• Question: If nobody knows what dark matter is how do we know it actually exists?

    Asked by matthewb to Alex, Jools, Lynz, Matt, Rika on 15 Jun 2011.
    • Photo: Lyndsey Fox

      Lyndsey Fox answered on 15 Jun 2011:

      More quantum physics?! My flat mate is a physicist, this is how she explained it to me….

      it is the name we invented for something that we think must be there in order to be able to explain what we know is there…

      For instance.. to prove how humans were first formed, you need to expect something that is exactly the opposite of US, and we call it “antimatter”.

      and dark matter is the same:

      there is so much energy in the universe we know that because we can measure it and in order to get so much energy you need places in the universe where there is the opposite – no energy – hence dark matter

      She then said “its not entirely true though, but good enough”.

      Hope this helps, I didn’t have a clue!

Comments

  • Photo: James_M

    James_M commented on :

    This got asked in our zone, too – to my mind the single most convincing piece of evidence for dark matter is the Bullet Cluster: http://ias.im/49.146 but there is also other evidence including the rotation rates of galaxies and the abundances of elements heavier than hydrogen in the very oldest stars.