Rate and Location of Expansion

[michel123456]

I am having some trouble understanding what you are trying to convey to me.

I understand the further in space it is, the further in time it is also.

But I don't see why you are moving from T1 to T2.

We are all in the same time. If we are at T2/G1, then G2, G3, G4, etc. are also at T2.

I agree that what we are seeing happened a long time ago and in a different location, but we are still just talking about what we can see now, that is, T2. And after another unit of time has passed it will look as it does at T3.

 

Yes.

we are still just talking about what we can see now

 

that is from T2.

 

Speaking more accurately, from T2 at G1 we cannot even see T2/G2 (because we cannot observe the present, only the past is observable)

 

what we are observing now today from T2/G1 is T1/G2

 

 

What you are discussing is what other planets in other galaxy clusters very far away from us are supposed to be observing , today.

What I discuss is what we are actualy observing from Earth today.

Edited January 5, 2012 by michel123456

[Spyman]

Anyway I would prefer to focus on what we are observing, not on any theorization or prediction.

Without theories and mathematical models we are only observing different redshifts, there are no distances nor any durations to focus on without them. Even if you want to discuss how far away they appear to be due to the light travel time, you will need some kind of interpretation of the measured redshift.

 

 

Here below I included the time stamp to make it clearer

What we are observing is:

 

T0.-T1.--T3.---T6.----T10.-----T15.------T21.-------T28.--------T36.---------T45

G1 s G2 ss G3 sss G4 ssss G5 sssss G6 ssssss G7 sssssss G8 ssssssss G9 sssssssss G10

 

Where T is directly linked to the amount of "s": time of observation in the past is a direct function of the distance through the constancy of Speed Of Light.

The duration for light to travel the distance is not the true distance to the objects, for instance an object with redshift 3.5 and another with redshift 0.78 might seem to be around 12 billion lightyears and 7 billion lightyears distant, but they where both around 5 billion lightyears away from us when they emitted the light we see now. The distance you speak of that is a "direct function of the distance through the constancy of Speed Of Light" is the distance light has traveled through space to reach us, but it is NOT the actual distance to the object, neither when the light was emitted nor when the light is recieved.

 

Also we might as well be observing:

 

T0.---------T9.--------T17.-------T24.------T30.-----T35.----T39.---T42.--T44.-T45

G1 sssssssss G2 ssssssss G3 sssssss G4 ssssss G5 sssss G6 ssss G7 sss G8 ss G9 s G10

 

The distance between different objects in any outward random direction are not related to expansion nor acceleration and only shows how they randomly happen to have been located when they emitted the light we see today. G10 is still the farthets galaxy cluster with 45s between us, but as already said that are not their true distance from us, G10 might very well have been closer than G6 was when they individuality emitted the light we see today. Expansion and its accelaration tells us how fast galaxies are receding from each other relative their distance to us but not how far away apart they actually are as that depends on where they started out.

 

 

 

To be compared to Spyman's second example

Where I put in red rectangle what we are (supposed to be) observing If we are today at T4.

We are today observing all those galaxies, all the way from G2 and out to G12, with different redshifts. The math in the standard model tells us how far away they where and when they emitted the light, the duration and distance for light travel and how far away from us they are supposed to be today.

 

 

 

We cannot see G3 where it is today, we cannot see the sequence

T2 - G1 ss G2 ss G3

We can't see where G3 is today but we can't see how old the light is either nor how far it has traveled to reach us. We observe the redshift which is calculated by a model to show us these things and it reveals them all, you can't cherry pick one type of value and say that it is what we see and claim that we can't see the other values. If you trust in the model then all values are true and if the model fails you can't trust any value at all.

 

 

 

What I discuss is what we are actualy observing from Earth today.

The further the distance to the object we are observing, the older the image we are recieving, but the relation between expansion and distance is something different, the rate of expansion is NOT constant over this timespan we can observe.

Edited January 5, 2012 by Spyman

[michel123456]

Spyman (my guardian angel), that was a complicated answer of yours. I read it twice.

 

On the assumption that the Standard Model is correct, and on the basis of Zapatos example:

 

What are we observing today from Earth ?

