<blockquote>
  <p>Could the expansion of universe be a side effect of gravity?</p>
</blockquote>

<p>Well, everything is possible I suppose. And we do see plenty of material that talks about the expansion of the universe as a kind of <a href="https://www.google.co.uk/search?source=hp&amp;q=repulsive+gravity&amp;oq=repulsive+gravity&amp;gs_l=psy-ab.3..0l3j0i22i30k1.936.3574.0.4075.18.17.0.0.0.0.150.1992.1j16.17.0....0...1.1.64.psy-ab..1.17.1989.0..46j35i39k1j0i131k1j0i46k1j0i67k1.dPNy5qyeJQI" rel="nofollow noreferrer">repulsive gravity</a>. But I would say no, the expansion isn't due to gravity, and it isn't some side effect of gravity. It's something different. </p>

<blockquote>
  <p>I mean maybe gravity "attracts things" at a "small" distances and repels them at "larger" distances?</p>
</blockquote>

<p>It doesn't. Gravity attracts things at all distances. It follows the inverse square rule. Some people like Mordehai Milgrom say it doesn't quite follow the inverse square law, see <a href="https://en.wikipedia.org/wiki/Modified_Newtonian_dynamics" rel="nofollow noreferrer">MOND</a>. But he isn't saying it repels at large distance. </p>

<blockquote>
  <p>Do we have any theory/hypothesis/paper on this topic? Is it possible to prove or disprove?</p>
</blockquote>

<p>We have general relativity. In general relativity <em>gravity sucks</em>. It doesn't blow. </p>

<blockquote>
  <p>Could gravity have a repulsive term that dominates at cosmological distances and could it be such a term that causes (accelerated) expansion?</p>
</blockquote>

<p>Like I said, everything is possible. But I will say no, the universe is expanding because of dark energy, not because of gravity. I rather like Erwin Schrödinger’s cosmic pressure myself. See the 2014 <a href="https://books.google.co.uk/books?id=lXGFAwAAQBAJ&amp;pg=PA268&amp;lpg=PA268&amp;dq=Einstein+%22cosmic+pressure%22&amp;source=bl&amp;ots=uaef6D4cQs&amp;sig=zDKcggRJ01ywTpiBTNPpdmdBYIc&amp;hl=en&amp;sa=X&amp;ved=0ahUKEwjCgfDlmNnUAhVRa1AKHSG_AYgQ6AEIKzAB#v=onepage&amp;q=Einstein%20%22cosmic%20pressure%22&amp;f=false" rel="nofollow noreferrer">Cambridge companion to Einstein</a> by Michel Janssen and ‎Christoph Lehner: <em>“Schrödinger [1918] had pointed out another way of treating the cosmological constant: moving it from the left-hand side of Equation [7], where it represents a contribution to space-time curvature, to the right-hand side, where it represents a contribution to the energy-matter distribution. Then it would correspond physically to a kind of cosmic pressure”</em>. Unfortunately Einstein didn’t like it. You can read more in Alex Harvey’s 2012 paper <a href="https://arxiv.org/abs/1211.6338" rel="nofollow noreferrer">How Einstein Discovered Dark Energy</a>. He gives a translation of Schrödinger’s paper and refers to <a href="http://einsteinpapers.press.princeton.edu/vol7-trans/47" rel="nofollow noreferrer">Einstein’s response</a>. If you were to ask a modern cosmologist, I think the answer would be that Schrödinger was pretty close to the mark. See <a href="https://books.google.co.uk/books?id=GUySYQaDM1cC&amp;pg=PA252&amp;lpg=PA252&amp;dq=lambourne+cosmic+pressure&amp;source=bl&amp;ots=1SQg2svc2s&amp;sig=Rc2w1PAWH_SpCXr1KGurqVCxOqo&amp;hl=en&amp;sa=X&amp;ved=0ahUKEwjqtLWw6d7UAhUHIcAKHc_QDxMQ6AEIJzAB#v=onepage&amp;q=lambourne%20cosmic%20pressure&amp;f=false" rel="nofollow noreferrer">page 252</a> of Relativity, Gravitation and Cosmology by Robert J Lambourne: </p>

<p><a href="https://i.sstatic.net/msU68.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/msU68.jpg" alt="enter image description here"></a> </p>

