Very old view of the Universe

[Spyman]

Believe me I don't play games. I just choose a step-by-step procedure in order to avoid misinterpretation.

Well, you might want to skip some unnecessary steps then, like the one in post #23.

 

 

You have already shown that CMBR is not invariant. CMBR was smaller in the past. That's why I spoke about a "small CMBR" and a "large CMBR" in the other thread, that was not understood by some other members of this Forum. I think it is clear to anyone looking at the diagram.

The Universe was smaller in the past so the CMBR must also have been smaller, but the Universe is filled with the CMBR so the CMBR is huuuuuuge if we talk about the size of it, it's much bigger than what we can observe both today and what we could observe in the past. Our view of the CMBR was smaller in the past but that doesn't make the CMBR itself smaller, as time goes we are able to see a larger and larger view of the Universe and the CMBR. How much of the Universe or the CMBR we are able to observe does not change the actual size of them. If you look at the diagram again you can notice that the Distant Galaxy and the Milky Way are observing different zones of the CMBR with a large overlapping part and the past location of the Distant Galaxy is at that time not yet able to view more than a part of what it will be able to overlook in the future.

 

 

Are Galaxies X, Y, Z, observable from Earth, today?

Images emitted from them in that past time are observable at Earth today and those were also observable in the past view of the distant galaxy.

Edited November 13, 2010 by Spyman

[michel123456]

Well, you might want to skip some unnecessary steps then, like the one in post #23.

O.K. sorry.

 

The Universe was smaller in the past so the CMBR must also have been smaller, but the Universe is filled with the CMBR so the CMBR is huuuuuuge if we talk about the size of it, it's much bigger than what we can observe both today and what we could observe in the past. Our view of the CMBR was smaller in the past but that doesn't make the CMBR itself smaller, as time goes we are able to see a larger and larger view of the Universe and the CMBR. How much of the Universe or the CMBR we are able to observe does not change the actual size of them. If you look at the diagram again you can notice that the Distant Galaxy and the Milky Way are observing different zones of the CMBR with a large overlapping part and the past location of the Distant Galaxy is at that time not yet able to view more than a part of what it will be able to overlook in the future.

 

Well understood. i have to be more carefull with my wording. I ment "observable part of CMBR" instead of "CMBR".

 

 

Images emitted from them in that past time are observable at Earth today and those were also observable in the past view of the distant galaxy.

 

So, galaxies X,Y,Z are seen today from the Earth exactly the same way they were observed from Distant Galaxy then, the only difference is that they are much far away from Earth. But they other properties, such as measured distances between them, are exactly the same. Here I hope you understand my wording. If Distant Galaxy was observing those xyz galaxies "10 times closer", we should observe the same thing today.

 

Now I'll post another diag. Wait.

 

Here.

 

Galaxies 1p,2p,3p, that were observable from Distant Galaxy, are observed from Earth today in places 1,2,3. All these Galaxies will be observed closer to Earth than Distant Galaxy. In other words, all galaxies that are farther than Distant Galaxy (such as galaxies XYZ) must obey to the precedent principle, i.e. that what we are observing today is the same that was observed from Distant Galaxy in the past.

 

The green part of the Distant Galaxy Observable Universe is to be seen from Earth today in the opposite direction that when observing Distant galaxy.

 

Is that O.K.?

Edited November 13, 2010 by michel123456

[Spyman]

So, galaxies X,Y,Z are seen today from the Earth exactly the same way they were observed from Distant Galaxy then, the only difference is that they are much far away from Earth. But they other properties, such as measured distances between them, are exactly the same. Here I hope you understand my wording. If Distant Galaxy was observing those xyz galaxies "10 times closer", we should observe the same thing today.

No, I am sorry but I don't understand your wording, nobody said that galaxies X, Y and Z where "10 times closer" in the way you seem to impose. You can not measure the distance between them like that or argue like you do, they are observed in different time periods.

 

The galaxies back at the time Z, like z₁, z₂ and z₃ were "10 times closer" together than what the same galaxies z₁, z₂ and z₃ are located today at the time NOW, since they have been separated by expansion during the time since back then.

 

If we want to compare distances between galaxies X, Y and Z, that are located in different time periods, then we need to first decide in which time period we want to compare their distance, after that we can calculate their proper position in that time period and then finally we can check the differences.

 

From the diagram I can say that galaxy Z and Y are roughly 1.5 times farther apart in time period Y than what they were in time period Z or that galaxy Z and X are roughly 2 times farther apart in time period X than what they were in time period Z.

