I would like to share some thoughts on the nature of dark matter and its relevance to the big bang.
I have never been comfortable with the idea that dark matter really is lumps of dark material floating around the universe as it would be continually drifting across our field of view and obscuring things. I think we have arrived at the term 'Dark Matter' purely because we cannot see it when we look out into the largely dark universe.
My own thought is that the universe exists in a super saturated solution of matter. Thinking back to the school physics lab a super saturated solution of for example sugar would ideally contain dissolved sugar crystals until you reached the point that when adding one more crystal you found it would not dissolve. If you have such a perfect solution with one sugar crystal in the bottom of your beaker and you then subject it to time lapse photography you find that actually the crystal does eventually dissolve and when it does so it displaces another crystal from the super saturated solution that then appears in a new random location in the bottom of the beaker.
It seems to me that the universe behaves in the same way. The majority of the (universe / solution) is invisible because it is in solution; only a small portion of (matter / sugar) is visible at any time. We know the rest is there because we can measure the effects of (gravity / specific gravity) and realise that there is more around than meets the eye.
Just as when the (universe / sugar crystal) dissolves and displaces a new (universe / crystal) so a big crunch displaces a new big bang.
Just my thoughts but this does seem more coherent to me than the idea that most of the matter in the universe is black and none reflective.
Would love to hear anyone else's thoughts on this.