Conservation of Mass and Energy issues.

The following physics results in ambiguous descriptions of reality.
a. General relativity predicts that as a photon travels though an expanding space-time field it’s wavelength increases. http://www.astronomycafe.net/qadir/q1384.html (Popular accounts of the cosmological red shift often “erroneously” call the observed red shift a “Doppler shift” or actual motion of galaxies through space. Since the expansion is so uniform and billions of galaxies are observed, it becomes extremely unlikely that we just happen to be located in the middle of billions of galaxies moving away from us. Anyone who has seriously studied astronomy at the college level is aware of this relativistic description of the cosmological red shift. Galaxies are carried by the expansion of space-time, they are not moving though it).
b. Special Relativity predicts that an object moving at the speed of light will not change. (The “Twin paradox” is the classic example used in special relativity to illustrate this point.)

Since a photon is traveling at the speed of light it should not change, yet according to general relativity, it has to. Does this strike anyone as odd?

Those who believe in General Relativity (as I do) need to have an explanation for this ambiguity.

Snowflake

1) GR says the energy that is lost is merely spread out, into the "new" volume that is created due to spacial expansion.

2) GR makes the prediction and explains it, this phenomena is not in the realm of SR.

Another aspect of the mass energy problem.

A gram of matter is converted to light energy with a specific number of photons with a specific wavelength. This packet of energy is beamed into space, bounced off a mirror, and then upon return, the energy is converted back into matter. There would now be less than 1 gram of material, based upon the principles of General Relativity. Where did the matter/energy go?

(Note, the “standard” model stops the expansion of space-time at the boundary of galaxies. This means that while traveling through a galaxy, (which is not expanding with the expansion of space-time), there is supposed to be no loss of energy. It is only while a photon is traveling between gravitationally bound galaxies that the loss of energy would be realized. This means that a galaxy that is viewed through another galaxy should be a bit bluer then expected. There is no experimental evidence of this effect. There is no “bluing” of galaxies viewed along the length of our galaxy over galaxies observed perpendicularly to our galaxy)

Those who believe in General Relativity (as I do) need to have an explanation for the ambiguity.

Snowflake.

Um. The recoil of the mirror acounts for it?

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I was under the impression that spacetime is expanding everywhere (including within galaxies). It's simply that gravity resists the expansion with the result that galaxies maintain their shape. This is also true of the strong and weak nuclear forces that hold atoms together so matter does not expand with spacetime either.

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Hi Ricimer

My understanding of the loss of energy due to spatial expansion is different from a “spreading” out of energy. A “spreading” out of energy implies that if one includes a bigger volume of space, the same amount of energy would still be there. This is not how I believe the expansion of space-time to be physically structured, as evidenced by the loss of mass problem indicated in the previous example.

General relativity and Special relativity both describe the properties of points in space time, they both describe the same “realm”. Exempting the relationships of Special Relativity from those of General Relativity is inconsistent.

Snowflake

Hi Mike

Clever idea considering a mirror. The red shift effect does not need a mirror to be expressed. One gram of energy could have been sent to Earth from some distant galaxy and when it finally arrived here, according to general relativity, (as presently expressed), there would no longer be one gram of energy.

Snowflake

Hi Patrator

I share your idea that the expansion of space does include the space within a galaxy, but this is not part of the standard model used by the majority of Astro-physicists. The standard model assumes that Gravity within a galaxy prevents the expansion of space-time. General Relativity describes the shape of space-time between orbiting objects, General Relativity also describes the shape of space-time for a universe that is expanding. If the shape of space-time between orbiting objects were expanding, it would alter the present formulation of how general relativity describes gravitational relationships.

Snowflake

I stand corrected.

Had a look around for the paper I read that formed the basis of my understanding. It is linked here.
I also did a bit of googling and found this paper which might be of interest to you - although the paper makes some rather sweeping statements based on just one observation. I would like to see some more corroborating observations before I accept any of the conclusions.

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Ignorance is the night of the mind, but a night without moon and star. - Confucius

Hi Patrator

Thank you for the links on expansion. The last link was by V. Gentry and it challenges the big bang model based upon the amount of heavy elements that appears so early in the universe. A young universe could not have much iron since it takes a stars lifetime to produce iron. The argument is valid but too many other explanations can be poised to counter. Gentry represents a number of “fringe” critics that find anomalous explanations regarding the expansion of the universe unsettling. My critic of the lack of the conservation of energy is another problem that “fringe” critics, (like myself), have with the presently accepted standard model.


Usually the standard response a professional Astro physicist would have regarding the situation of the lack of energy conservation is that on a “local” level there is conservation, but on a “global” level there is not. I prefer a model that is consistent. I am skeptical of any one touting a model that says for them to be right you have to believe this, and then you have to believe something else to explain something else. Whatever principle or basis you are building a physical model for the universe, it must be consistent in its application. There should be no differentiation between local and global events.


Another point usually expressed by the established, institutionalized theorists is that Special Relativity is a special case for general relativity, one that depends of the curvature of space-time. My use of arguments based upon principles of special relativity to argue that the energy of a photon should not change would be explained as not considering the more encompassing theory of general relativity. (A “flat” universe would make the relationships of special relativity a general case not a special case).