CC BY-SA 3.0
2017-09-10T19:50:34.357Z
These are all very nice links/references, and this is a great answer!
uhoh
CC BY-SA 3.0
2017-09-12T07:15:59.293Z
@uhoh : and thanks for the bounty. Much appreciated.
John Duffield
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2017-09-12T09:23:14.543Z
Answers that teach should always get extra credit :-)
uhoh
CC BY-SA 3.0
2017-09-10T11:56:56.683Z
2017-09-10T11:56:56.683Z
John Duffield
<p>Could the expansion of universe be a side effect of gravity? I mean maybe gravity "attracts things" at a "small" distances and repells them at "larger" distances?</p>

<p>Do we have any theory/hypothesis/paper on this topic? Is it possible to prove or disprove?</p>

<p><strong>UPD.</strong></p>

<p>There is another, more clear way to ask the same question:</p>

<blockquote>
  <p>Could gravity have a repulsive term that dominates at cosmological
  distances and could it be such a term that causes (accelerated)
  expansion?</p>
</blockquote>

<p><em>Thanks to @uhoh and @Richard, for helping to clarify question a bit.</em></p>

CC BY-SA 3.0
2017-09-07T13:10:23.703Z
I think gravity is simply a property of space and it has infinite range(see galaxy filaments,etc) and inflation set in and blew up the universe. So depending on the curvatures of space-time 2 objects can appears to accelerate away from each other. (Sorry not expert but that's how I feel)
user6760
CC BY-SA 3.0
2017-09-07T13:21:04.057Z
I'm voting to close this question as off-topic because this is a poorly defined and unrealistic question.
Carl Witthoft
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2017-09-07T14:06:16.453Z
Where is a poor definition, and how is it off-topic?
Евгений Артеменко
CC BY-SA 3.0
2017-09-07T14:09:57.950Z
Sometimes I think there are bots who place negative comments, there is nothing specific in this comments, nothing related to the topic (inflation in this case)...
Евгений Артеменко
CC BY-SA 3.0
2017-09-07T14:15:28.460Z
The question is on relation between inflation and gravity. Since both has something to do with space, I think, there may be a relation... At least to ask such question is better, than to think "Ah it is all just dark energy" - nonsense.
Евгений Артеменко
CC BY-SA 3.0
2017-09-08T09:53:55.643Z
I suppose you mean accelerated expansion, not expansion (which is just remaining from initial 'big bang', and which should be decelerated if we had a universe with just matter with attractive 'usual' gravity). Am I right ?
Richard
CC BY-SA 3.0
2017-09-10T07:25:31.617Z
This question is clear; could gravity have a repulsive term that dominates at cosmological distances and could it be such a term that causes (accelerated) expansion? Thanks to @Richard for the [clarification](https://astronomy.stackexchange.com/questions/22557/#comment38590_22557).
uhoh
CC BY-SA 3.0
2017-09-10T10:23:14.023Z
@Richard, I think you got me right. I didn't actually know those are two real separate things "expansion remained from initial big bang" and "accelerated expansion". If it will clarify something: I'm talking about expansion of space, not about matter flying out from center "explosion"... Thanks anyway.
Евгений Артеменко
<cosmological-inflation>
Could the expansion of universe be a side effect of gravity?
Евгений Артеменко
# Could the expansion of universe be a side effect of gravity?

(Asked by: username_0 on 2017-09-07)

Could the expansion of universe be a side effect of gravity? I mean maybe gravity "attracts things" at a "small" distances and repells them at "larger" distances?

Do we have any theory/hypothesis/paper on this topic? Is it possible to prove or disprove?

**UPD.**

There is another, more clear way to ask the same question:

> Could gravity have a repulsive term that dominates at cosmological
> distances and could it be such a term that causes (accelerated)
> expansion?

*Thanks to @uhoh and @Richard, for helping to clarify question a bit.*

**Tags:** cosmological-inflation
> **Comments:**
> **username_1**: I think gravity is simply a property of space and it has infinite range(see galaxy filaments,etc) and inflation set in and blew up the universe. So depending on the curvatures of space-time 2 objects can appears to accelerate away from each other. (Sorry not expert but that's how I feel)  
> **username_2**: I'm voting to close this question as off-topic because this is a poorly defined and unrealistic question.  
> **username_0**: Where is a poor definition, and how is it off-topic?  
> **username_0**: Sometimes I think there are bots who place negative comments, there is nothing specific in this comments, nothing related to the topic (inflation in this case)...  
> **username_0**: The question is on relation between inflation and gravity. Since both has something to do with space, I think, there may be a relation... At least to ask such question is better, than to think "Ah it is all just dark energy" - nonsense.  
> **username_3**: I suppose you mean accelerated expansion, not expansion (which is just remaining from initial 'big bang', and which should be decelerated if we had a universe with just matter with attractive 'usual' gravity). Am I right ?  
> **username_4**: This question is clear; could gravity have a repulsive term that dominates at cosmological distances and could it be such a term that causes (accelerated) expansion? Thanks to @Richard for the [clarification](https://astronomy.stackexchange.com/questions/22557/#comment38590_22557).  
> **username_0**: @Richard, I think you got me right. I didn't actually know those are two real separate things "expansion remained from initial big bang" and "accelerated expansion". If it will clarify something: I'm talking about expansion of space, not about matter flying out from center "explosion"... Thanks anyway.  

---

## 1 answers

### Answer by username_5 on 2017-09-10. Score: 2

> Could the expansion of universe be a side effect of gravity?

Well, everything is possible I suppose. And we do see plenty of material that talks about the expansion of the universe as a kind of [repulsive gravity](https://www.google.co.uk/search?source=hp&q=repulsive+gravity&oq=repulsive+gravity&gs_l=psy-ab.3..0l3j0i22i30k1.936.3574.0.4075.18.17.0.0.0.0.150.1992.1j16.17.0....0...1.1.64.psy-ab..1.17.1989.0..46j35i39k1j0i131k1j0i46k1j0i67k1.dPNy5qyeJQI). But I would say no, the expansion isn't due to gravity, and it isn't some side effect of gravity. It's something different.

> I mean maybe gravity "attracts things" at a "small" distances and repels them at "larger" distances?

It doesn't. Gravity attracts things at all distances. It follows the inverse square rule. Some people like Mordehai Milgrom say it doesn't quite follow the inverse square law, see [MOND](https://en.wikipedia.org/wiki/Modified_Newtonian_dynamics). But he isn't saying it repels at large distance.

> Do we have any theory/hypothesis/paper on this topic? Is it possible to prove or disprove?

We have general relativity. In general relativity *gravity sucks*. It doesn't blow.

> Could gravity have a repulsive term that dominates at cosmological distances and could it be such a term that causes (accelerated) expansion?

Like I said, everything is possible. But I will say no, the universe is expanding because of dark energy, not because of gravity. I rather like Erwin Schrödinger’s cosmic pressure myself. See the 2014 [Cambridge companion to Einstein](https://books.google.co.uk/books?id=lXGFAwAAQBAJ&pg=PA268&lpg=PA268&dq=Einstein+%22cosmic+pressure%22&source=bl&ots=uaef6D4cQs&sig=zDKcggRJ01ywTpiBTNPpdmdBYIc&hl=en&sa=X&ved=0ahUKEwjCgfDlmNnUAhVRa1AKHSG_AYgQ6AEIKzAB#v=onepage&q=Einstein%20%22cosmic%20pressure%22&f=false) by Michel Janssen and ‎Christoph Lehner: *“Schrödinger [1918] had pointed out another way of treating the cosmological constant: moving it from the left-hand side of Equation [7], where it represents a contribution to space-time curvature, to the right-hand side, where it represents a contribution to the energy-matter distribution. Then it would correspond physically to a kind of cosmic pressure”*. Unfortunately Einstein didn’t like it. You can read more in Alex Harvey’s 2012 paper [How Einstein Discovered Dark Energy](https://arxiv.org/abs/1211.6338). He gives a translation of Schrödinger’s paper and refers to [Einstein’s response](http://einsteinpapers.press.princeton.edu/vol7-trans/47). If you were to ask a modern cosmologist, I think the answer would be that Schrödinger was pretty close to the mark. See [page 252](https://books.google.co.uk/books?id=GUySYQaDM1cC&pg=PA252&lpg=PA252&dq=lambourne+cosmic+pressure&source=bl&ots=1SQg2svc2s&sig=Rc2w1PAWH_SpCXr1KGurqVCxOqo&hl=en&sa=X&ved=0ahUKEwjqtLWw6d7UAhUHIcAKHc_QDxMQ6AEIJzAB#v=onepage&q=lambourne%20cosmic%20pressure&f=false) of Relativity, Gravitation and Cosmology by Robert J Lambourne:

[![enter image description here](https://i.sstatic.net/msU68.jpg)](https://i.sstatic.net/msU68.jpg)

> **Comments:**
> **username_4**: These are all very nice links/references, and this is a great answer!  
> **username_5**: @uhoh : and thanks for the bounty. Much appreciated.  
> **username_4**: Answers that teach should always get extra credit :-)  

---

