What Is Beyond The Observable Universe?

In summary, the universe includes all that is possible to observe. Anything that is not within the observable universe is literally nothing.

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
  • #71
Its impossible to know exactly. We can speculate their are more stars and galaxies out there, and other things we would expect to find in the known universe. Its possible that if you went so far into the universe that you may find a place that is a duplicate, seeing as odds make no difference when looking at infinity.
 
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  • #72
I have a simple answer.

We don't know "yet"
 
  • #73
Okay. There is obviously no answer to this question... YET!
I think philosophically we have to assume both that there is both, something "beyond" our universe and that there also is nothing. You must assume both, seeing as you know neither to be true or false. Get it?
 
  • #74
Ok I have been trying to bend my mind around the whole there is nothing outside our universe (as in we can not know ever) But on the first page I read an analogy of a Sphere what's outside a sphere.. can anyone explain this to me?>
 
  • #75
Suppose we lived in sum world:

[tex]\sum_{n=1}^{\infty} \frac{1}{n^s}[/tex]

and we asked, "what is outside of sum world?". We know if we go far enough, sum world reaches a singularity (it diverges). But is there anything beyond that singularity? Is there something larger that encompasses sum world and reduces down to it when certain conditions are met? Of course the answer is yes: zeta world. How is zeta world different than sum world? We certainly can't use the same "methods" (convergent sums) of sum world to describe zeta world. The two worlds are qualitatively different but zeta world contains sum world and can completely describe sum world using zeta methods (a contour integral). How did we get to zeta methods? How can we get to those methods which can describe our Universe as well as the larger world for which ours is only a particular instantiation?
 
  • #76
Well.. c'mon guys. let's take it easy..
Forget about we being the tiny little human beings on this small planet that we call "earth".
Suppose we are BIG in size. about 10s of billions of times Bigger than the observable universe, that we even have to use microscopic equipments to actually see a galaxy floating in the empty space, it will take billions of light years for an earthling to travel from your toe to head. an earthling will be much much smaller than an "atom" - if we call it that way - on your body.

In that size, if you look around, what can you see?
Okay, just for a change, shall we not talk about philosophy and add a little bit of creative, sci-fiction like thought?
 
  • #77
If, instead of being here in the Milky Way, we are actually 11 billion light years away in a different galaxy, we're still going to see a universe that is homogenous in every direction. We're not going to look one way and see a giant black void. If we did, it would be because the universe is not homogenous at large scales, that there is and edge and there is a centre.

So, what's beyond our observable universe is more, similar universe.

We can't ever see it, but we can deduce it.
 
  • #78
I wonder how the recent "discovery" of dark flow plays into all this-- what if what's just beyond the visible universe can gravitationally affect that which is just within?
 
  • #79
there be dragons

at least that's what the old maps said
about the areas as yet unexplored
 
  • #80
That's the wonderful thing about cosmology -- fantastic possibilities and predictions -- most of which can never be proved wrong!

Just for the fun of it, I calculated -- using the current model I'm playing with -- how much the observable universe makes of the total amount that 'must' exist NOW due to the Cosmological Principle.

Answer was: 39.349307% meaning the other 60.650693% we can't see -- but by the Cosmological Principle should be more of the same. By this model it turns out that this percentage doesn't change -- but the universe just keeps getting bigger.

In order to get a limit I had to ASSUME that the photons did NOT travel backward in time on their way to us -- regrettable.

There were several other assumptions -- like ONLY considering matter as 'something to see' and a value for the expansion velocity for matter (0.8660254 of the speed of light). Nothing important.

Now I'm sure everyone feels much better knowing this.
 
  • #81
An interesting proposition, and unsupported. Do you have any papers in mind? Your calculations appear to be a naive solution to the Friedmann equation.
 
  • #82
more of the same.
 
  • #83
I know that this is a physics forum but just because physics can't explain the proposed question in totality doesn't mean you can't have some insight into a possible solution.

I doubt that the questioner wanted an exact answer. You should let your imagination explore these ideas sometime. Who knows what someone with your knowledge in physics might come up with. I bet you could come up with better answers than were given in this thread.

