Picture of galaxy from when expansion only 600 million years old

[Sisyphus]

Say I was 10 light years away and sent a picture of myself to earth. The signal takes 10 years to reach the earth. What the earth sees is a picture of me 10 years ago. This tells nothing of today but only what I looked like 10 years ago. If we assume we can predict the future it is a crap shoot without an energy balance.

 

One of the problem relative reference can create is a violation of energy conservation. SR has three eqautions, one for mass, one for distance and one for time. Although space-time references can be relative for moving references, mass can not be relative or else we could never complete an energy balance.

 

For example, I am sitting on a train moving at V looking out the window. Another person is at the station watching the train go by at V. We can use relative reference and call either person v=0. However, if we try to do an energy balance, mass/energy adds up different for each reference. The one on the train sees the landscape appear to move, which will take much more energy than the reference that will see the train move. We can create extra energy for the universe if we decide we like the train reference, since reference is relative, right?

 

If our reference choice creates energy out of the void ....

 

I don't know what this has to do with the rest of the thread, but:

 

That's not a violation of conservation of energy. Conservation of energy applies within a frame of reference, not between frames of reference. That's a bit like saying you can spin the world upside down by holding a map differently.

[michel123456]

I have edited my last diagram. Of course the "curtain" is horizontal.

If you turn it upside-down, it becomes a regular space-time diagram. The slope of Observable Universe represents Speed Of Light (the 45 degrees angle). The "curtain" is the second Bang as explained above in post #61 by Spyman (Recombination), and confirmed by Sysiphus in post #68 where he states that "It was already explained how the universe became transparently nearly simultaneously all around. There is nothing in that that contradicts relativity - relativity merely states that events simultaneous in one reference frame are not simultaneous in another.")

The fact that the "curtain" is horizontal makes it a phenomenon of simultaneity, in our Frame Of Reference. But also in any other FOR, which is part of my objections.

On the other side of the "curtain" happen a lot of strange phenomena's, like the curving, and the slope in the contrary direction.

Or please correct me.

Edited November 4, 2010 by michel123456

[Spyman]

[Sisyphus]

But also in any other FOR, which is part of my objections.

 

No, not in any other frame of reference. In our FOR and in the FOR of most objects, the CMBR is approximately at rest. But if you accelerate enough, the CMBR "ahead" will be blueshifted and behind will be redshifted.

 

On the other side of the "curtain" happen a lot of strange phenomena's, like the curving, and the slope in the contrary direction.

 

 

The curving happens on both sides of the "curtain." That's how it can be that that the space where it came from was only 40 million LY away at the time of emission.

[michel123456]

You see, a last we don't disagree on what represents the BBT. Simply, you agree on the BBT, I don't.

 

_Of course you draw this diagram quickly (thank you for that), and it is not to scale. CMBR is closer to the Bang, and distant galaxy is closer to CMBR. I am not sure the resulting curve would be so smooth when drawing the diagram at proper scale. In other diagrams, there is an abrupt change in the slope representing the inflation phase. and the change is behind CMBR, not in front of it.

 

_The frame of black lines pattern represents space expansion. Why aren't they straight lines? The curve as shown indicates a slowing down expansion. I thought it has been observed expansion was accelerating.?

 

_It is a space-time diagram. As such, all physical phenomenas ruled by Relativity happen along diagonals, like the red lines. Horizontal relations on this diagram have no physical meaning. "distance when light was emitted" and 'distance when light was received" are abstract concepts that cannot be measured. The same goes for the horizontal CMBR. For example, the distance (along diagonals) between each point of the CMBR and the Bang is different. Each particle of the CMBR has traveled a different (red)distance from the Bang, and enlighted at the same time. How come? (simultaneity is the question, again, not the mechanism).

 

_why are there horizontal lines at all? It seems there is an influence from the Mercator projection, and the division of the terrestrial globe in meridians and parallels (although its all about a 2d flat diagram and not a sphere). I see no reason why only the time axes are curved, and not the space ones. In a 4d curved Universe, everything should be curved (or nothing).

 

_I am sure you can find other configurations where there is no necessity for all vertical lines to join at the same point. It looks to me like a setting made on purpose to explain a concept, and not the result of observation. You can for example strighten the curved lines (meridians) and obtain a square diagram, without Bang, of course.

 

_by default, Time intervals are regular. In such a Universe, is that a correct assumption? if Time becomes irregular, maybe the square diagram can stand?

 

_The regularity of time intervals produces a strange result: the "real" distance (red line) is, beginning from Earth, reducing from step to step, and then suddenly increasing in the interval CMBR & Bang. Bizarre. As if the "real" displacement of light was never the same.?

