# Why is the sky dark at night? **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [January 8, 2015, 10:25pm UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346 "2015-01-08T22:25:39Z")\ **Posts on this page:** 20\ **Page:** 5
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 26, 2015, 8:37pm UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/81 "2015-01-26T20:37:16Z")
So, you’re saying that a patch of sky much bigger than the full moon being as bright as the full moon is equivalent to every square milliarcsecond of the sky being filled with the surface of a star? ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [January 26, 2015, 9:21pm UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/82 "2015-01-26T21:21:50Z")
> [@](#): > > the light of all the stars located toward the galaxy’s core would easily exceed that of a full moon. If you looked in that direction, you wouldn’t see much else but the combined glow of billions of stars. > > BOOM! Just like I have been saying. But that’s just looking right at the tiny little central core. But just that little dozen light years across region would be brighter than the full moon! No, it doesn’t say that. It says the combined light of **all** the stars located toward the galaxy’s core. The galactic core is massive, and covers several square degrees in the sky. The Moon, on the other hand, covers a small fraction of a square degree. So even if the galactic core plus all the other stars shone as brightly as the full Moon, each square degree would be much dimmer than the full Moon. ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [January 26, 2015, 11:55pm UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/83 "2015-01-26T23:55:13Z")
The dispute is not over the brightness of 200 billion stars, it’s over the assumption that dust isn’t obscuring them. > [@FXMastermind](#): > > It’s dust blocking out all the starlight, and it doesn’t ever glow as bright as a star. > [@eburacum45](#): > > The dust would shine as bright as a star if the universe were infinite and eternal; but it is not. It doesn’t matter if you add on “if the universe were infinite and eternal”, that has nothing to do with the here and now, where the Milky Way is not bright, when it should be. > [@](#): > > Clearly it doesn’t work that way, a puzzle astronomers call “Olbers’s paradox.” Why not? We can nix a few possibilities: The light emitted by the most distant stars is so faint it’s below the threshold of vision. Forget it. You can’t see an individual glowing atom, but you can see zillions of them massed together in a candle flame. **The same ought to hold true of a horde of distant stars**. The most distant stars are obscured by interstellar dust. Won’t work either. The dust would absorb so much light it’d eventually start glowing itself. [http://www.straightdope.com/columns/read/1356/why-is-the-night-sky-dark](http://www.straightdope.com/columns/read/1356/why-is-the-night-sky-dark) “The dust would absorb so much light it’d eventually start glowing itself.” I clearly stated that part is wrong. If it weretrue , the dust obscuring the nearby mass of hundreds of billions of stars should glow brighter than the full moon. The dust and the stars are almost as old as the Universe. The dust doesn’t glow as bright as the stars. It’s an assumption somebody made, but what we observe does not match. There isn’t any part of the Milky Way that we can see, where obscuring dust glows brightly, like starlight. We can check this looking at Andromeda as well. It’s 300, maybe 400 billion stars (estimated), with a huge center. The center should glow bright like a star, but it doesn’t. [image](http://www.noao.edu/image_gallery/images/d5/andromny.jpg) While appearing much smaller than the Milky Way core, it should still be quite bright. But it is very dim instead. Returning to the explanation. > [@](#): > > So what does explain the paradox? After 400 years of debate on the question, there is now fairly wide agreement among astronomers: there just aren’t enough stars in the observable universe to fill up the night sky. [http://www.straightdope.com/columns/read/1356/why-is-the-night-sky-dark](http://www.straightdope.com/columns/read/1356/why-is-the-night-sky-dark) That may be true, but it doesn’t explain why the regions of the sky that are full of stars (or very nearly so, we don’t actually know), also appear dark. Not a mass of glowing starlight. It’s the dust. ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [January 26, 2015, 11:59pm UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/84 "2015-01-26T23:59:40Z")
