An object O in the middle between two objects A and B. To visualize the picture, think of the three objects as they were fixed in the fabric of the spacetime. Due to the expansion of the spacetime each object move away from each other; as if the middle one is fixed while the two others move away from it. An observer on A would receive a cosmological redshift from B that is greater than the cosmological redshift that he received from O. Accordingly, to an observer on A; B would recede faster than O. After a time t, the distance separating O and B would be greater than that separating A and O. Since the spacetime is isotropic, there is no preferred position. Did an observer on B agree with this picture? An observer on B, conversely, would find after a time t that the distance separating O and A would be greater than that separating O and B. Whom should we believe? It would be a paradox if we believed both of them. The cosmological redshift and its consequence recession velocity are no longer a distance indicator. We must seek for another cause for the cosmological redshift? We interpret the cosmological redshift as a curvature`s manifest.
Article The Cosmological Redshift Manifests the Curvature and Interp...
The position of the observer is preferred; this contradicts the isotropic principle. Conversely the distant observer similarly would measure the cosmological redshift of the previous observer is the greater than the cosmological redshift of it is nearby objects. Am not confused.
The position of the observer is preferred; because an observer at that distant object would not agree with our local observer, in fact he would see the converse in the cosmological redshift.
The isotropic principle is true, The untrue is to interpret the cosmological red-shift as a distance indicator associated with an increase in the recession velocity.To be consistent with the isotropic principle, the increase in the cosmological red-shift of the distant object coincides with the increase of the curvature where the converse is also true.
The redshift-distance law is so that it preserves the homogeneity. Please read my paper on this at https://arxiv.org/abs/1501.03456
I hope it helps. Domingos
From older cameras, we know red shift. It is for light who travels longer way before reflected. That do not immediately imply cosmological red shift, so I don't believe it.
Sun has an unusual shift to green sometimes, at sunset, when the appearance also is a brick shape.
Adrian
Do you think you have the correct answer? I don't think
All the statements you used to covience us are:
"You dont understand"
" You are confused"
"Your error is that you think that the cosmological redshift is referenced with respect to a "center of universe"
There are no logical statemantds. So yiou are waisting ourr time.
I changed opinion. I think the red shift in a camera photo could be due to a change of curvature at reflexion. Observing the spectral decomposition in a prism in details, slightly curved paths are seen, and also a change of direction for violet and indigo.
No Salah, it is you who is wasting time. "Isotropic" means the same in all directions, it does not mean the same as "homogeneous". Check a dictionary for that, Adrian is perfectly correct.
As for your question, if they are equally spaced, O sees A and B moving away at speed v, A sees O moving at v and B moving at 2v. B sees O moving at v and A moving at 2v. They all agree that the speed of each is proportional to their distance from the observer which is the Hubble Law so there is no paradox at all.
No Dishman
Isotropic means "same in all directions". If the position of an observer is preferred, this contradicte " same in all directions" that violate the isotropic principle.
An observer in a rotating universe would see a preferred direction, the axis of rotation, but that would not imply a preferred location because all observers everywhere would identify the same preferred direction.
I can attach a photo of the prism. If it changes curvature between dark violet and indigo, then the red shift should be when not change of curvature, and at change of curvatures, maybe several times, the shadows and pupill will be correctly more dark, at the photo. It agrees with a dispersion in terms of wavenumber, such that the two colours correspond to the same frequency at nonlinear wave description. In cosmology, this observations for red shift will not imply that objects move in either or either direction.
Lena, redshift in cosmology refers to a change in the frequency of spectral lines, not the direction. In cosmology, for small values this is equivalent to Doppler shift.
https://en.wikipedia.org/wiki/Redshift
https://en.wikipedia.org/wiki/Doppler_effect
Dishman
"As for your question, if they are equally spaced, O sees A and B moving away at speed v, A sees O moving at v and B moving at 2v. B sees O moving at v and A moving at 2v. They all agree that the speed of each is proportional to their distance from the observer which is the Hubble Law so there is no paradox at all"
If A is a subset of B and if B is a subset of A, then A=B. Similarly, If A sees the distance OB is greater than AO and conversely B sees AO greater than OB then AO=OB. Hence no real expansion of the space exists.
If we believed all of them agree, then the cosmological red-shift as a distance indicator and increase in recession velocity would be just an illusion
Thus, the cosmological red-shift has nothing to do with the expansion of the universe
SAM: If A is a subset of B and if B is a subset of A
they aren't subsets, this was how you started your question:
SAM: An object O in the middle between two objects A and B ..
They are separate objects arranged like this:
A - O - B
If that's not what you meant, you need to rewrite the question.
According to the homogeneous principle there are not preferred locations. The matter is uniformly distributed through the universe at large structure scale. All Quasars are located far distant away (billions light years) due to their cosmological redshift , no even one Quasar is nearby. Thus our location is preferred that violates the homogeneous principle.
Moreover, the earliest objects (Galaxies...) in the universe are located far distant away from us. Is our location is preferred in time?
