Size Of The Universe

[Ascended]

Do we have a viable theory as to why the universe is its current size?, I mean I've heard of theories of expansion suggesting that the rate of expansion hasn't always been constant and indeed the universe has gone though periods of more rapid expansion, if this is indeed so do we have any theories of why this may have been?

[Village Idiot]

I've heard of theories of expansion suggesting that the rate of expansion hasn't always been constant and indeed the universe has gone though periods of more rapid expansion, if this is indeed so do we have any theories of why this may have been?

 

Dr. Kaku has pointed out to TV viewers that acceleration of the universe would happen if gravity were fading away. An equivalent phenomenon to that one would be if proton annihilations were to be outstripping electron annihilations. I did not add "or vice versa" because do not suppose that to be happening.

Edited December 7, 2012 by Heedless

[sanctus]

First of all "size of the universe" should be rephrased to "size of the observable universe"... on the part we can not observe we can't say much, or we can but it is not science since we cannot falsify an assumption which we have no means to verify...

 

The theory you are looking for is called [math]\Lambda[/math]CDM being the standard model of Cosmology. Just look it up on wiki or elsewhere...

 

Basically you had the big bang, then a period of exponential expansion (inflation), then a radiation dominated universe, then matter dominated and then (in this theory) a dark energy dominated universe (which again gives rise to accelerated expansion).

[Guest MacPhee]

First of all "size of the universe" should be rephrased to "size of the observable universe"... on the part we can not observe we can't say much, or we can but it is not science since we cannot falsify an assumption which we have no means to verify...

 

The theory you are looking for is called [math]\Lambda[/math]CDM being the standard model of Cosmology. Just look it up on wiki or elsewhere...

 

Basically you had the big bang, then a period of exponential expansion (inflation), then a radiation dominated universe, then matter dominated and then (in this theory) a dark energy dominated universe (which again gives rise to accelerated expansion).

 

The word "size" implies a comparison. For example, we may compare the size of the Earth and the Moon. The Earth is clearly bigger - it has a bigger "size". Two entities - Earth and Moon, one bigger, one smaller.

 

But in the case of the Universe - how can we make such a comparison? The Universe is a single entity - it's "all there is". It contains everything -by definition. There can be nothing outside it. No different body, or entity, to compare it with.

 

So if we say the Universe is increasing in "size", what does it mean?

[blamski]

 

So if we say the Universe is increasing in "size", what does it mean?

 

that its bigger than it was? we compare it to itself if a comparison is necessary.

[Pmb]

The word "size" implies a comparison. For example, we may compare the size of the Earth and the Moon. The Earth is clearly bigger - it has a bigger "size". Two entities - Earth and Moon, one bigger, one smaller.

We compare the size of the universe with length standards defined on Earth.

 

But in the case of the Universe - how can we make such a comparison?

Since the Earth is in the universe just as we are there are no problems with a standard of length).

 

The Universe is a single entity - it's "all there is". It contains everything -by definition.

It is quite forseeable that there are parallel universes. The universe is not defined as "all that exists" but is defined as "all the space that is reachable from any other place in the universe by a continuous line. Since such a line cannot reach parallel universes and those other units might have other stuff in it then we can't say that the universe contains everything by definition.

 

There can be nothing outside it. No different body, or entty, to compare it with.

There is a counter example of this on my website. Please see the diagram at

http://home.comcast.net/~peter.m.brown/religion/the_word_god.htm

 

(ignore the content of the page and condentrate only on diagram at the bottom.

 

So if we say the Universe is increasing in "size", what does it mean?

It's like an infinite sheet of rubber. One can easily imagine coordinate axes drawn on the surface and the distance between the lines increaseing with time. Think of a cloed universe. It's like the surface of a ballon. A spatiallyclosed universe is like the surface of a ballon. An increasing in size universe is like blowing the balloon up with air.

