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Dexter_Neo
Dexter_Neo • Jun 16, 2008

Why Space is so dark?

Hi CE's,

I always had this doubt in my mind that Why Space is so dark?.I used to think that if a small Bulb can lighten a room.Sun can lighten our nine planet's though its a yellow dwarf star.Now there are billions of star's out there in space but still the space is so dark.why???????????????
Kaustubh Katdare
Kaustubh Katdare • Jun 16, 2008
Dexter_Neo
Hi CE's,

I always had this doubt in my mind that Why Space is so dark?.I used to think that if a small Bulb can lighten a room.Sun can lighten our nine planet's though its a yellow dwarf star.Now there are billions of star's out there in space but still the space is so dark.why???????????????
Okay, I'll try to answer this in simple words:

The answer lies in the question itself. A small bulb can lighten up a big room. But couple of LEDs can't lighten up a BIG room!

How about that? 😀
Dexter_Neo
Dexter_Neo • Jun 16, 2008
Hmmm But m sure billions of LED's would surely do.If u r trying to say that universe is very huge and even billions of star r not enough to lighten it up,then i am not convinced coz u see light travels and by god's grace it travels really fast now think abt billions of stars and the brightness produced by them..!!!!!!!!!!!!!!!!!!!!!

I guess thats lots of lumens we r talking abt.............isnt it?
MaRo
MaRo • Jun 16, 2008
Stuff are visible when light reflects on it, space is like air if you're in dark room & lighten up a bulb you can see wall, desk...etc stuff that light reflects on & then our eyes can realize it but you can't see air.

The same thing in space you can see planets, moons & objects that are visible to the sun but this space doesn't reflect light.
Kaustubh Katdare
Kaustubh Katdare • Jun 16, 2008
Dexter_Neo
Hmmm But m sure billions of LED's would surely do.If u r trying to say that universe is very huge and even billions of star r not enough to lighten it up,then i am not convinced coz u see light travels and by god's grace it travels really fast now think abt billions of stars and the brightness produced by them..!!!!!!!!!!!!!!!!!!!!!

I guess thats lots of lumens we r talking abt.............isnt it?
There are billions of stars, however considering the size of the universe (which is infinite & expanding continuously), they are like tiny LEDs in a big dark room.
gohm
gohm • Jun 16, 2008
Biggie got it, due to the vast distances between stars. The stars are scattered so distant & the universe so vast that the stars only look tightly packed to our vantage point. Space is mostly void and being primarily a vacuum, few particulates to absorb/reflect light spectrum to produce what we perceive as color. One flashlight cannot light up an entire house, most of the house remains dark. However one flashlight in each house of a neighborhood if viewable from afar would look like a cluster.
Alexander
Alexander • Jun 17, 2008
You know what i think, i think you ugys should wonder why is it dark.?..is its original color dark?..is everything not colored, dark?. why is it that we dont find that atmosphere near our planet?. does the air hear make it differnt., but that would just defy the theroy tht air is around us, becoz then we could have seen it?...
gohm
gohm • Jun 17, 2008
The atmosphere is light & colored because of its composition. The Tyndall effect causes the color due to the blue light being scattered more because of its shorter wavelegnth by molecules in the atmosphere. The lightness is from both the sun, either directly with that side of the planet facing the sun and also indirectly via moon/earth glow. Sunrise/sunsets appear orange/red because you are seeing the sun through the furthest distance of atmosphere for its light to travel so only the red/yellow wavelengths make it through visually.

Actually, nothing is really colored, that is only how our light based vision perceives things based on light reflection/absorbtion properties of compounds.
Dexter_Neo
Dexter_Neo • Jun 18, 2008
yeah true...."Actually, nothing is really colored, that is only how our light based vision perceives things based on light reflection/absorbtion properties of compounds".

thats the reason we see sky blue most of the time's coz it scatters the most according to Rayleigh's criteria for scattering of light.

But my qyestion was about space.........
now some body posted that we should wonder if it is black.True I guess there is nothing in space to reflect the light.Its void

For visibility we need three things most importantly,They are
1.light
2.object
3 Eyes to see it

Now in space we have light and by god's grace we have beautifull eyes to see things also.But we dont have any "Object" there to see.No object hence no reflection hence the darkness.................

What do u guys have to say on this.?
MaRo
MaRo • Jun 18, 2008
Even if we have a huge sun that can relatively lighten up all the universe we don't have a wall at the end of the universe to reflect light and make everything visible.
Dexter_Neo
Dexter_Neo • Jun 18, 2008
yes exactly ...........I agree that's what i was trying to say .that nothin is there to reflect the light.................
prakash.athani
prakash.athani • Jul 7, 2008
It is believed by physicists and cosmologists that space contains huge amount of cold dark matter which is present thoughout the space, and by its very name, is invisible.

But this cold dark matter is constantly absorbing all the light radiation from stars, clusters of stars and galaxies. When this cold dark matter heats up enough, it will give out radiation back to space.

If we live upto that time then we may see the light coming from space but not from any sources. Our children may believe that space itself is source of light or light is coming from huge clouds of matter, apart from stars
gaurav.bhorkar
gaurav.bhorkar • Sep 25, 2008
Dexter_Neo
Hi CE's,

I always had this doubt in my mind that Why Space is so dark?.I used to think that if a small Bulb can lighten a room.Sun can lighten our nine planet's though its a yellow dwarf star.Now there are billions of star's out there in space but still the space is so dark.why???????????????
Its very simple.
on earth we see bright light because of the presence of atmosphere.
As atmosphere contains suspended particulate matter (SPM) (eg. Dust) it reflects light which which spreads all around.

In space there is no atmosphere, and hence no spreading of light.
Therefore we can see different planets with darkness all around them.
bluegeek
bluegeek • Dec 8, 2008
I believe the answer lies when we would compare a single system like our solar system..

More than 99% of our solar system is vaccum and hence light is not reflected from there..remember it is dust particles in Sky that give it blue color..similarly in space wherever spatial dust has been accumulated is lit up like anything...try t look for pictures of any 'Nebula'.

Hence as there is nothing to reflect light and that radiation loses energy when travelling even through empty space causes space to be so dark..
yash.kumar
yash.kumar • Sep 17, 2009
hey all, actually the thing is that we see something just because light is reflected by it. now, the outer Space is closest approximation of perfect vacuum. that is, it has almost nothing. It is rubbish to say that we will see something other than dark if we put billions of lights or LEDs etc. No matter how many light sources be there, but the light from them will not be reflected. The planets , asteroids etc are visible just because they reflect light coming from soureces like galaxies, etc.
Now if we want to see a white universe or white space, than it is only possible when the universe will be infinite. This is known as " OLBERT's Paradox"
Red Hawk
Red Hawk • Sep 20, 2009
prakash.athani
It is believed by physicists and cosmologists that space contains huge amount of cold dark matter which is present thoughout the space, and by its very name, is invisible.

But this cold dark matter is constantly absorbing all the light radiation from stars, clusters of stars and galaxies. When this cold dark matter heats up enough, it will give out radiation back to space.
It is true that all colors reflect other colors and absorb that color.. If i wear an orange shirt, then in the sunlight it absorbs only orange color and reflects all other colors.. But black color has a tendency to absorb all colors and reflect none.. That's why it is advised not to wear black dresses on sunny days because it wold absorb all radiation and get heated up..
I think this would be the reason for the space looking black or dark too.
What do you think?

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