To make it real simple. If there were 200 billion stars not obscured by dust, and they were near us (like in our Milky Way) the sky would not appear dark when looking at them. In fact, it would be much brighter than a full moon out. We can only see a small fraction of the stars looking towards our own galaxies center. If dust were not blocking the light, it would be very bright. The dust does not glow as bright as the star light it blocks. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 27, 2015, 12:29am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/85 "2015-01-27T00:29:25Z")
The question isn’t “why isn’t the night sky as bright as it is when there’s a full moon?”. The question is “why isn’t the entire night sky blazing with the light of the Sun?”. ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [January 27, 2015, 12:40am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/86 "2015-01-27T00:40:19Z")
> [@Chronos](#): > > The question isn’t “why isn’t the night sky as bright as it is when there’s a full moon?”. The question is “why isn’t the entire night sky blazing with the light of the Sun?”. No, it’s “if the Universe is infinite, then why doesn’t every last point we observe have a star visible?” ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [January 27, 2015, 1:22am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/87 "2015-01-27T01:22:52Z")
> [@FXMastermind](#): > > The dust does not glow as bright as the star light it blocks. Yes. It does. The dust absorbs the light and re-radiates it. Because there is so little light from the galaxy (only a full-moon’s worth, at most) it re-radiates it at a low temperature. The luminosity of the dust is the same as the stars it conceals, except at a different wavelength. If the luminosity of the dust were not the same as the stars inside it, the dust would heat up until it was. Given an infinite and eternal, non-expanding universe, the amount of light re-radiated would equal the incident light, so the dust would be as hot (and as bright) as a star. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [January 27, 2015, 1:47am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/88 "2015-01-27T01:47:19Z")
**FXMastermind** pointed at this ongoing discussion in a GD thread. Did FX just [dissed [del]Cuthulu[/del] Cecil?](http://tvtropes.org/pmwiki/pmwiki.php/Main/DidYouJustFlipOffCthulhu)🙂 As the **Bad Astronomer** points out there are still better explanations other than just dust: [http://blogs.discovermagazine.com/badastronomy/2012/10/01/why-is-the-sky-dark-at-night/](http://blogs.discovermagazine.com/badastronomy/2012/10/01/why-is-the-sky-dark-at-night/) A more detailed explanation can be found here by John Carlos Baez, American mathematical physicist and a professor of mathematics at the University of California, Riverside in Riverside. > [@](#): > > There are many possible explanations which have been considered. Here are a few: > > [ol] > [li]There’s too much dust to see the distant stars.[/li][li] The Universe has only a finite number of stars.[/li][li] The distribution of stars is not uniform. So, for example, there could be an infinity of stars,[/li][li] but they hide behind one another so that only a finite angular area is subtended by them.[/li][li] The Universe is expanding, so distant stars are red-shifted into obscurity.[/li][li] The Universe is young. Distant light hasn’t even reached us yet.[/li][/ol] > > The first explanation is just plain wrong. In a black body, the dust will heat up too. It does act like a radiation shield, exponentially damping the distant starlight. But you can’t put enough dust into the universe to get rid of enough starlight without also obscuring our own Sun. So this idea is bad. > > The premise of the second explanation may technically be correct. But the number of stars, finite as it might be, is still large enough to light up the entire sky, i.e., the total amount of luminous matter in the Universe is too large to allow this escape. The number of stars is close enough to infinite for the purpose of lighting up the sky. The third explanation might be partially correct. We just don’t know. If the stars are distributed fractally, then there could be large patches of empty space, and the sky could appear dark except in small areas. > > But the final two possibilities are surely each correct and partly responsible. There are numerical arguments that suggest that the effect of the finite age of the Universe is the larger effect. We live inside a spherical shell of “Observable Universe” which has radius equal to the lifetime of the Universe. Objects more than about 13.7 thousand million years old (the latest figure) are too far away for their light ever to reach us. > > Historically, after Hubble discovered that the Universe was expanding, but before the Big Bang was firmly established by the discovery of the cosmic background radiation, Olbers’ paradox was presented as proof of special relativity. You needed the red shift to get rid of the starlight. This effect certainly contributes, but the finite age of the Universe is the most important effect. ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [January 27, 2015, 1:58am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/89 "2015-01-27T01:58:32Z")
You switched from brightness to luminosity. > [@eburacum45](#): > > The luminosity of the dust is the same as the stars it conceals, except at a different wavelength. > [@FXMastermind](#): > > The dust does not glow as bright as the star light it blocks. The assumption that was used to declare Olbers wrong, was that the dust would glow as brightly as the star light it blocked. Not "the dust will re-radiate the star light as infrared, which we can’t see, so the sky will seem dark ". If that is the reasoning, it means Olbers was right, when he decided it was dust blocking the light from distant stars. Olbers was explaining why a sky full of stars (an infinite number) wouldn’t appear bright. If the sky was indeed a star in every last point of space, it wouldn’t be bright. Because of what we know from our own galaxy. The dust blocks the light. ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [January 27, 2015, 2:03am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/90 "2015-01-27T02:03:52Z")
> [@GIGObuster](#): > > As the **Bad Astronomer** points out there are still better explanations other than just dust: I didn’t see your post before my previous post. The dust is being discussed because it does block our own galaxies light, but doesn’t glow brightly, like the stars it is hiding from sight. > [@FXMastermind](#): > > The dust does not glow as bright as the star light it blocks. This is just an observation of reality, as it appears in our sky, right now. Certainly the galactic center of our Milky Way would be a very bright thing except for the dust. Remember we can only see 6000 light years towards the core. It’s maybe 25,000 light years away. There is no doubt that right now, there is no evidence that dust that blocks stars ever glows as bright as the stars. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [January 27, 2015, 2:08am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/91 "2015-01-27T02:08:17Z")
> [@FXMastermind](#): > > Olbers was explaining why a sky full of stars (an infinite number) wouldn’t appear bright. If the sky was indeed a star in every last point of space, it wouldn’t be bright. Because of what we know from our own galaxy. The dust blocks the light. Olbers was wrong. If the sky was full of stars then the dust would absorb the heat and re-radiate it at the same temperature, because there would be nowhere for the heat to go. You can only radiate the heat into a dark sky; if you try to radiate into a bright sky the flux inwards will be the same as the flux outward. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [January 27, 2015, 2:16am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/92 "2015-01-27T02:16:32Z")
> [@FXMastermind](#): > > Certainly the galactic center of our Milky Way would be a very bright thing except for the dust. Remember we can only see 6000 light years towards the core. It’s maybe 25,000 light years away. There is no doubt that right now, there is no evidence that dust that blocks stars ever glows as bright as the stars. Still wrong, no matter how many times you say it. The brightest estimate you have found so far is that the entire centre of the galaxy would be as bright as the Full Moon, if there were no dust; the galactic bulge subtends an area about 25° × 10°, whereas the Moon is only half a degree across. Each square degree would shine with about 1/500th the brightness of the Moon, assuming no dust. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [January 27, 2015, 2:18am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/93 "2015-01-27T02:18:38Z")
> [@FXMastermind](#): > > Olbers was explaining why a sky full of stars (an infinite number) wouldn’t appear bright. If the sky was indeed a star in every last point of space, it wouldn’t be bright. Because of what we know from our own galaxy. The dust blocks the light. Not enough dust, and it does not explain why in the many more areas of the observable universe outside the galactic plane, with less dust, is that we cannot see more stars. As I see what they are teaching currently in universities about Astronomy, I do not think this dust theory can hold a candle to what Edgar Alan Poe realized just by intuition, before Hubble and others could explain it scientifically: > [@](#): > > Based on what you have learned so far, you may have a few questions. > > [ul] > [li]Does it matter that we considered stars and not galaxies? No, because the same logic holds for galaxies. If every one of your sight lines ended on a galaxy, the night sky would be bright.