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1. If our distance to the near edge is R1 and the distance to the far edge is 1000R1, do you agree that the expansion impact of 1000R1 should be higher than R1 by 1000? If so, how could it be that we should get the same redshift in both directions?
2. If we are located only one Mpc from the edge, then the impact of the expansion is only 73Km/s. How that speed can set a redshift of 1100?
Quote1. If our distance to the near edge is R1 and the distance to the far edge is 1000R1, do you agree that the expansion impact of 1000R1 should be higher than R1 by 1000? If so, how could it be that we should get the same redshift in both directions?Since we can't see any visible boundary to the visible universe, the visible universe must have a radius of at least slightly less than R1, The visible universe represents the limits of what we can see, so anything happening more than a distance of R1 away from us simply would not be visible and therefore could not impact our observations.
The CMB is equidistant in all directions. It is a shell centered on us. Any CMB light that originated closer by has already passed by us. Any further out hasn't got here yet. Therefore the distance to the edge, in a model that has an edge at all, has zero effect on what is seen.
Space expanding in all directions would cause an equal redshift at all locations in the Universe.
Sorry, you both don't answer my question.
You have stated that Space expanding in all directions would cause an equal redshift at all locations in the Universe:
I wonder how the Space expanding can set the same redsift to different distances and different velocities due to the impact of space expansion.
1. How could it be that we get exactly the same redshift value from the near edge of the universe which is R1 and from the furthest edge which is higher by 1000 times than R1 (without the impact of space expansion)?
2. If we add the impact of space expansion, that it is clear that the edge which is located 1000 times R1 from us will move even further away at higher velocities. That should even make it much more difficult to get the same redshift. So, how can you claim that the space expansion adjust them all to the same level?
3. https://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objectsList of the most distant astronomical objectsWe see that GN-z11 galaxy is located at a distance of 13.39 billion LY away and its redshift is only z = 11.09.So, why we get exactly Z = 1400 in the CMB, while for a galaxy that is located at the furthest location (13.39 billion LY) in our Universe we only get 11.9?4. If in one side our distance to the edge is only 13.39 billion LY =R1, what do you think should be the CMB redshift?Do you agree that the radiation amplitude of the furthest galaxy gets to our location at the minimal value (as 1/R^2).So, if we look directly in this direction we should get radiations from all the galaxies which are located in that line. those galaxies has lower redshift but higher radiation amplitude.Hence, we should see in the CMB (at the direction of GN-z11 galaxy) the sum of all the radiations from all the galaxies/objects that are located in this direction.As the furthest galaxy has a minimal radiation amplitude with a redshift of 11.9, while closer galaxies with much more radiation amplitude have a lower redshift (lower even than 1), do you agree that the average redshift should actually be much lower than 11.9. (could it be 2 or even less than 1?).If so, how could it be that we get a redshift of 1400 in the CMB in all directions? Why not 5 or 11.9?Do you agree that this redshift value of 1400 is a real enigma for any finite Universe?
Radiation that has traveled further would be more redshifted because it has been moving through an expanding space for a longer period of time.
We can't see past R1 so what is happening 1,000 times further away isn't visible to us. I say that we can't see past R1 because the edge of the total Universe must be somewhere outside of the observable universe (otherwise we could detect that edge). So R1 must be at least slightly beyond the edge of the observable universe, putting R1000 just that much further beyond our observation abilities.
The visible universe represents the limits of what we can see...We are about 46 billion light-years from the edge of the visible universe, so we are at least that far from any hypothetical absolute edge of the Universe as well.
3. https://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objectsList of the most distant astronomical objectsWe see that GN-z11 galaxy is located at a distance of 13.39 billion LY away and its redshift is only z = 11.09.So, why we get exactly Z = 1400 in the CMB, while for a galaxy that is located at the furthest location (13.39 billion LY) in our Universe we only get 11.9?
Based on this answer it is clear to me that the radiation that has traveled further (from 1000 times R1) would be more redshifted than the radiation that traveled only one R1.
ased on this answer it is clear to me that the radiation that has traveled further (from 1000 times R1) would be more redshifted than the radiation that traveled only one R1.So, how could it be that we get the same radiation from a distance of R1 and 1000 times R1.
So, why in that direction we don't get higher redshift as the distance is longer by 1000 times?
