<p>Given that the expansion of the universe shows us that the distance between galaxies (or rather moreso between galaxy clusters) is increasing, without any change in the distances within or between atoms, or between stars within galaxies (apart from normal stellar motion), and that galaxies themselves are also not expanding, we could assume that a contraction would manifest as a decrease in the distances between galaxies/galaxy clusters. </p>

CC BY-SA 4.0
2019-04-02T12:09:43.233Z
2019-04-02T12:09:43.233Z
Mick
<p>Assume that the expansion of the universe stops and it starts to contract again. What would happen?</p>

<p>Would only distances between objects get smaller, or are there other effects we can expect?</p>

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2019-04-02T12:22:45.500Z
Global warming would eventually become less of a thread compared to the CMB.
pela
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2019-04-02T12:40:42.957Z
What timeframe for "effects" do you have in mind? A Big Crunch in xx billion years? What causes the contraction, and is it isotropic (does it apply to the whole universe)? Do the normal laws of physics still apply? NB given that the expansion is currently *accelerating*, you would need this acceleration to reduce to zero, and then the rate of expansion to decline to zero, before contraction can start.
Chappo Hasn't Forgotten
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2019-04-02T12:54:09.210Z
@Chappo 
but if the universe find the limit like a wall or a wave in a cliff?
Nicolas Oñate
<space-time>
What would happen if space-time began to contract?
Nicolas Oñate
# What would happen if space-time began to contract?

(Asked by: username_0 on 2019-04-02)

Assume that the expansion of the universe stops and it starts to contract again. What would happen?

Would only distances between objects get smaller, or are there other effects we can expect?

**Tags:** space-time
> **Comments:**
> **username_1**: Global warming would eventually become less of a thread compared to the CMB.  
> **username_2**: What timeframe for "effects" do you have in mind? A Big Crunch in xx billion years? What causes the contraction, and is it isotropic (does it apply to the whole universe)? Do the normal laws of physics still apply? NB given that the expansion is currently *accelerating*, you would need this acceleration to reduce to zero, and then the rate of expansion to decline to zero, before contraction can start.  
> **username_0**: @Chappo  but if the universe find the limit like a wall or a wave in a cliff?  

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## 1 answers

### Answer by username_3 on 2019-04-02. Score: 1

Given that the expansion of the universe shows us that the distance between galaxies (or rather moreso between galaxy clusters) is increasing, without any change in the distances within or between atoms, or between stars within galaxies (apart from normal stellar motion), and that galaxies themselves are also not expanding, we could assume that a contraction would manifest as a decrease in the distances between galaxies/galaxy clusters.


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