[/li][li] [/li][li] Is there enough dust in the Universe to block our sight lines to some stars or galaxies? Yes, but if the Universe was infinite and with an infinite number of stars and galaxies, the light from those objects would heat up the dust causing it to glow brightly enough to light up the night sky.[/li][/ul] > > The solution to the paradox (why is the night sky dark?) could be due to several different possibilities: > [ol] > [li]The universe is finite, that is, it ends at some point.[/li][li] The stars run out at large distances.[/li][li] There hasn’t been enough time for the light to reach us from the most distant stars.[/li][/ol] > > We will find out shortly that we can actually estimate the age of our universe. Because the universe is not infinitely old, the answer is number 3 listed above. Since light takes time to reach us, we can see only those objects that are near enough to us that their light has reached us. Curiously enough, the first published solution to Olbers’ Paradox is attributed to Edgar Allan Poe. In his essay Eureka, Poe says: > > > [@](#): > > > > Were the succession of stars endless, then the background of the sky would present us an uniform luminosity, like that displayed by the Galaxy - since there could be absolutely no point, in all that background, at which would not exist a star. The only mode, therefore, in which, under such a state of affairs, we could comprehend the voids which our telescopes find in innumerable directions, would be by supposing the distance of the invisible background so immense that no ray from it has yet been able to reach us at all. > > While we know the solution today for Olber’s Paradox, it took until well into the 20th century for us to truly understand the nature of the Universe well enough to explain the answer to this question. In the rest of this lesson you will find out how we came to understand the Universe and prove to ourselves the reason the night sky is dark. ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [January 27, 2015, 2:30am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/94 "2015-01-27T02:30:08Z")
> [@GIGObuster](#): > > As I see what they are teaching currently in universities about Astronomy You are required to provide the source when you quote somebody. > [@](#): > > Based on what you have learned so far, you may have a few questions. > > Does it matter that we considered stars and not galaxies? No, because the same logic holds for galaxies. If every one of your sight lines ended on a galaxy, the night sky would be bright. [https://www.e-education.psu.edu/astro801/content/l10\_p2.html](https://www.e-education.psu.edu/astro801/content/l10_p2.html) That claim is even easier to debunk. The nearby Andromeda Galaxy isn’t bright. In fact, if the entire sky was filled with galaxies that close, the sky would still seem dark. > [@GIGObuster](#): > > Not enough dust, and it does not explain why in the many more areas of the observable universe outside the galactic plane, with less dust, is that we cannot see more stars. You are talking about the actual issue of the number of galaxies we can see (because outside of our galaxy, you won’t ever see a regular star). That isn’t the question about the dust. Both the Milky Way and the Andromeda galaxy do not appear bright, nor does the obscuring dust glow like star light. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [January 27, 2015, 3:16am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/95 "2015-01-27T03:16:52Z")
> [@FXMastermind](#): > > The nearby Andromeda Galaxy isn’t bright. How bright do you think the Andromeda Galaxy would be if there were no dust obscuring its light? If it has 400 billion stars, with an average brightness similar to the Sun, and assuming no dust, the total brightness turns out to be mag. 0.2, about the same as Rigel. In fact, because the Andromeda Galaxy is turned sideways on to us, the dust inside it does not obscure the light of its stars very efficiently. Dust is not sufficient to explain the obscuration of galaxies. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 27, 2015, 3:35am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/96 "2015-01-27T03:35:35Z")
> [@](#): > > Quoth **FXMastermind** : > > No, it’s “if the Universe is infinite, then why doesn’t every last point we observe have a star visible?” This is the same thing as what I said. If every last point we observed had a star visible, then the entire sky would blaze like the surface of the Sun. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [January 27, 2015, 3:43am UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/97 "2015-01-27T03:43:09Z")
