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Frank Hovis

Why is the night sky dark?

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I read about this many years ago and it is a very good questiion given the vast numbers of stars pumping out light in all directions.

Well now we know.  I find that very satisfying so thank you the scientists of the University of Nottingham, even if they did make it harder on themselves by finding ten times the expected number of galaxies on the way.

http://www.telegraph.co.uk/science/2016/10/13/scientists-solve-riddle-of-why-the-sky-is-dark-at-night/
 

Quote

 

Answering the question of why the sky is dark at night might seem childishly simple, but it has puzzled scientists for generations.

If the universe is infinite, or holds a colossal number of stars, why isn’t it as bright when the Sun goes down, as in the middle of the day? Surely such a huge number of stars should blanket every inch of the night sky with starlight?

Most scientists concluded that the current number of stars – 1 billion trillion -  is too few to make the sky bright if the universe is expanding.

But a painstaking 15 year project by researchers at the University of Nottingham to reassess images from Nasa’s Hubble Space Telescope has found that the number of stars in the observable universe is actually far greater.

In fact, there are at least ten times more galaxies in the night sky than previously thought -  some two trillion - which would mean there is easily enough stars to make the sky bright even during the night.

The scientists have concluded that because these galaxies are so far away their starlight is absorbed by intergalactic dust and gas. They also believe the expansion of the universe stretches lightwaves which increases their wavelength resulting in a shift towards the red end of the spectrum. And red light is more difficult to see.  

 

 

Obvious?  Well you can speculate about these things but proving them is a different matter.  Many people had proposed evolution before Darwin, but having the idea is the easy bit.

 

Now if anybody can explain to me the proof for Fermat's last theorem in a manner which I can understand I would be grateful; though doing that may be harder than proving it in the first place.

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Edgar Allan Poe's explanation of Olber's paradox was enough for me. In fact makes more sense. The intergalactic dust theory does not convince me as the galaxies are observable. "Red light is more difficult to see" is infantile impo.

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I often wonder what it must look like to be on a planet towards the centre of the Milky Way where the density of stars is such that perhaps all you can see is bright light.

I wonder how the visual senses of such beings on those planets would develop and whether, right now, some scientists are theorising the possibility whether there are places in the Universe with no light - whether the Universe is indeed mostly a black darkness.

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1 hour ago, The Masked Tulip said:

I often wonder what it must look like to be on a planet towards the centre of the Milky Way where the density of stars is such that perhaps all you can see is bright light.

I wonder how the visual senses of such beings on those planets would develop and whether, right now, some scientists are theorising the possibility whether there are places in the Universe with no light - whether the Universe is indeed mostly a black darkness.

Wasn't there a SF short story about a triple sun planet which mysteriously succumbed to complete societal breakdown every few hundred years.

Turned-out that that interval coincided with all 3 suns being on one side of the planet and the inhabitants seeing night (and stars) for the first time in generations and realising that they were not alone in the universe,

which drove them all mad.

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"The darkness is coming." - quote from which Sci Fi show? Well, it could probably be from several. I think I heard it in the LOTR films but I am more a Sci Fi guy than a Dungeons & Dragons type.

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This is ridiculous, how is this even a paradox? Even if the observable universe were infinite, if the probability of meeting a star in any given direction decreases as distance tends to infinity, why on earth shouldn't the result be the observed quite dark rather than the supposed bright as the middle of the day? I dispair at scientists sometimes, I honestly think most of them haven't got a clue.

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You would think a finite number of stars in an infinite space would be dark. There's infinitely more space than stars. The space to stars ratio is infinite.

You might well as ask if there's so much pain in the world, why do I feel nothing?

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5 hours ago, XswampyX said:

You would think a finite number of stars in an infinite space would be dark. There's infinitely more space than stars. The space to stars ratio is infinite.

You might well as ask if there's so much pain in the world, why do I feel nothing?

That's what your burd says !!

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12 hours ago, The Masked Tulip said:

I often wonder what it must look like to be on a planet towards the centre of the Milky Way where the density of stars is such that perhaps all you can see is bright light.

I wonder how the visual senses of such beings on those planets would develop and whether, right now, some scientists are theorising the possibility whether there are places in the Universe with no light - whether the Universe is indeed mostly a black darkness.

Can a civilisation become technologically advanced if they never had the need to invent the Toc H lamp?

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