• Question: is space really black, if so, why?

    Asked by cookie to Betul, Bridget, Ceri-Wyn, Laurel, Maria on 23 Jun 2010 in Categories: .
    • Photo: Ceri-Wyn Thomas

      Ceri-Wyn Thomas answered on 16 Jun 2010:

      Oh I like this question. Space isn’t really any colour. Space isn’t really a thing itself- more an absence of things! The reason Space looks black is because if how we see colours: We see colours through different wavelengths of light bouncing off objects- some of the light is absorbed by the object and some bounces back to our eyes. In Space we can see sources of light like stars and we can see things that reflect light like planets and gas clouds. If there are no objects in Space to reflect any light then we won’t see them and we don’t see the packets of light travelling through space themselves. That’s why ’empty’ Space looks black.

      Also- did you know that if you were to mix all the colours in the Universe together you would get the colour beige! (I learnt that on Qi)

    • Photo: Laurel Fogarty

      Laurel Fogarty answered on 17 Jun 2010:

      Ok are you ready for this?? the answer is hard core physics…Yes space is dark…

      The fact that space is dark shows that the Universe is finite in age. Light travels at a constant speed. If the Universe were static, if you looked out in any direction you would eventually see light coming from some matter somewhere. And with an infinite amount of time for the light to travel to us, we would see uniform light all over the sky. So the Universe must be finite and not static (ie it is evolving). It’s called Olber’s paradox.

    • Photo: Bridget Waller

      Bridget Waller answered on 21 Jun 2010:

      I guess because the absence of light = black.

    • Photo: Betul Arslan

      Betul Arslan answered on 23 Jun 2010:

      Tough question! Actually the space is not really black, remember when during the day the sky is blue and in the night the sky is dark, so that tells us that the color of the sky has to do with the distance of earth from the sun. Sun is a big star, therefore it is really the stars out there that enlighten sky! There are not too many stars that are close to our planet therefore to us the space is black… Thanks for the question!

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