Why is space black?

seriously why is everything black in between stars and beyond them, is there some kind of big blck sheet covering our fish bowl or something.

 

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What is black?
If a room is painted white, why is it black when the lights are out?
Do the white walls get covered by a black sheet?

 

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This is a SCIENCE QUESTION!

STOP.

POSTING.

THINGS.

IN.

THE.

WRONG.

AREA.

 

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And the "blackness" of space is caused by the absence of sufficient light for us to see.

 

I agree that this should be posted elsewhere (unless he makes some yet unforseen philosophical point regarding this).
I have thought about this myself, however...
We have billions upon billions of stars in the universe, correct?
Light travels in the relative vaccuum od space unimpeded, correct?
Unimpeded light does not dissapate, die, fade etc, correct?

I imagine that if you had a telescope that was sufficiently powerful (and outside earth's atmosphere), you could aim it randomly at almost ANY point in the sky, and zoom until you eventually come across a star.

With all of that in mind, it seems that we should expect to see a LOT more "light" at night. Possibly so much that the sky should appear a dim white, with speckles of black in it, no?

 

One Raven:

Think of it this way. When one shines a flashlight right infront of one's face, the light is -very- bright, yes? But what if one moves back several feet? Less bright, no? What about a hundred feet? Less bright, nay? What about a mile? You can barely see it if at all, no? What about ten? I'd be surprised if even the most keen sighted human who has ever lived would still be able to see a flash light's light at that distance. The reason for this is simple, light "spreads out" over space. Here's a horrible rendition of this I just slapped together in MS Paint.

Well...um. Yeah. It keeps on giving me an error, so I hope you can imagine what I am telling you instead.

 

I understand what you are saying, but that's only a part of the story.

As far as I understood it, the main reason light from a flashlight fades is due to refraction/reflection from dust particles in the atmosphere.
Light "travels" in a stright line.
On a clear cool night across flat terrain you can see a flashlight for miles.

We can see light from stars millions of light years away.
As I said, I have been told that in the relative vaccuum of space, light travels forever -in a straight line- if there is nothing to impede it.

 

I think dark matter absorbs alot of light. our universe has a long way to go before enough energy exists to have a very bright night sky from starlight alone. I'm lacking in my astrophysics though, just my thought.

 

This isn't a philosophical question you dumbshit....

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the reason there is so much blackness is because the universe is only ~14 billion years old. the color black is what our mind puts there in place of nothing. there is no light being reflected from that area and so nothing (that we can see) is reaching our eyes.

light from the closest star (alpha centauri) takes over 4 years to reach us. light from the farthest known quasar has taken over 13 billion years to reach us, almost as long as the universe has been around for. that means that 13 billion years ago, light that we see now was just leaving that quasar. who knows if it even exists now.

so, relative to the universe, light takes a long, long time to travel. most of the light in the sky is from millions to billions of years ago. we see blackness because our eyes are not able to see what is really there. whether light from far away or dim objects is reflected off the atmosphere before it reaches us, or because it is higher or lower than the visible spectrum, or because (for the most part) there is simply no light coming from that part of the sky.

 

One Raven: Do a search for "Obler's Paradox"

 

I'm on it, Dinosaur.

 

one_raven:

This is true, on very clear nights you can see the flashlight much further, but one must also realize that eventually the concentration of the light beams in an area the human eye can resolve is so small, as to be incapable of being perceived. With stars, which are essentially spherical, we get this same effect.

Think of it this way: Suppose you have to make ten circles, each twice as large as the last, but you can only use the same amount of ink for the tenth circle as you you did the first and smallest. Wouldn't one end up with only a modest few curved lines every several inches or even feet? A similar thing happens with light. The same amount of light must fill a larger circle, thereby being more diffused.

Yes, but a star throws light in all directions, and we only get some of it.

 

Roy and Dinosaur,
That sums it up pretty well for me.
Thanks.

 

Dinosaur,
Olber's Paradox, by the way.

 

either because the universe is not infinitely big, or it is not infinitley old, is the most commonly accepted reason

 

ok about this bieng posted in the wrong section does anyone want to nit pick about philosophy and how it is nothing to do with scientific theory? i personally thought science was based on theory and i thought a theory was a philosophy excuse me if im wrong, but what im getting at is this, if there are so many stars everywhere and light travels millions and millions of miles why is everything in between the stars black? if you people think im dumb i dont care im just asking a question that i dont know the answer to.

 

assuming i undestand your question: because inbetween the stars it is (basically) a vacuum so there is nothing for the light to reflect off.the only things which can be seen against a back drop of stars would have to be very energetic not merely reflective.its all relative.put a candle 10 metres away from you on a dark night,you can see it fine.now put two 4000candle torches 20cm either side of it and try again.

 

Uhhhh... There's nothing to reflect any light? Color is a reflection of light.

 

The so-called vacuum of space contains particles that absorb and reflect the light. Otherwise space would be white.