<p>No.  The universe is not a sphere with water ice surrounding it.</p>

<p>Asking about "outside the universe" is akin to asking about what a candle flame is made of <em>before it is lit</em>.  Just because you can put the words together doesn't mean the question makes sense.</p>

<p>The universe is "all that exists".  Nothing can exist outside the universe, because then it would exist, and if it exists then it is part of the universe.</p>

<p>It is probably best to imagine the universe as stretching infinitely in all directions. This is not the only possible topology of the universe, but it does help to avoid visualisation of the universe as being like a "sphere" with something outside it. </p>

CC BY-SA 4.0
2019-05-09T05:36:37.213Z
You're talking semantics here. Yes. The definition of Universe is _everything_. Today, though, we have many astrophysicists who talked about Multiverse. That breaks your semantics talk...
Alexis Wilke
CC BY-SA 4.0
2019-05-10T04:13:25.777Z
I almost upvoted, but then asked myself if *No. The universe is not a sphere with water ice surrounding it* is worth the same +10 points as one of your really good answers, and decided to skip it this time ;-)
uhoh
CC BY-SA 4.0
2019-05-08T20:37:01.143Z
2019-05-08T20:37:01.143Z
James K
<p>It's very difficult to answer a question "Are there any theories ...." in the negative, since if nothing else, the questioner has probably just formulated such a theory. I can say with reasonable confidence that no such theory has any traction or credibility in any of the communities of research and scholarship that consider such things (astronomy, cosmology, etc.). Most of the theories I am aware of have the universe unconfined and without boundaries, although possibly of finite extent. </p>

<p>Some consider the possibility of "<a href="https://en.wikipedia.org/wiki/Domain_wall_(string_theory)" rel="nofollow noreferrer">domain walls</a>" -- two dimensional surfaces that are vaguely analagous to the boundaries between crystals in a solid -- the fundamental structure of the universe has "crystallised" differently on the two sides.</p>

CC BY-SA 4.0
2019-05-08T20:58:25.093Z
Would the "domain walls" in theory, be crystallized ice like materials on the "edge/walls" of the universe? If so, where could one go to study people who believe this view? Thank you for your time.
Doberg
CC BY-SA 4.0
2019-05-08T21:17:13.580Z
@Doberg No. They'd be more two dimensional elementary particles or maybe two dinmensional black holes than anything else, I think, but I'm no expert. To study these theories you'll likely need to study quantum gravity and string theory, for which purpose you probably need to start with maths degree and then plan on five to ten years postgrad study.
Steve Linton
CC BY-SA 4.0
2019-05-08T22:30:33.407Z
Okay thank you.
Doberg
CC BY-SA 4.0
2019-05-09T03:47:47.813Z
"Most of the theories I am aware of have the universe unconfined and without boundaries, although possibly of finite extent". You realise that's an outright contradiction, right? Wow. Also, the universe is infinite; it can't be anything but infinite. Any theories about a finite universe are born from the minds of people who require boundaries and limits.
White Prime
CC BY-SA 4.0
2019-05-09T03:50:53.393Z
@WhitePrime Boundless but finite could simply mean closed into itself. TBH, we don't truly know this one is infinite (and we may never know for sure), although it is true this is the hypothesis that makes the most sense currently.
Florin Andrei
CC BY-SA 4.0
2019-05-09T07:17:48.643Z
@WhitePrime consider the surface of a sphere. As a two dimensional "universe" that is finite, but has no edges or boundaries. It is seriously proposed that the universe may be a higher-dimensional analogue of this shape.
Steve Linton
CC BY-SA 4.0
2019-05-09T13:57:24.190Z
@Florin Andrei and Steve Linton Guys, I knew you'd say these things, of course. Look: A universe that folds in on itself, or a spherical universe, are both forms that would still be 'contained' in a larger space. There's just no getting away from the fact that space is literally infinite. As bold as this sounds, the infinity of space is probably the only thing we can be certain of, as empty space cannot have a boundary.
White Prime
CC BY-SA 4.0
2019-05-09T18:57:18.920Z
@WhitePrime A (hyper)sphere universe does *not* require a larger space to contain it. In standard cosmology, a universe with positive curvature can be the 3D "surface" of a 4D hypersphere. It doesn't need to be embedded in anything, so nothing exists apart from that 3D hypersurface, neither outside the 4D hypersphere nor inside it.
PM 2Ring
CC BY-SA 4.0
2019-05-08T20:33:13.163Z
2019-05-08T20:33:13.163Z
Steve Linton
<p>Is the Universe a sphere with water or ice surrounding its' confinement? Are there any theories that imply the Universe being confined within a sphere of water/ice material?</p>

CC BY-SA 4.0
2019-05-09T08:46:20.270Z
Your question implies that the universe has some kind of spatial boundary. There is no such boundary in any modern theory of cosmology, even in cosmologies that speak of multiple universes.
PM 2Ring
CC BY-SA 4.0
2019-05-09T14:53:02.833Z
At least we cannot *see* any such boundary in the visible universe. For all we actually know there's a close packed array of Bertrand Russell's teapots receding from us at just past c. -No evidence, so better no speculation, unless it leads to a testable hypothesis.
Wayfaring Stranger
CC BY-SA 4.0
2019-05-09T17:37:19.967Z
It's turtles all the way down.
Carl Witthoft
CC BY-SA 4.0
2019-05-09T17:37:42.960Z
I'm voting to close this question as off-topic because this is well beyond mainstream-related questioning
Carl Witthoft
<universe><cosmology><theories>
What covers the outside of the Universe?
Doberg
# What covers the outside of the Universe?