[JustinW]

From my understanding so far, it seems that the standard model by judging distance by light years, would mean that the objects observed are viewed now as they were that many years ago. As to say if you viewed something now that was 4 billion light years away, that isn't the way it looks now. It is the way it looked 4 billion years ago.

 

Is that not the case? Another question I've wondered, but probably as simply answered as my first, was if space is expanding at more than the speed of light then why does light reach us in the first place? If it is space that is expanding, and not galaxies moving at that speed, then how does the light outrun the growing distance?

[Airbrush]

"....[What] if space is expanding at more than the speed of light then why does light reach us in the first place? If it is space that is expanding, and not galaxies moving at that speed, then how does the light outrun the growing distance? "

Certain points of the universe are moving away from each other at beyond the speed of light. Light reaches us only if it had time to travel the distance. Light will never "outrun the growing distance", if the distance is great enough.

Edited January 6, 2012 by Airbrush

[michel123456]

Spyman (my guardian angel), that was a complicated answer of yours. I read it twice.

 

On the assumption that the Standard Model is correct, and on the basis of Zapatos example:

 

What are we observing today from Earth ?

 

After some more thought, and going back to the right definition of Hubble's law, I made these 2 following graphs:

 

1. Hubble's law, time on the vertical axis, distance on the horizontal, v is velocity, and we see on the graph that velocity is proportional to distance (G2 has velocity v, G3 has velocity 2v, G4 has velocity 3v)

 

 

 

Then the same graph using Zapatos notation:

 

 

If the above is right, all we need to do is to fill the diagram.

--------------------------------------------------------

Unfortunately, it is wrong. Bad of me.

 

Now i'll try to post the correct ones.

 

Hubble's law says (from wiki)

Hubble's law is the name for the astronomical observation in physical cosmology that: (1) all objects observed in deep space (interstellar space) are found to have a doppler shift observable relative velocity to Earth, and to each other; and (2) that this doppler-shift-measured velocity, of various galaxies receding from the Earth, is proportional to their distance from the Earth and all other interstellar bodies.

 

Resuming

velocity to Earth is proportional to their distance

 

So, when distance increases, velocity increases

 

Correcting my previous diagram, it goes like this:

 

Time is on the vertical axis, distance on the horizontal. Velocity is not the diagonal (that was the previous error) but velocity, which is the ratio distance/time, is represented by the angle (more accurately by the tangent of the angle). When the angle is zero, speed is null (the distance in any amount of time is zero), when the angle is orthogonal, speed is infinite (infinite distance in zero amount of time).

 

 

in the diagram, velocity increases with distance: the angle gets wider.

 

I hope it is O.K. now.

 

So, in Zapatos notation it becomes

Where d is the distance travelled by light.

Edited January 6, 2012 by michel123456

[JustinW]

Light reaches us only if it had time to travel the distance.

Light will never "outrun the growing distance", if the distance is great enough.

This was percisely my point in asking. Like michel123456 said above about the when distance increases so does velocity. But why is this if the expansion rate is the same throughout? Galaxies closer to us should expand from us at more than the SOL if the galaxies furthest from us are expanding at more than the SOL. I understand that we would observe the farther galaxies at the rate of expansion in corrolation to the time they emitted the light, but it still doesn't explain why the explansion is more than the SOL in some places but not in the others. Or am I missing something? Edited January 6, 2012 by JustinW

[zapatos]

This was percisely my point in asking. Like michel123456 said above about the when distance increases so does velocity. But why is this if the expansion rate is the same throughout? Galaxies closer to us should expand from us at more than the SOL if the galaxies furthest from us are expanding at more than the SOL. I understand that we would observe the farther galaxies at the rate of expansion in corrolation to the time they emitted the light, but it still doesn't explain why the explansion is more than the SOL in some places but not in the others. Or am I missing something?

Ok, back to this ugly example:

 

Let's say that at T1 (now), galaxies 1 - 12 are lined up as so, and there is an equal distance between each galaxy. And let's say the distance between each galaxy is 1 trillion miles.