 

_the whole diagram looks like a perspective drawing. A strong similarity with perspective is that "distance when light was emitted" and "distance when light was received" are the same: space has expanded, distance remains the same. Exactly as if it was a perspective. If one keeps in mind that Relativity is the nr one Theory that depicts accurately observation, and that perpective is also a way to represent observation, it may suggest that maybe "parallel lines" do not join at horizon.

 

-Am I the only one to ask such things?

 

_the way CMBR is positionned on the diagram does not seem to be compatible with Sysiphus's post #30. In Sysiphus's post, CMBR is like a horizon, always at the same distance from any observator. In Spyman's, CMBR is an absolute position closer to the distant Galaxy than it is from us.

(I cannot attach picture of post #30, page 2 of this thread).

Edited November 5, 2010 by michel123456

[michel123456]

empty post, I edited my post # 80 to avoid changing page. see page 4 of this thread.

 

Not an empty post anymore. Don't miss previous page to understand the following.

 

What i would propose is something like this:

 

In this diagram:

1.Everything is curved.

2.Any observator observes the same thing, no matter what position in Space and in Time.

3. in each observator's FOR, angles are conserved (the space & time axes are orthogonal, S.O.L. is always 45 degrees)

4.CMBR is something like a horizon. Sysiphus's diagram is compatible.

5.It is a diagram of the observable universe. Each observator has a horizon at the same distance in time from its position. There is no Big Bang.

Edited November 5, 2010 by michel123456

[Sisyphus]

 

_Of course you draw this diagram quickly (thank you for that), and it is not to scale. CMBR is closer to the Bang, and distant galaxy is closer to CMBR. I am not sure the resulting curve would be so smooth when drawing the diagram at proper scale. In other diagrams, there is an abrupt change in the slope representing the inflation phase. and the change is behind CMBR, not in front of it.

 

There would be more of a curve. The universe has expanded by a factor of 1000 since the CMBR was emitted. That is not "behind the curtain."

 

_The frame of black lines pattern represents space expansion. Why aren't they straight lines? The curve as shown indicates a slowing down expansion. I thought it has been observed expansion was accelerating.?

 

They are curved because the rate of expansion is not constant. It has only been accelerating for about 5 billion years.

 

_It is a space-time diagram. As such, all physical phenomenas ruled by Relativity happen along diagonals, like the red lines. Horizontal relations on this diagram have no physical meaning. "distance when light was emitted" and 'distance when light was received" are abstract concepts that cannot be measured.

 

This is not true. Horizontal lines represent simultaneity.

 

The same goes for the horizontal CMBR. For example, the distance (along diagonals) between each point of the CMBR and the Bang is different. Each particle of the CMBR has traveled a different (red)distance from the Bang, and enlighted at the same time. How come? (simultaneity is the question, again, not the mechanism).

 

There is no "distance traveled" from "the bang," only time elapsed. The time elapsed is the same.

 

_why are there horizontal lines at all? It seems there is an influence from the Mercator projection, and the division of the terrestrial globe in meridians and parallels (although its all about a 2d flat diagram and not a sphere). I see no reason why only the time axes are curved, and not the space ones. In a 4d curved Universe, everything should be curved (or nothing).

 

Horizontal lines are simultaneous in the FOR of the CMBR, and, by extension our approximate FOR. You could make a graph where lines of simultaneity were curved, but it would be pointlessly confusing.

 

_I am sure you can find other configurations where there is no necessity for all vertical lines to join at the same point. It looks to me like a setting made on purpose to explain a concept, and not the result of observation. You can for example strighten the curved lines (meridians) and obtain a square diagram, without Bang, of course.

 

You can draw any diagram you want, but it won't be consistent with observations.

 

_The regularity of time intervals produces a strange result: the "real" distance (red line) is, beginning from Earth, reducing from step to step, and then suddenly increasing in the interval CMBR & Bang. Bizarre. As if the "real" displacement of light was never the same.?

 

No, the speed of light is constant. What changes is the rate at which the space it is traveling through is expanding.

 

_the whole diagram looks like a perspective drawing. A strong similarity with perspective is that "distance when light was emitted" and "distance when light was received" are the same: space has expanded, distance remains the same. Exactly as if it was a perspective. If one keeps in mind that Relativity is the nr one Theory that depicts accurately observation, and that perpective is also a way to represent observation, it may suggest that maybe "parallel lines" do not join at horizon.

 

It's not a perspective drawing.

 

-Am I the only one to ask such things?

 

That, I think, is a question that you should think about.

