What Is Beyond The Observable Universe?

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The discussion centers on the nature of what lies beyond the observable universe, with participants debating whether it is simply empty space or if other universes exist. Many express skepticism about the idea that our universe is the only one, suggesting a multiverse or infinite cosmos. The concept of 'nothingness' beyond the observable universe is contested, with some arguing that the unobservable remains irrelevant to our understanding of the universe. The conversation also touches on the limitations of current scientific models, particularly regarding the conditions before the Big Bang and the implications of cosmic expansion. Ultimately, the topic straddles the line between scientific inquiry and philosophical speculation.

What Is Beyond The Observable Universe?

  • Just Infinite Black Space

    Votes: 27 13.6%

  • Blacks Space Until A Different Universe

    Votes: 36 18.1%

  • Other

    Votes: 136 68.3%
  • Total voters
    199
  • #331
harcel said:
Beyond the observable universe there is lots and lots of unobservable universe,


I like this answer the best.
 
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  • #332
Radrook said:
Where is the universe located?

Here.
 
  • #333
Is the universe infinite? If it isn't infinite, then how much bigger is it than the observable universe? How would humans ever be able to answer the second question?

I can't imagine the universe being finite, because that would mean besides there being a "here", there would have to be a "there". (At least in my mind)

And, I can't imagine a universe that is infinite, because my human brain, as magnificently constructed as it is, is woefully underpowered to do that job.

I pondered this a lot in my younger days, but now that I'm getting old I've decided to just be as happy as I can, in my little corner of whatever the universe really is. :biggrin:

*
 
  • #334
I don't understand this question.

If the poll asks what the change in structure is that the boundary of the observable universe represents (e.g. photon decoupling, looking back into the past up until close to the big bang, etc)

...that would put Earth at the centre of this sphere (at the "edges" of which something changes).

How can the Earth be at the centre of the universe? (or at the centre of the sphere at whose "edges" something changes?
 
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  • #335
If indeed the universe is infinite then how can it grow? You cannot add to the inifinite because if you do then it wasn't infinite to begin with.
 
  • #336
Radrook said:
If indeed the universe is infinite then how can it grow? You cannot add to the inifinite because if you do then it wasn't infinite to begin with.

This is a very fundamental misconception of what something means to be infinite. I do not really feel like writing a very long post explaining precisely why this is wrong (perhaps someone else will), so I suggest you google around for a short while and come to understand infinity a little better.
 
  • #337
universe is not flat it has three and some say it has four dimentions philosophically we can call it infinite. No one can measure its boundary if we say that the universe is finite its like counting sand in the shore ^_^ in the end even if the universe is finite or infinite we cannot measure its boundary ....
 
  • #338
periot123 said:
universe is not flat it has three and some say it has four dimentions philosophically we can call it infinite. No one can measure its boundary if we say that the universe is finite its like counting sand in the shore ^_^ in the end even if the universe is finite or infinite we cannot measure its boundary ....

What does any of that mean?

There are four basic dimension of the universe, not three - don't know where you pulled that from.

The number of grains of sand on a shore line is a finite number and nothing to do with infinity so I don't know where that comparison comes from.

We've already estimated the size of the universe, although it's only based on our current knowledge we are "measuring the boundary" if you will.
 
  • #339
What is black space? And what is blacks space? Do you mean empty space?

I believe that the observable universe is just a tiny (like 10-30 or far smaller) part of the whole universe. I think Penrose proposes this. I also ask if the observed homogeneity of our observable universe only appears that way because we are looking at just a tiny grain of sand part of the whole. I also sometimes wonder if given the above scenario whether the universe could still be undergoing continuous inflation at some point now a very great distance away, pushing the expansion of space everywhere else, including here. This would also be the same point that our observable universe inflated from 13.7B years ago. I recall that the Inflation and/or dark energy expansion of space can apparently separate any two points in space at a rate many, many times faster than the speed of light. However I am probably talking complete nonsense because I have little understanding of GR or advanced mathematics, I probably get my ideas from the water cycle here on earth!

So I guess I have to vote other!
 
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  • #340
Gold333 said:
...that would put Earth at the centre of this sphere (at the "edges" of which something changes).

How can the Earth be at the centre of the universe? (or at the centre of the sphere at whose "edges" something changes?

Where is the center on the surface of a sphere?

https://www.youtube.com/watch?v=I9Cjxd4Mjog

https://www.youtube.com/watch?v=17jymDn0W6U


See these threads for further info:

https://www.physicsforums.com/showthread.php?t=365912"

https://www.physicsforums.com/showthread.php?t=368057"
 
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  • #341
Wow, I wish I understood more of this, it's fascinating even based on conjecture.

I found this site recently that shows the assumed scales of things in our universe as well as the size of what is unobservable ( Planck scale to 900m light years ) They say the observable is 190m light years, and the unobservable is 900m light years.:eek:

http://primaxstudio.com/stuff/scale_of_universe/

How does one come to the conclusion of the size of the unobservable areas ? Or is it a necessary to satisfy some cosmological model ?

