"Laurent" wrote in message ...
"Old Man" wrote in message
news:3f3d31f7_3@newsfeed...

Starblade Darksquall wrote in message
om...
"Old Man" wrote in message
news:3f3c4617_2@newsfeed...
Uncle Al wrote in message
...
Starblade Darksquall wrote:

How can the gravitational field have an energy?

The gravitational stress-energy (energy-momentum) tensor in
General
Relativity is exactly zero. Any local gravitational field
in freefall
becomes Minkowski space.

Not all free-fall frames are equivalent, as GPS clearly
illustrates.
The un-equivalence principle rests upon gravitational gradient
and
gravitational potential (space-time curvature). [Old Man]

Uncle Al
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)

So what effect do these two things have on free fall?

Gravitational red shift and gravitational length contraction. All
GPS satellites are in free-fall, but, in addition to relativistic
speed
corrections, the clock rate depends upon the radius of the orbit.
At finite free-fall radius, the clock rate is slower than that in
free
space. In a GM / r^2 gravitational field, the clock rates are
identical
for free-fall and stationary observers at the same radius. This
is
not a violation of the equivalence principle which is restricted
to
uniform gravitational fields. [Old Man]



Gravitational field strength ( gravitic pressure) increases as we
get closer to Earth due to an increased density of the CBMR.


CBMR?

So, wait, doesn't this mean that energy is not conserved, and that
momentum is not conserved, and that maybe even E^2-p^2c^2 is not
conserved so that a things rest mass changes?

--
Laurent

--------------------------------------------------------

The data from all sources, including our extensive experience
with satellites, can be most simply interpreted as indicating that
our Earth completely determines the motion of the surrounding space
for many kilometers out, sweeping it along with it into its 30km/s
uniform motion through the larger volume of space that is entrained
by our Sun and Solar system. Our galaxy, being a larger collection
of matter, entrains a larger body of space. Thus the motion of space
in any location in this Cosmos is determined by the distribution and
motion of both nearby and distant matter.

[...]

In the boundary regions where there is interaction between the
space-flows of two bodies, such as between the Earth and Sun, and at
distances from bodies where entrained and non-entrained space
interact, there will be anomalous atomic clock-slowing and
accelerational effects which are not predicted by the static
solutions of the field equations of General Relativity. These could
be detected by studying the motion and atomic-clock rate of a
satellite which passes through the Earth-Sun gravitational saddle
point. --- Henry Lindner


http://www.geocities.com/hlindner1/W...ce/Physics.htm

http://www.geocities.com/hlindner1/W...plications.htm


-----------------------------------

THE ETHER, QUANTUM MECHANICS & MODELS OF MATTER -- M. C. DUFFY

http://www.cet.sunderland.ac.uk/webe...ce/quantum.htm




Is there any 'free' energy in GR? That is, energy of
gravitation?
Energy which depends on a thing's local passage through
gravitational
gradients?

(...Starblade Riven Darksquall...)



(...Starblade Riven Darksquall...)

"Old Man" wrote in message
news:3f3d31f7_3@newsfeed...

Starblade Darksquall wrote in message
om...
"Old Man" wrote in message
news:3f3c4617_2@newsfeed...
Uncle Al wrote in message
...
Starblade Darksquall wrote:

How can the gravitational field have an energy?

The gravitational stress-energy (energy-momentum) tensor in
General
Relativity is exactly zero. Any local gravitational field
in freefall
becomes Minkowski space.

Not all free-fall frames are equivalent, as GPS clearly
illustrates.
The un-equivalence principle rests upon gravitational gradient
and
gravitational potential (space-time curvature). [Old Man]

Uncle Al
http://www.mazepath.com/uncleal/eotvos.htm
(Do something naughty to physics)

So what effect do these two things have on free fall?