 

_the way CMBR is positionned on the diagram does not seem to be compatible with Sysiphus's post #30. In Sysiphus's post, CMBR is like a horizon, always at the same distance from any observator. In Spyman's, CMBR is an absolute position closer to the distant Galaxy than it is from us.

 

No, it isn't. Why do you say it is?

[Spyman]

You see, a last we don't disagree on what represents the BBT. Simply, you agree on the BBT, I don't.

No Michel, you don't seem to understand what the basics of the Big Bang theory represents. Secondly, I have not mentioned my personal opinion or made any judgements on said theory, I have only tried to explain it to you.

 

 

_Of course you draw this diagram quickly (thank you for that), and it is not to scale. CMBR is closer to the Bang, and distant galaxy is closer to CMBR. I am not sure the resulting curve would be so smooth when drawing the diagram at proper scale. In other diagrams, there is an abrupt change in the slope representing the inflation phase. and the change is behind CMBR, not in front of it.

It is a simple and crude picture to show the basics of Big Bang theory, it doesn't have to be in scale. Yes the CMBR is a little large and to far from the Bang, but it doesn't matter, the principle is what is important. A distant galaxy can be located more or less anywhere on our horizon, it doesn't have to be closer to the CMBR, a galaxy 5 billion lightyears distant is a distant galaxy. The inflation phase is behind the CMBR and even though the CMBR is off scale, the inflation phase is still behind it in my picture, it's located inside the black part on top above the CMBR.

 

It's important to note that there is a large change in rate of expansion on both sides of the CMBR, there is no mysterious "curtain" hiding how the expansion has slowed down from a higher rate or how space were smaller further back in time.

 

 

_The frame of black lines pattern represents space expansion. Why aren't they straight lines? The curve as shown indicates a slowing down expansion. I thought it has been observed expansion was accelerating.?

The expansion of space has not been linear and as such there can't be any straigh lines, the expansion have been sloving down since the Bang and then started to accelerate again some ~5 billion years ago. The acceleration is so far very small compared to the initial expansion and especially relative inflation.

 

 

_It is a space-time diagram. As such, all physical phenomenas ruled by Relativity happen along diagonals, like the red lines. Horizontal relations on this diagram have no physical meaning. "distance when light was emitted" and 'distance when light was received" are abstract concepts that cannot be measured. The same goes for the horizontal CMBR. For example, the distance (along diagonals) between each point of the CMBR and the Bang is different. Each particle of the CMBR has traveled a different (red)distance from the Bang, and enlighted at the same time. How come? (simultaneity is the question, again, not the mechanism).

Horizontal relations are crucial for understanding how space is expanding. The difference between "distance when light was emitted" and "distance when light was received" is needed to show that space was smaller or bigger in the past. Until you are able to understand this concept there is really no point in arguing anything else regarding the Big Bang theory.

 

 

_why are there horizontal lines at all? It seems there is an influence from the Mercator projection, and the division of the terrestrial globe in meridians and parallels (although its all about a 2d flat diagram and not a sphere). I see no reason why only the time axes are curved, and not the space ones. In a 4d curved Universe, everything should be curved (or nothing).

The horizontal lines shows how time progress. I se no reason for you to make things more complicated when you don't yet understand the simple version.

 

 

_I am sure you can find other configurations where there is no necessity for all vertical lines to join at the same point. It looks to me like a setting made on purpose to explain a concept, and not the result of observation. You can for example strighten the curved lines (meridians) and obtain a square diagram, without Bang, of course.

Yes, I made this picture for explanation, but the concept of the Big Bang theory is made from real observations, there is no hidden agenda by a huge secret society of all astronomers, cosmologists and scientist around the world, trying to hide the truth of the Big Bang from ordinary people. If you strighten the curved lines you end up with a steady state universe without expansion of space.

 

 

_by default, Time intervals are regular. In such a Universe, is that a correct assumption? if Time becomes irregular, maybe the square diagram can stand?

I don't understand why you want a square diagram, you should try to understand how space changes instead of messing with time.

 

 

_The regularity of time intervals produces a strange result: the "real" distance (red line) is, beginning from Earth, reducing from step to step, and then suddenly increasing in the interval CMBR & Bang. Bizarre. As if the "real" displacement of light was never the same.?

Light travel distance is NOT the proper distance, "distance when light was emitted" and "distance when light was received" are the REAL distances in those two events, Light travel distance is the distance when light was emitted together with the distance space has expanded while light traveled across it. The displacement of light changes as the rate of expansion changes and since the rate of expansion is not thought to be the same there is nothing bizarre at all.

