<p>Here's a simplified answer. "About" the farthest thing we can see with the naked eye is the Andromeda galaxy at about 2 million light years. Therefore, I would say that you just have to be in a void with no galaxies closer than about 2 or 3 million light years. I could be wrong, but I'm thinking that this is most of the known universe. 
   As far as future Earth goes, it won't be about distance, but about when the last star close enough to see "burns out, which will be a VERY long time from now. There may not even be an Earth then, if it is engulfed by the sun going red giant.</p>

CC BY-SA 3.0
2017-01-26T11:50:28.697Z
2-3 million lightyears is nowhere near the radius of the known Universe, which is 47 _billion_ lightyears in radius.
pela
CC BY-SA 3.0
2017-01-29T19:32:06.557Z
@pela .. Sorry, I'm afraid my sentence was ambiguous. What I meant is that, I'm not sure but, I think that most locations in the known universe are at least 2-3 million light from the nearest galaxy.
Jack R. Woods
CC BY-SA 3.0
2017-01-29T20:53:46.620Z
Okay, I see. You're right that this is roughly a typical distance between galaxies in filaments and sheets, but in voids it is much, much more.
pela
CC BY-SA 3.0
2017-01-26T01:03:57.530Z
2017-01-26T01:03:57.530Z
Jack R. Woods
<p>If you don't want to look at the stars and galaxies, you can do two things: You can travel so far that they're too far away to see, or you can block your vision.</p>

<h2>Go far away</h2>

<p>On large scales, i.e. above a billion lightyears or so, the Universe is observed to be roughly homogeneous. On smaller scales, however, matter is distributed in the so-called <em>cosmic web</em>, where galaxies lie in filaments and sheet, meeting each other in knots (where the largest clusters are found). In between these overdensities, there are underdensities known as <a href="https://en.wikipedia.org/wiki/Void_(astronomy)">voids</a>. These voids are virtually free of any luminous matter, and since they're up to several million lightyears across, you could place yourself in the middle of such a void and only see darkness.</p>

<p>As an example, consider a void of 100 Mpc (~300 million lightyears) in radius, corresponding to a distance modulus<sup>1</sup> of $\mu = 35$. If a Milky Way-like galaxy (absolute magnitude<sup>2</sup> $M=-20.5$) were at the border of the void, its apparent magnitude<sup>3</sup> would be $m = M+\mu = 14.5$, invisible to the naked eye.</p>

<p>A small telescope, however, <em>would</em> enable you to see galaxies from here.
The limiting magnitude<sup>4</sup> of the naked eye is roughly 6–7 (though some claim to be able to see $m=8$ objects), so the Milky Way-like galaxy would be roughly 8 magnitudes too faint to see. The gain in limiting magnitude when using a telescope is roughly $g = 5\log(D_\mathrm{tel}/D_\mathrm{pupil})$, so with your 6 mm pupil, a telescope with a diameter of
$$
D_\mathrm{tel} = D_\mathrm{pupil} 10^{g/5} \\
= 6\,\mathrm{mm}\times10^{8/5} \\
\simeq 200\mathrm{-}250\,\mathrm{mm},
$$
would enable you to see Milky Way-like galaxies from the center of the void.</p>

<p>Note though that no matter how far you are from galaxies, there will always be some radiation around, if nothing else then at least the <a href="https://en.wikipedia.org/wiki/Cosmic_microwave_background">CMB</a>. Of course, being microwaves, this is not visible to the naked eye.</p>

<h2>Block your vision</h2>

<p>Apart from going down in your basement and turn off the light, could there be "astronomical" places where you would be unable to see anything? As David Hammen comments, at the surface of a cloud-enshrouded planet or moon, you could face total darkness (at least on the night-side of the planet). But perhaps you could also, as Wayfaring Stranger comments, go inside a dense, interstellar cloud.</p>