> [@eburacum45](#): > > How bright do you think the Andromeda Galaxy would be if there were no dust obscuring its light? If it has 400 billion stars, with an average brightness similar to the Sun, and assuming no dust, the total brightness turns out to be mag. 0.2, about the same as Rigel. > > In fact, because the Andromeda Galaxy is turned sideways on to us, the dust inside it does not obscure the light of its stars very efficiently. Dust is not sufficient to explain the obscuration of galaxies. Indeed, and I have to apologize for forgetting the source, in any case, FX pointed at it but he is missing another point, almost all the experts and academics do not agree with him. As usual. [http://ephemeris.sjaa.net/0607/h.html](http://ephemeris.sjaa.net/0607/h.html) > [@](#): > > Olbers again started with the idea of concentric spheres although, instead of summing up the star light, he summed up the area of visible stellar disks. Halley and Cheseaux assumed that the stars are uniformly distributed. Olbers did not but he determined that it wouldn’t make much difference. > > Neither Cheseaux nor Olbers took into account that some foreground stars would block (occult) background stars but that would mean they need even more stars. In 1848, the attenuating dust answer was blown out of the water by John Herschel. If you have that much radiation hitting dust, that dust must have absorbed so much radiation that it must reradiate it back into space. Thus, if the sky isn’t filled with the light of stars, it would be filled with the light of irradiated dust. > > Another possibility is that stars are not distributed equally. For example, fractals have been shown to mimic nature’s distribution capabilities. A fractal distribution of stars might result in a lot of gaps which causes the sky to be mostly dark. In fact, the latest detailed pictures of the CMB look like they might be a fractal. This possible solution was put forward by the person most closely associated with fractals, Benoit Mandelbrot. > > The idea that it is the expansion of the universe that answers Olbers was promulgated by Hermann Bondi’s reformulation of the Olbers’ paradox. From 1948-1965 it was widely held that the universe was in a steady state. After Hubble demonstrated the universe is expanding, the steady state proponents saw this as a possible answer to Olbers’ Paradox: if there is a major systematic motion in the Universe, namely Hubble’s expansion, then some of Olbers’ assumptions are not correct. According to Wesson, this made some sense before the big-bang theory but not so much after it. Wesson says that the expansion answer was “uncritically repeated in research work and … textbooks” because there was “no account of the relative importance of the expansion and finite-age factors”. > > Wesson used a computer model to compare these two possible answers to this paradox: expansion versus the finite age of the universe. His program was based on principles of General Relativity. One key point of GR is that the light from sources moving away from us is still traveling at the speed of light regardless of the speed of the source. Using input data such as the age of the galaxies and the rate of expansion it calculates the extragalactic background light. Then Wesson ran the model again setting the rate of expansion to zero. The result in both cases was exactly what we see: a dark sky. But setting the rate of expansion to zero only made it slightly darker. Most astronomers now agree that the finite age of the universe is the primary answer to the paradox. And consider the answer to Olbers’ when thinking about Fermi’s Paradox – they haven’t had time to reach us yet. ---
**Author:** ![FXMastermind](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fxmastermind/32/7289_2.png) [@FXMastermind](https://boards.straightdope.com/u/FXMastermind)\ **Post date:** [January 28, 2015, 9:37pm UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/99 "2015-01-28T21:37:14Z")
> [@eburacum45](#): > > The brightest estimate you have found so far is that the entire centre of the galaxy would be as bright as the Full Moon, if there were no dust; No, that isn’t what the article said. > [@](#): > > The fact is that interstellar dust obscures more than just this central region. It also dims the light of billions of foreground stars, as well as stars surrounding the core itself. > > If there were no dust between us and the galactic center, the light of all the stars located toward the galaxy’s core would easily exceed that of a full moon. If you looked in that direction, you wouldn’t see much else but the combined glow of billions of stars. [EarthSky | What the center of the galaxy looks like](http://earthsky.org/space/what-does-the-center-of-the-galaxy-look-like) That is exactly what my point about dust was about. First, if there were no blocking dust, the sky would be much much brighter, just looking towards the core would be brighter than the full moon. (the rest of the