Universe Expanding

[RichardE]

Are there any theories about what the universe is expanding into?

 

[suszterpatt]

Infinite space?


I don't really understand the question.

 

[RichardE]

Originally posted by: suszterpatt
Infinite space?


I don't really understand the question.

Well, I understand I am just starting University next year, so I do not have knowledge on this subject at all, but solely from reading on physics ect, I wondered what exactly the universe is expending into?

IE, if you blow up a baloon it displaces the air around it as it expands, what is the universe displacing?

 

[DrPizza]

Just to be annoying.. someone posted this the other day...
We know the rate of expansion is *increasing* - which is quite mind boggling...
But, someone said suppose on the following, we're at point C
A---------------------------------------B----------C----------D
And, assume A is some incredible gravity well... The universe could be shrinking toward A, but we would observe B and D moving away from us (relatively speaking)

 

[RichardE]

Originally posted by: DrPizza
Just to be annoying.. someone posted this the other day...
We know the rate of expansion is *increasing* - which is quite mind boggling...
But, someone said suppose on the following, we're at point C
A---------------------------------------B----------C----------D
And, assume A is some incredible gravity well... The universe could be shrinking toward A, but we would observe B and D moving away from us (relatively speaking)

Unless it was spherical(which was shown to be false, and the current theory is the universe is flat), would you not see D moving towards you? Or, at least, D's distance would never change. The only thing I could think of is that we are anexing another matter, and the more we annex the easier it is, so in theory the expansion would increase.

 

[suszterpatt]

If by "the Universe" you mean matter of any kind, then by definition it's not displacing anything, it just moves through empty space.


However, I think what you're looking for is the dark matter hypothesis.

 

[jasonlclei]

Technically, the universe is supposedly "infinite." So it should be expanding into itself, infinity. Although this does not make much sense, it is how it is.

When the universe expands, it does NOT mean that the ends of the universe moves away, such as this:
A---B---C---D becoming A------B---C------D.

instead, all space expands:
A---B---C---D becoming A------B------C------D.

 

[RichardE]

Originally posted by: jasonlclei
Technically, the universe is supposedly "infinite." So it should be expanding into itself, infinity. Although this does not make much sense, it is how it is.

When the universe expands, it does NOT mean that the ends of the universe moves away, such as this:
A---B---C---D becoming A------B---C------D.

instead, all space expands:
A---B---C---D becoming A------B------C------D.

I understand that concept, but what is it expanding into? I mean

Say universe ends | 10 light years and it is now here |

^^^^^^^^^^^^^^^^^^^^^ What was in this space before the universe took it?

 

[suszterpatt]

Originally posted by: jasonlclei
Technically, the universe is supposedly "infinite." So it should be expanding into itself, infinity. Although this does not make much sense, it is how it is.

When the universe expands, it does NOT mean that the ends of the universe moves away, such as this:
A---B---C---D becoming A------B---C------D.

instead, all space expands:
A---B---C---D becoming A------B------C------D.

All within the reasonable gravitational limits of course. If I go up to the top of a cliff and throw something down, it sure as hell won't expand further away from the ground.

So A-----------B---C-----------D could become A---------------B-C---------------D, or even A---------------B---C---------------D for that matter (leaving only the ends moving away).

Nitpicking, I know.

 

[suszterpatt]

Originally posted by: RichardE
I understand that concept, but what is it expanding into? I mean

Say universe ends | 10 light years and it is now here |

^^^^^^^^^^^^^^^^^^^^^ What was in this space before the universe took it?

Nothing. Space can exist without the universe to fill it out (to my knowledge). In fact, space exists no matter what.

 

[RichardE]

Originally posted by: suszterpatt

Originally posted by: RichardE
I understand that concept, but what is it expanding into? I mean

Say universe ends | 10 light years and it is now here |

^^^^^^^^^^^^^^^^^^^^^ What was in this space before the universe took it?

Nothing. Space can exist without the universe to fill it out (to my knowledge). In fact, space exists no matter what.

If it is filling empty space would it not just fill it instantly instead of slowly? I mean, if it really is empty, there is nothing stopping it from filling in instataneously more or less rather than slowly increasing its expansion.

 

[suszterpatt]

Yes there is. Gravity for example. The speed of light being unpassable is another thing too. Just because there's no resistance, it doesn't mean that everything happens instantly.

 

[RichardE]

Alright, that makes sense, Gravity can hold it back so it is not instataneous, but why would it accelerate? I can't seem to fathom there being a massive region of nothingess after the edge (is that is a correct term) of the universe. Even when we though space was empty we theorized dark mater and dark energy.