 

 

_the whole diagram looks like a perspective drawing. A strong similarity with perspective is that "distance when light was emitted" and "distance when light was received" are the same: space has expanded, distance remains the same. Exactly as if it was a perspective. If one keeps in mind that Relativity is the nr one Theory that depicts accurately observation, and that perpective is also a way to represent observation, it may suggest that maybe "parallel lines" do not join at horizon.

The lines are not parallel if space is expanding, which is what the Big Bang theory is about and it is the most able model to explain observable phenoma with the knowledge we currently have.

 

 

-Am I the only one to ask such things?

I think most people read up a little more about the Big Bang theory before they come busting in here claiming that it's ridiculous nonsense.

 

 

_the way CMBR is positionned on the diagram does not seem to be compatible with Sysiphus's post #30. In Sysiphus's post, CMBR is like a horizon, always at the same distance from any observator. In Spyman's, CMBR is an absolute position closer to the distant Galaxy than it is from us.

My picture IS compatible with Sisyphus's image in post #30, the CMBR is a horizon and in my picture we only see it from Earth's perspective. An alien in the galaxy we are observing would observe a different CMBR and in that view we would be the ones closer to the CMBR.

 

 

 

5. It is a diagram of the observable universe. ... There is no Big Bang.

When looking at this diagram I notice that space is smaller in the past leading to that at some point in the remote past both the Earth and the distant galaxy will occupy the same location or at least be very close.

 

How does that fit with your claim that the Universe was bigger in the past?

Edited November 5, 2010 by Spyman

[imatfaal]

Michel,

 

Through reading this thread I can see at least one stumbling block - you seem to be convinced that the event that caused the CMBR happened in a defined and limited part of the universe. This is not the case. The early universe was hot everywhere - and each point gave off radiation, we now see that light after it has been redshifted down. We see the CMBR in a sphere because the sphere is the locus of points in space from which light has taken 13 billion years to reach us.

 

The distant galaxy is no closer nor further away from the CMBR, as the CMBR is everywhere. An observer there will see the same as us, microwave light coming from every direction. Sisyphus' post #30 displayed the fact that both earth observers and distant observers both see the CMBR in the same way. Spyman's diagram showed the CMBR as everywhere in the universe in the past of 13 bill years ago. Neither shows CMBR as a distinct position in space nor as a defined horizon.

[michel123456]

Michel,

 

Through reading this thread I can see at least one stumbling block - you seem to be convinced that the event that caused the CMBR happened in a defined and limited part of the universe. This is not the case. The early universe was hot everywhere - and each point gave off radiation, we now see that light after it has been redshifted down. We see the CMBR in a sphere because the sphere is the locus of points in space from which light has taken 13 billion years to reach us.

 

The distant galaxy is no closer nor further away from the CMBR, as the CMBR is everywhere. An observer there will see the same as us, microwave light coming from every direction. Sisyphus' post #30 displayed the fact that both earth observers and distant observers both see the CMBR in the same way. Spyman's diagram showed the CMBR as everywhere in the universe in the past of 13 bill years ago. Neither shows CMBR as a distinct position in space nor as a defined horizon.

 

Let's focus on this.

CMBR happened everywhere on Spyman's diagram. O.K.

But

CMBR happened in a definite time: correct?

[imatfaal]

The CMBR is the red-shifted remnants of the last radiation of the ionised hot universe - so its not instantaneous but a fairly short period in the history of the universe.

 

The early universe was a sea of white-hot hydrogen plasma - light is not transmitted through this medium as it is re-absorbed. As the universe cooled it reached a point at which some matter was still radiating and other matter had coalesced into neutral atoms (which are much worse at absorbing radiation); a portion of the radiation from this epoch was not absorbed. It is that portion of unabsorbed radiation that we now see as the CMBR.

 

So the answer to your second question is a qualified yes.

Edited November 5, 2010 by imatfaal

[michel123456]

The CMBR is the red-shifted remnants of the last radiation of the ionised hot universe - so its not instantaneous but a fairly short period in the history of the universe.

 

The early universe was a sea of white-hot hydrogen plasma - light is not transmitted through this medium as it is re-absorbed. As the universe cooled it reached a point at which some matter was still radiating and other matter had coalesced into neutral atoms (which are much worse at absorbing radiation); a portion of the radiation from this epoch was not absorbed. It is that portion of unabsorbed radiation that we now see as the CMBR.

 

So the answer to your second question is a qualified yes.

 

If the answer is yes, it means that a young Galaxy is closer IN TIME to the CMBR than we are. Correct?