Just because you don't have an answer doesn't mean you shouldn't try to answer.
 
  • #84
Onslaught said:
I know that this is a physics forum but just because physics can't explain the proposed question in totality doesn't mean you can't have some insight into a possible solution.

I doubt that the questioner wanted an exact answer. You should let your imagination explore these ideas sometime. Who knows what someone with your knowledge in physics might come up with. I bet you could come up with better answers than were given in this thread.

Just because you don't have an answer doesn't mean you shouldn't try to answer.

Nah they don't like that here, I have learned. Just another bastion of closed-minded reactionism, like the horrible bautforum.
 
  • #85
I was also wondering what people thought about poincare dodecahedral space. I haven't found any papers refuting this theory about the shape of space. Especially with the recent WMAP data.
 
  • #86
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  • #87
Thanks for the link, thought it sounded to good to be true.

I find it impossible to comprehend a universe that is infinite, because no matter how you try to explain it, it HAS to end somewhere. Even if you use the balloon analogy that's like saying walking on a straight path on Earth will bring you back to where you started. However if you take a rocket at escape velocity you can go beyond this.

Should there be a way, no matter how inconceivable, to escape from this so called Universe. i.e. an escape velocity for our Universe?
 
  • #88
By most models, the speed of light is the escape velocity of this universe. That is obviously impossible to achieve. It is unclear if the universe is finite. I tend to think it is from a strictly observational standpoint - e.g.. Olber's paradox. There may be 'stuff' outside our universe but I see no possible way to confirm this by observation,
 
  • #89
hmm. a very hard question to consider with no definite answers.

i tend to believe that there is nothing outside our universe. just... nothing

btw. even if youu were traveling at lightspeed you could never escape"" or even reach anywhere near the edge of our universe. (the furtherst particle away from the "middle")
simply because it is also expanding at the speed of light.
 
  • #90
danda22 said:
hmm. a very hard question to consider with no definite answers.

i tend to believe that there is nothing outside our universe. just... nothing

btw. even if youu were traveling at lightspeed you could never escape"" or even reach anywhere near the edge of our universe. (the furtherst particle away from the "middle")
simply because it is also expanding at the speed of light.

The universe has no middle. The universe has no edge.

The best model that shows how this can be so is that the universe is curved and closed. A 4-spatial-dimensional sphere.

Travel in any direction long enough and you will arrive back at your starting point.
 
  • #91
This is what I know about the structure of the universe.

In our universe there are 2 parts. The observable part, like many have said, is +/-13.7 billions light years long. Then outside the observable you've got the unobservable part of the universe.

It's unobservable simply because light isn't catching up with the speed at which the universe expands. The distance between the edge of the universe and the light that's trying to reach the edge of the universe is what we meant by unobservable universe.

In other words, the universe is being expanded and light is trying to fill in and cover the created space-time, but the space-time being created is faster than what light can cover, so there is always an unobservable part of the universe where light hasn't reach.

But even without light, this unilluminated space-time obeys the laws of physics, it's nothing more than space without light. With that said, the unobservable universe is existing and so it's relevant that we understand what it is.

However, what's outside the edge of our expanding universe? There could be something like a higher dimension or a turtleback, though as much as there is a possibility of something outside, there's an equal chance that there is non-existence (if existence involves space-time). But if you want a correct answer to the question, what's outside the edge of the universe, the answer would be: there is the edge of our universe.

Many who understands often label the question pointless to ask, since one is asked to describe an object that is non-existing in the world.
Likewise if there's a non-existing object called Mr.X, how would you describe Mr.X to me? Seriously, try answering that until you get a sense of impossibility.

To see how it's unanswerable, Steven Hawking once rephrase such questions along the following: What is north of North Pole? North Pole, probably.
 
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  • #92
Our universe could be embedded in an infinitely large 'void', but, I fail to see how that helps us understand the universe. It would also raise issues like why matter occupies just an infinitesimal volume in all that can be characterized as 'spacetime'. Creepy. Cosmology is hard enough as is. All we can say with any certainty at present is the universe is observationally finite. That may not be all there is to it, but, it is all we can hope to describe for now. Better theories may give us new perspectives, but, better observations would raise my comfort level more quickly.
 
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  • #93
DaveC426913 said:
The universe has no middle. The universe has no edge.

The best model that shows how this can be so is that the universe is curved and closed. A 4-spatial-dimensional sphere.

Travel in any direction long enough and you will arrive back at your starting point.

do you have any proof of that last statement ??
 
  • #94
ray b said:
do you have any proof of that last statement ??

No, I'm not stating it is so, I'm stating there exists a model of the universe with this geometry.
 
  • #95
DaveC426913 said:
The universe has no middle. ...[edit]...

But Dave, isn't it _all_ middle? :)

diogenesNY
 
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  • #96
diogenesNY said:
But Dave, isn't it _all_ middle? :)

diogenesNY
Sure, that too.

But of course, 'middle' is only meaningful inasmuch as it is distinguishable from every other point; it is unique.

If it is all middle, then it is not unique.


To modify your statement: it all was middle.
 
  • #97
DaveC426913 said:
Sure, that too.

[edit]

To modify your statement: it all was middle.

A point lucidly made, well taken, and appreciated.

diogenesNY
 
  • #98
Chronos said:
By most models, the speed of light is the escape velocity of this universe. That is obviously impossible to achieve. It is unclear if the universe is finite. I tend to think it is from a strictly observational standpoint - e.g.. Olber's paradox. There may be 'stuff' outside our universe but I see no possible way to confirm this by observation,


I would be careful in saying that it is impossible to achieve faster than light travel, it may be highly improbable but not impossible. These are theories for a reason. If scientists have learned anything in our short time in this universe it is that "universal truth is not measured in mass appeal."

I agree that the universe will most likely turn out to be finite, but what if the speed of light can be reached or even surpassed, imagine the implications. Now I am admittedly slightly ignorant when it comes to these matters but my understanding of Einstein's famous equation E=mc^2 is that the amount of energy it takes to move an object is that objects mass multiplied by the speed of light squared. Hypothetically if we were able to control this much or MORE energy and focus it we should be able to travel light speed.

One problem I can't explain is that the faster you go or more energy you use your mass seems to increase a lot, which would require more energy to move but maybe when your mass reaches a certain amount you tear through the fabric of space-time.

Just a thought I had, feel free to mathematically, logically, or theoretically tear my argument to shreds. :-)
 
  • #99
E = mc^2 is nothing to do with moving mass. It is the energy equivalence of mass.
To move mass the simple F = ma is all that is needed.
As you go faster your mass does NOT increase. It's the problem posed by Special Relativity that a "Stationary" observer appears to see your mass increase. Or putting it another way, if you are moving compared with another frame of reference, observers on that frame see your mass as increased, while you see their masses as increased.
In your own frame, and their own frame, there is no increase.
 
  • #100
Thanks for the clarification, I guess that idea is DOA.

Is there any reason to believe that F=ma doesn't work or works differently towards the 'edge' of the Universe or do we assume that since it works here it must work everywhere?
 
  • #101
No. From astronomical observations it seems that the same rules of physics apply all over. And the same chemistry.
However, you can never say never.
 
  • #102
I think that to make a statement like "conceptualizing the nature of the universe's 'edge' is irrelevant because it's unobservable" and refusing to even consider the possibilities is rather unproductive, if not downright unscientific. Through simulation and modeling we can construct hypotheticals, and quite accidentally run across something useful or testable. Just because we can't fly a probe to the edge of the cosmos doesn't mean we won't construct a model that just so happens to explain, say, lambda/the cosmological constant/whatever as an added bonus. Many times, a theory been made to explain one thing - and then, quite accidentally, someone steps back and says 'hey! this also explains THIS wacky phenomenon!' They may never experimentally verify the thing they originally set out to explain, but those happy accidentals that end up getting explained as a result certainly can go a ways in supporting the theory.