 

There are two possible scenarios (a) the universe is spatially closed or (2) the universe is spatially open. An open universe means that the universe is finite in spatial extent whereas to be closed means to be of infinite spatial extent. A geometric plane is an example of an open space whereas the surface of a sphere is an example of a closed space. These examples are quite often used as analogies so I'll use them in this post as analogies too.

 

The spatially open universe is infinite in size. A spatially closed universe is finite in size. A person in a closed universe is like an ant walking on the surface of a sphere. Since an ant can make measurements on the sphere (the length of the ant namked "Frank" is used as the unit length). We can then easily define the size of such a universe as well as the area on the surface

[Natural]

Do we have a viable theory as to why the universe is its current size?, I mean I've heard of theories of expansion suggesting that the rate of expansion hasn't always been constant and indeed the universe has gone though periods of more rapid expansion, if this is indeed so do we have any theories of why this may have been?

I have a few questions for you to ponder, and would welcome any attempts to answer, concerning the size and age of the universe and perhaps more aptly a question delving into the relationship between the size of the universe and the expansion of the universe starting with the big bang up until today. So let me start with a few accepted scientific observations.

Thanks to images like the "Hubble deep field" and others we can see "primitive" galaxies that appear to be about 14 billion light years away. (forgive me for rounding up) And it would appear that no matter which direction you look you can see just as far or maybe better put "far back in time".

The current line of thinking is that the universe started at a point and has been expanding outward for 14 billion years.

Since we have no way of knowing how much the universe expanded in the first "expansion phase", or for that matter even if "expansion" happened, it's probably pretty hard to say how big the universe is.

But the scientific community still holds to the idea that the universe is about 14 billion years old.

And two more obvious assumption to keep in mind are that the Earth is NOT the center of the universe. Meaning that even though we can see the same in all directions, the universe would not be "expanding away from us" but rather just expanding. And the universe is not a flat sheet of rubber but maybe more like an infinitely sized bowl of Jello.

So taking these observations and theories into consideration let me ask you the first question.

If the universe is only 14 billion years old how is it that you can look in opposite directions and still see 14 billion years into the past? (14+14=28)

Secondly, and in contradiction to the big bang theory, if we can look back in time 14 billion years and when we do we can see galaxies that are 28 billion light years apart, wouldn't the observations show that the farther back in time you look the farther apart the universe seems to be. Because when we look at galaxies 14 billion light years away we are seeing them "where" they were 14 billion years ago.

Plus the question that if the universe is truly expanding and we can see where the galaxies were 14 billion years ago, and we think that the expansion rate is increasing, wouldn't that mean that the galaxies that we see at 14 billion light years away now are actually (according to our time) 14+14 billion years away. ( plus whatever the increasing expansion rate is)

So instead of the universe being closer together the farther back in time you look, the observations would suggest that the farther back in time you look, the farther apart the galaxies are. (plus how far they have expanded in the 14 billion years that we cannot see) Which is the opposite of the singularity theory.

And I can hear some of you already saying... "space didn't exist before the big bang so it has expanded to where we see it now and that is why the galaxies are so far apart". But that is assuming that what you see is where they are now and that they have been expanding to that point from "the beginning". But what we see is not where they are now but where they were 14 billion years ago.

Any thoughts?

[Aethelwulf]

Using the General Theory of Relativity makes a limit on things as well. Computers can be built, designed specifically to understand the expansion - so we must have some kind of idea how old it is... 14 billion years, give or take a few billion.

[Natural]

Using the General Theory of Relativity makes a limit on things as well. Computers can be built, designed specifically to understand the expansion - so we must have some kind of idea how old it is... 14 billion years, give or take a few billion.

 

Thank you for your input but doesn't the universe limit relativity and not vise-versa? Plus computers only operate on mathematical calculations that were thought of and input by us mere humans. So the computer will only calculate our own formulas and not come up with new formulas of their own. (yet) ;)

So it would seem that our only answers will come from observation and then an attempt to understand what we have observed. Which as I pointed out shows the universe to be very far spread out 14 billion years ago.