galaxy, especially the stars closer to us, would be much brighter as well) Second, even with the dust and stars being almost as old as the Universe, there is no dust blocking out the stars, glowing as bright as stars. Herschel dismissed the very idea that dust could be a reason for the sky to be dark, and I am showing that reality does not match this. You change the goal post to “in an infinite Universe with infinite stars it would”, and I say from the view of reality, that does not mean what I pointed out is wrong. In reality, dust is exactly why the areas of our sky, that we know are almost a solid mass of stars, (like the paradox deal with), doesn’t glow brightly. And dust is the reason. And the dust does not heat up and glow as bright as starlight. The paradox may very well be resolved by the fact there isn’t an infinite Universe, and there aren’t enough stars, and the redshift dims distant galaxies, but none of that changes the facts about obscuring dust. If there actually were a solid sky of galaxies, no redshift, the sky were solid stars, like Andromeda and the Milky way, in every last direction we can see, it would still look dark. Just as the Milky Way and Andromeda look dark, in the actual real sky at night. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 28, 2015, 9:52pm UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/100 "2015-01-28T21:52:24Z")
A sky lit by the equivalent of a full moon is still a night sky, and it’s still by most standards dark. It is not even remotely similar to a sky blazing with the fire of the Sun, which is what Olber’s paradox is about. ---
**Author:** ![BruceVoigt](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@BruceVoigt](https://boards.straightdope.com/u/BruceVoigt)\ **Post date:** [January 28, 2015, 10:45pm UTC](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346/101 "2015-01-28T22:45:46Z")
> [@BruceVoigt](#): > > Unknown to education and science are the true workings of fire, water, air, light, magnetism, sound, sight, cold, hot, electricity, earthquakes, tides – and I could go on and on. I ask you, without knowing the truth of such things, how in bloody hell can one determine the simple working of our universe?!Like every cell, molecule, quark, planet, moon or star incorporates a black hole at its nucleus. Instigated reactions to a black hole produce its atomic reactions. > > INSTIGATED REACTION is the black hole’s intake or its nutritional feeding of Bruce’s Stuph (particles). > > Like all cells etc, our Sun spews its info cells or atomic energy. This energy atomically interacts creating heat, creating light with most of what it encounters, the smallness of Bruce’s Stuph (dark matter, energy) being one exception. > > From this encounter or collision, created light feeds on the Aura or Info Cells (Bruce’s Stuph) of what it has come in contact with. Using this continuous magnetic energy connection, info cells of Earth are affectively transported to the sun to be used as nutrition or fuel of its black hole. This of course means we’re no longer #1 on the food chain! > > Our sun is a cold, cold activated black hole. It appears to us as being hot and bright but it is not. What we observe as a fiery object is in fact collision or reaction between the force emitting from this black hole and the accumulation of packed STUPH – the sun’s digestive system if you like. > > When you stand back from a fire you no longer feel its heat. The sun being no exception; we do not receive heat and light from the sun’s outer fire! > > If we could see into the center of the Earth it would appear to us as being hollow (black hole). It’s the same for all cells of matter. > > The Earth’s digestive system is that of the sun’s, the difference being size, speed and quantity. To explain these statements multiply the heat and light of just one meteor (shooting star). > > Go out on a dark, starry night; every star that you can see is producing food (dark matter) that feeds our Earth’s black hole! The energy created from this food is like any other cell and spews from its poles. Our Earth’s atmosphere, including everything out from its black hole, has and is being created from this energy! A black God if you like! > Think HOT as being nuclear particles orbiting in chaotic orbit directions and Cold being chaotic nuclear particles orbiting harmonically in same orbit directions. (cause a reaction) blow on your hand. And if that did not screw you people up I will mention and you will agree when you to discover what sound really is, is that sound is much faster than light. PS - my education is grade eight, nine if they had not failed me! [Previous page](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346.md?page=4) [Next page](https://boards.straightdope.com/t/why-is-the-sky-dark-at-night/709346.md?page=6)