 

G1 s G2 s G3 s G4 s G5 s G6 s G7 s G8 s G9 s G10 s G11 s G12

 

We know that all space is expanding equally. That is, the space between G1 and G2 will expand at the same rate as the space between G7 and G8, etc.

 

So now let's say we have moved forward in time 1 year to T2, and during that one year, space has expanded and the distance between each galaxy has grown by 1 trillion miles to 2 trillion miles, as shown here:

 

G1 ss G2 ss G3 ss G4 ss G5 ss G6 ss G7 ss G8 ss G9 ss G10 ss G11 ss G12

 

Since there was one trillion miles between G1 and G2 at T1, and there are now two trillion miles between G1 and G2 at T2, we can say that the distance between G1 and G2 has grown at 1 trillion miles per year.

 

And since there were two trillion miles between G1 and G3 at T1, and there are now four trillion miles between G1 and G3, we can say that the distance between G1 and G3 has grown at 2 trillion miles per year.

 

Now take a look at what happened between G1 and G8.

 

At T1, there were 7 trillion miles between G1 and G8.

At T2, there are 14 trillion miles between G1 and G8.

That means the distance between G1 and G8 grew at 7 trillion light years per year.

 

That is why the distances to galaxies further away from us are growing at a greater rate than the distance to galaxies closer to us, even though the rate of expansion is the same everywhere in the universe.

 

And since light can only travel 6 trillion miles per year, the light from G8 (or anything further away from G1 than G8) will never be able to reach G1 as long as the expansion continues at this or a greater rate.

[michel123456]

Ok, back to this ugly example:

 

Let's say that at T1 (now), galaxies 1 - 12 are lined up as so, and there is an equal distance between each galaxy. And let's say the distance between each galaxy is 1 trillion miles.

 

G1 s G2 s G3 s G4 s G5 s G6 s G7 s G8 s G9 s G10 s G11 s G12

 

We know that all space is expanding equally. That is, the space between G1 and G2 will expand at the same rate as the space between G7 and G8, etc.

 

So now let's say we have moved forward in time 1 year to T2, and during that one year, space has expanded and the distance between each galaxy has grown by 1 trillion miles to 2 trillion miles, as shown here:

 

G1 ss G2 ss G3 ss G4 ss G5 ss G6 ss G7 ss G8 ss G9 ss G10 ss G11 ss G12

 

Since there was one trillion miles between G1 and G2 at T1, and there are now two trillion miles between G1 and G2 at T2, we can say that the distance between G1 and G2 has grown at 1 trillion miles per year.

 

And since there were two trillion miles between G1 and G3 at T1, and there are now four trillion miles between G1 and G3, we can say that the distance between G1 and G3 has grown at 2 trillion miles per year.

 

Now take a look at what happened between G1 and G8.

 

At T1, there were 7 trillion miles between G1 and G8.

At T2, there are 14 trillion miles between G1 and G8.

That means the distance between G1 and G8 grew at 7 trillion light years per year.

 

That is why the distances to galaxies further away from us are growing at a greater rate than the distance to galaxies closer to us, even though the rate of expansion is the same everywhere in the universe.

 

And since light can only travel 6 trillion miles per year, the light from G8 (or anything further away from G1 than G8) will never be able to reach G1 as long as the expansion continues at this or a greater rate.

Bolded mine.

Zapatos, you are forgetting something: observation doesn't happen horizontally. G1 cannot observe G8 at the same time.

Please look back at my last post. #31

And tell me if I am wrong.

Edited January 6, 2012 by michel123456

[zapatos]

Bolded mine.

Zapatos, you are forgetting something: observation doesn't happen horizontally. G1 cannot observe G8 at the same time.

Please look back at my last post. #31

And tell me if I am wrong.

Assuming I understand correctly what you are saying, I agree. If G1 and G8 were born in the same instant of time, G1 would look older to me than G8 because the light from G8 has been traveling to me for so long.

 

I think we are looking at the same thing from two different points of view. If I go outside tonight with a telescope I can indeed look at G1 and G8 at the same time, meaning I can see both of those galaxies tonight. I am graphing what I can see tonight, knowing full well that the G8 I am looking at is how it was many billions of years ago.

I think when you graph it you are building in how to have them both appear to be the same age.