<p><a href="https://en.wikipedia.org/wiki/Bok_globule">Bok globules</a> are small ($R\sim10^4\,\mathrm{AU}$), dense ($n\sim10^{4\mathrm{-}6}\,\mathrm{cm}^{-3}$) nebulae of gas and dust. A sightline from the center of such a cloud would result in the apparent magnitude being extincted (i.e. increased) by up to several tens in visual light. The largest extinction through the center of a Bok globule <em>that I've been able to find</em> — but I'm not expert on this — is "FeSt 1-457" with a visual extinction of $A_V = 41$ (<a href="https://arxiv.org/abs/astro-ph/0506205">Kandori et al. 2005</a>), so from the center and out is roughly $A_V\simeq20$. That means that the fraction of light from outside sources that make it into the center is
$$
f = 10^{-A_V/2.5} \sim 10^{-8},
$$
which is not a lot. However, Bok globules are found in the vicinity of young stars which tend to be bright. An O star has an absolute magnitude of $M\simeq-4$. Such a star located right outside the cloud (say, at a distance of $d=2\times10^4\,\mathrm{AU}=0.1\,\mathrm{pc}$) would have an apparent magnitude of $m=M+\mu+A_V\simeq6$, and thus be just visible to the naked eye, albeit very faint. And if it were just a little farther away, you wouldn't be able to see it.</p>

<p>I assume that you're human, but if you are in fact a cichlid, you should be able to see infrared light (<a href="http://link.springer.com/article/10.1007%2Fs00114-012-0980-7">Meuthen et al. 2012</a>). In the IR, the extinction is much smaller than in the visible, so hiding in a Bok globule won't help you.</p>

<hr>

<p><sup>1</sup><sub>The <em>distance modulus</em> $\mu$ is a logarithmic way of expressing distances: $\mu \equiv 5\log(d/10\mathrm{pc})$.</sub></p>

<p><sup>2</sup><sub>The <em>absolute magnitude</em> $M$ is a (logarithmic) measure of the luminosity $L$ of an object: $M=-2.5\log(L)+\mathrm{constant}$. Note the minus sign; the brighter an object is, the smaller $M$ is.</sub></p>

<p><sup>3</sup><sub>The <em>apparent magnitude</em> $m$ is a logarithmic measure of how bright an object looks to an observer, and so depends on the distance to the object: $m = M + \mu$. Stars visible to the naked have roughly $m=0$–$6$. Again, the smaller the number, the brighter the object is. An extremely distant galaxy may have $m=30$, while the Sun has $m=-27$. </sub></p>

<p><sup>4</sup><sub>The <em>limiting magnitude</em> is the largest magnitude (i.e. faintest object) visible.</sub></p>

CC BY-SA 3.0
2017-01-15T03:47:23.740Z
I think the statement you're trying to make is... **No**... but it's hard to tell with all of the extraneous jargon you've used. If that is the case. +1
LaserYeti
CC BY-SA 3.0
2017-01-16T08:31:16.980Z
@LaserYeti: My answer is "Yes, there is such a place; you can put the telescope in the middle of a void", but as I try to explain — using extraneous jargon — it depends on what the OP means with "naked eye strength telescope".
pela
CC BY-SA 3.0
2017-01-16T09:28:09.927Z
I added some footnotes to explain the astronomical terms.
pela
CC BY-SA 3.0
2017-01-16T18:00:41.823Z
@pela - I was meaning as if someone with normal vision were floating in a hypothetical glass bubble with nothing else to aid their vision (telescope, binoculars, etc). Horrific as that sounds.
iMerchant
CC BY-SA 3.0
2017-01-17T09:47:22.913Z
@iMerchant: Okay, in that case you should be fine in the center of a void. Well, perhaps "fine" is not the right word here…
pela
CC BY-SA 3.0
2017-01-17T11:53:07.410Z
@iMerchant: I added a section on hiding in a Bok globule.
pela
CC BY-SA 3.0
2017-01-17T11:53:35.603Z
I wonder what's with the -1…
pela
CC BY-SA 3.0
2018-04-15T22:23:39.610Z
@pela - Why would turning off the light matter? Lol
iMerchant
CC BY-SA 3.0
2018-04-16T09:16:14.147Z
@iMerchant Don't remember why I wrote that. I was probably thinking "no visible light", and not "no visible light from other stars/galaxies"…
pela
CC BY-SA 3.0
2017-01-14T11:10:11.450Z
2017-01-17T11:52:31.993Z
2017-01-17T11:52:31.993Z
pela
<p>Is there a place in the universe where, with the naked eye, you wouldn't see any stars, galaxies or light emitting phenomena? From what I understand at some point into the far future in Earth's location, we wouldn't be able to see anything. Is there a place like that could be like that now?</p>

