limitation of the possibilities.

The model cannot limit the possibilities. If anti-gravity
is possible, then GR is wrong, or in need of serious
modification. However only an experiment can demonstrate
anti-gravity. If (and most likely when) experimental
evidence that seriously conflicts with GR is found,
a new theory will be found. However this new theory
will make very similar predictions to GR for all
of the experiments that have been done so far.

Stephen

"Grav" wrote in message
ups.com...
Bill Hobba wrote:
"Grav" wrote in message
oups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message
ups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message
oups.com...


[snip]

Bottomline is. The fabric of spacetime must be a real
entity enough to cause all this gravity trick.

Yet the GR gurus would likely say that its just geometry.
But there must be something that cause my entire body
to be attracted to earth. Remember when I'm in deep
space. I'm only moving in time. When the earth and
ladder say suddenly materialize in front of me. I got stuck
to the ladder. So there should be something in space that
can do all this.

If you'd say no. Pls. enlighten me using intuitive words how
come no and why not.

If you say there should be something in space that can do all
this, that doesn't imply there *is* something that can do all
this.
Nature doesn't care about what you think it should do.
Physicists deal with the model of gravity. Not with the cause.
If you really want to know the real cause, turn to religion or
new-age or intelligent design or whatever you fancy.

Dirk Vdm

If we are dealing with knowing the properties of some particle
inside the atom. It's understandable that a model without
physical cause can suffice. But we are dealing with something
as concrete as gravity. When you fall from the bed to the floor.
This is something solid.

Come on, guys, there must be something. I described in
the geometry aspect. Now what's physically causing my body
to be stucked to this chair typing this.

We don't know.
Try a non-science newsgroup. I'm sure they know.

Dirk Vdm


We should extend science to explaining why too. Who
knows. When we know why. We may even learn how
to shield gravity and take the monopoly out of Boieng.

Grav

Maybe only you don't know. It seems Bill and Bilge knew.
They stated that by understanding the geometry, the answer
would come out and one can understand why it correlates
to reality.

That is not what I said. I said you will be able to understand GR (which
is
a theory) if you understood math better. Why theories exist that have
experimental support is a deep mystery. But the mystery not only applies
to
GR - it apples to good old Euclidian geometry as well. When faced with
such issues simply think back to it and ask how it solves the issue.

You mentioned "Why theories exist that have experimental support
is a deep mystery.". That's why we have to figure out the mechanism
of interaction.

First answer the question why do right triangles obey Pythagoras's theorem?
Why is the mechanism for that any less important than the mechanism for
gravitational interaction? Surely the points and lines of a math theory
can not affect the points and lines of 'reality'. So why do right triangles
obey Pythagoras? When you can answer that then we can look for a mechanism
for gravity.

The gravitational ether can gave that role.. partly.
When you mentioned that it applies to the good old Euclidean
geometry as well. Are you talking about the Noether Theorem?

No I am talking about something far more fundamental - so fundamental it
really is off topic for sci.physics.relativity, so fundamental people
unconsciously cotton onto it without even being told or even being aware of
it. Once you understand it you will realize all your musings are 'silly'.
Euclidian geometry is a math theory. How does it cause right triangles to
obey Pythagoras's theorem? Surely a math theory can not affect reality -
there must be some actual mechanism that causes it - what is that mechanism?

Isn't it that the symmetry of space and time is related to
conservation laws.

Well. Its either Aether or Matrix at least. If there is
no relativistic ether and absolutely no physical mechanism.
Then our universe is some kind of holograms following the
rules of pure mathematics written in higher dimension..

You may understand what you wrote, but I, and a suspect others that read it,
don't.

Bill


Grav

Bill Hobba wrote:

