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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
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?
The CMB does fill all of space today.
How could it be that the CMB fills all space?
After any given moment the Universe is bigger. If it is bigger than the CMB covers more space over time. So how can you claim that it fills all space while we know that at any given moment it moves to new space?
As the CMB is radiation - do you agree that it must move at speed of light?
So, do you agree that the CMB covers much more sphere than our real Universe?
Our scientists only focus on the hypothetical sphere of our real Universe, but what about the Hypothetical sphere of the CMB?
If they are identical - than do you agree that there must be an envelope to our Universe?
However, what kind of force keeps the CMB in our finite universe (without envelope)?
Why it isn't moving to the infinity in just few moments or years?
What is the possibility for any kind of envelope around our real Universe?
How the CMB could have a black body radiation without an envelope, while it moves to the infinity at the speed of light?
Actually, if the CMB is moving to the infinity at the speed of light, it is still in the infinity.Therefore, it fills the whole infinite space.
Hence, do you agree that the Idea that CMB must fill all of space today, proves that the Universe is infinite?
So how can you claim that it fills all space while we know that at any given moment it moves to new space?
I don't know, but it must be beyond what we can see if it is there.
The Universe in total would represent all of the space there is. If there is a limited amount of space, then the CMB cannot move outside of that limited space (outside of space is an oxymoron).
No viable model has anything moving to 'new space'. The universe does not occupy a fraction of space. It is the space. All of it, be it finite or not. The plasma once filled all of space, meaning there is nowhere where it wasn't.
No force, just the fact that you can't move outside of a finite space because there is no space outside of space to move into (that should go without saying).
There doesn't have to be any kind of solid barrier around the Universe, if that is what you are saying. In a hypersphere universe, for example, space is closed and travel in any one direction will eventually bring you back to your starting point. That represents a limited amount of space but there are no physical barriers present at any point to stop your movement.
There is nowhere else to go to get out. That's what finite space means.You keep picturing an enclosure (delimiting 'universe') with space inside and more outside, but the stuff inside is not all of space then. It isn't a model of finite space at all.
Quote from: Kryptid The Universe in total would represent all of the space there is. If there is a limited amount of space, then the CMB cannot move outside of that limited space (outside of space is an oxymoron).Quote from: HalcNo viable model has anything moving to 'new space'. The universe does not occupy a fraction of space. It is the space. All of it, be it finite or not.Thanks for the explanation.So, what is the difference between the Universe and space?
No viable model has anything moving to 'new space'. The universe does not occupy a fraction of space. It is the space. All of it, be it finite or not.
I had the impression that the space represents the infinity, as there is no limit in space
while the Universe represents the size of our universe. (Therefore the Universe can take the whole size of the open infinity space or just part of it).
So, let's assume that our Universe/space is finite and go back to year 400,000 - just after the inflation process while the CMB gets already its Black body radiation.
Let's assume that the radius of the Universe/space at that time was only R1 - which represents a compact universe/space.All the matter of our current Universe had been there in this compact universe/space.There was nothing outside of this radius.
Due to the expansion in space of 70 km/s/Mpc, the space of our universe had been increased and therefore after 13.4 Billion year from that moment, our current Universe/space get's to its maximal radius of R2.
However, as our Universe/space had been increased at a rate of 70 km/s/Mpc, the CMB was moving in all directions at the speed of light.
Sooner or later all the energy of the CMB must get to the edge
As there is no space outside the edge,
But, the radiation must move in direct line to all directions.So, how could it be that a radiation/light which starts at point A moves in a direct line to point B, cross that point while it moves in the same direction and eventually gets back to point A without meeting the edge of the Universe?
If that is correct, do you agree that when we look at the left side of the space/Universe, we could see the light/radiation which is coming from the right side of the finite space/universe?
Is it real?
Yes, now I do understand the meaning of Finite space.However, any finite space must have some sort of size. Therefore, I don't understand how a light can cross a limited space or Finite space without getting to the edge of the space.
Once we set a sphere for the finite space
The speed of light is 299 792.458 kilometers / second, while the speed of the expansion is only 70 km/s/MpcThe ratio between the two is : 4285 : 1
However, any finite space must have some sort of size. Therefore, I don't understand how a light can cross a limited space or Finite space without getting to the edge of the space.If the Universe has a limited/finite size than somewhere there must be an edge, otherwise it should go to the infinity.Therefore, I can't understand how a finite Universe with a radius R has no edge.
Nor inside either. The model I am assuming is the surface of a hypersphere, so space at a given moment covers only the surface, and R1 is not measured in a spatial dimension, but rather the time dimension. The past lies inside R1 and the future lies outside it. If the past and future do not exist, then time is external to the universe (making it an object of sorts again) and there is nothing inside or outside of R1.
QuoteIf that is correct, do you agree that when we look at the left side of the space/Universe, we could see the light/radiation which is coming from the right side of the finite space/universe?If the size was really small, light may have had time to go around, yes. Maybe all the CMB radiation (the oldest light there is) has done that. How would you tell?
