<p>Parallel universes are a theory, we just don't know yet.  No one has slid into one.  (slid coming from the series Sliders )  According to the Big Bang theory, multiverses are possible.  <a href="https://www.universeguide.com/facts/multiverse" rel="nofollow">https://www.universeguide.com/facts/multiverse</a> Britains' most well known physics scientist/presenter Prof Brian Cox @ProfBrianCox recently said that multiverses makes sense ( <a href="http://www.bbc.co.uk/news/science-environment-29321771" rel="nofollow">http://www.bbc.co.uk/news/science-environment-29321771</a> ).  </p>

CC BY-SA 3.0
2014-10-11T11:15:02.380Z
2014-10-11T11:15:02.380Z
John whitworth
<p>If they exist, they are out of anything we can ever reach. They are (by definition) out of our Universe, so we can not affect them and they can not affect us in any way. That's the same as saying that, for any experimental definition, they do not exist.</p>

CC BY-SA 3.0
2013-12-05T20:39:51.000Z
2013-12-05T20:39:51.000Z
Envite
<p>The simple answer is (as with so much in astronomy):<br/>
<strong>We Don't Know</strong></p>

<p>Parallel universes may or may not exist. There is no definitive way to prove that these universes do or don't exist.</p>

<p>A parallel universe is a separate existence to ours. The Theories that suggest that there may be parallel universes are classified as theories of <strong>multiverses</strong>. There are many theories of multiverse, all of which propose different ideas about what could exist beyond the limits of our universe. There are also theories that suggest that the multiverse doesn't exist, although the theories with most support are by far the multiverse theories.</p>

<p>For a nice reference in book form, see Steinhardt and Turok's "Endless Universe: Beyond the Big Bang". Also, see Max Tegmark's work on multiverses levels I-IV (<a href="http://space.mit.edu/home/tegmark/crazy.html">Max Tegmark -> See his Scientific American article entitled Parallel Universes</a>).</p>

CC BY-SA 3.0
2017-08-14T19:11:50.877Z
@ashu See the book called 'Our Mathematical Universe' by Max Tegmark for a very extensive treatment of current hypotheses related to multiple universes. Please understand that this is all hypothetical. Current accepted science says nothing about multiple universes. The book is about 1/3 established science, 1/3 somewhere on the outer edges, and 1/3 speculation. But it's written by a leading cosmologist, so it should give you a good idea of what scientists in this field are thinking about when trying to expand this field.
Florin Andrei
CC BY-SA 3.0
2013-09-25T13:05:31.397Z
Can you please provide any reference to a theory which suggests that multiverse doesn't exists?
ashu
CC BY-SA 3.0
2013-09-25T13:14:35.643Z
@ashu good point. There are some, but I do not have the time at the moment to trawl through the whole internet to find them. Pretty much all of the mainstream theories are multiverse/parallel universe theories, meaning that singular universe theories are hard to find.
damned truths
CC BY-SA 3.0
2013-09-25T12:59:54.703Z
2013-09-26T01:34:24.047Z
2013-09-26T01:34:24.047Z
damned truths
<p>Do other universes like ours exist?
If they exist, <strong>how do we know that they exist when we have even not seen the ends of our own universe?</strong></p>

CC BY-SA 3.0
2014-08-14T13:26:02.593Z
In another universe right now, an exact copy of you posted the question "Do parallel universes not exist?"
Paul
CC BY-SA 3.0
2014-08-14T13:49:53.100Z
@Paul : could you please elaborate it and give some reference.
ashu
CC BY-SA 3.0
2014-08-14T17:14:46.943Z
@ashu - it was simply a joke. Apparently not a good one. Please disregard!
Paul
<universe>
Do parallel universes exist?
ashu
# Do parallel universes exist?

(Asked by: username_0 on 2013-09-25)

Do other universes like ours exist?
If they exist, **how do we know that they exist when we have even not seen the ends of our own universe?**

**Tags:** universe
> **Comments:**
> **username_1**: In another universe right now, an exact copy of you posted the question "Do parallel universes not exist?"  
> **username_0**: @Paul : could you please elaborate it and give some reference.  
> **username_1**: @ashu - it was simply a joke. Apparently not a good one. Please disregard!  

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## 3 answers

### Answer by username_4 on 2013-09-25. Score: 12 | Accepted answer

The simple answer is (as with so much in astronomy):  
**We Don't Know**

Parallel universes may or may not exist. There is no definitive way to prove that these universes do or don't exist.

A parallel universe is a separate existence to ours. The Theories that suggest that there may be parallel universes are classified as theories of **multiverses**. There are many theories of multiverse, all of which propose different ideas about what could exist beyond the limits of our universe. There are also theories that suggest that the multiverse doesn't exist, although the theories with most support are by far the multiverse theories.

For a nice reference in book form, see Steinhardt and Turok's "Endless Universe: Beyond the Big Bang". Also, see Max Tegmark's work on multiverses levels I-IV ([Max Tegmark -> See his Scientific American article entitled Parallel Universes](http://space.mit.edu/home/tegmark/crazy.html)).

> **Comments:**
> **username_0**: Can you please provide any reference to a theory which suggests that multiverse doesn't exists?  
> **username_4**: @ashu good point. There are some, but I do not have the time at the moment to trawl through the whole internet to find them. Pretty much all of the mainstream theories are multiverse/parallel universe theories, meaning that singular universe theories are hard to find.  
> **username_5**: @ashu See the book called 'Our Mathematical Universe' by Max Tegmark for a very extensive treatment of current hypotheses related to multiple universes. Please understand that this is all hypothetical. Current accepted science says nothing about multiple universes. The book is about 1/3 established science, 1/3 somewhere on the outer edges, and 1/3 speculation. But it's written by a leading cosmologist, so it should give you a good idea of what scientists in this field are thinking about when trying to expand this field.  

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### Answer by username_2 on 2014-10-11. Score: 3

Parallel universes are a theory, we just don't know yet. No one has slid into one. (slid coming from the series Sliders ) According to the Big Bang theory, multiverses are possible. <https://www.universeguide.com/facts/multiverse> Britains' most well known physics scientist/presenter Prof Brian Cox @ProfBrianCox recently said that multiverses makes sense ( <http://www.bbc.co.uk/news/science-environment-29321771> ).


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### Answer by username_3 on 2013-12-05. Score: 3

If they exist, they are out of anything we can ever reach. They are (by definition) out of our Universe, so we can not affect them and they can not affect us in any way. That's the same as saying that, for any experimental definition, they do not exist.


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