I get sensitive about those sorts of statements because they half-seem to be actively trying to stifle progress. String theory, for instance, predicts nothing, and instead of simply being content to simply not believe it, some people go out of there way to call it useless, a waste of time, etc. Those people will be in for a surprise if ever some testable prediction does pop up at some point as a result of the work that's been put into it (Note, I'm not trying to turn this into a string theory discussion, I just used it as an example).

In any case, it's a fun question whether verifiable or not. Now, to get more on topic:

When I was 15, I was puzzing over this same question (or one similar enough). Assuming the universe is a finite bubble of spacetime, what happens to the traveller that sneaks up to the 'edge' and tries to push beyond? Is there a beyond?

I followed a few assumptions (and note they're only assumptions):

The universe is
- finite
- spherical
- spacetime is the 'medium' in which matter, energy, and measureable dimensions exist
- anything 'outside' of the bubble of spacetime must have zero measurable distance. There is no 'there' there

Okay. The universe obviously has a measurable diameter, and a volume. Here's where I ran into a puzzler: How can a universe have an edge, a perimeter, and outside surface area as it were, and be 'surrounded' by an area of zero distance? I figured that was impossible - that a traveller moving toward the outside edge would be getting closer and closer to an area of zero distance. There can be no such thing as a 'perimeter' or surface area to the bubble if it's rubbing elbows, or expanding into, with an 'area' of zero distance.

But the universe does have pockets of measurable area that 'rub up' against areas of (theoretically) zero distance: singularities.

Therefore, as one would travel to the 'edge' of the universe, he'd find that he's moving through space that curves into a singularity. That's the only way the universe can be 'surrounded' by an area of zero distance - no matter what direction you travel in, go far enough and you'll fall into a black hole, basically. This means the universe has a diameter and an area, but no perimeter.

It would also mean that the 'edge' of the universe is a massive gravity well. :)

I invented a word for this all-encompassing singularity; 'pangularity', from the latin pan meaning 'all'. (It was easier to pronounce than 'omnigularity'.)

This tied into something else I was pontificating about at the same time: relativity in a spinning disc. If you take a disc and spin it so the outer edge accelerates near the speed of light, the measured perimeter would shrink, but the diameter and area remains the same. If it was a magical disc whose edge could spin at the speed of light, you'd have a perimeter of zero distance. Given the equivalence of acceleration and gravity, the relativistic spinning disc could serve (at least mathematically) as a two-dimensional model for the pangularity idea. This was good news for me, because I was failing Algebra at the time. :)

I ran into a problem. At the time, it was 'common knowledge' that the universe's expansion was slowing. According to my hypothesis, the further you traveled away from the center of the universe, you should start falling into the 4D curvature of space into the pangularity, and therefore start speeding up instead of slowing down. So I said 'well, so much for that', congratulated myself for having a neat idea and forgot all about it, until I read an article about a year later about the surprising new measurements that demonstrated the universe was accelerating in its expansion. I did a happy jig and congratulated myself for being the smartest human being on the planet.

I started getting silly and conjecturing completely baseless speculations, such as the existence of a white hole, a convex singularity, at the center of the universe serving as the 'other side' of the pangularity, and the universe constantly recycling its matter and energy... etc.

Of course, that was almost 15 years ago, and I've gotten a little wiser, if not smarter. I don't think it can be adapted to explain why everything is moving apart from everything else at an accelerating rate. As two objects get closer to the outer edge of the universe, they should actually come closer together as they fall into the pangularity. And if the gravity well's effects were to extend into our local observable area of the universe, movement of objects should seem biased in one direction, assuming we're not parked in the exact center of the universe, etc. Of course, the volume and diameter of the universe could still be expanding due to inflation in this model, but the perimeter is always zero.

I still suspect that if spacetime is expanding 'into nothing', then the perimeter must have zero distance.

But it was fun speculation, and speculation can lead to some very interesting ideas. I think that the culture of strict positivism ('the question is irrelevant!', etc) seems counterproductive.
 