QuoteBut, the radiation must move in direct line to all directions.So, how could it be that a radiation/light which starts at point A moves in a direct line to point B, cross that point while it moves in the same direction and eventually gets back to point A without meeting the edge of the Universe?All "straight" lines in a hypersphere-shaped universe are actually curved. They eventually loop back around on themselves. It's like the lines of longitude and latitude on a globe. Walk far enough on the Earth, and you'll end up back where you started (ignoring the fact that the oceans are in the way, of course). It's a similar idea.
The Earth is finite in size. If you walk far enough, will you reach the edge of the Earth? No, you won't. There is no edge. It's a similar idea to a hypersphere universe.
If such a universe was small enough, old enough and expanding slowly enough, yes.
If not, then the light either hasn't had time to make a complete circuit around the universe yet or the universe is expanding too quickly at those distances for it to ever complete the journey.
You actually contedicts the Fermat’s principle. http://scipp.ucsc.edu/~haber/ph5B/fermat09.pdfFermat’s principle states that “light travels between two points along the paththat requires the least time, as compared to other nearby paths.
There is no obligation how do we walk. We can waltk in three dimentions, two dimentions or even one dimention.
However, light must move in a direct line and in the least time!
We can't band the light/radiation just becouse it meet our exectation.
So, if we shot a lazer beam in one direction - it woun't come back to us unless it meets the law of Reflection and Refraction!Hence, we can't assume that light/radiation can "walk" on the hypersphere universe and come back without any real impact as Reflection and Refraction.
Hence, we can't assume that light/radiation can "walk" on the hypersphere universe and come back without any real impact as Reflection and Refraction.
OKBut, we have to find a way how to overcome on the Fermat’s Principle and the Laws of Reflection and Refraction.
How can you keep the energy in the CMB if the Universe expands at the speed of light and the radiation is moving away in all directions?
Don't you agree that in just few moments after the bang - any bang, the radiation should go to zero?
How can you get any sort of radiation after 13.8 Billion years from the bang, while nothing from the radiation is reflected back?
I'm willing to accept any model that you wish.
However, I can't understand how we can use one Universe modeling for the CMB and other modeling for the expansion.
If we wish to explain the expansion based on three dimensions x,y,z - and one more for -t, than we must also to use the same modeling also for the CMB.
If we wish to explain the CMB based on two diminutions x,y (the surface of a hypersphere)
and one external for -t, than we have to use the same modeling also for the expansion.
We are living in one Universe. This Universe is the home for the expansion and the CMB (and also for us).Therefore, I assume that we can't use different modeling for each one.
Our scientists have stated that the expansion rate today is 70 km/s/MpcIf I understand it correctly - The Mpc represents a cube with x = 1Mpc, y = 1Mpc = 1Mpc.
I don't understand how can we force the radiation/light to move around the surface of a hypersphere when we know that it must move in a direct line?
In any case, if there is a size to our Universe/space, do you agree that it also must have a volume?
If there is a volume, then there must be three dimensions to this volume.
So, don't you agree that we must explain the CMB radiation based on the real modeling for three dimensions?
You actually contradicts the Fermat’s principle. http://scipp.ucsc.edu/~haber/ph5B/fermat09.pdfFermat’s principle states that “light travels between two points along the paththat requires the least time, as compared to other nearby paths.
There is no obligation how do we walk. We can walk in three dimensions, two dimensions or even one dimension.
Exactly. The shortest path in a curved space is therefore a curved line.
Let's assume that we are located just at the center of the Space/Universe which its radius is 52 BLY.
If I understand it correctly, this line should come back to us
At some point in this line to the infinity
we should get to the furthest galaxy that we still can see - Let's assume that it is located 13 BLY away.
This galaxy (Galaxy A) is moving away from us at almost the speed of light.
Now, let's assume that we can jump and be there in less than one second.Once we are at galaxy A, do you agree that we should see a similar view as we see from our galaxy?
If we continue to jump on the same direction from galaxy to galaxy (while each jump represents 13 BLY) - after 4 jumps we should get to 52 BLY away from us.
Let's assume that this point represents the last furthest galaxy in this direction.
So, what kind of view shall we see from this last galaxy?What will happen if we will try to jump in the same direction that we have set?Based on the curvature, does it mean that we should make a U turn at the edge of the space (however - now I know that there is no edge) and come back to galaxy C then B, A and finely to our galaxy?
All of that while we think that we still move in the same direction to the infinity.
So, do you mean that this scenario sets the shortest path in a curved space?
Hence, even if we are actually always jumping in one direction, eventually we are coming back to the starting point.If that is correct, I must say that it is very difficult for me to accept this idea.
Based on the curvature, does it mean that we should make a U turn at the edge of the space (however - now I know that there is no edge) and come back to galaxy C then B, A and finely to our galaxy?