Edited November 15, 2010 by Spyman

[michel123456]

No, I am sorry but I don't understand your wording, nobody said that galaxies X, Y and Z where "10 times closer" in the way you seem to impose. You can not measure the distance between them like that or argue like you do, they are observed in different time periods.

 

The galaxies back at the time Z, like z₁, z₂ and z₃ were "10 times closer" together than what the same galaxies z₁, z₂ and z₃ are located today at the time NOW, since they have been separated by expansion during the time since back then.

 

If we want to compare distances between galaxies X, Y and Z, that are located in different time periods, then we need to first decide in which time period we want to compare their distance, after that we can calculate their proper position in that time period and then finally we can check the differences.

 

From the diagram I can say that galaxy Z and Y are roughly 1.5 times farther apart in time period Y than what they were in time period Z or that galaxy Z and X are roughly 2 times farther apart in time period X than what they were in time period Z.

 

O.K.

You are right in all you say.

What I try to say is that one side of the past "triangle" of Distant Galaxy coincides with a segment of our past triangle. I have a problem in expressing my ideas properly.

 

Do you agree with the following sentence:

The relative position of galaxies X,Y,Z as seen today from the Earth today is the same as they were observed from Distant Galaxy then.

Edited November 15, 2010 by michel123456

[Sisyphus]

X, Y, and Z are not galaxies, they are events. The galaxies where they took place would be lines extended through them, and those lines spread apart over time. Since those events are not simultaneous, when "distance between them" is not one quantity. The locations of those events were much closer together at time Z than at time X, for example.

 

So no, while it is true that you would be witness the same events (albeit with different redshifts), you would not calculate the same distance between those galaxies from Earth today as you would from Distant Galaxy then - there has been additional expansion since then.

[michel123456]

(...)

So no, while it is true that you would be witness the same events (albeit with different redshifts), you would not calculate the same distance between those galaxies from Earth today as you would from Distant Galaxy then - there has been additional expansion since then.

 

That's the point. We are witness of the same events. If you whish to calculate today's position of these galaxies, yes of course you are right, you would not calculate the same distance between those galaxies because there has been additional expansion since then. But if we are talking about the events we are looking at, these are exactly the same events in the same place, and in "real time". The events we are looking at now were observed by the Distant Galaxy then exactly the same way. Expansion of space don't play role.

Edited November 15, 2010 by michel123456

[Spyman]

Do you agree with the following sentence:

The relative position of galaxies X,Y,Z as seen today from the Earth today is the same as they were observed from Distant Galaxy then.

Please define: "relative position as seen", since while say you agree with me you still seem to continue talking about distances through time.

 

An Alien in the Distant Galaxy at that past time, using identical equipment and cosmological model as us, would calculate the galaxies relative proper distance to be the same as what we do today for that past time.

 

If the galaxies would have syncronized clocks continuously transmitting time and date, then their individual differences due to locations would be equal for us and the alien on the Distant Galaxy in the past.

[michel123456]

what I am trying to say is that, when Martin says in the beginning of thread:

And objects would be abouty 10 times closer

(from post #5)

and

But if you allow for that qualitative adjustment in your imagination it would be OK to say, I think, that galaxies were 10 times closer.

 

I am thus trying to say that we should observe the same thing today from the Earth concerning objects farther than the distant galaxy. We should observe today an increasing density of galaxies as much we look far away & into the past.

Edited November 15, 2010 by michel123456

[Spyman]

what I am trying to say is that, when Martin says in the beginning of thread:

I don't understand why we follow "a step-by-step procedure in order to avoid misinterpretation" that takes us on a two pages long discussion ending with a question you simply could have asked back in your post #7.

 

 

 

I am thus trying to say that we should observe the same thing today from the Earth concerning objects farther than the distant galaxy. We should observe today an increasing density of galaxies as much we look far away & into the past.

I don't think it would be that easy to observe and measure the change in density of galaxies as the Universe has evolved.

 

Look at this famous picture from the Hubble Space Telescope:

 

"Astronomers observe considerable structure in the universe, from stars to galaxies to clusters and superclusters of galaxies. The famous "Deep Field Image" taken by the Hubble Space Telescope, shown below, provides a stunning view of such structure."

http://map.gsfc.nasa.gov/universe/bb_cosmo_struct.html

"Representing a narrow "keyhole" view stretching to the visible horizon of the universe, the HDF image covers a speck of the sky only about the width of a dime located 75 feet away. Though the field is a very small sample of the heavens, it is considered representative of the typical distribution of galaxies in space because the universe, statistically, looks largely the same in all directions. Gazing into this small field, Hubble uncovered a bewildering assortment of at least 1,500 galaxies at various stages of evolution.