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  • #103
Anticitizen said:
I think that to make a statement like "conceptualizing the nature of the universe's 'edge' is irrelevant because it's unobservable" and refusing to even consider the possibilities is rather unproductive, if not downright unscientific. Through simulation and modeling we can construct hypotheticals, and quite accidentally run across something useful or testable. Just because we can't fly a probe to the edge of the cosmos doesn't mean we won't construct a model that just so happens to explain, say, lambda/the cosmological constant/whatever as an added bonus. Many times, a theory been made to explain one thing - and then, quite accidentally, someone steps back and says 'hey! this also explains THIS wacky phenomenon!' They may never experimentally verify the thing they originally set out to explain, but those happy accidentals that end up getting explained as a result certainly can go a ways in supporting the theory.

I get sensitive about those sorts of statements because they half-seem to be actively trying to stifle progress. String theory, for instance, predicts nothing, and instead of simply being content to simply not believe it, some people go out of there way to call it useless, a waste of time, etc. Those people will be in for a surprise if ever some testable prediction does pop up at some point as a result of the work that's been put into it (Note, I'm not trying to turn this into a string theory discussion, I just used it as an example).

In any case, it's a fun question whether verifiable or not. Now, to get more on topic:

When I was 15, I was puzzing over this same question (or one similar enough). Assuming the universe is a finite bubble of spacetime, what happens to the traveller that sneaks up to the 'edge' and tries to push beyond? Is there a beyond?

I followed a few assumptions (and note they're only assumptions):

The universe is
- finite
- spherical
- spacetime is the 'medium' in which matter, energy, and measureable dimensions exist
- anything 'outside' of the bubble of spacetime must have zero measurable distance. There is no 'there' there

Okay. The universe obviously has a measurable diameter, and a volume. Here's where I ran into a puzzler: How can a universe have an edge, a perimeter, and outside surface area as it were, and be 'surrounded' by an area of zero distance? I figured that was impossible - that a traveller moving toward the outside edge would be getting closer and closer to an area of zero distance. There can be no such thing as a 'perimeter' or surface area to the bubble if it's rubbing elbows, or expanding into, with an 'area' of zero distance.

But the universe does have pockets of measurable area that 'rub up' against areas of (theoretically) zero distance: singularities.

Therefore, as one would travel to the 'edge' of the universe, he'd find that he's moving through space that curves into a singularity. That's the only way the universe can be 'surrounded' by an area of zero distance - no matter what direction you travel in, go far enough and you'll fall into a black hole, basically. This means the universe has a diameter and an area, but no perimeter.

It would also mean that the 'edge' of the universe is a massive gravity well. :)

I invented a word for this all-encompassing singularity; 'pangularity', from the latin pan meaning 'all'. (It was easier to pronounce than 'omnigularity'.)

This tied into something else I was pontificating about at the same time: relativity in a spinning disc. If you take a disc and spin it so the outer edge accelerates near the speed of light, the measured perimeter would shrink, but the diameter and area remains the same. If it was a magical disc whose edge could spin at the speed of light, you'd have a perimeter of zero distance. Given the equivalence of acceleration and gravity, the relativistic spinning disc could serve (at least mathematically) as a two-dimensional model for the pangularity idea. This was good news for me, because I was failing Algebra at the time. :)

I ran into a problem. At the time, it was 'common knowledge' that the universe's expansion was slowing. According to my hypothesis, the further you traveled away from the center of the universe, you should start falling into the 4D curvature of space into the pangularity, and therefore start speeding up instead of slowing down. So I said 'well, so much for that', congratulated myself for having a neat idea and forgot all about it, until I read an article about a year later about the surprising new measurements that demonstrated the universe was accelerating in its expansion. I did a happy jig and congratulated myself for being the smartest human being on the planet.

I started getting silly and conjecturing completely baseless speculations, such as the existence of a white hole, a convex singularity, at the center of the universe serving as the 'other side' of the pangularity, and the universe constantly recycling its matter and energy... etc.

