• Question: do you believe in dark matter? if so, is there a greater percentage of dark matter or reality?? (sorry idk the scientific name for reality of the opposite of dark matter)

    Asked by sunish to Anna, Hayley, Iain, Rebecca on 16 Jun 2015. This question was also asked by Jasmine Y.
    • Photo: Iain Bethune

      Iain Bethune answered on 16 Jun 2015:

      Cosmologists estimate that about 5% of the universe is ordinary matter (the technical name is Baryonic matter i.e. stuff made of atoms), 27% is dark matter, and the remaining 68% is dark energy.

      Dark matter is believed to exist because the gravitational effects of most galaxies (e.g. their rotation, gravitational lensing…) gives a much larger mass than what we can see in terms of stars, gas & dust. This matter that we can’t see is called Dark Matter. Lots more info and evidence can be found on https://en.wikipedia.org/wiki/Dark_matter (look in the references for the data!)

      Dark Energy is used to explain the fact that the universe expands at a rate that is not consistent with the total mass of everything (including the dark matter that we know must exist). It’s still an open question if dark energy is the same everywhere, or if it varies throughout space.

Comments