How it could be that we get a redshift of 1400 if the edge is just slightly beyond the edge of the observable universe or if it 1000 times longer? Actually, if we get a redshift of 1400 from a far end galaxy, can we calculate/extract the estimated distance to this galaxy?If so, what is the distance that redshift of 1400 represents?
If we get the same redshift from all directions, why we can't assume that we are located just at the center of the Universe?
I am going to protest the top statement. The visible universe represents the current proper distance of the furthest material that could ever have had a causal effect on our current location. That by no means says we can see that far. The event horizon is only about a third that distance and anything beyond that cannot have an effect here ever, so that's the absolute limit of how far we can see if we're willing to wait forever.The light from the CMB is the furthest we can see, and it was emitted a scant ~1.3 million light years (proper distance) from the comoving location corresponding to here. The journey from there to us/here/now took it considerably further away than that, but no more than say a single digit of BLY away (proper distance again). That's the furthest we can see, which is well inside the Hubble sphere. If that light's journey took it to the edge of the universe, it would presumably be affected by that. We'd see it. We cannot see any further away than that. So R1 is not very far at all, no more than 20% of that 46 BLY radius of the 'visible universe'.
I don't think there are any galaxies in the observable universe with a redshift anywhere near that high, but you can estimate distances to galaxies based on redshift. I don't know what the equation involved is, though.
I don't know the equation offhand either, but if you look at the redshift figures for the list of 'furthest galaxies' linked, you notice that the whole list has not much distance variance, but the redshift factor number goes up dramatically for the entries at the top of the list. The number apparently come from the Lambda-CDM model, a plot (from wiki) appearing here:https://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/Distance_compared_to_z.png/400px-Distance_compared_to_z.pngNotice that a galaxy at 13.4 GLY (that funny figure that corresponds to nothing physical) plots nicely at 11, and the CMB with z=1100 seems to be 46 GLY away by that measure.
The CMB is considerably further away than that, yet is not listed as it isn't a distinct galaxy or other object. And yet the CMB light was emitted only 1.3 million (not billion) light years away.
That's contradictory to what I've read about most distant objects since they've measured a quazar at something like 22 GLY away, meaning that object is now that far away, but within our event horizon back when the light reaching us now was first emitted. So I don't know exactly what is being measured on the vertical axis of that graph.Notice that the graph levels off at 46 GLY, with z approaching indefinite values as distance approaches the 'size of the visible universe'. If we could see through the CMB barrier, we'd observer redshifts far greater than 1100.The red line is the Hubble red shift, and that goes to infinite z at the Hubble radius.
Hence, the CMB with z=1100 seems to be 46 GLY away by that measure!So, why do you claim that the CMB was emitted only 1.3 million (not billion) light years away.
Quote from: HalcThe CMB is considerably further away than that, yet is not listed as it isn't a distinct galaxy or other object. And yet the CMB light was emitted only 1.3 million (not billion) light years away.I really don't understand that contradiction. You also see the contradiction, but I couldn't understand what do you really mean:
Actually, our scientists claim that the CMB is evidence for the BBT.
So, if the Big bang had been set 13.8 Billion years ago, how could it be that the CMB which is consider as a product of the BBT comes from a distance of 46GLY?
Actually, if we see today a radiation which had been emitted from a distance of 46GLY,
don't you think that it proves that our real universe should be much bigger than the estimated size of the observable Universe?
If so, how can we fit that size of the Universe in only 13.8 BY?
Do you think that it could set a contradiction in the BBT?
The 'distant' galaxies (or at least the material that would become them) were closer than 1.3 million LY away back at the same time that the CMB light we see now was emitted. Everything was closer back then. That's what expansion of space means.
I don't understand how a redshift which we are using for galaxies can't also be used for the CMB?
A redshift is a redshift. It comes as an information in the radiation. It comes from any kind of matter. We can call this matter: dust, Gas cloud, stars, galaxies... (What about CMB radiation from dark matter or dark energy?)
So, if we claim that a radiation from a galaxy with a redshift of 1100 represents a distance of 46GLY, why a radiation which we call CMB with a redshift of 1100 doesn't represents a radiation which had been emitted from a distance of 46GLY?
Few more questions:1. Do you mean that the whole mass of the Universe were at some point of time at a maximal distance of only 1.3 Million LY from each other?