 

[Raibeaux]

Wondering. Assuming the big bang from an infinitely compressed mass of....mass. The universe is expanding, but the rate of expansion is slowing. Wondering if in a gazillion millenia the universe reverses back to the same type of mass until ....BOOM, another big bang. Like a huge, super-slow pulse. If that's true, the universe would indeed be literaly alive in perpetuity. I always think of the universe as having no beginning, no end and no edges. Kinda weird.

 

[silverpig]

Originally posted by: DrPizza
Just to be annoying.. someone posted this the other day...
We know the rate of expansion is *increasing* - which is quite mind boggling...
But, someone said suppose on the following, we're at point C
A---------------------------------------B----------C----------D
And, assume A is some incredible gravity well... The universe could be shrinking toward A, but we would observe B and D moving away from us (relatively speaking)

Except that wouldn't work. If you looked in a direction not in line with our acceleration you wouldn't see the same effect, you'd see us moving closer to them. And then there's the CMB, you'd see a much larger dipole effect than we actually do.

 

[onezeroone]

Originally posted by: Raibeaux
Wondering. Assuming the big bang from an infinitely compressed mass of....mass. The universe is expanding, but the rate of expansion is slowing. Wondering if in a gazillion millenia the universe reverses back to the same type of mass until ....BOOM, another big bang. Like a huge, super-slow pulse. If that's true, the universe would indeed be literaly alive in perpetuity. I always think of the universe as having no beginning, no end and no edges. Kinda weird.

I too share this theory. Every observable process oscillates on some period, no reason to think the universe itself is any different. If the big bang theory is correct, then the only event that could have possibly preceded it, is the big implosion Perhaps someday people will argue about how many big bangs have occured, or if they can even be counted.

 

[DrPizza]

Originally posted by: silverpig

Originally posted by: DrPizza
Just to be annoying.. someone posted this the other day...
We know the rate of expansion is *increasing* - which is quite mind boggling...
But, someone said suppose on the following, we're at point C
A---------------------------------------B----------C----------D
And, assume A is some incredible gravity well... The universe could be shrinking toward A, but we would observe B and D moving away from us (relatively speaking)

Except that wouldn't work. If you looked in a direction not in line with our acceleration you wouldn't see the same effect, you'd see us moving closer to them. And then there's the CMB, you'd see a much larger dipole effect than we actually do.

I didn't say I believed him... I just reposted it to be annoying.

 

[Woodchuck2000]

Originally posted by: Raibeaux
Wondering. Assuming the big bang from an infinitely compressed mass of....mass. The universe is expanding, but the rate of expansion is slowing. Wondering if in a gazillion millenia the universe reverses back to the same type of mass until ....BOOM, another big bang. Like a huge, super-slow pulse. If that's true, the universe would indeed be literaly alive in perpetuity. I always think of the universe as having no beginning, no end and no edges. Kinda weird.

Equally, it's possible that the big bang is a one-off, freak occurrence which simply happened because something not happening was too unlikely. We're getting into the realms of metaphysics here where all (most) speculations are equally valid!

 

[silverpig]

Originally posted by: onezeroone

Originally posted by: Raibeaux
Wondering. Assuming the big bang from an infinitely compressed mass of....mass. The universe is expanding, but the rate of expansion is slowing. Wondering if in a gazillion millenia the universe reverses back to the same type of mass until ....BOOM, another big bang. Like a huge, super-slow pulse. If that's true, the universe would indeed be literaly alive in perpetuity. I always think of the universe as having no beginning, no end and no edges. Kinda weird.

I too share this theory. Every observable process oscillates on some period, no reason to think the universe itself is any different. If the big bang theory is correct, then the only event that could have possibly preceded it, is the big implosion Perhaps someday people will argue about how many big bangs have occured, or if they can even be counted.

Except it's not slowing. The rate of expansion is increasing. And not every observable process oscillates on some period. And, well there's a lot more... try googling for cosmology.

 

[Smilin]

Originally posted by: DrPizza

Originally posted by: silverpig

Originally posted by: DrPizza
Just to be annoying.. someone posted this the other day...
We know the rate of expansion is *increasing* - which is quite mind boggling...
But, someone said suppose on the following, we're at point C
A---------------------------------------B----------C----------D
And, assume A is some incredible gravity well... The universe could be shrinking toward A, but we would observe B and D moving away from us (relatively speaking)

Except that wouldn't work. If you looked in a direction not in line with our acceleration you wouldn't see the same effect, you'd see us moving closer to them. And then there's the CMB, you'd see a much larger dipole effect than we actually do.

I didn't say I believed him... I just reposted it to be annoying.

I was the one that posted it. Go lookup the original post if you would like to see it in context.

It would work actually. If you look in a direction exactly perpendicular to your direction of acceleration (plus or minus a certain angle) things will appear blue shifted. The "certain angle" will decrease the further the singularity gets from you. If it's an infinite distance away the slice of space that will be blue shifted by something other than local motion is infinitely thin.

That CMB crap keeps getting pulled out too. See original post.

The "mind boggling" part of expansion increasing at an accelerating rate is so very easily explained and not "mind boggling" at all if you are simply willing to believe the universe is collapsing. Everyone just sees red-shift and says "AHA! Expanding!". It's just as simplistic as people seeing the sun go across the sky and assuming it's orbiting around us.

 

[Smilin]

Originally posted by: RichardE
IE, if you blow up a baloon it displaces the air around it as it expands, what is the universe displacing?

Time.

 

[silverpig]

Originally posted by: Smilin
I was the one that posted it. Go lookup the original post if you would like to see it in context.

It would work actually. If you look in a direction exactly perpendicular to your direction of acceleration (plus or minus a certain angle) things will appear blue shifted. The "certain angle" will decrease the further the singularity gets from you. If it's an infinite distance away the slice of space that will be blue shifted by something other than local motion is infinitely thin.

That CMB crap keeps getting pulled out too. See original post.

The "mind boggling" part of expansion increasing at an accelerating rate is so very easily explained and not "mind boggling" at all if you are simply willing to believe the universe is collapsing. Everyone just sees red-shift and says "AHA! Expanding!". It's just as simplistic as people seeing the sun go across the sky and assuming it's orbiting around us.

Absolutely. That is how it WOULD look. But it doesn't. No matter what direction we look, we see redshift. Explain that.

CMB crap? You really need to read a bit about it. You can get a whole ton of information out of it.

 

[suszterpatt]

Originally posted by: Smilin

Originally posted by: RichardE
IE, if you blow up a baloon it displaces the air around it as it expands, what is the universe displacing?

Time.

My brain just exploded.

 

[Smilin]

Originally posted by: silverpig

Originally posted by: Smilin
I was the one that posted it. Go lookup the original post if you would like to see it in context.

It would work actually. If you look in a direction exactly perpendicular to your direction of acceleration (plus or minus a certain angle) things will appear blue shifted. The "certain angle" will decrease the further the singularity gets from you. If it's an infinite distance away the slice of space that will be blue shifted by something other than local motion is infinitely thin.

That CMB crap keeps getting pulled out too. See original post.

The "mind boggling" part of expansion increasing at an accelerating rate is so very easily explained and not "mind boggling" at all if you are simply willing to believe the universe is collapsing. Everyone just sees red-shift and says "AHA! Expanding!". It's just as simplistic as people seeing the sun go across the sky and assuming it's orbiting around us.

Absolutely. That is how it WOULD look. But it doesn't. No matter what direction we look, we see redshift. Explain that.

CMB crap? You really need to read a bit about it. You can get a whole ton of information out of it.

uh. The way I explained it WOULD look is "redshifted in every direction". What is it you want me to explain?

Ah! You want me to explain that the number of blue shifted objects in an infinitely thin slice of space = 0. Hence everything is red shifted. Was that the confusion? Mind you "infinitely thin" doesn't really mean the plane doesn't intersect an object. It's possible at close distances but at great distances the probability per object approaches zero. Of course that pretty much fits observation as well (only blue shifted objects in universe are nearby)

I say CMB crap because like in the other thread (where you said CMB was uniform btw) it was used in a context that has no relation to this explanation I've given.

As this is a theory I pulled out of my butt some years ago I'm certainly open to a rational reason why it couldn't be. Why do you think would we see a much larger dipole effect?

Just because this was pulled out ma butt doesn't mean it wasn't well thought out. I'm not going to say that I necessarily believe it, but I've discussed it quite a bit and haven't found a problem yet.

 

[Smilin]

Originally posted by: suszterpatt

Originally posted by: Smilin

Originally posted by: RichardE
IE, if you blow up a baloon it displaces the air around it as it expands, what is the universe displacing?

Time.

My brain just exploded.

2-D surface of a balloon = space without end but not infinite.
When expanding it is simply doing so by traveling into dimension #3 right?

Wouldn't then our 3D universe be expanding into dimension #4?

..

mmm, but where is the end of #4 then?
#5?

Kinda comes down to "where is the edge of the universe?". This is where: find the furthest most object then find the light that was emmited from it going outward. Catch up to and pass that light and you get to see what's outside the universe. Scary part is that when you look back the universe will simply appear to be a singularity as will anything if you travel far enough.