 

Hope I said that clearly enough...

[michel123456]

Assuming I understand correctly what you are saying, I agree. If G1 and G8 were born in the same instant of time, G1 would look older to me than G8 because the light from G8 has been traveling to me for so long.

 

I think we are looking at the same thing from two different points of view. If I go outside tonight with a telescope I can indeed look at G1 and G8 at the same time, meaning I can see both of those galaxies tonight. I am graphing what I can see tonight, knowing full well that the G8 I am looking at is how it was many billions of years ago.

I think when you graph it you are building in how to have them both appear to be the same age.

 

Hope I said that clearly enough...

 

We don't see the same thing.

 

In this diagram, the Earth today is at T4,G1

From G1, we are observing around us what happen.

We see G2, G3, G4.

 

 

Time goes from T1 to T4, up to down.

When looking at G2, we are looking in the past (blue arrow). G2 is far away AND in the past

G3 is more distant, it is also more in the past.

If you draw a straight line from G1 (where you are) to G3 (the red arrow) this line will have a different slope that the G1-G2 blue line: the difference in slope is the difference in speed as observed from G1.

It follows from Hubble's law: speed is a function of distance.

 

 

IF this diagram is correct, then the universe is not expanding.

So look at it ten times.

Edited January 7, 2012 by michel123456

[guenter]

This was percisely my point in asking. Like michel123456 said above about the when distance increases so does velocity. But why is this if the expansion rate is the same throughout? Galaxies closer to us should expand from us at more than the SOL if the galaxies furthest from us are expanding at more than the SOL. I understand that we would observe the farther galaxies at the rate of expansion in corrolation to the time they emitted the light, but it still doesn't explain why the explansion is more than the SOL in some places but not in the others. Or am I missing something?

Justin, the universe expands everywhere at the same rate and consequently double distance means double velocity.

 

It's easy to see that, remembering the dotted balloon. Imagine 3 dots in one line and equally spaced, us on A, B 1 cm away from us and C 1 cm away from B, but 2 cm from us.

Now we let the balloon expand to double it's radius. Then B is 2 cm away from A = us and also C is 2 cm away from B, but 4 cm from us. Thus from our viewpoint B receded 1 cm and C receded 2 cm within the same time. So, C's velocity is twice as much as B's velocity viewed from A, us. This is Hubble's law, v = d*Ho, the receding velocity is proportional to the distance, as mentioned already in this Thread.

[michel123456]

Justin, the universe expands everywhere at the same rate and consequently double distance means double velocity.

 

It's easy to see that, remembering the dotted balloon. Imagine 3 dots in one line and equally spaced, us on A, B 1 cm away from us and C 1 cm away from B, but 2 cm from us.

Now we let the balloon expand to double it's radius. Then B is 2 cm away from A = us and also C is 2 cm away from B, but 4 cm from us. Thus from our viewpoint B receded 1 cm and C receded 2 cm within the same time. So, C's velocity is twice as much as B's velocity viewed from A, us. This is Hubble's law, v = d*Ho, the receding velocity is proportional to the distance, as mentioned already in this Thread.

Guenter, you're an intelligent guy:

Use your critical mind against me.

Did I made any mistake in my diagram in post #36?

Edited January 7, 2012 by michel123456

[guenter]

Use your critical mind against me.

Did I made any mistake in my diagram in post #36?

michel123456,

 

if you want to show a 'look back time' vs. distance diagram, it's convenient to choose the distance expressed in lightyears and the time axis in years. Then you obtain a straight line under 45°. Choosing miles instead of lightyears the line remains straight, but the angle changes.

 

However, perhaps you want to show something else.

[michel123456]

michel123456,

 

if you want to show a 'look back time' vs. distance diagram, it's convenient to choose the distance expressed in lightyears and the time axis in years. Then you obtain a straight line under 45°. Choosing miles instead of lightyears the line remains straight, but the angle changes.

 

However, perhaps you want to show something else.

Agree, but yes I want to show something else. It is not about Speed of Light.

It is about observed recessing speed of galaxy clusters.

