How is space expanding ?

[Spyman]

There seems to be a lot of threads discussing dark energy and dark matter, but non about how, in what way, space is expanding.

(Or have I missed someone ?)

 

When space expands, is it known if the space is streatching or new space is inserted ?

[BlackHole]

No one knows. Cosmologists are convinced that there's a mysterious 'force' or 'dark energy' which is pushing the galaxies apart. Therefore it is reasonable to think that dark energy is causing space to expand (like a balloon) and when space expands, dark energy is created.

 

Take note that all this could also hint to a failure of general relativity on very large distances.

[Cadmus]

When space expands, is it known if the space is streatching or new space is inserted ?

I think that a good, though not exact, analogy is a rubber band. As a rubber band is stretched, there is no increase in matter. The band expands. I think that whatever you might mean by new space is inserted, you should probably drop the idea.

 

One of the most important questions outstanding is whether the unverse, like a rubber band, will eventually reach the end of its expansion and return to its starting condition.

 

As scientists look to new distances in space, they get the impression that the rate of expansion is much greater at great distances. Scientists want to label such phenomema, but with the wisdom to realize that they really have no idea what is going on and that they should use a modern naming convention to make that fact explicit, they use the label dark to represent the fact that terms such as dark matter and dark energy are names of poorly understand packets of bahavior.

[Jacques]

Compare the volume of expanding space to the volume of stationary and contracting space. Stationary space is inside the galaxie cluster where the space does expand. Contracting space are more near the galaxies nucleus.

That proportion may suggest that the normal thing is expanding space ?

Many scientist told if there was no motion nothing would hapen or something like this. Motion is space over time. Space is only an aspect of that universal motion. Space cannot exist without time and time can not exist without space. Gravity is simply the opposite motion of the expansion.

Just some thougth

[H2SO4]

i thought it was because it was still expanding because of the kinetic energy the big bang created. we (humans) say one day it will finaly stop and beggin to decrease, and eventualy implode and thus creating another big bang

[Jacques]

H2SO4 To explain the expansion of the universe cosmologistes concluded that the only way to explain that strange phenomena is the bigbang. Like you said the recession is kinetic motion from the big bang. That was a good way to explain the observed motion, until the supernova This thread explain better than me:

The accelerating universe - Cosmic inflation

For the big crunchs it is happening right now at the center of each galaxies.

 

Other theories explain the redshift in the spectrum of galaxies: gravity redshift, tired light etc where not accepted by the scientific community. Do some google and you will find a lot alternate cosmology.

Two years ago I did some search and I found one theory of every thing that looked very logical and was making a lot of senses. I read ther books and the more I was reading the more I was making sense. It start from two postulates and developed a theorical universe that look very similar to the real one from the photon, the atom and molecule and up to the galaxies...

Some parts of the development where not very clear and I found some problems in the theory. Other person found the same problem and developped the second version. By clarifying the nature of the photon some of the problems where solved.

Now I try to see if the most interesting concept can make sense to others persons who tries to understand the universe.

I know this is not an alternate science site, that's why I post here to get a scientific opinion.

[star dust]

at the moment there isn't enough matter acounted for in the universe to create the strong forces of gravity needed for the "big Crunch" to occur, and so consequently it may not even happen and the universe continue to expand (steady state theory) however i dont believe this. Dark matter must exsist in our universe somewhere...matter sucked into a black hole for instance, whole galaxies could have imploded in on themselves way back when the universe was "born".

 

thats just my thoughts...

[Klaynos]

I read something a couple of months ago that was something like if we are wrong about the nutrino decay time by a small amount then dark energy isn't required by current theories, and that there is some evidence now that we are wrong about said time.

[J.C.MacSwell]

at the moment there isn't enough matter acounted for in the universe to create the strong forces of gravity needed for the "big Crunch" to occur' date=' and so consequently it may not even happen and the universe continue to expand ([b']steady state theory[/b]) however i dont believe this. Dark matter must exsist in our universe somewhere...matter sucked into a black hole for instance, whole galaxies could have imploded in on themselves way back when the universe was "born".

 

thats just my thoughts...

 

The steady state theory (read model/s) has no big bang. One model had continuous creation of matter to balance the expansion, thus creating a steady state.

[Cadmus]

Dark matter must exsist in our universe somewhere..

The word dark does not mean that we can't see it. It means that we do not understand the phenomenon involved. Dark matter is a name for a phenomenon that scientists think that they see but cannot account for.

 

To account for the missing mass, consider that we can only see light from about 15 billion years away. Anything farther away in space would not be visible, and this could account for most of the universe.

[Spyman]

Thanks for all your answers !

 

I liked the analogy about the rubber band, Space is stretching like a rubber band so lenght grows, so lets continue with it.

 

If space is stretching then how can space bring the matter with it, space has no friction ?

Or is it the other way around, matter is moving away from us very fast and stretches the space behind them ?

With matter I mean other galaxies moving away from us with what looks like higher speed than light.

[Cadmus]

I liked the analogy about the rubber band' date=' Space is stretching like a rubber band so lenght grows, so lets continue with it.

 

If space is stretching then how can space bring the matter with it, space has no friction ?[/quote']You are separating matter from space. Space is not a container for matter. Space is the matter.