Thanks,

Isaac
 
  • #342
Isaacsname said:
I found this site recently that shows the assumed scales of things in our universe as well as the size of what is unobservable ( Planck scale to 900m light years ) They say the observable is 190m light years, and the unobservable is 900m light years.:eek:

How big?

Try 93 billion light years in size, with the observable universe being ~48 billion light years if my memory is correct.
 
  • #343
Tanelorn said:
What is black space? And what is blacks space? Do you mean empty space?

I believe that the observable universe is just a tiny (like 10-30 or far smaller) part of the whole universe. I think Penrose proposes this. I also ask if the observed homogeneity of our observable universe only appears that way because we are looking at just a tiny grain of sand part of the whole. I also sometimes wonder if given the above scenario whether the universe could still be undergoing continuous inflation at some point now a very great distance away, pushing the expansion of space everywhere else, including here. This would also be the same point that our observable universe inflated from 13.7B years ago. I recall that the Inflation and/or dark energy expansion of space can apparently separate any two points in space at a rate many, many times faster than the speed of light. However I am probably talking complete nonsense because I have little understanding of GR or advanced mathematics, I probably get my ideas from the water cycle here on earth!

So I guess I have to vote other!

No, I think you are correct, at least according to what I understand so far myself.:-p

Have you checked out Leonard Susskind's Stanford lectures on FLRW standard cosmology ? They're on Youtube, 8 of them , iirc, and he explains how the relative velocity of two galaxies in an expanding space traveling apart from each other can excede c by some factor, lecture 7 or 8 I think.

Good stuff, sometimes Susskind gets a little derailed with a train of thought, but still worth watching imho.

Isaac
 
  • #344
Isaacsname said:
How does one come to the conclusion of the size of the unobservable areas ? Or is it a necessary to satisfy some cosmological model ?

Here is good info on the Observable universe:
http://en.wikipedia.org/wiki/Observable_universe

The diameter of the observable universe is estimated to be about 28 billion parsecs (93 billion light-years),[3] putting the edge of the observable universe at about 46–47 billion light-years away.


If you are puzzled by the fact the universe can be 93 billion light years 'wide', while it is 'only' 13.75 billion years old!? :eek:

The answer is: There is no speed limit for the expansion of the universe, but any object moving inside the universe is always limited to the speed of light.


EDIT:
Check out this thread for info expansion of the universe: https://www.physicsforums.com/showthread.php?t=365912"
 
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  • #345
jarednjames said:
How big?

Try 93 billion light years in size, with the observable universe being ~48 billion light years if my memory is correct.

Yoikes, reminds me to always check the source. Had I just looked on the wiki page for " Observable universe " I would have found that the ~ 180/190m lightyear estimation originated from a model that stated an age of 15.8b years for the age of the universe. ( ...under " misconceptions " )

I guess the idea was flawed..:-p and shown to be incorrect.

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

from

http://www.astro.ucla.edu/~wright/old_new_cosmo.html#05Aug06

" The claim that the Universe would be 15% larger is partially incorrect. Even though relatively nearby galaxies would be 15% further away the actual size of the Universe would go from infinite (flat) to finite (closed) but very big, which is a smaller Universe. The distance to distant quasars at redshift z=6 would increase by only 4%, and the distance to the last scattering surface changes less than 0.5% because this is what is fixed by the CMB. "

Thank you, I just learned some things.
 
  • #346
could antimatter lay beyond the universe?
 
  • #347
pibb said:
could antimatter lay beyond the universe?

Judging by your two posts you have something for antimatter.

The answer to this one is basically no, but we could also say who knows.

I'd be swinging against that option though.
 
  • #348
selfAdjoint said:
Listen to yourself! Do events we can never know about exist or not? How the hell can you or I or anyone ever know? It's just a fantasy!

If a tree falls in a forest and nobody is there to hear it, see it, feel it, or observe it does it still fall and affect its surroundings?

Yes it does even though nobody knows about it. and if you go back to the spot at which it fell you could figure out what happened.

So asking the questions about this universe may lead us to understand what's outside our space time even though we will never observe it it still occurs

As Einstein said "everything is relative"
 
  • #349
sorry i just jumped to the end. how about a process like quarks. is it possible all light sent out pops back to feul the big bang? i came to this conclusion with wild speculation and the use of a magic 8 ball.
 
  • #350
awhalen said:
As Einstein said "everything is relative"
And Ted Stevens said "the internet is a series of tubes".

Spurious out-of-context quotes don't help much.

Darken-Sol said:
sorry i just jumped to the end. how about a process like quarks. is it possible all light sent out pops back to feul the big bang? i came to this conclusion with wild speculation and the use of a magic 8 ball.
:biggrin: Magic 8 ball.
 
  • #351
periot123 said:
universe is not flat it has three and some say it has four dimentions philosophically we can call it infinite. No one can measure its boundary if we say that the universe is finite its like counting sand in the shore ^_^ in the end even if the universe is finite or infinite we cannot measure its boundary ....

the universe is said to have four basic dimensions that make up our three dimensional space.
There are another seven that deal on a subatomic level.

