So then really we have almost no speculation in either area, only a difference of opinion on how the term observable should be used.  Yes, I did miss that qualifier didn't I? 

Very well.

 If greater than c expansion is possible then, given that we are not at the center of it all, the Earth is travelling "relative" to some other place in the universe" faster than the speed of light. If we are in motion in some direction at this speed then all of our measurements are skewed from our vantage point. We cannot assume to be standing still in the middle of it all.

Honestly, we have got to come up with the real reason we see cosmological red shift. First we said matter is expanding into space, then we said that space itself must be expanding. Whats next?

The answer could have more to do with the effects of gravity of dark matter on light than with all this make believe expansion BS. Hubble was wrong and someday we will know the truth about redshift.

San Mig anyone?

BQ

 

We never said matter is expanding into space.

blast-of-giant-atom-created-our-universe

The above link is to 3 pages from Popular Science magazine, from December 1932.

At the beginning of the article it looks like they are talking about some sort of an explosion, but on page 2 we have the following:

"The nebulae are not running away from us. Their recession is due to expansion of space. This may, perhaps, seem to be quibbling over terms, since it amounts to the same thing in the end. Nevertheless, the distinction is worth keeping. According to the relativity theory, there is a difference between the running away of the nebulae and expansion of the medium in which they are embedded."

The idea that the Earth is apparently receding from a distant galaxy faster than c does not mean measurements are skewed from our vantage point as relativity tells us that all vantage points are essentially equivalent.

Apart from the relatively small peculiar motions of galaxies with respect to their close neighbours due to gravitation, all galaxies can consider themselves at rest and that the rest of the universe is expanding away from them. Wherever you are, the further you look the faster a galaxy apparently recedes.

 

If you wish to discuss this with me Speed, then I choose to start it here, where we left off. 

Quote from SpeedFreek:

"There is no sense in saying the CMBR we currently detect was emitted only 42 million light-years away, but took 13.7 billion years to reach us at the speed of light, unless we also say that the universe is expanding and that the place where those CMBR photons were emitted is now 46 billion light-years away."

Right you are Speed. People should know that the universe is expanding, but sadly there are still many who have a hard time even accepting this.

Quote from SpeedFreek:

"You understand the principles involved, but you don't like the term used for them in mainstream cosmology. That is understandable, but what term would you choose instead to define where everything we have seen is thought to be today?"

How about the way they normally tell us. “The object we have seen dates back to when the universe was only X billion years old.” Is that not true? The information we are getting is just like you explained. It is time dated information.

Consider I mail you a picture of myself as an infant. It is time dated information.

Now it’s true that the universe is expanding and so you can make an estimate of where these objects are now, in the present day, but you cannot observe them. Should we now lie to the public, who has a hard enough time just understanding that the universe is expanding, and is 13.7 billion years old, and tell them that the observable universe is now 30+ billion light years in diameter? Is that even an accurate statement, that a lay person would understand?

Looking at my infant photograph which is dated information, over in the UK where you live, would you tell a friend that you are observing someone now living in the U.S.? Would you say that you are observing me?

If that is not the case, then why would you be so inaccurate as to tell people that we can observe objects 30+ billion light years away, when you only have a dated image of a galaxy from 12 Billion or so years ago, and was really only a few million light years away, and that’s the image you really have? You have a baby photo, and yet you are pretending to act as though you can see it, where it is today.

You should not use a distant galaxies current distance in stating what the observable universe is. You should only use observable in terms of it’s age in relation to the universe itself. Distance is a different issue, and should not be used in conjunction with the observable universe, unless you can give a full explanation of what you are talking about.

To say the observable universe is 30+billion light years in diameter, is wrong.

To say that some of the earliest galaxies seen are now 30+ billion light years away, is correct.

Those are the terms I choose to use, because they are more accurate. I do not have to accept mainstream anything, if I feel it is wrong.  "String Theory" is another example of something I choose not to accept.   Truth is more important than acceptance.