The orthodoxian interpretation of the cosmological redshift as a distance indicator and recession velocity is problematic.
SAM: Is our location is preferred in time?
The "Cosmological Principle" says the universe is homogeneous and isotropic at large scales at any given cosmological age, but the averages will vary with age.
The "Perfect Cosmological Principle" proposed that the averages were also homogeneous in time. That was the basis of Fred Hoyle's "Steady State" and "Quasi-Steady State" models. However we know that they do not stay the same, the density in the past was much higher than it is today.
Quasars were very numerous in the early universe, there are far fewer now because the gas that fed them has mostly been used up. Galaxies near us may have been quasars in the past but are quiet now so we only see them far away where we can look back to earlier times.
SAM and all.
Homogeneity and isotropy becomes less distinct when including the observer. An example is fog, which is homogenous, apart from that it rotates, at least if one try to sail in it. It is probably measured how it rotates by itself, and if the rotational direction is determined by the sailor or more by hazard/happenstance.
Lena, an observer anywhere in a rotating fog cloud will still see a homogeneous and isotropic cloud, and all observers anywhere in the cloud will measure the same angular velocity for the cloud. Each can consider they are at the centre of the circular region they can observe where the radius is determined by the density of the cloud.
According to the cosmological redshift:
No any Quasar is nearby around us.
No any earliest galaxy is nearby around us.
All of them are billions light years distant away.
After all that Adrian Sfarti and Dishman said that our location (due to the cosmological redshift) is not preferred!!!!!!!
SAM: No any Quasar is nearby around us.
The Milky Way was a quasar (as seen from outside the galaxy) for about 4 to 8 million years, finishing 6 million years ago. See the link.
SAM: No any earliest galaxy is nearby around us. All of them are billions light years distant away.
Right, and for an alien scientist living in one of those galaxies looking at us, the Milky Way is an "early galaxy" because light from here is still travelling to them. If you look at a galaxy a billion light years, you see it as it was a billion years ago. Are you having trouble understanding that simple fact?
SAM: After all that Adrian Sfarti and Dishman said that our location (due to the cosmological redshift) is not preferred!!!!!!!
Correct, and nothing you have said casts any doubt on that.
http://www.skyatnightmagazine.com/news/milky-ways-energetic-outburst
How an observer located at an earliest Galaxy could visualize our location from the point view given by the cosmological shift he received?
According to the back time concept, could he think that we are the earliest not him?
How an observer located at a distant Quasar could visualize our location from the point view given by the cosmological shift he received?
According to the back time concept, could he see Quasars that formed earlier are rich around us?
Those distant galaxies are 13.8 billion years old now. From their point of view, they see our region as it was when the universe was young.
I just add this, I didn't make it clear:
SAM: According to the back time concept, could he think that we are the earliest not him?
SAM: According to the back time concept, could he see Quasars that formed earlier are rich around us?
Yes, both of those are correct.
Dishman :Yes, both of those are correct.
Although, according to the back time concept, the distant observer would see Quasars that formed earlier are rich around us, but no any Quasar is nearby around us!
SAM: Although, according to the back time concept, the distant observer would see Quasars that formed earlier are rich around us,
That is correct.
SAM: but no any Quasar is nearby around us!
That is also correct, because they were 'rich' in the past everywhere but are few now everywhere. The distant observer is seeing our region as it was in the past, we are seeing their region as it was in the past.
Light does not travel instantaneously, if you look at a star that is 100 light years away, the light you are seeing today left the star 100 years ago. The same is true at much greater distances but you have to factor in the expansion that occurred while the light was travelling to get accurate numbers.
George Dishman: "That is also correct, because they were 'rich' in the past everywhere but are few now everywhere. The distant observer is seeing our region as it was in the past, we are seeing their region as it was in the past."
Ok, thus in the past locally the Quasars were existed. Did they now turn into Galaxies (Note that a Quasar is just one light year in diameter) or they just disappeared?!
SAM: Ok, thus in the past locally the Quasars were existed. Did they now turn into Galaxies (Note that a Quasar is just one light year in diameter) or they just disappeared?
Quasars were the accretion discs of super-massive black holes, fed by large amounts of raw hydrogen/helium gas. The black holes are still here, the one in the Milky Way is known as Sag A*, but the gas has been use up creating the stars of the galaxy. I gave you a link a few posts back that said that Sag A* turned into a quasar for a few million years until about 6 million years ago. I'll repeat it below. I'll also add a ink to an image of galaxy M87 which is only 54 million light years away. You can see a thin jet coming from the galaxy. If we happened to lie along the line of that jet, we would see M87 as a quasar. There are still a few around but not nearly as many as in the past.
https://en.wikipedia.org/wiki/Sagittarius_A*
http://www.skyatnightmagazine.com/news/milky-ways-energetic-outburst
https://apod.nasa.gov/apod/ap110828.html
SAM: َQuasars do not possess any time dilation
That is not true, see the link.
http://physicsworld.com/cws/article/news/2012/may/04/quasars-shine-a-new-light-on-cosmic-distances
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