...

Essentially a narrow, deep "core sample" of sky, the HDF is analogous to a geologic core sample of the Earth's crust. Just as a terrestrial core sample is a history of events which took place as Earth's surface evolved, the HDF image contains information about the universe at many different stages in time. Unlike a geologic sample though, it is not clear what galaxies are nearby and therefore old, and what fraction are very distant and therefore existed when the universe was newborn. "It's like looking down a long tube and seeing all the galaxies along that line of sight. They're all stacked up against one another in this picture and the challenge now is to disentangle them," said Mark Dickinson of the HDF team.

http://hubblesite.org/newscenter/archive/releases/1996/01/text/

 

Are you able to discern which galaxies are more distanced and if they seem more crowded?

 

 

There are also some arguments against observing galaxies getting more and more close when we look at greater distances even in spite of the Universe on average being more dense back then:

 

¤ We are on the verge of our technological abilities and currently not able to see everything at every possible distance, so as we look farther away we will see less galaxies because they will be to faint for our equipment to observe.

 

¤ In the early times there were no galaxies in the Universe, over time gravity created galaxies by pulling matter together, thus we will see less galaxies farther away because they have not yet formed or grown big and bright enough.

 

¤ While gravity was accumulating matter into galaxies it also forged them into a very large scale structure like a cosmic web, gravity caused galaxies to get larger and more numerous in denser parts of the universe, whereas expansion caused empty voids between the filaments to also grow greater. This process causes us to see less galaxies gathered together farther away because they would have had less time to pile up.

 

 

Here is a simulation of how gravity and Dark Matter could have shaped our neighbourhood:

 

"The present day dark matter distribution in a slice cut through a simulation of a flat universe with cosmological constant, using the overall pattern of structure in our local neighbourhood as a simulation constraint. The distribution reveals fine, filamentary structures. The slice has a side length of 520 million light years, and a thickness of 100 million light years. It contains the so-called "supergalactic plane". The major nearby clusters, like Coma, Virgo, Perseus cluster, are labelled."

http://en.wikipedia.org/wiki/Galaxy_filament

 

 

But we do have a method to measure how the density in our observable part of the Universe is changing, we can measure the Redshift of the light from those distant galaxies we are able to observe. The redshift are similar to the Doppler effect, causing changes in frequency depending on how fast the emitter is moving relative us.

"An animation illustrating how the Doppler effect causes a car engine or siren to sound higher in pitch when it is approaching than when it is receding. The pink circles are sound waves. When the car is moving to the left, each successive wave is emitted from a position further to the left than the previous wave. So for an observer in front (left) of the car, each wave takes slightly less time to reach him than the previous wave. The waves "bunch together", so the time between arrival of successive wavefronts is reduced, giving them a higher frequency. For an observer in back (right) of the car, each wave takes a slightly longer time to reach him than the previous wave. The waves "stretch apart", so the time between the arrival of successive wavefronts is increased slightly, giving them a lower frequency."

http://en.wikipedia.org/wiki/Doppler_effect

 

When Universe is expanding it causes Cosmological Redshift corresponding to the rate of increase in the distance of other galaxies from our viewpoint. Our observations and measurements of redshifts from distant objects tells us that the distance between every distant object in all directions around us are increasing today, thus the logical conclusion is that everything must have been closer together in the past.

 

Our best observations and model shows us this picture:

 

"A representation of the evolution of the universe over 13.7 billion years. The far left depicts the earliest moment we can now probe, when a period of "inflation" produced a burst of exponential growth in the universe. (Size is depicted by the vertical extent of the grid in this graphic.) For the next several billion years, the expansion of the universe gradually slowed down as the matter in the universe pulled on itself via gravity. More recently, the expansion has begun to speed up again as the repulsive effects of dark energy have come to dominate the expansion of the universe. The afterglow light seen by WMAP was emitted about 380,000 years after inflation and has traversed the universe largely unimpeded since then. The conditions of earlier times are imprinted on this light; it also forms a backlight for later developments of the universe."

http://map.gsfc.nasa.gov/m_ig/060915/

Edited November 16, 2010 by Spyman

[michel123456]

From your last post I understand that the short answer to my question is:

"it is not what we are observing".