I do understand you, but there is a very subtle point here that I think you might have overlooked.

Does the term "observable" mean it has to have already been observed, or that it may be observable in the future?

Your definition always seems to mean that which has already been observed, as in the visible or observed universe.

Cosmologists are interested in making predictions about what we should see, in the future.

Consider a galaxy we have already seen, with a redshift of z=1.6. We see that galaxy as it was 9.5 billion years ago, when it was 5.7 billion light-years away. We estimate the comoving radial distance to that galaxy today to be 15 billion light-years. This galaxy is inside our cosmological event horizon (otherwise known as the light horizon), so we will eventually see it as it is today, sitting there, 15 billion light-years away. This galaxy is therefore part of our observable universe where it is right now, as it will be observable to us in the far distant future. It is part of the future light-cone of our observable universe.

 

 

How large was the observable universe back in the days of Galileo? How large was the observable universe back in the days of Hubble? Was predicting how far we could someday be able to see, ever used as a prediction in stating how large the observable universe is? Is stating that the observable universe is some 60 to 80+ billion light years in diameter only a prediction of how far we may someday be able to see? Do you expect me to believe this? How far into the future are they saying it will be before we can see that far? Considering your galaxy question, we will never see it in a current position. Supposing we could eventually see an object 15 billion light years away in a few billion years, again that galaxy would have moved on to much further away. But distance is not really the issue with what we observe, it's time. If the further we look, the further back in time we're looking then we hit a time barrier. We can only see 13.7 billion years back in time. And until the universe ages further, that's all we will be able to see. That's my prediction anyway.

I think it is human nature to ask how big things are - "How tall is that mountain?", "How wide is the ocean?", "How large is the universe we can see?"

Dusty_Matter:

Is stating that the observable universe is some 60 to 80+ billion light years in diameter only a prediction of how far we may someday be able to see? Do you expect me to believe this? How far into the future are they saying it will be before we can see that far?

Unfortunately, the acceleration of the expansion rate will preclude us from seeing events currently 40 billion light-years away. But we will eventually see events currently 15 billion light years away, in tens of billions of years time.

Dusty_Matter:

Considering your galaxy question, we will never see it in a current position.

Of course. We never see anything (in cosmological terms) in a "current" position, due to the finite speed of light.

Dusty_Matter:

Supposing we could eventually see an object 15 billion light years away in a few billion years, again that galaxy would have moved on to much further away.

Quite right, our information is always out of date, and we know that. As we know that, we have to try to account for it in order to understand the universe around us.

Dusty_Matter:

But distance is not really the issue with what we observe, it's time. If the further we look, the further back in time we're looking then we hit a time barrier. We can only see 13.7 billion years back in time. And until the universe ages further, that's all we will be able to see. That's my prediction anyway.

By your rationale, all we should ever say about the universe is how out of date our information is. Is that all we need to know about our universe? Aren't we interested in where the things we see were when the light left them billions of years ago, or where they would be today if we could see them?

Some people (cosmologists) are interested in how the universe has evolved, over time. For that they need to understand how the universe is expanding, rather than just how old our information about it is.

What do we want, a conceptual map of the universe or just a conceptual clock? When you look up into the sky at night, aren't you interested in how far away things are? How far away things were?

When we map how far away things were, we get a very strange map indeed, as different galaxies are seen during different epochs. We have close looking high redshift galaxies that are very dim due to the very long time the light took to reach us, and further away looking but lower redshift galaxies that are brighter because the light took less time to reach us. The most distant (in space) galaxy we have seen was 5.7 billion light-years away, 9.1 billion years ago. The most distant (in time) galaxy we have seen was 3.5 billion light-years away, 12.9 billion years ago. What a map!

What we want is a map of how far away things are, built using the information of where things were, the expansion rate at that time and the time it took the light from those events to reach us. Angular diameter, redshift, and apparent luminosity.

