• Question: What is Dark matter?

    Asked by Authorized to Aaron, Abbey, Keith, Natalie, Pete on 17 Nov 2015. This question was also asked by jade.proctor.
    • Photo: Aaron Boardley

      Aaron Boardley answered on 17 Nov 2015:

      This is an area of science which still has a lot of mysteries.

      We can see the effects of large clumps of matter (which just means ‘stuff’) by the way it has a gravitational pull on other things. Even if you couldn’t see the sun, a scientist measuring the way the earth is going round could work out that there must be a big star in the middle of the solar system just by the forces the earth experiences. Of course, then we can look and confirm that there definitely is a big star there – the sun!

      However, there are lots of gravitational effects in the universe that are unexplained – we can’t see what causes them. Scientists have developed the theory of ‘dark matter’ to explain this stuff – stuff that causes gravity, but can’t be seen.

    • Photo: Natalie Garrett

      Natalie Garrett answered on 20 Nov 2015:

      Astrophysicists have been looking through their telescopes and taking measurements and making calculations for a very long time. It turns out that their numbers just don’t add up based on what they can see is in the universe – there has to be some extra mass somewhere out there for the stars and planets to be behaving the way they do. They hypothesised that there could be extra stuff out there that isn’t visible through telescopes, and they dubbed it ‘dark matter’.

      We can’t detect this dark matter (yet) but a lot of people think and hope that it’s out there somewhere, otherwise we will have to rethink a lot of basic stuff about our understanding of the universe!

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