Comments by "zenith parsec" (@zenithparsec) on "The Absurd Search For Dark Matter" video.

  1. 1:16 "...a huge sphere of dark matter." It's aball of dark matter, not a sphere. A sphere centered on the galaxy wouldn't permeate it, as it is just a surface. circle <==> sphere <= both are hollow. disk <==> ball <= both are filled in. Mathematicians consider a sphere to be a two-dimensional closed surface embedded in three-dimensional Euclidean space. They draw a distinction a sphere and a ball, which is a three-dimensional manifold with boundary that includes the volume contained by the sphere.
    1