Gravitational red shift and gravitational length contraction. All
GPS satellites are in free-fall, but, in addition to relativistic
speed
corrections, the clock rate depends upon the radius of the orbit.
At finite free-fall radius, the clock rate is slower than that in
free
space. In a GM / r^2 gravitational field, the clock rates are
identical
for free-fall and stationary observers at the same radius. This
is
not a violation of the equivalence principle which is restricted
to
uniform gravitational fields. [Old Man]


Gravitational field strength ( gravitic pressure) increases as we
get closer to Earth due to an increased density of the CBMR.

--
Laurent

--------------------------------------------------------

The data from all sources, including our extensive experience
with satellites, can be most simply interpreted as indicating that
our Earth completely determines the motion of the surrounding space
for many kilometers out, sweeping it along with it into its 30km/s
uniform motion through the larger volume of space that is entrained
by our Sun and Solar system. Our galaxy, being a larger collection
of matter, entrains a larger body of space. Thus the motion of space
in any location in this Cosmos is determined by the distribution and
motion of both nearby and distant matter.

[...]

In the boundary regions where there is interaction between the
space-flows of two bodies, such as between the Earth and Sun, and at
distances from bodies where entrained and non-entrained space
interact, there will be anomalous atomic clock-slowing and
accelerational effects which are not predicted by the static
solutions of the field equations of General Relativity. These could
be detected by studying the motion and atomic-clock rate of a
satellite which passes through the Earth-Sun gravitational saddle
point. --- Henry Lindner


http://www.geocities.com/hlindner1/W...ce/Physics.htm

http://www.geocities.com/hlindner1/W...plications.htm


-----------------------------------

THE ETHER, QUANTUM MECHANICS & MODELS OF MATTER -- M. C. DUFFY

http://www.cet.sunderland.ac.uk/webe...ce/quantum.htm




Is there any 'free' energy in GR? That is, energy of
gravitation?
Energy which depends on a thing's local passage through
gravitational
gradients?

(...Starblade Riven Darksquall...)

Laurent wrote in message
...

Gravitational field strength ( gravitic pressure) increases as we
get closer to Earth due to an increased density of the CBMR.

--
Laurent

Ludicrous Crackpot. [Old Man]

In message , Starblade
Darksquall writes

[...]

This doesn't make any sense to me at all. And I'm not stupid or
anything. I don't see why they found it necessary to do these things.
Maybe either I need to be educated more, or their theory needs some
tweaking.

"either" ... "or". That's two hypotheses.

Fermi problem for the reader: calculate their relative probabilities.

--
Richard Herring

Starblade Darksquall wrote:

How can the gravitational field have an energy? Isn't energy what
CREATES the gravitational field? Also, why is it that this energy does
not create any curvature effects while all other energies do? Doesn't
this violate the equivilence between all types of energies?


The gravitational field generates itself because Einstein's equations are
non-linear.
The Schwarzschild solution is an exact solution of the Einstein equations
and there is no energy-momentum tensor anywhere. It's a vacuum solution.

In GR, there really isn't a gravitational force, so the idea of eneregy
associated with it requires careful interpretation of Einstein's
equations.

Trying to identify the energy in a gravitational field is a bit
problematic
in GR but that's a technical difficulty. See Wald's book for a discussion
of this.

John Anderson

(Starblade Darksquall) wrote in message . com...
How can the gravitational field have an energy? Isn't energy what
CREATES the gravitational field? Also, why is it that this energy does
not create any curvature effects while all other energies do? Doesn't
this violate the equivilence between all types of energies?

Where does the energy come from if free fall doesn't create any
energy? Do they mean the energy created when one accelerates up in a
gravitational field? If so, then why don't they just say so? And,
furthermore, this WOULD have an effect on its energy, at least from a
free-fall frame of reference, so why not include it in its
calculations?

This doesn't make any sense to me at all. And I'm not stupid or
anything. I don't see why they found it necessary to do these things.
Maybe either I need to be educated more, or their theory needs some
tweaking.