[Spyman]

From my understanding so far, it seems that the standard model by judging distance by light years, would mean that the objects observed are viewed now as they were that many years ago. As to say if you viewed something now that was 4 billion light years away, that isn't the way it looks now. It is the way it looked 4 billion years ago.

The image we see would be 4 billion years old but while it took 4 billion years for light to travel 4 billion lightyears through space, the object (with redshift 0.369) must have been closer when it emitted the light if space expanded during the time light was moving towards us (like around 3.41 billion lightyears) and it must also be further away now when we recieve the light than what it was when it emitted it (like around 4.67 billion lightyears).

 

Imagine that you have a rubber band with a length of 1 meter and a wheel with a circumference of 10 centimeters, so that the length of the band equals 10 rotations with the wheel. If someone simultaneously and slowly streaches the band to the double length of 2 meter while you measure the rope by rolling the wheel on it, you will find that it takes more than 10 rotations and less than 20 from one end to the other.

 

 

Another question I've wondered, but probably as simply answered as my first, was if space is expanding at more than the speed of light then why does light reach us in the first place? If it is space that is expanding, and not galaxies moving at that speed, then how does the light outrun the growing distance?

That depends on the rate of expansion which changes with both distance and time. When space expands the border where expansion equals lightspeed (the Hubble shell/sphere) also moves further out and with time lightrays that where right outside unable to reach us finds themselves inside where space expands slower than lightspeed, so they can now proceed to us.

 

Let's imagine a rubber band again, it has a 4 meter start length (space), it is fixed to the ground in one end and tied to the rear car bumber in the other end. The car goes away with 4 meters per second (4 times lightspeed) and on the middle is a very fast ant placed running towards the safety at the fixed ground location with 1 meters per second (lightspeed).

 

If we make a mark on the road beneath the ant the band above the mark will recede with half the speed of the car in the beginning since it is half way between the car and the ground, but after one second the band is streached to 8 meters, making the band above the mark at 2 meters to recede with 2/8*4 = 1 meters per second, and after three seconds the band is streached to 16 meters, making the band above the mark at 2 meters to recede with 2/16*4 = 1/2 meters per second and so on...

 

Now the ant won't get it that easy since it is not fixed to the ground like the mark and will be brought back by the expanding band, but nevertheless the same principle will let the ant escape from the band down to safety. Lets do a simple test where we first we move the car, then streach the band and finally let the ant move along the band, repeat until finished:

 

At 0s the band is 400 cm long and the is placed at the middle at 200 cm -> ant is located at 200/400 = 50%

At 1s the band is 800 cm ant is at 50% = 400 cm where ant moves 100 cm to location 300 cm -> new location is 300/800 = 38%

At 2s the band is 1200 cm ant is at 38% = 456 cm where ant moves 100 cm to location 356 cm -> new location is 356/1200 = 30%

At 3s the band is 1600 cm ant is at 30% = 480 cm where ant moves 100 cm to location 380 cm -> new location is 380/1600 = 24%

At 4s the band is 2000 cm ant is at 24% = 480 cm where ant moves 100 cm to location 386 cm -> new location is 380/2000 = 19%

At 5s the band is 2400 cm ant is at 19% = 456 cm where ant moves 100 cm to location 356 cm -> new location is 356/2400 = 15%

At 6s the band is 2800 cm ant is at 15% = 420 cm where ant moves 100 cm to location 320 cm -> new location is 320/2800 = 12%

At 7s the band is 3200 cm ant is at 12% = 384 cm where ant moves 100 cm to location 284 cm -> new location is 284/3200 = 9%

At 8s the band is 3600 cm ant is at 9% = 324 cm where ant moves 100 cm to location 224 cm -> new location is 224/3600 = 7%

At 9s the band is 4000 cm ant is at 7% = 280 cm where ant moves 100 cm to location 180 cm -> new location is 180/4000 = 5%

At 10s the band is 4400 cm ant is at 5% = 220 cm where ant moves 100 cm to location 120 cm -> new location is 120/4400 = 3%

At 11s the band is 4800 cm ant is at 3% = 144 cm where ant moves 100 cm to location 44 cm -> new location is 44/4800 = 1%

At 12s the band is 5200 cm ant is at 1% = 52 cm where ant moves 100 cm to location -48 cm -> it has managed leave the rubber band.

