(February 8, 2016 at 4:41 pm)Rhondazvous Wrote: As CD said, dark matter is just one explanation for what we are observing. One other that occurs to me right now is, the deficiency of matter may explain our observation that the universe is expanding. What we see as the galaxies being held together is really just a blink of the eye in the vast eons of the universe. So there may indeed be enough matter for that blink.
On your first point, it happens to also be the best explanation (so far).
On the second point, not really. We can look back ~13 billion years in time and see that it's not merely a blink in time.