Not correct -
http://math.ucr.edu/home/baez/RelWWW/wrong.html#aether
'Albert Einstein, in his essay On the Aether (1924), made some
injudicious
comments to the effect that relativity theory could be said to ascribe
physical properties to spacetime itself, and in that sense, to involve a
kind of "aether". He clearly did not mean the kind of "aether" which had
been envisioned by Maxwell and others in the nineteenth century, but his
remarks have been seized upon ever since, by various cranks and other
ill-informed persons, as evidence that "gtr is an aether theory". Here's
a
typical claim of this sort: 'the aether is restored in General Relativity
see Einstein's 1924 essay "On the Aether". Einstein recanted on his 1905
rejection of the aether since the mutable curved space-geometry is a
dynamical object (with shift and lapse fields in ADM formulation), hence
an
aether. This claim is misleading, to say the least. What Einstein really
meant was that the aether which had been overthrown by str (and thus was
incompatible with gtr, which incorporates str) involved a a specific
"preferred frame of reference" in the classical field theory, whereas the
field equation of gtr involves no "prior geometry" (such as the euclidean
geometry of "space" which has assumed by Maxwell and his contemporaries),
much less any "preferred frame". Nonetheless, gtr does not quite say
there
is "nothing" in "empty space"; in general there will be gravitational
waves
running about, and these carry (very tiny) amounts of energy, which
gravitate. So in this sense, a very different kind of "aether" in the
very
weak sense of there being "something there" in a vacuum (namely
nonlocalizable gravitational field energy, metric properties of "space"
in a
3+1 decomposition, etc.), could be said to enter into gtr. In modern
quantum
field theories, of course, there are still more "things which are there"
in
a vacuum, but again these do not constitute an "aether" in the nineteenth
century sense in which this word was used as a technical term. Einstein
was
criticizing people who claimed, in effect, that the classical notion of
the
aether was such nonsense that people like Maxwell should have known
better.
He was saying that the problem with the classical aether was not
ontological, merely that it is inconsistent with observation and
experiment;
hence the need for str'


That's not entirely accurate. I read Ludwik Kostro book
"Einstein and the Ether" in the libary in one sitting last
night. What Einstein is saying is that STR can't have
any ether of the maxwell kind to avoid a preferred frame
of reference that can violate the principle of relativity.
So the new ether he proposed can't have particles that
can be tracked in time and place. So the Einstein ether
is nothing but space-time itself which can give it a more
physical sounding nature. Again quoting Kostro (there
are more Einstein quotes in the book which I borrowed):

That is the point. The aether by definition is a real medium like a fluid
or gas. Einstein was basically talking about introducing a new concept of
the aether to replace its usual definition. As he says
http://www.tu-harburg.de/rzt/rzt/it/Ether.html
'As to the part which the new ether is to play in the physics of the future
we are not yet clear.'. That was written in 1920. We now know the answer -
up to this point none at all. Because of this the usage of aether in
physics has not changed and is not what Einstein proposed, so we can cay
with 100% certainty; and even by Einstein's own admission is not how the
term is used:
'But this ether may not be thought of as endowed with the quality
characteristic of ponderable inedia, as consisting of parts which may be
tracked through time. The idea of motion may not be applied to it.'

But there is a difference if the Einstein Ether is true. Although
it doesn't consist of parts which may be tracked through time.
It can physically bind matter to matter or glue them producing
the predictions of the EFE. In other words, Einstein Ether
is the physical mechanism. Without it. How does GR
correlate to physicality as far as binding matter to matter
(gravity) is concerned.




"When we use only the expression "space-time continuum",
its materiality is not indicated in any way. We therefore
need a special word to express it. The traditional word
"ether" is ideally suited to this purpose.

The expression "new ether" and "relativistic ether" are
particularly useful from the physical point of view because
they indicate immediately that in the Theory of Relativity,
space-time is of a material nature. It is well to recall the
reasons why Einstein attributed material properties to
the space-time continuum:

1. The space-time continuum participates, in a real and
active way, in physical becoming. E.g. the gravitational
potentials described mathematically by the Guv
components of the metrical tensor g determine the
inertio-gravitational behavior of test particles.

2. Space-time is a field, and there is no quantitative
difference between field and matter. Field is characterized
by a certain distribution of energy, and therefore,
materiality."


But I'm puzzled how come
physicists (such as Bilge) don't believed them nowadays.

Because it never has been detected and theories do not require it.

What if it is possible to program space itself which can
affect material properties? Some experiments can done
it.

I have no idea what you mean by 'program space itself'. Define precisely
what you mean by that and propose an experiment to test it.

Never mind.





When I'm sitting on top of the ladder, the Gravitational
Ether can interact with my mass-energy and guiding
its position in space.

Read the link above - current evidence does not require a gravitational
aether nor did Einstein believe it was required.

Because Einstein doesn't know of the extra evidence.

What extra evidence?

But let's talk of purely GR. An Einstein Ether is the
only one which can coordinate my mass energy body to
gravitate to earth with the Einstein Field Equations describing
how the Einstein Ether should behave interlinking the earth
and my body mass. Why not??

Because in the usual sense of the term no aether is required to explain
gravity. Stick to the definitions standard to physics. It is one thing for
a scientist of Einstein's stature to propose a new use of the term and for
time to prove it is a dead end - it is quite another for a person like
yourself; who, well to put it bluntly, does not understand the
technicalities of the theories he is talking about; to propose it and think
it provides physical insight - it doesn't - semantic word games is not
physics.

You have to explain the physical mechanism of GR. If there
is no Einstein Ether to bind the connections. Then what is?
Unless we are living inside some kind of Matrix with
mathematics its only language.

Grav


None of the above of course proves an aether does not exist - it simply, as
far as we can tell today, is not required, ie is superfluous, which his why
Einstein's conception never caught on. For an example of an aether theory
see
http://www.ilja-schmelzer.de/GET/

Bill


Grav



Bill


If Bilge will agree to it. I'll be
satisfied. I just want to gain that one crucial insight
on the physical mechanism of General Relativity.
Give me that and I'm outta here and you'd be happy.


Grav

Bill Hobba wrote:
"Grav" wrote in message
ups.com...
Bill Hobba wrote:
"Grav" wrote in message
oups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message
ups.com...

Dirk Van de moortel wrote:
"Grav" wrote in message
oups.com...


[snip]

Bottomline is. The fabric of spacetime must be a real
entity enough to cause all this gravity trick.

Yet the GR gurus would likely say that its just geometry.
But there must be something that cause my entire body
to be attracted to earth. Remember when I'm in deep
space. I'm only moving in time. When the earth and
ladder say suddenly materialize in front of me. I got stuck
to the ladder. So there should be something in space that
can do all this.

If you'd say no. Pls. enlighten me using intuitive words how
come no and why not.

If you say there should be something in space that can do all
this, that doesn't imply there *is* something that can do all
this.
Nature doesn't care about what you think it should do.
Physicists deal with the model of gravity. Not with the cause.
If you really want to know the real cause, turn to religion or
new-age or intelligent design or whatever you fancy.

Dirk Vdm

If we are dealing with knowing the properties of some particle
inside the atom. It's understandable that a model without
physical cause can suffice. But we are dealing with something
as concrete as gravity. When you fall from the bed to the floor.
This is something solid.

Come on, guys, there must be something. I described in
the geometry aspect. Now what's physically causing my body
to be stucked to this chair typing this.

We don't know.
Try a non-science newsgroup. I'm sure they know.

Dirk Vdm


We should extend science to explaining why too. Who
knows. When we know why. We may even learn how
to shield gravity and take the monopoly out of Boieng.

Grav

Maybe only you don't know. It seems Bill and Bilge knew.
They stated that by understanding the geometry, the answer
would come out and one can understand why it correlates
to reality.

That is not what I said. I said you will be able to understand GR (which
is
a theory) if you understood math better. Why theories exist that have
experimental support is a deep mystery. But the mystery not only applies
to
GR - it apples to good old Euclidian geometry as well. When faced with
such issues simply think back to it and ask how it solves the issue.

You mentioned "Why theories exist that have experimental support
is a deep mystery.". That's why we have to figure out the mechanism
of interaction.

First answer the question why do right triangles obey Pythagoras's theorem?
Why is the mechanism for that any less important than the mechanism for
gravitational interaction? Surely the points and lines of a math theory
can not affect the points and lines of 'reality'. So why do right triangles
obey Pythagoras? When you can answer that then we can look for a mechanism
for gravity.

It's all spatial. But in General Relativity. You are adding time.
As time moves, there is an evolving relationship in the
Minkowski graph such that our bodies are guided to the
earth as time evolves. Without time, there is no GR. So
that's the difference. Pythagoras Theorem is entirely spatial.
GR is an evolving relationship. The primary question is, what
physically bring our bodies to earth as described by the EFE.


The gravitational ether can gave that role.. partly.
When you mentioned that it applies to the good old Euclidean
geometry as well. Are you talking about the Noether Theorem?

No I am talking about something far more fundamental - so fundamental it
really is off topic for sci.physics.relativity, so fundamental people
unconsciously cotton onto it without even being told or even being aware of
it. Once you understand it you will realize all your musings are 'silly'.
Euclidian geometry is a math theory. How does it cause right triangles to
obey Pythagoras's theorem? Surely a math theory can not affect reality -
there must be some actual mechanism that causes it - what is that mechanism?

Hmm.. even let's say there is a more primary reality that can
create space. You still have to explain how tracking events thru
time can orient our bodies to earth producing gravity. Unless
that same something can plot our mass-energy to orient
itself in the same way it created space? This is what I mean
by the Matrix Model of GR.

Grav



Isn't it that the symmetry of space and time is related to
conservation laws.

Well. Its either Aether or Matrix at least. If there is
no relativistic ether and absolutely no physical mechanism.
Then our universe is some kind of holograms following the
rules of pure mathematics written in higher dimension..

You may understand what you wrote, but I, and a suspect others that read it,
don't.

Bill


Grav