The way i look at it is as follows. Before the big bang everything was packed into a infinatly small point call a sigularity(i'm sure you guys know that). Some rupture caused this singularity to explode. With the singularity being so small and so much being pack in, this seneriao would make it naturally unstable, the slightest inbalence could could have cuased it to explode as stated before(sorry for repeating myself ) Now bring a black hole into the subject. A black hole gravitaional pull, pulls serveral million of different things into a similar singularity. Once to much is pack into the singularity it again becomes unstabe and another big bang could occur. How ever two question arise 1. if this happening, why dont see it or 2. has it even happened yet