 

However if the car where to accelerate at an increasing rate it could make the band above the mark to recede at or even increase it's speed above the ants and continually force the ant further and further away. If the rate of expansion is increasing fast enough the Hubble sphere will shrink, making our view darker and darker.

 

 

On the assumption that the Standard Model is correct, and on the basis of Zapatos example:

 

What are we observing today from Earth ?

What we observe today are a range of redshifts from zero to a current maximum of 8.6 (UDFy-38135539) and further on we see the cosmic microwave background radiation with a redshift of 1089.

http://en.wikipedia.org/wiki/Redshift#Highest_redshifts

 

I used the Cosmos Calculator with the values: Omega=0.27 Lambda=0.73 Hubble=71 and Redshift= 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00, 3.00, 4.00, 5.00, 6.00, 7.00, 8.00 to obtain the data in the graph.

 

X-axis is age of the Universe in billion years and Y-axis is distance in billion lightyears. Red dots indicates the distance the light we recieve today was emitted from, green dots is the distance light have travelled through space to reach us from the red dots and blue dots are the estimated distance to where the objects are located today.

Edited January 9, 2012 by Spyman

[michel123456]

The image we see would be 4 billion years old but while it took 4 billion years for light to travel 4 billion lightyears through space, the object (with redshift 0.369) must have been closer when it emitted the light if space expanded during the time light was moving towards us (like around 3.41 billion lightyears) and it must also be further away now when we recieve the light than what it was when it emitted it (like around 4.67 billion lightyears).

 

Imagine that you have a rubber band with a length of 1 meter and a wheel with a circumference of 10 centimeters, so that the length of the band equals 10 rotations with the wheel. If someone simultaneously and slowly streaches the band to the double length of 2 meter while you measure the rope by rolling the wheel on it, you will find that it takes more than 10 rotations and less than 20 from one end to the other.

 

 

 

That depends on the rate of expansion which changes with both distance and time. When space expands the border where expansion equals lightspeed (the Hubble shell/sphere) also moves further out and with time lightrays that where right outside unable to reach us finds themselves inside where space expands slower than lightspeed, so they can now proceed to us.

 

Let's imagine a rubber band again, it has a 4 meter start length (space), it is fixed to the ground in one end and tied to the rear car bumber in the other end. The car goes away with 4 meters per second (4 times lightspeed) and on the middle is a very fast ant placed running towards the safety at the fixed ground location with 1 meters per second (lightspeed).

 

If we make a mark on the road beneath the ant the band above the mark will recede with half the speed of the car in the beginning since it is half way between the car and the ground, but after one second the band is streached to 8 meters, making the band above the mark at 2 meters to recede with 2/8*4 = 1 meters per second, and after three seconds the band is streached to 16 meters, making the band above the mark at 2 meters to recede with 2/16*4 = 1/2 meters per second and so on...

 

Now the ant won't get it that easy since it is not fixed to the ground like the mark and will be brought back by the expanding band, but nevertheless the same principle will let the ant escape from the band down to safety. Lets do a simple test where we first we move the car, then streach the band and finally let the ant move along the band, repeat until finished:

 

At 0s the band is 400 cm long and the is placed at the middle at 200 cm -> ant is located at 200/400 = 50%

At 1s the band is 800 cm ant is at 50% = 400 cm where ant moves 100 cm to location 300 cm -> new location is 300/800 = 38%

At 2s the band is 1200 cm ant is at 38% = 456 cm where ant moves 100 cm to location 356 cm -> new location is 356/1200 = 30%

At 3s the band is 1600 cm ant is at 30% = 480 cm where ant moves 100 cm to location 380 cm -> new location is 380/1600 = 24%

At 4s the band is 2000 cm ant is at 24% = 480 cm where ant moves 100 cm to location 386 cm -> new location is 380/2000 = 19%

At 5s the band is 2400 cm ant is at 19% = 456 cm where ant moves 100 cm to location 356 cm -> new location is 356/2400 = 15%