I know you understand all this already, so you must understand why an extrapolated model of "now" across the universe is useful to cosmologists. So, what should they call "where we think everything is now"?

I do understand how the term "observable universe" is misleading. It is meant to mean where we think the emission points of all the light we have observed are, today. The term pre-dates our discovery of the acceleration of the expansion of the universe. It comes from a time when we thought the rate of expansion was slowing down and I have just realised that this is important! (dowp!)

Before we discovered the acceleration of the expansion, it was understood that the light from the edge of our observable universe might eventually reach us. In a decelerating universe, there is no cosmological event horizon as the Hubble horizon recedes as long as it decelerates! Now I think I understand!

The term is a carry-over from the time when the observable universe was considered to be eventually observable!

Now then, what is a better term? A better term for an observable universe destined to gradually pass out of our view forever, eventually, but where we will see a lot more of it for a long time yet...

Yes it is quite interesting to know how big, old, or fast things are. Maps are good too, and if we can extrapolate how far away things may be in real time, then that's fantastic as well. I just think that science should describe things accurately. That's what science is supposed to be all about, and measuring things is important. I have no issue with how close or far away objects may have been or where they may be now, I only take issue with what I consider an inaccurate statement. I feel that "10 Misconceptions About the Big Bang" has a misconception of it's own. It's like a slap in the face to see such a misleading statement, that the observable universe is 30+billion light years in distance. That statement is like a fly in a perfectly good bowl of soup. I am not mad at you or anybody else, but I just can't swallow that fly. I don't know why I can't swallow that fly... I just want a more accurate description, so that people aren't mislead into thinking we can actually see that far away.

SpeedFreek:

So, what should they call "where we think everything is now"?

How about we call it. " where we think everything is now"?

How about we call it. " where we think everything is now"?

 

Heheh, yup... that just about sums it up! Or how about:

Where we think everything (in the observable universe) is, now.

You think the term "observable universe" should only represent where everything was. In that case, it is true that you can only meaninfully describe its evolution in terms of light-travel time. But there are three distance measures used in cosmology, and they are all describing the same observable universe.

We need to differentiate the parts of the universe we have seen at sometime during the history of the universe from the parts we have never received a photon from, as those parts constantly recede from us due to the expansion of the universe. The observable universe is simply the parts we have seen at any time.

Maybe it should be called the has been observable universe?

SpeedFreek:

You think the term "observable universe" should only represent where everything was.

No. I think the term observable should represent all we have seen. And all we have seen (at great distances) can only be described in terms of how far in the past we are viewing them. Actual distances can be inferred, but because of their great distances and time lag, we cannot actually view these distant galaxies as they are now. They are unobservable to us in their present locations.

SpeedFreek:

But there are three distance measures used in cosmology, and they are all describing the same observable universe.

No they don't. You have to account for time which changes things. You cannot see the future. You cannot see distant objects in real time, and those objects are forever lost to our observations at 30 + billion light years away, You cannot see them where they are now, and you will never see them again. You only have a faint image of where they once existed back in the early universe. Time, light speed, and the expansion of the universe has cut them off at the distances that you want to claim is observable. This argument will get neither of us anywhere, so why discuss this further?

Dusty_Matter:

SpeedFreek:

You think the term "observable universe" should only represent where everything was.

No. I think the term observable should represent all we have seen. And all we have seen (at great distances) can only be described in terms of how far in the past we are viewing them. Actual distances can be inferred, but because of their great distances and time lag, we cannot actually view these distant galaxies as they are now. They are unobservable to us in their present locations.

You say the actual distances can be inferred, but they are inferred in exactly the same way as cosmological time. "How far in the past we are viewing them" is just as inferred as how far away in space they were at the time. All three distance measures (angular diameter, light travel time, comoving distance) are just as theoretical as each other.

So to say what we have seen can "only be described in terms of how far in the past we are viewing them" is just as inferred and just as theoretical as describing them in terms of how far away they were in space.

