The Andromeda Galaxy

Comments and questions about the APOD on the main view screen.
Frank
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The Andromeda Galaxy

Post by Frank » Sun Oct 23, 2005 4:04 am

I understand that the Andromeda Galaxy is approaching our Milky Way Galaxy.
If the Universe is expanding why arn't all galaxies moving away from each other? :roll:

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Post by Fahad » Sun Oct 23, 2005 7:34 am

They are. However, a few of them are so close to each other that they will collide.

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Re: The Andromeda Galaxy

Post by Empeda » Mon Oct 24, 2005 8:22 am

Frank wrote:I understand that the Andromeda Galaxy is approaching our Milky Way Galaxy.
If the Universe is expanding why arn't all galaxies moving away from each other? :roll:
It's because the two of us are close enogh together for our gravity to attract each other

The local group of galaxies as a collection though is moving away from all other groups.
I'm an Astrophysics Graduate from Keele University, England - doesn't mean I know anything but I might be able to help!

harry
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Expanding Universe

Post by harry » Mon Nov 21, 2005 1:13 pm

Expanding Universe is a false statement. The dating and distant calculation is under question.
If the Universe is "All" how can it expand within itself.
Parts of the Universe may expand from themsleves in the overal process of recycling and this does not mean the universe is expanding.
Our Local group of galaxies being about 35 has M87 as its centre. The group behaves like a unit and not expanding. This group forms a unit that belongs to a larger group which behaves like a unit a super cluster. There are something like 9 known super clusters and with deep field more are to be found.
The question is this: Are the superclusters moving away from each other.

The expanding universe idea came from the Big Bang Theory which has gone out with a big Bang.
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Re: Expanding Universe

Post by craterchains » Mon Nov 21, 2005 1:31 pm

harry wrote:The dating and distant calculation is under question.
There are something like 9 known super clusters and with deep field more are to be found. The question is this: Are the superclusters moving away from each other.
The expanding universe idea came from the Big Bang Theory which has gone out with a big Bang.
Or maybe it is just being modified to fit some new facts? :wink:
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Re: Expanding Universe

Post by Orca » Tue Nov 22, 2005 3:33 am

harry wrote:Expanding Universe is a false statement. The dating and distant calculation is under question.
If the Universe is "All" how can it expand within itself.
Parts of the Universe may expand from themsleves in the overal process of recycling and this does not mean the universe is expanding.
Our Local group of galaxies being about 35 has M87 as its centre. The group behaves like a unit and not expanding. This group forms a unit that belongs to a larger group which behaves like a unit a super cluster. There are something like 9 known super clusters and with deep field more are to be found.
The question is this: Are the superclusters moving away from each other.

The expanding universe idea came from the Big Bang Theory which has gone out with a big Bang.
On the contrary, not only is the universe expanding, but is expanding at an accelerating rate.

harry
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Expanding Universe

Post by harry » Tue Nov 22, 2005 4:11 am

Tell me what part of the universe is expanding.

Is it all the universe or parts of the universe.

You will find that we have been led up the garden path as so to speak.

An which parts are accelerating away from ?????????.
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Post by Empeda2 » Tue Nov 22, 2005 1:26 pm

there are an awful lot more than 9 superclusters....try 9 billion at least...

The universe is expanding in the sense that the medium of our universe is expanding - we're not expanding into anything, everything is exanding away from everything else.

You cannot think of the big bang as an explosion - nor can you think about all the galaxies travelling away from each other as they implies that they are travelling through something - the medium itself is expanding.

The word universe no longer encompasses everything - we speak of our unvierse and other universes, in the same way that the word atom - which literally translates and the smallest possible 'element' - is now known to be made of smaller things still.

If your into String theory (which like I've said before I'm not so no complicated questions please!) our 4 dimensional universe is just part of a larger 11 dimensional world, in which we live on energy strings and membranes adn such like.....

The point is that we cannot say that we are expanding into anything - the current inflation model suggests that 'our' universe is massively bigger than the 'visible' universe anyway.

Time and space... who'd have it eh? :)
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Post by Doum » Wed Nov 23, 2005 12:54 am

:D Empeda2, reading your opinion make me happy. Cause it make so much more sense then reading sumthing else. I read that their might be 26 dimensions. So the story continue. :wink:

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Post by harry » Wed Nov 23, 2005 6:02 am

Hello empeda
I know there is more than 9 super clusters.
But! for now the super clusters of galaxies is quite different to normal clusters.
Our local cluster contain 35 galaxies and forms a unit, which belongs to part of a super cluster, its these super clusters that are important to find.
If you have found billions i like to know where.
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Post by Empeda2 » Wed Nov 23, 2005 12:25 pm

Billions may have been an exagerration - try millions:

http://www.anzwers.org/free/universe/universe.html

Incidently - this is a well cool map that I think everyone would be quite interested in 8)
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Post by makc » Wed Nov 23, 2005 1:02 pm

Empeda2 wrote:http://www.anzwers.org/free/universe/universe.html

Incidently - this is a well cool map that I think everyone would be quite interested in 8)
together with this it gives you whole idea: http://www.anzwers.org/free/universe/stardist.html

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Post by harry » Thu Nov 24, 2005 5:03 am

Hello empeda

Thank you for the map, niceeeeeeeeee
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Post by Helena » Tue Nov 29, 2005 4:48 pm

Empeda2 wrote:The point is that we cannot say that we are expanding into anything - the current inflation model suggests that 'our' universe is massively bigger than the 'visible' universe anyway.
Hi Empeda,

Thanks for your msg.. and I don't understand the inflation concept, could you explain it 'briefly'? and why 'our' universe is massively bigger than the 'visible' universe?

