English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

2006-07-02 06:03:50 · 15 answers · asked by Anonymous in Science & Mathematics Astronomy & Space

15 answers

The only things in the universe that do not appear black to us are objects that emit light or reflect light to our eyes. That is why we can see the stars (emitting light) and the planets (reflecting light) and nothing else but blackness.

2006-07-02 06:08:21 · answer #1 · answered by Anonymous · 0 0

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).

2006-07-02 13:10:19 · answer #2 · answered by Wilde Enchantress 5 · 0 0

Space is basic black because God knew black goes with everything and makes a good background to show off the stars

2006-07-02 13:21:56 · answer #3 · answered by bergle 2 · 0 0

Ughhh. The universe isn't black because there is NO light. There is TONS of light in space. The sun is extremely bright and shines into our corner of space constantly. Why we see black is because said light isn't REFLECTING off of anything. We can't see actual light, per se, but only reflected light, if that makes sense.

2006-07-02 14:24:56 · answer #4 · answered by A Guy 3 · 0 0

Actually the color of the universe is bluish-green, I saw an article on it a long time ago. But yea, we see the universe as black because that is what "black" is, an absense of light. There is a lot of "nothing" out there, and light doesnt reach there so we see darkness.

EDIT: Pale turquoise to be exact.

2006-07-02 13:06:43 · answer #5 · answered by TheAnomaly 4 · 0 0

I'm not too sure myself, and without looking it up, I'd say outter space appears black because of not enough light reflection and its mass. Plus it allows us to see the stars at night...

2006-07-02 13:08:49 · answer #6 · answered by AJ 4 · 0 0

First of all the is plenty of light in space, it's black because there is nothing there to reflect the light...

2006-07-02 13:08:23 · answer #7 · answered by MC 7 · 0 0

because there is no light in space, except for the stars and when no light is reflected into our eyes, we see black. For example, when we look at a black object, no light is reflected into our eyes because the objject absorbs it all.

2006-07-02 13:05:33 · answer #8 · answered by porky 4 · 0 0

Because the light from stars decreases to the inverse square as distance increases

2006-07-09 08:12:31 · answer #9 · answered by Anonymous · 0 0

because the universe had a beginning and stars have an end

s the numer of visible stars is finite and not enough to make it light

in an infinite universe that had ben here forever it would be uniformly light

2006-07-02 15:31:01 · answer #10 · answered by Epidavros 4 · 0 0

fedest.com, questions and answers