Dusty_Matter:

This argument will get neither of us anywhere, so why discuss this further?

 

Because you keep making statements like the above. You seem to think that cosmological time is in some way more accurate than cosmological distance, when they are both inferred from the same data and fall out of the same equations.

SpeedFreek:

"How far in the past we are viewing them" is just as inferred as how far away in space they were at the time.

Yes, you are correct. It is inferred. We look at them, and then make a reasonably educated guess as to where they were, based on angular diameter, and red shift, and we can even infer where they may be today, but although the first examples can actually be observed, the last inference is not observable. It is only an educated guess.

SpeedFreek:

You seem to think that cosmological time is in some way more accurate than cosmological distance

Bingo, you got it. When it comes to our observations, we can only see what cosmological time is showing us. What is it showing us when it comes to the early universe? That galaxies very close to us are rushing away at great speeds. Can we observe these galaxies now, in real time, at their estimated 30+ billion light years away? No. Cosmological time reigns supreme when it comes to our actual observations.  Time cannot be ignored.

 

Dusty_Matter:

SpeedFreek:

"How far in the past we are viewing them" is just as inferred as how far away in space they were at the time.

Yes, you are correct. It is inferred. We look at them, and then make a reasonably educated guess as to where they were, based on angular diameter, and red shift, and we can even infer where they may be today, but although the first examples can actually be observed, the last inference is not observable. It is only an educated guess.

Yes, true. But the subtle point I think you might be missing here is that the way we make the educated guess for proper distance and the way we make the educated guess for proper time are identical, and therefore absolutely equivalent in their validity.

Dusty_Matter:

SpeedFreek:

You seem to think that cosmological time is in some way more accurate than cosmological distance

Bingo, you got it. When it comes to our observations, we can only see what cosmological time is showing us. What is it showing us when it comes to the early universe? That galaxies very close to us are rushing away at great speeds. Can we observe these galaxies now, in real time, at their estimated 30+ billion light years away? No. Cosmological time reigns supreme when it comes to our actual observations.  Time cannot be ignored.

No, we cannot only see what cosmological (proper) time is showing us, we also see what cosmological proper distance is telling us, in exactly the same way. Both are inferred using the same equations from the same relationships for redshift. Neither proper time nor proper distance can be ignored. This is my point, and has been from the beginning.

Additionally, it can be argued that, in terms of what we actually see, proper distance has more validity in that there is less inference involved - proper distance is a more intuitive concept. It is easy to understand how we might estimate proper distance, based on angular size. How big it looks shows how far away it was. But how easy is it to understand how we might estimate proper time?

I hope you don't think I am being argumentative for the sake of it! There is a reason I am hanging on like a dog with a bone, and I am sure the same goes for you...  

SpeedFreek:

But the subtle point I think you might be missing here is that the way we make the educated guess for proper distance and the way we make the educated guess for proper time are identical, and therefore absolutely equivalent in their validity.

I’m not missing any subtle point. The validity of distance and time is not in question. It’s what’s actually observable that’s in question.

SpeedFreek:

Neither proper time nor proper distance can be ignored.

They aren’t being ignored. They are all being considered. You have this faint image of a distant galaxy that has a large angular diameter, and you can calculate it to have been only a few million light years distant when that light first began it’s journey. This is observable.

It’s redshift tells you how fast it was receding from us and therefore you know that the universe is expanding. This is observable.

From the calculation of it’s apparent acceleration and speed of recession, you can infer where it might lie in light years distance today. This is not observable, only inferred.

SpeedFreek:

Neither proper time nor proper distance can be ignored. This is my point, and has been from the beginning.

This was not your point, and it is not what we are debating. What we are debating is how large the observable universe is. The observable universe goes back 13.7 billion years in time. Don’t try and change the subject.

SpeedFreek:

proper distance has more validity in that there is less inference involved

Proper distance?  Proper distance according to it’s angular diameter is telling you that the galaxy was only a few million light years away.

