More like a virus actually, the diameter of a single galaxy in the mosaic can be anywhere from a few hundred thousand to a few million light years across.
I truly agree with the commentator that "simply saying that number doesn't really mean much to us because it doesn't provide any context, our brains have no way to accurately put that in any meaningful perspective".
Dark energy and dark matter accounts for nearly 74% and 22% of the overall mass in the universe, and yet these are complete mysteries to astronomers and cosmologists. Truly the human species knows so much, and yet so little.
The original article that accompanied the video can be located at Deep Astronomy.Com. Good read. :thumbsup: