<p>Your friend is right (in a way), see tables in <a href="https://academic.oup.com/mnras/article/516/2/2281/6678564" rel="nofollow noreferrer">Shamir 2022</a> and introduction there-in:</p>
<p>Galaxy spin axes are „aligned“ to the large scale structure of the universe and in turn these large scale structures are believed to have formed due to <a href="https://en.wikipedia.org/wiki/Inflation_(cosmology)" rel="nofollow noreferrer">inflation</a>, which is believed to be the first epoch of the expansion of the universe.</p>
<p>The „in a way“ part means that this holds for certain definitions of „aligned“, which very likely are not what your friend had in mind:</p>
<p>E.g. there are „significant“ deviations e.g. from the assumption that galaxies should spin either way (clock-wise vs. counter-clock-wise) when looking in a certain direction. The effect is rather small and on the order of 1%. This does <em>not</em> mean that spin axes are going into the same direction.</p>
<p>Caveats also apply to <a href="https://xkcd.com/882/" rel="nofollow noreferrer">significance</a> and this result is likely going to be debated in future as new data becomes available.</p>
<p>Thanks for this brain teaser, it was fun researching that!</p>

CC BY-SA 4.0
2024-06-06T04:57:06.097Z
Maybe you should say that the claimed effect is of order 1% and that other researchers don't find it.
ProfRob
CC BY-SA 4.0
2024-06-06T12:52:07.370Z
@profrob 1%, with an uncertainty of .002%. Have other researchers tried to reproduce the results? The data from the Desi Survey is publicly available.
Miss Understands
CC BY-SA 4.0
2024-06-06T13:59:18.077Z
@Miss_Understands Clearly, the statistical noise is not the only, or the most important, element since other researchers with different sampes and different methodologies have arrived at different conclusions. And it is fair to mention that.
ProfRob
CC BY-SA 4.0
2024-06-05T21:39:05.393Z
2024-06-06T05:48:46.337Z
2024-06-06T05:48:46.337Z
Grimaldi
<p>My friend thinks that the expansion of the the universe should cause the galaxies on the same side of the sky to be aligned.</p>
<p>I don't believe that because I haven't seen any evidence of it, but he came up with that idea when he read about the axis of evil. <a href="https://www.space.com/37334-earth-ordinary-cosmological-axis-evil.html" rel="nofollow noreferrer">https://www.space.com/37334-earth-ordinary-cosmological-axis-evil.html</a></p>
<p>Is there correlation in galactic rotation axes between ANY groups of galaxies, old / young, distant /close, etc?</p>
<p>I suspect not, but I wanted to make sure.</p>

CC BY-SA 4.0
2024-06-05T18:18:24.850Z
Why does your friend think that the expansion of the universe should cause such alignment? That is, what process could result in a non-random distribution of the galaxies' rotation axes?
PM 2Ring
CC BY-SA 4.0
2024-06-05T18:43:24.217Z
I don't want to justify this because I really am not the one who thinks it. Bu my housemate was thinking about things like revolving planets rotating, and the individual rotating "cups" in the tilt-a-whirl ride. I mainly wanted to assure myself this is not the case. It appears not to be. if nobody else says anythimg; I'll just close this. ty.
Miss Understands
CC BY-SA 4.0
2024-06-05T18:51:10.853Z
I think the coriolous(sp) force was supposed to do it.
Miss Understands
CC BY-SA 4.0
2024-06-06T09:19:53.520Z
different but related (and interesting): [Do we know two neighbor galaxies that are parallel?](https://astronomy.stackexchange.com/q/55507/7982) and [How co-planar and co-rotatory are the Milky Way and its constituents?](https://astronomy.stackexchange.com/q/40755/7982)
uhoh
<galaxy>
Are the rotational axes of galaxies ever aligned?
Miss Understands
# Are the rotational axes of galaxies ever aligned?

(Asked by: username_0 on 2024-06-05)

My friend thinks that the expansion of the the universe should cause the galaxies on the same side of the sky to be aligned.

I don't believe that because I haven't seen any evidence of it, but he came up with that idea when he read about the axis of evil. <https://www.space.com/37334-earth-ordinary-cosmological-axis-evil.html>

Is there correlation in galactic rotation axes between ANY groups of galaxies, old / young, distant /close, etc?

I suspect not, but I wanted to make sure.

**Tags:** galaxy
> **Comments:**
> **username_1**: Why does your friend think that the expansion of the universe should cause such alignment? That is, what process could result in a non-random distribution of the galaxies' rotation axes?  
> **username_0**: I don't want to justify this because I really am not the one who thinks it. Bu my housemate was thinking about things like revolving planets rotating, and the individual rotating "cups" in the tilt-a-whirl ride. I mainly wanted to assure myself this is not the case. It appears not to be. if nobody else says anythimg; I'll just close this. ty.  
> **username_0**: I think the coriolous(sp) force was supposed to do it.  
> **username_2**: different but related (and interesting): [Do we know two neighbor galaxies that are parallel?](https://astronomy.stackexchange.com/q/55507/7982) and [How co-planar and co-rotatory are the Milky Way and its constituents?](https://astronomy.stackexchange.com/q/40755/7982)  

---

## 1 answers

### Answer by username_3 on 2024-06-05. Score: 2 | Accepted answer

Your friend is right (in a way), see tables in [Shamir 2022](https://academic.oup.com/mnras/article/516/2/2281/6678564) and introduction there-in:

Galaxy spin axes are „aligned“ to the large scale structure of the universe and in turn these large scale structures are believed to have formed due to [inflation](https://en.wikipedia.org/wiki/Inflation_(cosmology)), which is believed to be the first epoch of the expansion of the universe.

The „in a way“ part means that this holds for certain definitions of „aligned“, which very likely are not what your friend had in mind:

E.g. there are „significant“ deviations e.g. from the assumption that galaxies should spin either way (clock-wise vs. counter-clock-wise) when looking in a certain direction. The effect is rather small and on the order of 1%. This does *not* mean that spin axes are going into the same direction.

Caveats also apply to [significance](https://xkcd.com/882/) and this result is likely going to be debated in future as new data becomes available.

Thanks for this brain teaser, it was fun researching that!

> **Comments:**
> **username_4**: Maybe you should say that the claimed effect is of order 1% and that other researchers don't find it.  
> **username_0**: @profrob 1%, with an uncertainty of .002%. Have other researchers tried to reproduce the results? The data from the Desi Survey is publicly available.  
> **username_4**: @Miss_Understands Clearly, the statistical noise is not the only, or the most important, element since other researchers with different sampes and different methodologies have arrived at different conclusions. And it is fair to mention that.  

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