You cannot and have not observed anything 30 to 38 billion light years away. This much you have already admitted too.

SpeedFreek:

how easy is it to understand how we might estimate proper time?

I believe they base it on Earth years, and the speed of light.

SpeedFreek:

There is a reason I am hanging on like a dog with a bone, and I am sure the same goes for you

Yes, the reason I’m hanging on is because I know what’s true, and I refuse to swallow flies.

Dusty_Matter:

The validity of distance and time is not in question. It’s what’s actually observable that’s in question.

All that is actually observable is that how big things look tells us where they were. This is not inferred, it is actually seen. Everything else is inferred, i,e, what luminosity means, what redshift means. But what angular size means is not inferred, therefore it is the only thing that is actually observable.

Dusty_Matter:

SpeedFreek:

Neither proper time nor proper distance can be ignored. This is my point, and has been from the beginning.

This was not your point, and it is not what we are debating. What we are debating is how large the observable universe is. The observable universe goes back 13.7 billion years in time. Don’t try and change the subject.

I am not changing the subject. I alluded to this in my first post in this thread, and spoke of it directly in my second:

SpeedFreek:

 Quite correct. So how large is the observable universe? If we take the angular diameter distance, which seems to be your favored choice, then the universe has an observed radius of 5.7 billion light-years. The objects we have observed as having the largest angular diameter distances are those that were at the edge of our Hubble Sphere, 9.1 billion years ago. All older light, that has been travelling for longer than 9.1 billion years, was emitted at an original distance of less than 5.7 billion light-years.

And my third:

SpeedFreek:

The look-back time is the most useful, but what use is it on its own? We can see these galaxies, and the galaxies with the highest look-back times (z=7 or 13 billion years) were much closer to this region of space when their light was emitted than a galaxy at z=1.4 was (9.1 billion years). The z=1.4 galaxy had nearly twice the proper distance at the time of emission.

How can we assign a coordinate in space-time if we only use time?

And my fourth:

SpeedFreek:

 

And here we have the essence of two distance measures, one "observed", and one inferred from what we have observed, but referred to as "true time"?

And my fifth:

SpeedFreek:

  

Yes I can give you a specific distance, and I have done so already. We have seen out to a distance of 5.7 billion light-years, the Hubble distance as we see it. Not where it is thought to be "now" (around 14 billion light-years), but where it was "then".

And my ninth:

SpeedFreek:

   

The angular diameter is what is actually seen.

I am certainly not changing the subject!

What is actually seen is angular diameter - how big things are show where they were. All other distance measures make assumptions about what has happened to the light since it was emitted (apparent luminosity, redshift).

Now, in order to make sense of those distances, we have make assumptions about the time the light has been travelling in an expanding universe.

Again - how can closer looking objects have larger light-travel times than further away looking objects? The only way is if the closer objects were further away still by the time their light passed those further objects.

The two inferences - light-travel time and comoving distance, fall out of the same calculation based on what we know of where things were. This is why I asked you, early on, why you weren't concentrating on angular diameter if you were only concerned with what is actually observed! I have been asking this question all along... I am not changing the subject.

Dusty_Matter:

You cannot and have not observed anything 30 to 38 billion light years away. This much you have already admitted too.

Of course.

Dusty_Matter:

SpeedFreek:

how easy is it to understand how we might estimate proper time?

I believe they base it on Earth years, and the speed of light.

Cosmological proper time is based on a set of theoretical co-moving clocks across the history of the universe, at rest in relation to the expansion, in theoretical regions of space with the lowest gravitational potential. It is purely theoretical, based in General Relativity.

In physical cosmology, the cosmological event horizon (also known as a particle horizon) is the maximum distance from which particles could have travelled to the observer in the age of the universe. It represents the boundary between the portion of the universe which could have conceivably been observed at a given time (the observable universe) and the unobservable regions of the universe.