<p>p.s. Not sure what the appropriate tags to put on this question. Feel free to add/change tags as needed. </p>

CC BY-SA 3.0
2017-01-14T21:02:08.983Z
The surface of Venus or Titan.
David Hammen
CC BY-SA 3.0
2017-01-16T10:41:12.913Z
@DavidHammen Or [Krikkit](http://hitchhikers.wikia.com/wiki/Krikkit)...
zibadawa timmy
CC BY-SA 3.0
2017-01-16T16:57:16.790Z
Quite possibly Bok globules: https://en.wikipedia.org/wiki/Bok_globule
Wayfaring Stranger
<light>
Is there a place in the known universe that there would be no visible light from other stars/galaxies?
iMerchant
# Is there a place in the known universe that there would be no visible light from other stars/galaxies?

(Asked by: username_0 on 2017-01-14)

Is there a place in the universe where, with the naked eye, you wouldn't see any stars, galaxies or light emitting phenomena? From what I understand at some point into the far future in Earth's location, we wouldn't be able to see anything. Is there a place like that could be like that now?

p.s. Not sure what the appropriate tags to put on this question. Feel free to add/change tags as needed.

**Tags:** light
> **Comments:**
> **username_1**: The surface of Venus or Titan.  
> **username_2**: @DavidHammen Or [Krikkit](http://hitchhikers.wikia.com/wiki/Krikkit)...  
> **username_3**: Quite possibly Bok globules: https://en.wikipedia.org/wiki/Bok_globule  

---

## 2 answers

### Answer by username_5 on 2017-01-14. Score: 12 | Accepted answer

If you don't want to look at the stars and galaxies, you can do two things: You can travel so far that they're too far away to see, or you can block your vision.

## Go far away

On large scales, i.e. above a billion lightyears or so, the Universe is observed to be roughly homogeneous. On smaller scales, however, matter is distributed in the so-called *cosmic web*, where galaxies lie in filaments and sheet, meeting each other in knots (where the largest clusters are found). In between these overdensities, there are underdensities known as [voids](https://en.wikipedia.org/wiki/Void_(astronomy)). These voids are virtually free of any luminous matter, and since they're up to several million lightyears across, you could place yourself in the middle of such a void and only see darkness.

As an example, consider a void of 100 Mpc (~300 million lightyears) in radius, corresponding to a distance modulus1 of $\mu = 35$. If a Milky Way-like galaxy (absolute magnitude2 $M=-20.5$) were at the border of the void, its apparent magnitude3 would be $m = M+\mu = 14.5$, invisible to the naked eye.

A small telescope, however, *would* enable you to see galaxies from here.
The limiting magnitude4 of the naked eye is roughly 6–7 (though some claim to be able to see $m=8$ objects), so the Milky Way-like galaxy would be roughly 8 magnitudes too faint to see. The gain in limiting magnitude when using a telescope is roughly $g = 5\log(D\_\mathrm{tel}/D\_\mathrm{pupil})$, so with your 6 mm pupil, a telescope with a diameter of
$$
D\_\mathrm{tel} = D\_\mathrm{pupil} 10^{g/5} \\
= 6\,\mathrm{mm}\times10^{8/5} \\
\simeq 200\mathrm{-}250\,\mathrm{mm},
$$
would enable you to see Milky Way-like galaxies from the center of the void.

Note though that no matter how far you are from galaxies, there will always be some radiation around, if nothing else then at least the [CMB](https://en.wikipedia.org/wiki/Cosmic_microwave_background). Of course, being microwaves, this is not visible to the naked eye.

## Block your vision

Apart from going down in your basement and turn off the light, could there be "astronomical" places where you would be unable to see anything? As David Hammen comments, at the surface of a cloud-enshrouded planet or moon, you could face total darkness (at least on the night-side of the planet). But perhaps you could also, as Wayfaring Stranger comments, go inside a dense, interstellar cloud.