Of course, that was almost 15 years ago, and I've gotten a little wiser, if not smarter. I don't think it can be adapted to explain why everything is moving apart from everything else at an accelerating rate. As two objects get closer to the outer edge of the universe, they should actually come closer together as they fall into the pangularity. And if the gravity well's effects were to extend into our local observable area of the universe, movement of objects should seem biased in one direction, assuming we're not parked in the exact center of the universe, etc. Of course, the volume and diameter of the universe could still be expanding due to inflation in this model, but the perimeter is always zero.

I still suspect that if spacetime is expanding 'into nothing', then the perimeter must have zero distance.

But it was fun speculation, and speculation can lead to some very interesting ideas. I think that the culture of strict positivism ('the question is irrelevant!', etc) seems counterproductive.
While speculation can be fun, it is a fine line you walk here. Overly-speculative discussion and personal theories are expressly forbidden. (Remember that PF is first and foremost a homework help forum, and thus concentrates on currently-accepted physics.)
 
  • #104
I understand and apologize - I went a little too deep into it. The purpose of the post wasn't really about the idea itself, though - the moral of the story was the point I made in the first two paragraphs about keeping an open mind. In this case, a wacky, arguably untestable idea I had made one prediction one I didn't intend to make - that the universe's expansion would accelerate. Turns out it is. I'm 99.9% sure it's for a completely different reason, of course, but I think my point stands that 'irrelevant' concepts may lead to real conclusions. I suppose I should've used a real-world example (that is, something established in physics).
 
  • #105
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?
nobody can really say what was before the big bang or what's beyond the observable universe simply because it is beyond our comprehension(for now anyways). their are lots of different theories for those things but until we gain the technology to see beyond what we can see now and to go out their we will never really know. any thoughts on this?
 
<h2>1. What is the observable universe?</h2><p>The observable universe is the portion of the universe that we can see and detect through our instruments and technology. It is estimated to be about 93 billion light-years in diameter.</p><h2>2. What is beyond the observable universe?</h2><p>Beyond the observable universe lies the non-observable universe, also known as the unobservable universe. This is the part of the universe that we cannot see or detect, as it is beyond the reach of our current technology and understanding.</p><h2>3. How do scientists know that there is something beyond the observable universe?</h2><p>Scientists have observed the expansion of the universe and have determined that it is expanding faster than the speed of light. This suggests that there must be something beyond the observable universe that is causing this expansion.</p><h2>4. Is it possible to ever see or know what is beyond the observable universe?</h2><p>At this point in time, it is not possible for us to see or know what is beyond the observable universe. However, with advancements in technology and scientific understanding, it is possible that we may one day be able to explore and understand the non-observable universe.</p><h2>5. Are there any theories about what could be beyond the observable universe?</h2><p>There are various theories about what could be beyond the observable universe. Some scientists believe that there could be other universes beyond our own, while others propose the idea of a multiverse. However, these are all currently just theories and have not been confirmed by scientific evidence.</p>

1. What is the observable universe?

The observable universe is the portion of the universe that we can see and detect through our instruments and technology. It is estimated to be about 93 billion light-years in diameter.

2. What is beyond the observable universe?

Beyond the observable universe lies the non-observable universe, also known as the unobservable universe. This is the part of the universe that we cannot see or detect, as it is beyond the reach of our current technology and understanding.

3. How do scientists know that there is something beyond the observable universe?

Scientists have observed the expansion of the universe and have determined that it is expanding faster than the speed of light. This suggests that there must be something beyond the observable universe that is causing this expansion.

4. Is it possible to ever see or know what is beyond the observable universe?

At this point in time, it is not possible for us to see or know what is beyond the observable universe. However, with advancements in technology and scientific understanding, it is possible that we may one day be able to explore and understand the non-observable universe.

5. Are there any theories about what could be beyond the observable universe?

There are various theories about what could be beyond the observable universe. Some scientists believe that there could be other universes beyond our own, while others propose the idea of a multiverse. However, these are all currently just theories and have not been confirmed by scientific evidence.

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