2. If so, do you agree that there is no way to set an infinite Universe in only 13.8 BY?
3. Do you agree that based on the BBT the Universe must be finite?
4. If we could eliminate completely the impact of the BBT on the CMBWhat is the expected CMB that we should get with regards to Amplitude, Redshift and isotroic?
5. Do we have any idea what is the estimated amplitude degradation in the CMB per one million year?
6. If we could come back to our Universe in one Billion or 10 Billion years from now, then what kind of CMB we might find?
7. Can we extract from the CMB the total mass of the whole Universe?
3000K if you go all the way back to when it was emitted.
The CMB is the big bang itself we are seeing. Without the BB, there would be no CMB.
Let me ask the following:Is there any way, any evidence, any discovery any issue which could convince you that there is a problem with the BBT?...If we could travel in time: If we could verify that at the early days (about 13 Billion years ago) the CMB was exactly as it is today, while also 10 Billion years from now in the future, the CMB is also the same. What can we learn from that?
Why are you so sure that without the Big bang there is no CMB?.
For example:Thermal emission of dust in the Milky way:https://irsa.ipac.caltech.edu/applications/DUST/docs/background.html."The dust temperature varies from 17 K to 21 K, which is modest but does modify the estimate of the dust column by a factor of 5".So, the Milky Way has a thermal emission..
Let's assume that we could set the whole Milky way in some sort of closed sphere or galactic Oven.In this case, what would be the thermal radiation amplitude in that galactic oven or closed sphere?.
So, I wonder what might be the "CMB" of the Milky Way if we could set it in some sort of a galactic oven.
Why are you so sure that without the Big bang there is no CMB?
The CMB is extremely uniform (temperature fluctuations from one place to another amount to a mere + 0.00335 kelvins), which means that it isn't radiation emitted by localized sources like stars or galaxies. It must have been emitted by something that once evenly filled all of space.
It must have been emitted by something that once evenly filled all of space.
QuoteLet's assume that we could set the whole Milky way in some sort of closed sphere or galactic Oven.In this case, what would be the thermal radiation amplitude in that galactic oven or closed sphere?.If you put part of it in a closed sphere like that it would get warm in there and there would be no thermal radiation to the outside because the enclosure would reflect it back in. Removing the enclosure would be something like opening an oven door, yes.
However, once we start the inflation and the expansion we actually kill any possibility for black body radiation.
So, in order to get the black boday radiation in the CMB, it must also filled all of space today
WowThat exactly the message which I was looking for.
It is stated clearly:"A body emits radiation at a given temperature and frequency exactly as well as it absorbs the same radiation"Therefore:"Blackbody radiator is any object that is a perfect emitter and a perfect absorber of radiation."So, if I understand it correctly, in order to get from a black body radiation, all/most of the radiation must stay at the object.
Quote from: KryptidIt must have been emitted by something that once evenly filled all of space.Therefore, at the early time the Big bang took all the early available space.
Therefore at the first moment the radiation of the Bang was clearly black body.
However, once we start the inflation
"Blackbody radiator is any object that is a perfect emitter and a perfect absorber of radiation"Therefore I have stated: "It is emitted by something that filled all of space."So, in order to get the black boday radiation in the CMB, it must also filled all of space today
Quote from: HalcIf you put part of it in a closed sphere like that it would get warm in there and there would be no thermal radiation to the outside because the enclosure would reflect it back in. Removing the enclosure would be something like opening an oven door, yes.So, you agree that we should get some thermal radiation if we put the Milky way at a galactic oven.
If you put part of it in a closed sphere like that it would get warm in there and there would be no thermal radiation to the outside because the enclosure would reflect it back in. Removing the enclosure would be something like opening an oven door, yes.
I do not claim that it is feasible to set the Milky way in an oven, but I would like you to look at the impact of this hypothetical activity.Therefore, do you agree that as long as the Milky Way will be in a galactic oven it will create a "CMB" which carry a black body radiation?
Do you also agree that once we open the oven, the black body radiation will be gone forever?
If so, how could it be that we still get a black body radiation from a CMB while the universe expands?
However, if the matter in our universe expands to the open infinity space
- I really don't see any possibility to keep the black body radiation in the CMB.Do you agree with that?