(Asked by: username_0 on 2019-05-08)

Is the Universe a sphere with water or ice surrounding its' confinement? Are there any theories that imply the Universe being confined within a sphere of water/ice material?

**Tags:** universe, cosmology, theories
> **Comments:**
> **username_1**: Your question implies that the universe has some kind of spatial boundary. There is no such boundary in any modern theory of cosmology, even in cosmologies that speak of multiple universes.  
> **username_2**: At least we cannot *see* any such boundary in the visible universe. For all we actually know there's a close packed array of Bertrand Russell's teapots receding from us at just past c. -No evidence, so better no speculation, unless it leads to a testable hypothesis.  
> **username_3**: It's turtles all the way down.  
> **username_3**: I'm voting to close this question as off-topic because this is well beyond mainstream-related questioning  

---

## 2 answers

### Answer by username_4 on 2019-05-08. Score: 6

No. The universe is not a sphere with water ice surrounding it.

Asking about "outside the universe" is akin to asking about what a candle flame is made of *before it is lit*. Just because you can put the words together doesn't mean the question makes sense.

The universe is "all that exists". Nothing can exist outside the universe, because then it would exist, and if it exists then it is part of the universe.

It is probably best to imagine the universe as stretching infinitely in all directions. This is not the only possible topology of the universe, but it does help to avoid visualisation of the universe as being like a "sphere" with something outside it.

> **Comments:**
> **username_5**: You're talking semantics here. Yes. The definition of Universe is _everything_. Today, though, we have many astrophysicists who talked about Multiverse. That breaks your semantics talk...  
> **username_6**: I almost upvoted, but then asked myself if *No. The universe is not a sphere with water ice surrounding it* is worth the same +10 points as one of your really good answers, and decided to skip it this time ;-)  

---

### Answer by username_7 on 2019-05-08. Score: 1

It's very difficult to answer a question "Are there any theories ...." in the negative, since if nothing else, the questioner has probably just formulated such a theory. I can say with reasonable confidence that no such theory has any traction or credibility in any of the communities of research and scholarship that consider such things (astronomy, cosmology, etc.). Most of the theories I am aware of have the universe unconfined and without boundaries, although possibly of finite extent.

Some consider the possibility of "[domain walls](https://en.wikipedia.org/wiki/Domain_wall_(string_theory))" -- two dimensional surfaces that are vaguely analagous to the boundaries between crystals in a solid -- the fundamental structure of the universe has "crystallised" differently on the two sides.

> **Comments:**
> **username_0**: Would the "domain walls" in theory, be crystallized ice like materials on the "edge/walls" of the universe? If so, where could one go to study people who believe this view? Thank you for your time.  
> **username_7**: @Doberg No. They'd be more two dimensional elementary particles or maybe two dinmensional black holes than anything else, I think, but I'm no expert. To study these theories you'll likely need to study quantum gravity and string theory, for which purpose you probably need to start with maths degree and then plan on five to ten years postgrad study.  
> **username_0**: Okay thank you.  
> **username_8**: "Most of the theories I am aware of have the universe unconfined and without boundaries, although possibly of finite extent". You realise that's an outright contradiction, right? Wow. Also, the universe is infinite; it can't be anything but infinite. Any theories about a finite universe are born from the minds of people who require boundaries and limits.  
> **username_9**: @WhitePrime Boundless but finite could simply mean closed into itself. TBH, we don't truly know this one is infinite (and we may never know for sure), although it is true this is the hypothesis that makes the most sense currently.  
> **username_7**: @WhitePrime consider the surface of a sphere. As a two dimensional "universe" that is finite, but has no edges or boundaries. It is seriously proposed that the universe may be a higher-dimensional analogue of this shape.  
> **username_8**: @Florin Andrei and Steve Linton Guys, I knew you'd say these things, of course. Look: A universe that folds in on itself, or a spherical universe, are both forms that would still be 'contained' in a larger space. There's just no getting away from the fact that space is literally infinite. As bold as this sounds, the infinity of space is probably the only thing we can be certain of, as empty space cannot have a boundary.  
> **username_1**: @WhitePrime A (hyper)sphere universe does *not* require a larger space to contain it. In standard cosmology, a universe with positive curvature can be the 3D "surface" of a 4D hypersphere. It doesn't need to be embedded in anything, so nothing exists apart from that 3D hypersurface, neither outside the 4D hypersphere nor inside it.  

---

