If outer space is infinite why is it black?

Question

Why isn't it white?

Answer 1

Here is why space is black ..

Your question, which seems simple, is actually very difficult to answer! It is a question that many scientists pondered for many centuries - including Johannes Kepler, Edmond Halley , and German physician-astronomer Wilhelm Olbers.

There are two things to think about here. Let's take the easy one first and ask "why is the daytime sky blue here on Earth?" That is a question we can answer. The daytime sky is blue because light from the nearby Sun hits molecules in the Earth's atmosphere and scatters off in all directions. The blue color of the sky is a result of this scattering process. At night, when that part of Earth is facing away from the Sun, space looks black because there is no nearby bright source of light, like the Sun, to be scattered. If you were on the Moon, which has no atmosphere, the sky would be black both night and day. You can see this in photographs taken during the Apollo Moon landings.

So, now on to the harder part - if the Universe is full of stars, why doesn't the light from all of them add up to make the whole sky bright all the time? It turns out that if the Universe was infinitely large and infinitely old, then we would expect the night sky to be bright from the light of all those stars. Every direction you looked in space you would be looking at a star. Yet we know from experience that space is black! This paradox is known as Olbers' Paradox. It is a paradox because of the apparent contradiction between our expectation that the night sky be bright and our experience that it is black.

Many different explanations have been put forward to resolve Olbers' Paradox. The best solution at present is that the Universe is not infinitely old; it is somewhere around 15 billion years old. That means we can only see objects as far away as the distance light can travel in 15 billion years. The light from stars farther away than that has not yet had time to reach us and so can't contribute to making the sky bright.

Another reason that the sky may not be bright with the visible light of all the stars is because when a source of light is moving away from you, the wavelength of that light is made longer (which for light means more red.) This means that the light from stars that are moving away from us will become shifted towards red, and may shift so far that it is no longer visible at all. (Note: You hear the same effect when an ambulance passes you, and the pitch of the siren gets lower as the ambulance travels away from you; this effect is called the Doppler Effect).

Answer 2

The short answer is because black is the absence of colors and since space is infinite there's an infinite amount of nothingness.

The long answer gets quite complicated. Your question draws itself from something called Olbers' Paradox (look it up in wikipedia for a detailed explanation). Olbers paradox says that if every single object in the universe is still, then the night sky should be bright. This is because the brightness of an object does not depend on how far away you are from the object. So this would make every point in the universe bright, making the night sky bright.

The resolution to Olbers' Paradox lies within the fact that the universe is actually EXPANDING. And objects that are moving away from each other get their light red-shifted (to such a degree that it becomes cosmic microwave background radiation, which is not visible to the naked eye). So actually, the universe isn't quite black, there is radiation everywhere whose color is not visible to the naked eye.

Answer 3

First we don't know if it is infinite or not. Secondly let say that space is indeed infinite.
What would make it white? The stars and galaxies?
Saying that space is infinite isn't saying that there is an infinite amount of matter in that space.
In other words our entire universe of stars and galaxies might only be a minuscule speckle of light in that infinite amount of space.
Our most powerful telescopes still show the black background of a theoretically "infinite space".
I'm not even going into M-theory(string theory) which suggests that our universe is a membrane in which its matter cannot escape and is surrounded by many other smaller and larger membranes believed to be in higher dimensions.
Owww, my membrane has a headache now, thanks!

Answer 4

no individual has ever taken an surely image of a black hollow. in view that gentle can not get away a black hollow the in ordinary words thanks to ensure one will be if a telescope or probe took pictures of the gentle of our environment of a black hollow, which could supply us the silhouette of the black hollow. the photographs that we at present have are in ordinary terms an artists concept of what a black hollow would or could seem as if. all the aspects are disintegrated on the shape horizon surrounding a black hollow. All that power is going into the black hollow into inner-dimensional area, previous darkish remember, right into a commonly used reservoir the position power is ultimately transduced and redistributed back into area. Black holes are led to through hypernovas and some supernovas. Exploding stars rip a hollow contained in the textile of area and gravity rushes through such openings as a direction of least resistance. So, black holes are gravity vortexes or wells. A black hollow itself is the textile of area ripped open through an exploding movie star.

Answer 5

From: lifhapnz

Subject: thanks

Message: This aint bible class pal. Keep your biblical answers for the mice





Hi There,

The bible might not seem like a scientific text book, but it sure have many answers even thought God would not tell you how space and darkness was created, but if it did would our puny minds be able to comprehend even if you are Einstein with 1000 PHD in all the fields on earth.

The Genesis bible verses, I actually take some time to post it here, hoping that it will be beneficial to you or someone else, It might not seem to be a very scientific answer but for a lot of people it really solved the question. I didn’t intend to start a bible study here but just to let you know what the bible said about light and darkness perhaps it might solve your answer or someone else with the same question.

But you insult God and by calling me or other bible students a mice, by sending me this E-mail. Let me tell you something, the bible didn’t refer to people as mice, but this is what the bible said about dogs and pigs…

“Do not give what is holy to the dogs, and do not throw your pearls before swine, lest they trample them under their feet, and turn and tear you to pieces” (Matthew 7:6).


Do not misunderstand me, I once was worse than a dog or a pig, but now I am transform man, it is the most wonderful experience.
You swear by science, I walk in faith. I might not be educated as you are but I am just glad that God is in control of things and not man-made science.

Answer 6

First, space is not infinite, but the night sky still appears black because there are finite number of visible stars in the Universe, and the Universe is expanding (as a matter of fact, the expansion of space is accelerating).

So while space is growing exponentially larger every moment, the number of stars in the Universe is not keeping pace because as new stars are born, old stars dies (some become blackholes and some become white or brown dwarf stars). Therefore, there is simply not enough light to fill the sky to make it appear not black.

Answer 7

Despite some very good answers, I suspect (as you implied in your question) that this a damn good indication that space is not infinite.

Too many loopholes in the theories as to why it isn't infinitely bright if, indeed. it is infinitely large.

For example, the most often heard argument: The light hasn't reached us yet. Well that one shoots the hell out Albert's theory that no object can travel faster than the speed of light - either that, or the Big Bang is bogus.

Answer 8

Black is just absence of light .. Outer space is infinite so it take infinite time for light to reach us. so there is no light reaching us from the infinite to us.. ( whatever is there will take another infinite years to reach us ) so till then it will be dark..

Answer 9

HI there...
the outer space is not black. It looks blacks to ur eyes because there is no light.
When sun's rays reach our eyes... we see the space as blue... similarly if there will be light u'll be able to see the space at a different colour...

Answer 10

White is the addition of all the colours in the visible spectrum. Black is the absence of colour.