That maximum distance has an angular diameter distance of 42 million light-years, a light travel time of 13.7 billion light-years and a comoving radial distance of 46.5 billion light-years. All are as relevant as each other, if you want any of it to make any sense!

“Neither proper time nor proper distance can be ignored. This is my point, and has been from the beginning.” 

SpeedFreek:

I am certainly not changing the subject!

Well if it’s not the case, then I’m sorry. Time and distance are not being ignored. This is not an issue. What’s observable and not observable is the issue.

SpeedFreek:

All that is actually observable is that how big things look tells us where they were. This is not inferred, it is actually seen. Everything else is inferred, i,e, what luminosity means, what redshift means. But what angular size means is not inferred, therefore it is the only thing that is actually observable.

SpeedFreek:

What is actually seen is angular diameter - how big things are show where they were. All other distance measures make assumptions about what has happened to the light since it was emitted (apparent luminosity, redshift).

But we can observe the redshift, and we can observe how luminous an object is. If all of what we can observe has only a speculative meaning? Then how is it that you are so determined to try and say that we can observe 30 to 40+ billion light years away? Angular diameter only shows how close the object was to us, in the past.

SpeedFreek:

But what angular size means is not inferred, therefore it is the only thing that is actually observable.

So we are not observing any galaxies with a redshift or luminosity drop off?  These other qualities are not observable?

SpeedFreek:

This is why I asked you, early on, why you weren't concentrating on angular diameter if you were only concerned with what is actually observed! I have been asking this question all along... I am not changing the subject.

Angular diameter is something I knew nothing about previously. It was not an issue. Knowing about angular diameter now I see that it is stating basically that the image is very large, because it was much closer to us, and this is the light we are finally receiving.

"But, how easy is it to understand how we might estimate proper time?"  Your answer:

SpeedFreek:

Cosmological proper time is based on a set of theoretical co-moving clocks across the history of the universe, at rest in relation to the expansion, in theoretical regions of space with the lowest gravitational potential. It is purely theoretical, based in General Relativity.

If you know how it is that proper time is estimated, then why did you ask me? You know more than I do about that stuff.

SpeedFreek:

That maximum distance has an angular diameter distance of 42 million light-years, a light travel time of 13.7 billion light-years and a comoving radial distance of 46.5 billion light-years. All are as relevant as each other, if you want any of it to make any sense!

This is obviously in reference to the CMB?

Yes all of what you've mentioned is relevant, but not all of it is observable. This has been my point from the very beginning.

Look Speed, I’m going to be off line for a for awhile. I have some other things that require my attention. It seems to me though, that the only thing we are disagreeing on, is the definition of what’s observable, and I’m not going to change my opinion on it, and I‘m sure you aren‘t going to change yours. I’d rather learn from you, than argue with you. Can’t we just agree to disagree on this topic, and move on from here? It may be awhile before I can respond to you, so please forgive the delay. I hope things go well with you in the meantime. Take care.

Of course we can agree to disagree! My postings are really aimed at the lurker who might read these threads without posting questions - I want to make sure people have no misconceptions about what the Big-Bang theory means and what is meant when cosmologists refer to the "observable" universe. Also, sometimes when you explain something to someone else, it helps with your own understanding.

Good luck with your endeavours, I look forward to more dialogue in the future! :)

Dusty_Matter:

But we can observe the redshift, and we can observe how luminous an object is. If all of what we can observe has only a speculative meaning? Then how is it that you are so determined to try and say that we can observe 30 to 40+ billion light years away? Angular diameter only shows how close the object was to us, in the past.

SpeedFreek:

But what angular size means is not inferred, therefore it is the only thing that is actually observable.

So we are not observing any galaxies with a redshift or luminosity drop off?  These other qualities are not observable?

As to the above, what I meant was that we have to make assumptions about the meaning of the observed differences in redshift and luminosity, but we need make no such assumptions about the meaning of angular-diameter. The apparent size of something tells you how far away it was, full stop. If you know how big something is, how small it looks tells you how far away it is. The same is not necessarily true for luminosity or redshift - these apparent effects might be subject to influences like interstellar dust or differences in gravitational potential, for instance.