Hopefully I can get some more thinkers to give their input on this tricky subject.

:)

[Lancewen]

Thank you for your input but doesn't the universe limit relativity and not vise-versa? Plus computers only operate on mathematical calculations that were thought of and input by us mere humans. So the computer will only calculate our own formulas and not come up with new formulas of their own. (yet) ;)

So it would seem that our only answers will come from observation and then an attempt to understand what we have observed. Which as I pointed out shows the universe to be very far spread out 14 billion years ago.

Hopefully I can get some more thinkers to give their input on this tricky subject.

:)

 

This is always an interesting topic. When I think in terms of the universe ( I like to think of it as the local universe). We know it had a starting time which means it will have an ending time. That sounds a great deal like the nature we know and love. So now if our local universe is natural, it becomes reasonable to assume it's only a part of a much larger system that is beyond our capabilities to perceive. As a part of a much larger system, it also becomes reasonable to assume it's happened before, it may be happening now as other universes are being created as ours was and we can expect it to continue into the far future. Current belief says time started with the big bang, but I say that's only our time in the local universe. The larger structure that our universe was created in has it's own time.

 

If you spend much time thinking about infinity, it becomes apparent that what we call size is only meaningful from our point of view. The universe is very large from our limited point of view. But if we could expand our point of view so that our universe was small. What would the larger structure look like?

[sanctus]

Natural, a bit late replies.

If the universe is only 14 billion years old how is it that you can look in opposite directions and still see 14 billion years into the past? (14+14=28)

The easy way to imagine this is, two points touching at time zero and then exapnding/moving away in two opposite directions, then you wait 14 billion years and in the two diections you will see 14 billion years into the past when you see this 2 points....so no need for 28 billions.

 

Secondly, and in contradiction to the big bang theory, if we can look back in time 14 billion years and when we do we can see galaxies that are 28 billion light years apart, wouldn't the observations show that the farther back in time you look the farther apart the universe seems to be. Because when we look at galaxies 14 billion light years away we are seeing them "where" they were 14 billion years ago.

 

Why? seems exactly the opposite to me. We see them where they were 14bill. years ago that's right. What do you not consider is that the universe stretched and also the light we receive today from this two galaxies underwent this stretching and distances etc too....so in order to see them today they had to be much closer back then...

 

 

Plus the question that if the universe is truly expanding and we can see where the galaxies were 14 billion years ago, and we think that the expansion rate is increasing, wouldn't that mean that the galaxies that we see at 14 billion light years away now are actually (according to our time) 14+14 billion years away. ( plus whatever the increasing expansion rate is)

 

Hope that helps a bit

Yes, and even more funny they might even retreat quicker than light from us (their peculiar velocity (always<c)+ space expansion).

[Guest MacPhee]

This idea that the Universe is "expanding". Where does it come from? Isn't it only from prisms.

Prisms show a "redshift" in the light from a galaxy. Which apparently means the galaxy is moving further away.

 

But might it not be just an artifact of the prism? I mean prisms are just triangular lumps of glass. And glass can produce all kinds of illusions.

 

For example, consider a pair of binoculars, with their glass lenses. When you look through them in the normal way - ie through the eyepieces - everything looks bigger. However suppose you turn the binoculars round, and look through them the other way - ie through the object glasses. That makes everything seem smaller.

 

The glass makes things change their appearance. But the things don't really change size, it's just an illusion produced by glass.

 

So could our glass prisms, be giving us illusions?

Edited March 14, 2013 by MacPhee

[Lancewen]

Natural, a bit late replies.

 

The easy way to imagine this is, two points touching at time zero and then expanding/moving away in two opposite directions, then you wait 14 billion years and in the two directions you will see 14 billion years into the past when you see this 2 points....so no need for 28 billions.

 

The one problem with this point of view is I doubt if we are at the center of the universe, but we can still only see galaxies at 14 billion light years in all directions. So how would you account for that?