Thanks!

P.S. I'm new to this forum, though I knew the APOD site about a year ago, so 'Hi' to all other ppl here :)

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Post by Empeda2 » Tue Nov 29, 2005 5:30 pm

Hi Helena and Welcome!

Right, inflation in a nutshell attempt :?

The comic microwave background (CMB) of our universe is a remnant from when the universe became "see-through" about 300,000 after the big bang. The problem with it is that it displays a symmetry that cannot be accounted for - i.e. if you look in one direction it's displays symmetry with itself in completely the other direction.....

This is fine, except that we can "see" 13 billion light years, so the CMB we are looking at the 13 billion years old. In the big bang model, the universe itself is about 13 billions years old. But, the CMB is one direction is separated from the CMB in the other direction by 26 billion light years.

What that means is that the two cannot have come into 'causal' contact within the life span of our universe, so how can the symmetry have formed?

This is when inflation comes in. A few milliseconds after the big bang, the model states that the universe started a rapid expansion - an expansion much faster than light - that 'blew up' the universe like a bubble.

Since the universe is 13 billions years old, we can only see 13 billion light years, but if there is symmetry in the CMB, this implies that there is plenty more universe beyond our sight - we just can't see it as when we look great distances, we are looking back in time, so we cannot see anything further than ~13 billion light years.

I hope that makes a little sense. :?
Basically, in order to account for an observation of the CMB, cosmologists had to include this rapid inflation period into the big bang in order to explain the observation.

Now of course, they are linking that to dark matter as welll...... :!:
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Post by gordhaddow » Wed Nov 30, 2005 3:10 am

Maybe what we see 13b l/y to the right is EXACTLY what we see 13b l/y to the left? Are we 'living' in a Klein bottle?
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Post by Empeda2 » Wed Nov 30, 2005 9:34 am

It's certainly a possibility, though it's only the CMB that behaves like this - the distribution of galaxies doesn't as far as I know.

Hey, if we look far enough we might see ourselves 8)
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Post by makc » Wed Nov 30, 2005 2:03 pm

Empeda2 wrote:Hey, if we look far enough we might see ourselves 8)
Only if we'll live another 26b years.

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Post by harry » Thu Dec 01, 2005 1:11 am

hello to all

The recent findings has put the Big Bang on the burner.

As for seeing ourseleves forget it, 26 or 100 billion no way. Unless you see a reflection.

We are now going through some important findings, when the dust settles we shall see new models maybe old ones or a combination.

Keep Cool
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Post by Empeda2 » Thu Dec 01, 2005 9:27 am

My personal opinion is that we'll probably see a combination of a lot fo things - just like most other theories :D
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harry
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Post by harry » Fri Dec 02, 2005 8:27 am

I see the model as a big square block of rock.
If we chip away at it one day we shale see its form.
Harry : Smile and live another day.

Empeda2
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Post by Empeda2 » Fri Dec 02, 2005 12:25 pm

harry wrote:I see the model as a big square block of rock.
If we chip away at it one day we shale see its form.
Hey Harry - I think you and me are actually in total agreement on that one!!!
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harry
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Post by harry » Fri Dec 02, 2005 10:15 pm

smile yes.

As for the other ideas it is not that I disagree. Its just in my nature to go on a limb. I look at all ideas with an open mind.
Harry : Smile and live another day.

Empeda2
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Post by Empeda2 » Mon Dec 05, 2005 4:34 pm

Yep, I agree with that statement too. We have to probe and make sure not to close off too abruptly. 8)
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Post by Helena » Mon Dec 05, 2005 5:23 pm

Empeda2 wrote:What that means is that the two cannot have come into 'causal' contact within the life span of our universe, so how can the symmetry have formed?

Basically, in order to account for an observation of the CMB, cosmologists had to include this rapid inflation period into the big bang in order to explain the observation.

Now of course, they are linking that to dark matter as welll...... :!:
Hi Empeda2

Thanks very much for your reply...

I can understand that our universe that our universe may be '26 billion light year', but i don't understand that why there is a symmetry as mentioned and why such symmetry require "casual contact of two" as suggested? also, how the CMB lead to the condition that we must have an inflation period after the big bang?

sorry if I have too many questions to ask. :shock: