Where are we

[Mordred]

The observable portion for total mass yes and the same for around BB. We have no idea beyond the observable.

To add to Delta1212 excellent post.

If we were to take the slight curvature we have from flat via the Planck 2012 dataset. Assuming expansion stopped.

 

If we were to fire a laser beam under that ever so slight curvature it would theotetically take 880 Billion years for the beam to return to its original point.

 

This is of course assuming expansion were to suddenly stop. This is the closest approximation we can infer for a finite universe. However it is based on curvature. The cosmological constant however indicates with curvature that our universe is unbounded. Meaning it will expand forever

Edited December 6, 2016 by Mordred

[imatfaal]

The observable portion for total mass yes and the same for around BB. We have no idea beyond the observable.

To add to Delta1212 excellent post.

If we were to take the slight curvature we have from flat via the Planck 2012 dataset. Assuming expansion stopped.

 

If we were to fire a laser beam under that ever so slight curvature it would theotetically take 880 Billion years for the beam to return to its original point.

 

This is of course assuming expansion were to suddenly stop. This is the closest approximation we can infer for a finite universe. However it is based on curvature. The cosmological constant however indicates with curvature that our universe is unbounded. Meaning it will expand forever

 

Mordred - you know these data far better than I do; didn't Planck allow for flat or +ly curved within the margin of error?

[Mordred]

That is correct, it favored flat but still allowed for the possibility of a positive curvature under msrgin of error. Though that 880 Gly figure came from the collected data from Planck and the South pole Observatory on a paper published shortly after the 2012 results. I came across the paper while I was still active on Physicforums. It was one of the discussions we had there.

 

Unfortunately I never kept a copy of that paper but if you would like to read it I could search the threads I was involved in there. Though it would take some time.

Edited December 7, 2016 by Mordred

[Airbrush]

We have no idea beyond the observable.

 

I often hear this, but it is a slight exaggeration. We DO have ideas beyond the observable. As an non-expert I would dare to suggest that immediately beyond the edge of the observable universe is much more of the same. Probably much more of the same for quite some distance.

 

Other than that, you know far more about this subject than I do. Thank you.

[Mordred]

Yes correct I mentioned indirect thermodynamic evidence earlier this thread.

Good question. The answer surprisingly is yes to a certain extent. To understand that you can examine expansion itself. If the region immediately outside or observable portion had a different mass distribution. Ie one greater or less mass average per volume. This would influence our observable portion by causing a preferred direction to expansion.

 

Ie you would have an effective pressure gradient. So if the pressure outside our OU. Is less than our OU expansion will be anistropic. Same if the pressure is greater it would essentially compress our OU.

 

As we do not see any anistropy in expansion we can safely assume it has the same mass distribution as our observable portion.

 

Lol you have no idea just how many altetnative models get overthrown by not being able to maintain the cosmological principle.

 

However there is a limit to how far we can apply this. For example if your far enough away from our OU that there can never be any possible causal connection. You can have a completely different dynamic that will never influence our OU.

Edited December 8, 2016 by Mordred

[36grit]

They can infer from reversing the rate of expansion and distances between galaxies how long ago it was that they were all physically connected into a dense mass.

So, when people talk about the age of the universe they are really only talking about the age of the observable universe, correct?

[Mordred]

technically yes this is correct we can only approximate how our observable portion evolves over time

Edited December 9, 2016 by Mordred

[StringJunky]

technically yes this is correct we can only approximate how our observable portion evolves over time

Based on the observable universe being isotropic and homogenous, we assume the rest evolves the same though, do we not?

[Mordred]

Correct provided its within a possible causal connection to our OU. Think of two observable universes overlapping. If there is an overlap you have a causal connection. However only in the overlapped regions. That's your causal connected region.

Edited December 9, 2016 by Mordred

[StringJunky]

Correct provided its within a possible causal connection to our OU. Think of two observable universes overlapping. If there is an overlap you have a causal connection. However only in the overlapped regions. That's your causal connected region.

Right.

[Sriman Dutta]

Our address should be-

 

The Earth,

The Solar System,

Near the planet Mars,

Surrounded by Kuiper Belt,

In the Milky Way Galaxy,

In the Universe,

PIN Code: x,y,z,t

[Mordred]

Our address should be-

 

The Earth,

The Solar System,

Near the planet Mars,

Surrounded by Kuiper Belt,

In the Milky Way Galaxy,

In the Universe,

PIN Code: x,y,z,t

😅😂😂😂

 

Good one +1

 

But first you gotta agree where coordinate (0,0,0,0) is lol

Edited December 9, 2016 by Mordred

[Sriman Dutta]

Thanks Mordred

[Airbrush]

But first you gotta agree where coordinate (0,0,0,0) is lol

 

IF the universe is finite and bounded, then there is a center (0,0,0,0) and our address would be (x,y,z,t).

[Mordred]

If the universe is finite and bounded yes.

[36grit]

Does the depth of the micro wave back ground's depth resemble the dark matter structure of the universe?

 

Is the observable universe still producing hydrogen? Oxygen?

 

Are we sure the universe doesn't have a geometrical center point? I could see where it might be hard to find with all that bending and twisting of time and space out there, and we all seem to believe that it came from a single point expanding outwards in all directions. and the microwave background does look like the inside of a pea, howbeit a really really big pea now.

 

It just really seems to me that an alien half a universe to the left of us. would see the mass from the "north and south" poles of our inner sphere to the left of his, as stars of course. Distance is relative to position in this scenario. a finite universe of infinite expansion.

 

Or, The stars on his left are from another universe all together, because they exist beyond our cosmic microwave's edge. This seems to suggest that, there were many, many bangs, perhaps even every single point through out all of eternity banged, with the exception of black holes. The age of this universe would be relative to a beings position.

[imatfaal]

That is correct, it favored flat but still allowed for the possibility of a positive curvature under msrgin of error. Though that 880 Gly figure came from the collected data from Planck and the South pole Observatory on a paper published shortly after the 2012 results. I came across the paper while I was still active on Physicforums. It was one of the discussions we had there.

 

Unfortunately I never kept a copy of that paper but if you would like to read it I could search the threads I was involved in there. Though it would take some time.

 

No thanks - would almost certainly be above my head. Thanks anyway

[StringJunky]

 

No thanks - would almost certainly be above my head. Thanks anyway

You don't fancy a cognitive seizure?

[imatfaal]

You don't fancy a cognitive seizure?

 

Been stuck in one of those since 1993!

[36grit]

Perhaps the universe is infinite, and I believe it is. But this seems to suggest that the big bang came from an infinite source of energy, and if that is true then the universe should still be banging, and that somewhere on the edge of expansion planets and stars are still being born.

And many other things like, The expansion is causing an inward force and that our visible universe has some uniform like pressure regulating it's expansion, and that our visible universe maybe pitching in and helping the edge to expand.

The thought leaves me envisioning black hole fractals through out rings of realities, lol

The possibility of an infinite universe is a mind blowing concept. I know that it's been said that during the wee moments of the big bang that distance (space?) traveled faster than light, this may suggest the possibility that vacuum energy may be the result of distance stabilizing into a vector within the speed of light realm, that is to say, a point of electromagnetic possibility. And this tends to lead me to think that, algorithms of spin between these distance particles make up the normal matter that we are. They're local spin probably determines the local time, which is to say particles of distance govern time dilation. Hmmmm, Good enough for science fiction? Anyone? Trying to hit warp speed here : )

[StringJunky]

Perhaps the universe is infinite, and I believe it is. But this seems to suggest that the big bang came from an infinite source of energy, and if that is true then the universe should still be banging, and that somewhere on the edge of expansion planets and stars are still being born.

 

If the universe is infinite then it's always been around because it would take an infinite amount of time to become infinite in extent. It wouldn't have come from a source since it was always in existence. It is still banging; that's what the expansion is. There is no edge. If, as you say, you believe it to be infinite, how can it have an edge?

 

 

And many other things like, The expansion is causing an inward force and that our visible universe has some uniform like pressure regulating it's expansion, and that our visible universe maybe pitching in and helping the edge to expand.

The thought leaves me envisioning black hole fractals through out rings of realities, lol

The possibility of an infinite universe is a mind blowing concept. I know that it's been said that during the wee moments of the big bang that distance (space?) traveled faster than light, this may suggest the possibility that vacuum energy may be the result of distance stabilizing into a vector within the speed of light realm, that is to say, a point of electromagnetic possibility. And this tends to lead me to think that, algorithms of spin between these distance particles make up the normal matter that we are. They're local spin probably determines the local time, which is to say particles of distance govern time dilation. Hmmmm, Good enough for science fiction? Anyone? Trying to hit warp speed here : )

Your life would be far more enriching if you read some real science.

[Strange]

Perhaps the universe is infinite, and I believe it is. But this seems to suggest that the big bang came from an infinite source of energy, and if that is true then the universe should still be banging, and that somewhere on the edge of expansion planets and stars are still being born.

 

 

You are right that if the universe is infinite then it has always been infinite.

 

And it is still "banging" as the big bang is a description of the continuing expansion and cooling of the universe. (It is badly named in that sense; it is not a theory of creation of explosion.)

 

And, yes, galaxies, stars and planets are still being formed.

 

 

 

And many other things like, The expansion is causing an inward force and that our visible universe has some uniform like pressure regulating it's expansion, and that our visible universe maybe pitching in and helping the edge to expand.

 

Why would it cause an inward force? If you release the pressure on some gas it expands - it doesn't provide any inward force.

 

 

 

I know that it's been said that during the wee moments of the big bang that distance (space?) traveled faster than light,

 

As expansion means that speed is proportional to distance there are now, and always have been, places that are moving apart faster than the speed of light.

 

The rest of your post doesn't make much sense (see StringJunky's final point).

[Berj / KI3U]

Hi everyone

 

Interesting discussion. I was looking for it to continue a bit further (pun intended

 

Toward that end I'll try stir the pot a little : how about cosmological solitons ?

 

Solitons are pretty cool as regards their properties compared with ordinary waves in the same medium. So for instance

an acoustic soliton can travel faster than the ordinary speed of sound.

 

So what could we imagine for a cosmo-soliton that would make for interesting perspectives on the topics in this thread ?

 

Oh, and I do know where I am : I am home ;-)

 

Berj / KI3U

[Berj / KI3U]

So let us assume for a moment that - in the absence of compelling / convincing evidence that cosmological solitons are impossible, that cosmo-solitons are possible and do indeed exist. Then :

1.) cosmic information from beyond any "cosmological horizon" may traverse said horizon, including inbound.

2. hence there is no definitive cosmological horizon.

Berj / KI3U

[Strange]

Hi everyone

 

Interesting discussion. I was looking for it to continue a bit further (pun intended

 

Toward that end I'll try stir the pot a little : how about cosmological solitons ?

 

Solitons are pretty cool as regards their properties compared with ordinary waves in the same medium. So for instance

an acoustic soliton can travel faster than the ordinary speed of sound.

 

What medium are you imagining these waves travel through?