One example of what I mean is to look at a "tired-light" model. These models are attempts to find a cosmology for a static universe, and assume the decrease in luminosity and the increase in redshift are due to something happening to the light on its way towards us, rather than the expansion of the universe. But tired light models cannot readily explain the apparently large angular diameters of the dimmest most redshifted galaxies predicted by the Big-Bang theory, or more accurately the current best-fitting mainstream model for the Big-Bang, the Lambda-Cold Dark Matter concordance model.

Yes, I very much enjoy these dialogues too, Speedfreek. The subject matter here is of great interest to me. It’s good to be back. With that being said I will continue with your last response.

SpeedFreek:

I want to make sure people have no misconceptions about ... what is meant when cosmologists refer to the "observable" universe.

I too, don’t want anyone to have any misconceptions about what the “observable universe” really means. This means stating that, what they are calling the “observable universe”, the supposed distance of 30 to 38 billion light years is actually not visible to us. It is a speculation.

SpeedFreek:

we have to make assumptions about the meaning of the observed differences in redshift and luminosity, but we need make no such assumptions about the meaning of angular-diameter. The apparent size of something tells you how far away it was, full stop. If you know how big something is, how small it looks tells you how far away it is. The same is not necessarily true for luminosity or redshift

That is an interesting statement. Angular diameter then is a concrete way of showing that the universe was at one time, much smaller in the past. That some of the furthest visible galaxies seen now, were once very close to us. It is their lack of luminosity and redshift, that is making it very difficult for us to see them. So then they are very large superimposed images that are in the background, and yet for the most part are not noticed in the images that we get through ordinary optical telescopes.

It is also a fact that the further we see, the further back in time we are looking. So these very large transparent images show that they were very close to us in the distant past. So then by deductive reasoning, the very farthest we can see is not in distance, but is to the very beginning of the age of the universe. It is not distance but time that is the ultimate horizon to what we can see, because the further back in time you go, the closer objects actually were. Time then trumps all. 

Redshift implies a motion which you say is speculative. I think we can safely assume that the universe is getting larger, but you are saying that the actual figures may be speculative. You are also saying that luminosity drop off is also speculative, but it is with these two indicators that you are saying that the calculations simply fall out in telling us where the earliest galaxies in the universe are now.

It is the supposed "scientific definition" of how “big” the observable universe is now, that is speculative then!   That is what your statements are implying then, is it not?

If you whish to state that the age of the universe is also speculative, that’s fine. Maybe it is. That being the case, a more accurate statement of the size of the visible universe should only then be limited to how old the estimated age of the universe is, as actual distances would be much more speculative, and are subject to much greater change.

I would like for people to know that.

 

Dusty:

What is "large" in these images (what objects are large)?

Dusty_Matter:

So then they are very large superimposed images that are in the background, and yet for the most part are not noticed in the images that we get through ordinary optical telescopes.

... the galaxies themselves don't expand, along with the universe ... is that what you meant?

No, I'm not referring to galaxies expanding Chipdata, I’m sorry but I was referring, in an inaccurate manner, to “angular diameter”.

The galaxies that we have observed that are seen to exist say 12 billion years ago, were actually very close to us back then, because the universe was much smaller. Their angular diameter (or visual size) indicates that they were only a few million light years away when the light that we are receiving now, actually left them. I was stating that their image is very large although they are also very faint and extremely redshifted. That means that with regular telescopes we cannot see their images. In order to actually see these images, we have to look with equipment designed to pick up infrared light, and be able to examine a certain area for long periods of time, in order to pick up enough of their light so as to see these images. (like the Hubble telescope is able to do) It is because these galaxies from 12 billion years ago were so close at that time, that they appear very large to us as an image, although they are invisible in regular light.

I know Speedfreek could explain it better, but I’m happy to try.  I should have explained it better.