One of the theories that was at one time in competition with the big-bang theory was based on the idea of continuous creation of matter at the center of the universe and the idea that something was being created there from unknown sources. I don't believe this has many followers as it doesn't agree with other theories that have more physical evidence - or at least are more coherent, encompassing theories.
The big-bang does seem to imply that some central point would show a lack of mass density because everything was ejected away from that point. It could certainly be argued that as the mass expanded and differentiated, that parts would take on characteristics that would cause their velocity to vary from other parts, therefore explaining the lack of an obvious "smoke ring" effect. There would be a dispersion of the matter through varying rates of speed.
View Question Answers