 

Why? seems exactly the opposite to me. We see them where they were 14bill. years ago that's right. What do you not consider is that the universe stretched and also the light we receive today from this two galaxies underwent this stretching and distances etc too....so in order to see them today they had to be much closer back then...

 

That's true, but once the light from any source in the universe reaches us, it will always continue reaching us until it's no longer a light source.

 

Hope that helps a bit

Yes, and even more funny they might even retreat quicker than light from us (their peculiar velocity (always<c)+ space expansion).

 

No matter how fast a light source is moving away from us (even at FTL speeds), once the photon is released (at that point in space wherever that may be) it will travel at the speed of light until it reaches us however long that may take. (Or how red shifted it may be when it gets here). One might ask can light be red shifted enough to become completely undetectible by our instruments?

[Turtle]

This idea that the Universe is "expanding". Where does it come from? Isn't it only from prisms.

Prisms show a "redshift" in the light from a galaxy. Which apparently means the galaxy is moving further away.

 

But might it not be just an artifact of the prism? I mean prisms are just triangular lumps of glass. And glass can produce all kinds of illusions.

 

For example, consider a pair of binoculars, with their glass lenses. When you look through them in the normal way - ie through the eyepieces - everything looks bigger. However suppose you turn the binoculars round, and look through them the other way - ie through the object glasses. That makes everything seem smaller.

 

The glass makes things change their appearance. But the things don't really change size, it's just an illusion produced by glass.

 

So could our glass prisms, be giving us illusions?

 

Are you aware that bincoculars have prisms?

 

 

Binoculars @ Wikipedia

 

Do you doubt what you see with bincoculars -size notwithstanding- when compared to your naked eye view?

 

There are no unintended or misunderstood "illusions" in our prisms. Physics is as Physics does. :smart:

[LaurieAG]

There are no unintended or misunderstood "illusions" in our prisms. Physics is as Physics does. :smart:

Hi Turtle,

 

But do we take these understood illusions into consideration in our observations? While Gunter Nimtz doesn't have many takers for his FTL explanation there is a potential for similar universal phenomena via nonlinear optics and simple emission structures viewed from a long distance over time.

 

http://en.wikipedia.org/wiki/G%C3%BCnter_Nimtz

 

If the basic atomic elements were generated progressively after the BB via early star/galaxy formation etc and the atomic table goes Hydrogen, Helium, Lithium and then Beryllium, all the components exist for short term distortions, based on non linear optics, of our current physical observations to the extent that our perceptions may be misplaced with regards to universal expansion etc.

 

http://encyclopedia2.thefreedictionary.com/Nonlinear+optics

 

The study of the interaction of radiation with matter in which certain variables describing the response of the matter (such as electric polarization or power absorption) are not proportional to variables describing the radiation (such as electric field strength or energy flux).

Edited March 15, 2013 by LaurieAG

[Turtle]

Hi Turtle,

 

But do we take these understood illusions into consideration in our observations? ...

 

 

 

Yes; it's called Optics.

 

Optics @Wikipedia [bolding Mine]

Optics is the branch of physics which involves the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it.^[1] Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Because light is an electromagnetic wave, other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties.^[1]

 

[LaurieAG]

Yes; it's called Optics.

Hi Turtle,

 

I suppose I didn't go into enough detail in my earlier post.

 

Beryllium is used to dope lenses and the Gunter Nimtz experiments prisms were heavily doped. As Beryllium, according to the BB theory, was produced after initial Hydrogen, Helium and Lithium production at a relatively fixed period after the BB could not the structure of these short lived clouds, when light waves passing through them were collected over large distances, actually behave like doped lensing structures? i.e. in both the micro and the macro.

 

The most distant galaxies that have been imaged are irregular and not oval or circular in shape so there is potential for optical vortex/laser structures.

 

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

http://wwwrsphysse.anu.edu.au/nonlinear/research/vortex/