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Author Topic: Is spacial expansion really accelerating?  (Read 3364 times)

Offline kenhikage

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Is spacial expansion really accelerating?
« on: 07/10/2010 14:55:42 »
Please correct the error in my thinking. If there is more redshift as we look through space, and we are looking farther into the past at the same time, doesn't that mean that the past space was moving more quickly than the current?


 

Offline CPT ArkAngel

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Is spacial expansion really accelerating?
« Reply #1 on: 07/10/2010 17:19:17 »
You need specific data to conclude anything about the rate of expansion because it is not homogeneous.

You can be sure scientists who concluded that the rate of expansion is increasing did calculations relative to time references. But there is no way to have an instant picture of the Universe and the farther you look the more uncertainty you have... So, no one can be 100% sure...

(It is not spatial expansion but Universe expansion...)
 
« Last Edit: 07/10/2010 20:56:46 by CPT ArkAngel »
 

Offline kenhikage

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Is spacial expansion really accelerating?
« Reply #2 on: 08/10/2010 11:26:21 »
Quote
(It is not spatial expansion but Universe expansion...)

Can you differentiate the two for me? I thought it was the fabric of the Universe (space-time) that was expanding. That is to say, I didn't expect that the contents of the Universe (matter and energy... and the forces?) were also expanding.
 

Offline flr

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Is spacial expansion really accelerating?
« Reply #3 on: 12/10/2010 20:19:29 »

If the space is expanding, then it must be 'something' which own a property, rather than just a abstract geometric concept as I used to see it.

 

Offline Don_1

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Is spacial expansion really accelerating?
« Reply #4 on: 13/10/2010 11:43:09 »
Is the universe still expanding? I see no reason why not.

Is the rate of acceleration increasing? Again, I see no reason why not. If the universe is 13.7b years old, that, in cosmological terms, is not a very long time. But I do have a problem with the idea that the universe will continue to expand ad infinitum. This, for me, poses a question as great as any.

I can accept, to some extent, that the universe could continue to expand until matter is so sparse that gravity might cease to have any effect. But even here, I would think that there must be some bodies large enough to have influence over the remaining space dust. By the way, I do not have a problem with endless empty space, even though the concept is baffling.

But my big problem with this ever expanding universe is quite simply, what came before the big bang and why did it only happen 13.7b years ago? Why not 20b, 100b, 1,000,000,000,000,000,000,000,000 trillion years ago?

I just have to stick with the idea that the universe is cyclic. At some time in the far distant future all matter will begin to collapse in on itself and the big bang will happen again, just as it has happened over and over again in the past.
 

Offline Geezer

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Is spacial expansion really accelerating?
« Reply #5 on: 13/10/2010 21:09:01 »
I can accept, to some extent, that the universe could continue to expand until matter is so sparse that gravity might cease to have any effect. But even here, I would think that there must be some bodies large enough to have influence over the remaining space dust.

It may be even worse than that. Some theories conclude that atoms disintegrate, in which case there won't even be any dust.
 

Offline Don_1

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Is spacial expansion really accelerating?
« Reply #6 on: 14/10/2010 09:08:58 »
If it is true that the rate acceleration of universe expansion will continue, then the matter at the outer reaches of the universe will have, or will at some time, reach or exceed the speed of light, in which case any such matter can never be observed. This would suggest that the universe could be far more than 13.7b years old already, would it not?
 

Offline Ethos

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Is spacial expansion really accelerating?
« Reply #7 on: 14/10/2010 11:05:32 »
There are several points of view regarding these questions but none satisfy my personal instincts as yet. It seems very possible to me that the so-called "Big Bang" is nothing more than a local event in a much larger and very likely infinite space. And when I use the term; "Local", who's to say when considering the infinite that what we observe is too large to be only local????

Perhaps the "Big Bang" we observe is only one of many in an infinite space and is only visable to us because of the vast distances involved. Unlike The Standard Model, I see no need for a "Big Bang" to create space, I believe space can exist without such an event.

Space is just an infinite void where matter and energy find a place to exist. Space is without borders and endless................Ethos

 

Offline Joe L. Ogan

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Is spacial expansion really accelerating?
« Reply #8 on: 14/10/2010 18:10:50 »
Well, who is to say.  Perhaps everything has a beginning and an end.  Just because we can not see it or identify it does not mean that it doesn't exist. Thanks for comments.  Joe L. Ogan
 

Offline daveshorts

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Is spacial expansion really accelerating?
« Reply #9 on: 15/10/2010 13:25:11 »
Please correct the error in my thinking. If there is more redshift as we look through space, and we are looking farther into the past at the same time, doesn't that mean that the past space was moving more quickly than the current?
It means that the further away you look the faster the object was moving relative to you now, when the light was emmitted.

This is entirely consistent with any (sane) expanding universe model, you don't need the universe to be accelerating for it to work. If you are in a normal explosion sitting on a fragment, the further away you look the faster the fragments are moving relative to you, wherever you are sitting, even if all the fragments are going at a constant speed..
 

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Is spacial expansion really accelerating?
« Reply #9 on: 15/10/2010 13:25:11 »

 

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