(...Starblade Riven Darksquall...)

Gravitational field has no energy - if you change the definitions (see
Brans and Dicke). In that case the theory will be linear (see
http://www.arxiv.org/html/physics/0109038).

In sci.physics Starblade Darksquall wrote:

[...]
Also, what about this article:

http://www.npl.washington.edu/AV/altvw100.html

Yilmaz's theory is simply wrong. I suggest that you start with
Misner's paper, gr-qc/9504050.

The basic problem with Yilmaz's is precisely the one Yilmaz
(mistakenly) thinks is a problem for general relativity: for a
many-body problem, it leads to a violation of the Newtonian
limit of the equations of motion for the bodies. For example,
a two-body solution of general relativity is inconsistent if the
bodies remain at rest---they must necessarily accelerate in a
manner that is, to a good approximation, just the acceleration
predicted in Newtonian gravity. In Yilmaz's theory, on the
other hand, a solution with two bodies at rest is consistent,
while one in which they accelerate towards each other is
inconsistent with the Bianchi identities.

Yilmaz's underlying mistake is a misunderstanding of
gravitational energy in general relativity. As others have
pointed out in this thread, the nonlinearity of the Einstein
field equations implies that gravity generates gravity, i.e.,
that gravitational energy is already included. This can be
made explicit in the weak field approximation -- see, for
example, Feynman's _Lectures on Gravitation_, in which
he builds up the field equations of general relativity by
starting with a linear theory and then adding in the energy
of the gravitational field as a source. (The rigorous version
of this has been done by Deser, Gen. Rel. Grav. 1 (1970) 9
and Class. Quant. grav. 4 (1987) L99.)

Because Yilmaz does not recognize this, he essentially
double-counts gravitational energy by including it as a
separate source. Actually, there's a funny choice of sign,
so Yilmaz's right-hand side turns out to cancel the energy
of the gravitational field that's already there. As a result,
Yilmaz's theory is inconsistent with the motion of its sources
under each other's gravitational field; his field equations
imply that sources must be, and remain, at rest.

What's wrong with having a gravitational stress energy tensor?
Especially if the energy in the gravitational field itself causes
curvature.

First of all, it's not a tensor. This is easy to see. A basic
property of a tensor is that if it's zero at a point in one set
of coordinates, then it's zero there in any other coordinate
system. But you can always transform away gravity at a
single point, by going to a freely falling reference frame.
(You can't do this in a finite region, so you *can* define a
``quasilocal gravitational energy'' in a finite region with
specified boundaries. But that's not a tensor.)

Second of all, as I explained above, gravitational energy is
already there in the Einstein field equations. Adding it in
is redundant. Subtracting it out, as Yilmaz does, is wrong,
observably.

Steve Carlip

(Starblade Darksquall) wrote in message . com...
(György Szondy) wrote in message . com...
(Starblade Darksquall) wrote in message . com...
How can the gravitational field have an energy? Isn't energy what
CREATES the gravitational field? Also, why is it that this energy does
not create any curvature effects while all other energies do? Doesn't
this violate the equivilence between all types of energies?

Where does the energy come from if free fall doesn't create any
energy? Do they mean the energy created when one accelerates up in a
gravitational field? If so, then why don't they just say so? And,
furthermore, this WOULD have an effect on its energy, at least from a
free-fall frame of reference, so why not include it in its
calculations?

This doesn't make any sense to me at all. And I'm not stupid or
anything. I don't see why they found it necessary to do these things.
Maybe either I need to be educated more, or their theory needs some
tweaking.

(...Starblade Riven Darksquall...)

Gravitational field has no energy - if you change the definitions (see
Brans and Dicke). In that case the theory will be linear (see
http://www.arxiv.org/html/physics/0109038).

What exactly is meant when they say that the gravitational field does
or does not have energy?
It means:
1.) gravitational field does not have energy means: Energy causes
gravity
2.) gravitational field does have energy means: Energy and Gravity
causes Gravity.

