Quote:
Starhawk said:we KNOW dark matter exists for a fact.
|
Only after a fashion - stars at the outer rim of the galaxy seem to be moving at the wrong rate for what gravity can account for with the mass we can verify with our telescopes once you get past about halfway from the galactic core. Dark matter - that is, matter we can't account for via our telescopes (of various sorts) - is the most widely accepted option for explaning the phenomina; but it's only one. There might also be a gravity-esq force that we are unaware of having a similar effect; we could just have a random convergence of stars with no force involved to keep them in the galaxy, and the stars we see past that point are really on their way towards escaping the galaxy. We don't know dark matter exists for a fact.