[Bok globules](https://en.wikipedia.org/wiki/Bok_globule) are small ($R\sim10^4\,\mathrm{AU}$), dense ($n\sim10^{4\mathrm{-}6}\,\mathrm{cm}^{-3}$) nebulae of gas and dust. A sightline from the center of such a cloud would result in the apparent magnitude being extincted (i.e. increased) by up to several tens in visual light. The largest extinction through the center of a Bok globule *that I've been able to find* — but I'm not expert on this — is "FeSt 1-457" with a visual extinction of $A\_V = 41$ ([Kandori et al. 2005](https://arxiv.org/abs/astro-ph/0506205)), so from the center and out is roughly $A\_V\simeq20$. That means that the fraction of light from outside sources that make it into the center is
$$
f = 10^{-A\_V/2.5} \sim 10^{-8},
$$
which is not a lot. However, Bok globules are found in the vicinity of young stars which tend to be bright. An O star has an absolute magnitude of $M\simeq-4$. Such a star located right outside the cloud (say, at a distance of $d=2\times10^4\,\mathrm{AU}=0.1\,\mathrm{pc}$) would have an apparent magnitude of $m=M+\mu+A\_V\simeq6$, and thus be just visible to the naked eye, albeit very faint. And if it were just a little farther away, you wouldn't be able to see it.

I assume that you're human, but if you are in fact a cichlid, you should be able to see infrared light ([Meuthen et al. 2012](http://link.springer.com/article/10.1007%2Fs00114-012-0980-7)). In the IR, the extinction is much smaller than in the visible, so hiding in a Bok globule won't help you.

---

1The *distance modulus* $\mu$ is a logarithmic way of expressing distances: $\mu \equiv 5\log(d/10\mathrm{pc})$.

2The *absolute magnitude* $M$ is a (logarithmic) measure of the luminosity $L$ of an object: $M=-2.5\log(L)+\mathrm{constant}$. Note the minus sign; the brighter an object is, the smaller $M$ is.

3The *apparent magnitude* $m$ is a logarithmic measure of how bright an object looks to an observer, and so depends on the distance to the object: $m = M + \mu$. Stars visible to the naked have roughly $m=0$–$6$. Again, the smaller the number, the brighter the object is. An extremely distant galaxy may have $m=30$, while the Sun has $m=-27$.

4The *limiting magnitude* is the largest magnitude (i.e. faintest object) visible.

> **Comments:**
> **username_6**: I think the statement you're trying to make is... **No**... but it's hard to tell with all of the extraneous jargon you've used. If that is the case. +1  
> **username_5**: @LaserYeti: My answer is "Yes, there is such a place; you can put the telescope in the middle of a void", but as I try to explain — using extraneous jargon — it depends on what the OP means with "naked eye strength telescope".  
> **username_5**: I added some footnotes to explain the astronomical terms.  
> **username_0**: @pela - I was meaning as if someone with normal vision were floating in a hypothetical glass bubble with nothing else to aid their vision (telescope, binoculars, etc). Horrific as that sounds.  
> **username_5**: @iMerchant: Okay, in that case you should be fine in the center of a void. Well, perhaps "fine" is not the right word here…  
> **username_5**: @iMerchant: I added a section on hiding in a Bok globule.  
> **username_5**: I wonder what's with the -1…  
> **username_0**: @pela - Why would turning off the light matter? Lol  
> **username_5**: @iMerchant Don't remember why I wrote that. I was probably thinking "no visible light", and not "no visible light from other stars/galaxies"…  

---

### Answer by username_4 on 2017-01-26. Score: 3

Here's a simplified answer. "About" the farthest thing we can see with the naked eye is the Andromeda galaxy at about 2 million light years. Therefore, I would say that you just have to be in a void with no galaxies closer than about 2 or 3 million light years. I could be wrong, but I'm thinking that this is most of the known universe.
As far as future Earth goes, it won't be about distance, but about when the last star close enough to see "burns out, which will be a VERY long time from now. There may not even be an Earth then, if it is engulfed by the sun going red giant.

> **Comments:**
> **username_5**: 2-3 million lightyears is nowhere near the radius of the known Universe, which is 47 _billion_ lightyears in radius.  
> **username_4**: @pela .. Sorry, I'm afraid my sentence was ambiguous. What I meant is that, I'm not sure but, I think that most locations in the known universe are at least 2-3 million light from the nearest galaxy.  
> **username_5**: Okay, I see. You're right that this is roughly a typical distance between galaxies in filaments and sheets, but in voids it is much, much more.  

---