[Spyman]

You are separating matter from space. Space is not a container for matter. Space is the matter.

I thought matter was things that could be touched and space was the emptyness between the things.

[Cadmus]

I thought matter was things that could be touched and space was the emptyness between the things.

There is no such thing as "space". There is only space-time. Everything that exists, in the form that you call matter, is space-time. There is no "emptiness".

[Spyman]

There is no such thing as "space". There is only space-time. Everything that exists, in the form that you call matter, is space-time. There is no "emptiness".

I must admitt that at first I thought You where joking, but after reading Your posts in the "Location of Big Bang?" thread I recognized that this is Your belief. I respect Your belief, but I don't share it.

 

Although I think I understand how it answers my questions, Thanks.

[The Holy Mol]

I think it's also important to note that not only is the universe expanding but the expansion is accelerating.

 

If I'm incorrect please correct me!

[Johnny5]

I think it's also important to note that not only is the universe expanding but the expansion is accelerating.

 

If I'm incorrect please correct me!

 

That is the fact which is setting everyone wild these days.

 

Actually let me modify this somewhat.

 

It's not space that is expanding, the matter is moving away from the center of mass of the universe at an accelerated rate, rather than a constant one.

 

You say tomAto I say tomahto kind of thing.

[Spyman]

It's not space that is expanding, the matter is moving away from the center of mass of the universe at an accelerated rate, rather than a constant one.

I thought it was from our point of view the matter is moving away at an accelerated rate in all directions...

Is this an optical illusion or are we in the center ???

And if this is an optical illusion then way can't the expansion also be an illusion ?

[swansont]

I thought it was from our point of view the matter is moving away at an accelerated rate in all directions...

Is this an optical illusion or are we in the center ???

And if this is an optical illusion then way can't the expansion also be an illusion ?

 

Realize that Johnny5 does not agree with relativity, so his posts relating to the topic need to have a permanent "not to be confused with mainstream physics" disclaimer on them.

[ed84c]

I thought it was from our point of view the matter is moving away at an accelerated rate in all directions...

Is this an optical illusion or are we in the center ???

And if this is an optical illusion then way can't the expansion also be an illusion ?

 

Heard of the Drunken Ballon Blower's Balloon Model.........?

[Spyman]

Realize that Johnny5 does not agree with relativity, so his posts relating to the topic need to have a permanent "not to be confused with mainstream physics" disclaimer on them.

I have realized that Johnny5, Cadmus and others have different opinions that are not "mainstream", that is to be expected in an open forum.

 

My own posts should also be marked in some way, not because I am against the mainstream but for I am still trying to understand and learn what the mainstream are.

 

If everybody should agree then I guess it would be boring, and when people don't - who is the one to trust ?

 

Thus I try to be open minded and draw my own conclusions from several posters/answers if they are able to convince me.

(Which You should know by now is not impossible but not so easy either. )

[Spyman]

Heard of the Drunken Ballon Blower's Balloon Model.........?

Nope, but I have read about several balloon analogies, which all have in common that they create an optical illusion of the Earth in center of the Universe.

[Spyman]

So could someone give me an "mainstream" answere to this question ?

If space is stretching then how can space bring the matter with it' date=' space has no friction ?

Or is it the other way around, matter is moving away from us very fast and stretches the space behind them ?

With matter I mean other galaxies moving away from us with what looks like higher speed than light.[/quote']

[Johnny5]

So could someone give me an "mainstream" answere to this question ?

 

Originally Posted by Spyman

If space is stretching then how can space bring the matter with it, space has no friction ?

Or is it the other way around, matter is moving away from us very fast and stretches the space behind them ?

With matter I mean other galaxies moving away from us with what looks like higher speed than light.

 

As swansont correctly pointed out, I do not share the mainstream view of special relativity. It is clear that I don't, no disclaimer is necessary.

 

Now, I do not know GR, so I am not the best person in the world to answer this. However, I do have execellent spatial reasoning ability, and I think I understand your question, but first I have to make sure. I want to try and answer it, because the subject matter interests me.

 

Ok so...

 

Let it be stipulated to be true, that space expands in the sense associated with the General theory of relativity.

 

First I want to understand your question, I don't want to answer a different question, I want to answer yours.

 

Let us call any reference frame at rest on the surface of the earth, an earth frame.

 

So observatories are earth frames.

 

We could also reference observations of distant galaxies to the location of the hubble telescope, and call such frames hubble telescope frames.

 

Or we could reference our observations to a frame in which the center of our solar system is at rest, and call them solar reference frames.

 

The mathematical description of the motion is going to have varying complexity, depending on which frame we choose. When actual measurments are made in one of the frames, we have no recourse but to use that frame.

 

Now I think that the idea that space is expanding, has recently been bolstered by the discovery that distant galaxies are accelerating away from us. I need to be corrected if that's wrong.

 

And I also think this, that General relativists explain that acceleration by saying that "the rate of expansion of space is accelerating"

 

So now, to your question...

 

You ask, if space is expanding, how does it "grip the material" and pull the center of mass of the material with it.

 

Did I understand your question right?

[ed84c]

Nope, but I have read about several balloon analogies, which all have in common that they create an optical illusion of the Earth in center of the Universe.

Thats the base of it yes