At 6s the band is 2800 cm ant is at 15% = 420 cm where ant moves 100 cm to location 320 cm -> new location is 320/2800 = 12%

At 7s the band is 3200 cm ant is at 12% = 384 cm where ant moves 100 cm to location 284 cm -> new location is 284/3200 = 9%

At 8s the band is 3600 cm ant is at 9% = 324 cm where ant moves 100 cm to location 224 cm -> new location is 224/3600 = 7%

At 9s the band is 4000 cm ant is at 7% = 280 cm where ant moves 100 cm to location 180 cm -> new location is 180/4000 = 5%

At 10s the band is 4400 cm ant is at 5% = 220 cm where ant moves 100 cm to location 120 cm -> new location is 120/4400 = 3%

At 11s the band is 4800 cm ant is at 3% = 144 cm where ant moves 100 cm to location 44 cm -> new location is 44/4800 = 1%

At 12s the band is 5200 cm ant is at 1% = 52 cm where ant moves 100 cm to location -48 cm -> it has managed leave the rubber band.

 

However if the car where to accelerate at an increasing rate it could make the band above the mark to recede at or even increase it's speed above the ants and continually force the ant further and further away. If the rate of expansion is increasing fast enough the Hubble sphere will shrink, making our view darker and darker.

 

 

 

What we observe today are a range of redshifts from zero to a current maximum of 8.6 (UDFy-38135539) and further on we see the cosmic microwave background radiation with a redshift of 1089.

http://en.wikipedia.org/wiki/Redshift#Highest_redshifts

 

I used the Cosmos Calculator with the values: Omega=0.27 Lambda=0.73 Hubble=71 and Redshift= 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00, 3.00, 4.00, 5.00, 6.00, 7.00, 8.00 to obtain the data in the graph.

 

X-axis is age of the Universe in billion years and Y-axis is distance in billion lightyears. Red dots indicates the distance the light we recieve today was emitted from, green dots is the distance light have travelled through space to reach us from the red dots and blue dots are the estimated distance to where the objects are located today.

 

@Spyman.

Your are answering using the Standard Model of cosmology, I can understand all the above.

However, I would like you to have a look at my simple diagram from post#36, without rubber band, and tell me where is the flaw.

[michel123456]

At 0s the band is 400 cm long and the is placed at the middle at 200 cm -> ant is located at 200/400 = 50%

At 1s the band is 800 cm ant is at 50% = 400 cm where ant moves 100 cm to location 300 cm -> new location is 300/800 = 38%

At 2s the band is 1200 cm ant is at 38% = 456 cm where ant moves 100 cm to location 356 cm -> new location is 356/1200 = 30%

At 3s the band is 1600 cm ant is at 30% = 480 cm where ant moves 100 cm to location 380 cm -> new location is 380/1600 = 24%

At 4s the band is 2000 cm ant is at 24% = 480 cm where ant moves 100 cm to location 386 cm -> new location is 380/2000 = 19%

At 5s the band is 2400 cm ant is at 19% = 456 cm where ant moves 100 cm to location 356 cm -> new location is 356/2400 = 15%

At 6s the band is 2800 cm ant is at 15% = 420 cm where ant moves 100 cm to location 320 cm -> new location is 320/2800 = 12%

At 7s the band is 3200 cm ant is at 12% = 384 cm where ant moves 100 cm to location 284 cm -> new location is 284/3200 = 9%

At 8s the band is 3600 cm ant is at 9% = 324 cm where ant moves 100 cm to location 224 cm -> new location is 224/3600 = 7%

At 9s the band is 4000 cm ant is at 7% = 280 cm where ant moves 100 cm to location 180 cm -> new location is 180/4000 = 5%

At 10s the band is 4400 cm ant is at 5% = 220 cm where ant moves 100 cm to location 120 cm -> new location is 120/4400 = 3%

At 11s the band is 4800 cm ant is at 3% = 144 cm where ant moves 100 cm to location 44 cm -> new location is 44/4800 = 1%

At 12s the band is 5200 cm ant is at 1% = 52 cm where ant moves 100 cm to location -48 cm -> it has managed leave the rubber band.

 

Here is your example in a graph.