The first link you gave which went to the work of Cooperstock, Faraoni and Vollick and their paper directly pertains to the idea of where to stop the expansion. They do refer to the kind of expansion you are referring to as to how it would affect gravitational systems. As you noted they decide that the issue of where to stop and how to interact the expansion of space-time with celestial systems is as follows. “ The recurrent attention paid to this issue indicates that to this point a definitive answer is still lacking. However, it is our sense that the prevalent perception is that the physics of systems which are small compared to the radius of curvature of the cosmological background is essentially unaffected by the expansion of the Universe.”

(I will refer to this paper in the future since it raises some interesting ideas about “pseudo-expansion”. I would not dismiss such theoretical models just because the rulers could not detect such change. If one established an “absolute” ruler exempt from the expansion, it would be possible to measure the uniform expansion of space-time, such a model would result in an additional dimensional measures of distance and time).


Snowflake

Hi snowflakeuniverse,

Many thanks for the additional information regarding the papers and theories. I am not up-to-date on BBT and the anomolies it presents. Personally, I accept the general principles of the theory but I suspect that there will be many surprises and changes to BBT over the coming years (I wouldn't rule out a completely new theory either).

In the meantime, I guess I'll have to do some more reading when I have some spare time.

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Ignorance is the night of the mind, but a night without moon and star. - Confucius

From this statement, it's obvious you don't fully understand how GR describes the expansion. Either (galaxies moving through space or galaxies moving with space) are valid descriptions. It depends on what frame you chose to use.



Could you please be more specific? In what way should a photon not change under SR? Ricimer pointed out the flaw in this idea, SR is only valid for inertial frames and the expanding universe is not inertial. GR must be used.

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Neptune- The original Dark Matter.

The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth

This is the way GR explains it. How do you reconcile the rejection of this with your statement:

You're being inconsistent here. Either you accept GR or you don't. Which is it?

It appears here that you don't fully understand relativity. They do not describe the same "realm". SR's "realm" only applies to inertial frames. GR, while it can apply to inertial frames (and matches SR's predicitions) also applies to accelerated motion (which through the EP includes gravity). The expanding universe is not inertial.

__________________
Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Neptune- The original Dark Matter.

The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth

Hi Tensor.

You question my understanding of General Relativity, which it turn I could question yours. These kinds of assertions are fruitless and needlessly adversarial. Even among my friends who have studied general relativity from the same teachers, we have had disagreements. Even within popular texts on General Relativity there are “issues” (You probably have Misner’s Thorne;s and Wheeler’s book called “Gravitation” since it is a fairly standard study of general relativity. That text is full of Issues itself. One example that comes to mind is on page 742 called “Homogeneous isotropic model universes that violate Einstein’s conception of cosmology”)

You stated that
“Either (galaxies moving through space or galaxies moving with space) are valid descriptions. It depends on what frame you chose to use. “


General Relativity does allow choices of frames of reference but those frames of references describe a real structure to space-time. The expansion of space-time is usually described, utilizing general relativity, as the stretching of a membrane, which can be visualized as stretching the established frame of reference. Another example illustrating the structure of space-time is a bowling ball on a membrane “deforming space”, which is visualized by the deformation of a frame of reference or coordinate system established in space-time. (we could play semantics and say that it is the fixed coordinate system that is describing the shape of space time, but this is not the usual way the distortions of space time are visualized).

This structure to space-time results in a much different physical description causing the cosmological red shift. A galaxy moving though space-time causes a Doppler shift. A galaxy being carried by the expansion of space-time produces a recessional red shift because the photon looses energy while traveling through space-time. Perhaps reviewing the link initially given in the posting is clearer than what I have described.

Assuming you now see that general relativity predicts a loss of energy of a photon while it travels through an expanding space time field, you will see the discrepancy when special relativity is considered (for a flat universe).

An object moving at the speed of light does not change. This is a principle of special relativity, (again for a flat universe). . As stated before, the famous special relativity twin example is a case in point. If the twin could move at the speed of light, time would stand still for the twin and would experience no physical changes. This contradicts the prediction of general relativity, which has a photon “experiencing changes” while traveling at the speed of light.

Special Relativity and General relativity describe properties of reality, which, to my mind, describes the same “realm”. You again accused me of not fully understanding relativity, which again I find a bit presumptuous. I was very careful of ascribing to the situation at the very start a “flat” universe, which corresponds to observation. The case of a flat universe points leads to a description for space-time that maps point for point between special relativity and general relativity.

This issue can be resolved utilizing principles of general relativity by ascribing to a cosmological constant and specific rates of deceleration. (see reference given in Gravitation) I find such resolutions very contrived, artificial and suspect. It is reminiscent to the situation in which ever increasing amounts of offsets and epicycles were needed to keep the Ptolemaic system in correlation with observation.

Regarding my belief that general relativity is correct yet produces the anomalous conservation issues I do have a solution to the problem, but I was interested to see how many really knew that general relativity predicts a “violation” of the conservation of energy principle.

Snowflake.