• Question: What does dark matter do ?

    Asked by shasow15 to Colm, Eoin, Joseph, Lauren, Stephen on 17 Nov 2013.
    • Photo: Eoin O Colgain

      Eoin O Colgain answered on 17 Nov 2013:

      Dark matter does what it says on the tin. 🙂

      It does not emit light, but interacts gravitationally, so we can see the effect it has on nearby matter that does emit light. It also bends light and can cause multiple images of the same galaxy to appear, in much the same way as a lens bends light.

      So we know it is there by observing the effect it has.

    • Photo: Joseph Roche

      Joseph Roche answered on 17 Nov 2013:

      Dark matter manages to make up a huge portion of the universe while remaining virtually invisible to us. It’s sneaky stuff!

    • Photo: Stephen Scully

      Stephen Scully answered on 18 Nov 2013:

      We know very little about Dark Matter. Dark matter causes gravity. So we can see the effects of dark matter in the light that it bends from far away stars.

    • Photo: colm bracken

      colm bracken answered on 18 Nov 2013:

      I am very skeptical of dark matter, although I am probably in the minority on this one. Dark matter was invented as a way to explain the extra gravity that stars and galaxies seem to experience as they orbit. We still have not detected a particle of dark matter and i would be surprised if we ever do. I think we will require a correction for Einstein’s theory of gravity.
      We have made this mistake before. When astronomers could not explain a slight perturbation (wobble) in the orbit of Mercury with Newton’s theory of gravity they invented a new planet that they called Vulcan which they said was tugging on Mercury. They said that this planet Vulcan was made of a new type of matter that had all the properties of dark matter, or in other words that it was invisible. We now know that we really needed to adjust our theory of gravity to really explain what was happening. This is what Einstein did with his theory of General Relativity. I believe that we now need to modify Einstein’s theory to really explain this dark matter effect.
      More importantly, what do you think is really going on?

    • Photo: Lauren Mc Keown

      Lauren Mc Keown answered on 18 Nov 2013:

      Dark matter and dark energy take up a huge amount of the Universe for something we know very little about.

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