This being said how can we philosophically call the universe infinite based on the information you provided?
 
  • #352
awhalen said:
the universe is said to have four basic dimensions that make up our three dimensional space.
There are another seven that deal on a subatomic level.

This being said how can we philosophically call the universe infinite based on the information you provided?

I wouldn't spend too much time examining periot's argument. It's an 'argument by befuddlement'*, as in: after enough enough smoke and mirrors, one can simply finish with 'so no one can say otherwise'.

* © DaveC426913 20110412
 
  • #353
I voted 'other' because the observable universe is just our past light-cone. Our past light-cone is like a slice of the onion and we make inferences about the entire onion from that one slice.
 
  • #354
Silverbackman said:
Our guess the space and time in our universe is finite. However it is just hard to believe there was no time before the big bang and no content beyond our observable universe. It doesn't make sense how things can by finite. I mean what happened before the big bang and why are there boundaries at the ends of our universe?

By studying the universe and the physical world one can truly see things aren't orderly per se. They far beyond the realms of organized imagination and can only be understood with observation and empiricism. Limits on the universe would truly make things beyond confusing.

BTW, what do scientists think happened before the big bang. Since the universe is expanding according to most of the evidence today, the cyclical big crunch is unlikely. What do scientists think are the likely choices?

There is the "shell" of our universe which is our expansion into the emptyness of the "Greater Universe". Let's call that the "Greater Universe" the ExtraVerse. Within the ExtraVerse there may be other universes that are expanding into it...maybe even expanding towards ours.

If we talk about time as being the point of creation of our universe then we must also assume that it will end at the last light of the last star...or at maybe when the dust and black holes break down as they expand outwards into the ExtraVerse. But is that correct?

Should we think of time existing only as our universe expands into the ExtraVerse? That is silly. If we could some how transport ourselves outside of our universe (lets say 5 minutes in distance), and watch for it in that 5 minutes as it expands towards us...would we even see it coming towards us? Probably not since it is the very light and energy that is our known universe that makes up the edge of it. But getting back to us sitting there, waiting for it to come to us...if we transported ourselves with a watch, that watch would be ticking. So we wouldn't just come into existence as the edge of the universe passes us and we become a part of it again.

I like to think of time as something that existed forever before and will exist forever afterwards...our universe just exists in a minute portion of it.
 
  • #355
SirFishSlayer said:
Should we think of time existing only as our universe expands into the ExtraVerse? That is silly. If we could some how transport ourselves outside of our universe (lets say 5 minutes in distance), and watch for it in that 5 minutes as it expands towards us...would we even see it coming towards us?
Funny thing about invoking magical abilities such as instant teleportation in thought experiments - they tend to run afoul of established inderstanding - such as SR.

SirFishSlayer said:
I like to think of time as something that existed forever...
Ah but so did Newton. Einstein showed him up.
 
  • #356
DaveC426913 said:
Funny thing about invoking magical abilities such as instant teleportation in thought experiments - they tend to run afoul of established inderstanding - such as SR. QUOTE]

No "magical abilities"...just putting the variable out there.

Seems to be that our universe isn't creating more of itself as it expands. It is not creating anything, it is just expanding into a "space" that is void of anything until you put something in it.

So, what IF there is another universe whose edge was approaching ours? If they are living in their own universe's space and time and we are living in ours, then does the 2 space-times collide? What happens? Whose space-time would rule? Would they just merge if their universe's laws are the same as ours?
 
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  • #357
you're making some large assumptions..

who's to say 'space' exists beyond our universe.
 
  • #358
Who is to say it doesn't.

Is there a truly empty place waiting for a universe to encroach upon it, or is the universe creating it as it goes along?

Again, what if there is the Multi-Verse thing happening and has been happening...Our universe in the grander scheme of the ExrtaVerse. Then there is something else out there and and so it is not empty. What do we call that "place" in between universes?

We would assume that it is truly empty...but we used to think that of deep space until we realized that there is stuff out there and our universe if filled with it, even if we can't see it.

BTW, love the discussion. Thanks guys.
 
  • #359
SirFishSlayer said:
It is not creating anything, it is just expanding into a "space" that is void of anything until you put something in it.
No, that is not the current understanding. The universe is not expanding into any void.
 
  • #360
I love the discussion as well :)

I would say that it doesn't need to be one or the other.

The universe could be expanding, without creating and without there being a void in which it is expanding.

as Dave said above.. the current understanding doesn't claim the existence of a void. Truthfully I don't know how one would really describe this void anyways.

Outside of the universe, the void would have to be space-less, and time-less.

The issue with most of cosmology (at least in my limited experience) is that the real mathematical representations cannot be efficiently translated into simplified conceptualizations.

I feel like that's the issue with most physics these days, and with the increase in pop-sci books.. the truth is being twisted and contorted into a conceptual mold that it just can't fit in, which is the only con.

The pro, is that more everyday people are becoming interested in science. That is such an amazing thing... even if it's storybook science, the bottom line is everyday people are starting to be curious :) and I like that.
 

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