• Question: What is dark matter?

    Asked by rhooper821 to Ben, Dave, Ed, Sam, Susana on 19 Jun 2013. This question was also asked by bradleyf13, thatkid1.
    • Photo: David Briggs

      David Briggs answered on 19 Jun 2013:

      Dark matter is basically a theory – when we look at the universe we can only see about 5% of what we think should be there.
      This 5% is matter.

      The remaining 95% is unknown, and has been split into Dark Matter and Dark Energy.

      Dark matter is about 30% of the universe (in theory) but is invisible, as it doesn’t absorb or emit any sort of light or radiation. It does however, have an effect on gravity, and we can get clues about where it might be and how much of it there is by looking at how galaxies move and spin.

    • Photo: Susana Teixeira

      Susana Teixeira answered on 21 Jun 2013:

      Whenever I hear Dark Matter I think of Darth Vader… but back to your question. The answer to your question is: nobody knows!

      Scientists named it after something they cannot see, but that would be holding galaxies together. Stars, planets, etc are spinning around in a galaxy, and the reason why we think they don’t fly off is because there is enough matter in there to pull them in by gravity. Or so we think! The amount of matter required to do that is however much larger than what we can see exists, so there must be something else there and we call it Darth, pardon, Dark Matter!

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