[imatfaal]

Your question is not clear - "young galaxy" needs clarification. Also CMBR is the evidence of an period 13 billion years ago - do you mean end of epoch when you refer to CMBR or the evidence we see now?

 

 

The event that caused the CMBR happened everywhere at roughly the same time. A billion years ago - an observer on earth (and on distant galaxy) would have seen less red-shifted light that had travelled for around 12 billion years.

[michel123456]

Your question is not clear - "young galaxy" needs clarification. Also CMBR is the evidence of an period 13 billion years ago - do you mean end of epoch when you refer to CMBR or the evidence we see now?

 

 

The event that caused the CMBR happened everywhere at roughly the same time. A billion years ago - an observer on earth (and on distant galaxy) would have seen less red-shifted light that had travelled for around 12 billion years.

 

We are currently observing UDFy-38135539. In this Galaxy there is (was) a star with a planet and an alien waving his hand. That event (the alien waving his hand) happened 13 billions years ago. At that time, this alien was observing a CMBR closer to him (in time) than what we are observing today from the Earth. Correct?

Edited November 5, 2010 by michel123456

[Sisyphus]

We are currently observing UDFy-38135539. In this Galaxy there is (was) a star with a planet and an alien waving his hand. That event (the alien waving his hand) happened 13 billions years ago. At that time, this alien was observing a CMBR closer to him (in time) than what we are observing today from the Earth. Correct?

 

That is correct.

[michel123456]

It has a radius from our perspective. It isn't actually a sphere of stuff. An observer located at some point on our sphere of CMBR would see CMBR at our location, and also be centered inside a sphere. The BB was everywhere, not in a hollow shell around us.

(...)

 

So, as I can understand, following the Theory, an observer located at some point of our sphere of CMBR (i.e. UDFy-38135539 in the past) would not see CMBR at our location, but much closer to him. That observer would be in our past, obligatory. An observer located on the same Galaxy today would observe the same CMBR as we do and would observe a very young Earth as it was 13billions years ago if the Earth existed at this time. And a very young Earth was observing a smaller CMBR. Correct?

[Sisyphus]

Yes, of course.

[imatfaal]

And a very young Earth was observing a smaller CMBR. Correct?

Smaller? mmm. The light that was impinging on the earth (i know it didn't exist) would have travelled for a shorter period of time and would have been radiated at a position less physically distant. The portion of the universe wide CMBR that was manifested on earth would come from a smaller spherical locus of points - but the CMBR wasnt smaller (well it was if you take expansion into account, but I think we are ignoring that).

[michel123456]

Yes, of course.

 

That is the reason why I wrote that your sketch on post # 30, page 2 of this thread, was not compatible with Spyman's diagram.

 

Smaller? mmm. The light that was impinging on the earth (i know it didn't exist) would have travelled for a shorter period of time and would have been radiated at a position less physically distant. The portion of the universe wide CMBR that was manifested on earth would come from a smaller spherical locus of points - but the CMBR wasnt smaller (well it was if you take expansion into account, but I think we are ignoring that).

 

I hope I am not the only one here to be confused with this post.

[Sisyphus]

That is the reason why I wrote that your sketch on post # 30, page 2 of this thread, was not compatible with Spyman's diagram.

 

How so?

[michel123456]

How so?

 

could you re-post your sketch here?

[Sisyphus]

could you re-post your sketch here?

 

Sure.

 

 

What this drawing depicts is this sentence you just wrote:

 

"An observer located on the same Galaxy today would observe the same CMBR as we do and would observe a very young Earth as it was 13billions years ago if the Earth existed at this time."

[michel123456]

Sure.

 

 

What this drawing depicts is this sentence you just wrote:

 

"An observer located on the same Galaxy today would observe the same CMBR as we do and would observe a very young Earth as it was 13billions years ago if the Earth existed at this time."

 

And I added "And a very young Earth was observing a smaller CMBR."

 

In other words, when the great CMBR circle is centered on the Galaxy, the second circle centered on the Earth is small. And inversely when the big circle is centered on the Earth, the galaxy observes a small CMBR. There exist no situation with 2 big circles as presented on the sketch. If I understand correctly.

[Sisyphus]

Then you don't understand correctly. That is the present day view of both observers.

[imatfaal]

Michel - what do you think the CMBR is?

 

I don't think my post was un-intelligible (but then I wouldn't - its very hard not to understand yourself no matter how confused one's witterings are). I really think we might be able to get the nub of why we disagree - I think your ideas of the actuality of the CMBR are incorrect. The fact that you used the phrase "smaller CMBR", and I think meant just that, makes me sure of it. Sisy's diagram is quite understandable.