 

 

The curve represents the ant's path.

when the observer is at T12, the ant represents light coming from some distant object.

If you zoom in the circle you get my diagram of post #36

The only differences are: there is no rubber band, there is no car.

Edited January 10, 2012 by michel123456

[Spyman]

Nice picture Michel.

 

The curve represents the ant's path.

If space and the rubber band did not expand then the ant's and light's paths would be a straight line, you need to explain why the light from G3 in your post #36 makes a detour around G2 on it's path towards G1, in a non expanding space the light would follow a straight path and the only possibility for it to pass by G2 would be if G2 was in the middle of it.

Edited January 10, 2012 by Spyman

[michel123456]

Nice picture Michel.

Thanks. You did it, I simply drawed it.

 

 

If space and the rubber band did not expand then the ant's and light's paths would be a straight line,

yes

 

you need to explain why the light from G3 in your post #36 makes a detour around G2 on it's path towards G1, in a non expanding space the light would follow a straight path and the only possibility for it to pass by G2 would be if G2 was in the middle of it.

Now you are discussing something else: the curved path of light induced by gravity.

Relativity still holds.

 

In your diagram with the rubber band, the path is curved but light don't "make a detour". Light do not go round an object to avoid it, light follows a smooth curve. It is nothing different than a straight line in curved space. For the light to "make a detour" you need all the subtilities of Relativity.

[Spyman]

Now you are discussing something else...

No, I am trying to understand your post #36. If space is not expanding and G2 is smack in the middle between G1 and G3, then how can there be different slopes?

[michel123456]

No, I am trying to understand your post #36. If space is not expanding and G2 is smack in the middle between G1 and G3, then how can there be different slopes?

I repost the diagram.

G2 is not "smack" in the middle of anything. G2 is a random galaxy cluster receding from us. Simply its distance from us is between less than G3: direction is not important, G2 can be north, G3 East and G4 west.

The slope is the observed receding speed (under the assumption that redshift is a doppler effect)

You can imagine as many clusters you want (G4,G5, G8)

G8 would be a cluster far away, on the right of the diagram. Because it is far away, it is also far in the past, so it will be up in the diagram. And since it has a large observed redshift, it would have a slope more horizontal than G1,G2 and G3.

You could plot this way all the observable universe.

And you would obtain a universe expanding in the past.

Edited January 10, 2012 by michel123456

[Spyman]

G2 is not "smack" in the middle of anything. G2 is a random galaxy cluster receding from us. Simply its distance from us is between less than G3: direction is not important, G2 can be north, G3 East and G4 west.

Yes, you are correct direction is not important, but that was not what I was trying to say.

 

 

The slope is the observed receding speed (under the assumption that redshift is a doppler effect)

We are only observing one single slope and it's angle is the Hubble constant.

 

"Hubble's law is the name for the astronomical observation in physical cosmology that: (1) all objects observed in deep space (interstellar space) are found to have a doppler shift observable relative velocity to Earth, and to each other; and (2) that this doppler-shift-measured velocity, of various galaxies receding from the Earth, is proportional to their distance from the Earth and all other interstellar bodies."

http://en.wikipedia.org/wiki/Hubble's_law

[michel123456]

Yes, you are correct direction is not important, but that was not what I was trying to say.

 

 

 

We are only observing one single slope and it's angle is the Hubble constant.

 

"Hubble's law is the name for the astronomical observation in physical cosmology that: (1) all objects observed in deep space (interstellar space) are found to have a doppler shift observable relative velocity to Earth, and to each other; and (2) that this doppler-shift-measured velocity, of various galaxies receding from the Earth, is proportional to their distance from the Earth and all other interstellar bodies."

http://en.wikipedia.org/wiki/Hubble's_law

emphasis mine.

Redshift is proportional to distance.

Redshift (aka speed) increases with distance.

If speed increases with distance, there is more than one slope on my diagram.

Edited January 11, 2012 by michel123456

[Spyman]

If speed increases with distance, there is more than one slope on my diagram.

AFAIK, if speed increases proportional to distance then there is only one slope following the relation between them.

(Look at the blue line in the latest picture you posted, one single slope for all objects.)