To solve the second case it is obvious that the equation must be
changed so that Energy remains on one side and Gravity is arranged to
be only on the other side. (Separate them) The result is equation 1.)
So then why do not we start with equation 1.)?


Also, what about this article:

http://www.npl.washington.edu/AV/altvw100.html

What's wrong with having a gravitational stress energy tensor?
Especially if the energy in the gravitational field itself causes
curvature.
Nothing is wrong, except that in case of multi objects the result is
an unsolvable nonlineal equation.


(...Starblade Riven Darksquall...)

Gy\"orgy Szondy wrote:
Steve Carlip wrote in message ...
In sci.physics Starblade Darksquall wrote:

[...]
Also, what about this article:

http://www.npl.washington.edu/AV/altvw100.html

Yilmaz's theory is simply wrong. I suggest that you start with
Misner's paper, gr-qc/9504050.
Please also see the refutation of Misners claims...

Einstein's theory is also wrong - as it is a heuristic theory:
1.) it defines the rest mass of the particle being constant, that
causes the nonlynearity of his model.

Why do you not take the nonlinearity as given ?

2.) Stress energy tensor contains stress-part that has been counted in
the energy part. (mass of the moving particle...)
3.) In Schwarzschild solution the metric is defined being non conform:
a radial anisotropy is allowed/defined/predicted that has been never
validated (AFIK).

There are several Schwarzschild solutions. The isotropic solution is

ds^2 = (\frac{r-R}{r+R})^2 dt^2 - (1+\frac{R}{r})^4
\dot (dr^2 + r^2(d\theta^2 + sin^2\theta d\phi^2))

with R = \frac{\kappa m}{16 \pi} .

So what we are talking about?
GR is the best - but there were many attempts to correct it's errors.
Any attempt to validate predictions or correct errors should be
welcome and must be critised in details, but partial results should be
admitted indeed.

GR's only one error is the assumption of _distributed_ matter sources -
it makes GR crazy. Only this false assumption is inconsistent with
the quantum phenomena, the rest not ! See
http://home.t-online.de/home/Ulrich.Bruchholz/
One can of course see particle numbers in solutions of the Einstein-
Maxwell equations regarding this essential.

Ulrich Bruchholz

Steve Carlip wrote in message ...
In sci.physics Starblade Darksquall wrote:

One thing I want to know is... if two bodies are falling toward
eachother, doesn't the system increase in gravity due to the added
energy? At least with respect to an outside observer?

I don't understand what ``increase in gravity'' means. ``Gravity''
is not a scalar. What, exactly, do you expect to ``increase''? If two
objects fall toward each other, the form of the gravitational field
around them will change, of course. But how, exactly, do you
want to decide whether such a change is an ``increase''?


Meaning if you're an observer at a fixxed distance from their center
of mass by accelerating likewise you will have to accelerate with a
greater power (I'm taking accelerations to be in the spaceship's frame
of reference, BTW) in order to remain at the same position. As the two
large bodies approach, there will be more gravitational attraction
because they will gain net total energy but remain with the same net
total momentum, or at least from your reference frame they will.

Also, how does GR deal with the time lag involved with gravity? Like
if there are two extremely powerful rays of light going in opposite
directions each fired about 10 light seconds away from you, GR ought
to say that at the 'same time' as they are fired there is no gravity,

Why? Are you proposing to create these light rays out of nothing?
The energfy that gets converted to light will have a gravitational
field.

It *is* true, according to GR, that the gravitational field you observe
won't *change* for ten seconds. But that's a different matter...


Yes, that is what I'm talking about. How does GR figure this? Does it
measure how gravitational fields change with time? I know that it does
specify that it takes time for a change, differeing based on the
metric, but what I'm not sure of is if anybody's actually done the
mathematics for this so that it can actually be calculated.

Steve Carlip

(...Starblade Riven Darksquall...)