My "theory" is (it's not really a theory because I have no data to support it) that black holes continually gain gravitational energy through the sucking up of matter. Mass essentially leaves our universe once it crosses the event horizon. The laws of time and space and dimension and physical matter cease to apply.. The only attribute that remains is the gravitational effect of the accumulation. This becomes an incubation holding tank for another universe to be spawned from. Throughout the entire lifetime of our universe, the moment of "Big Bang" in another universe is constantly happening. Time in that universe begins 'when' there is sufficient matter/energy potential to begin expanding space-time. I call this a "Perpendicular Universe"; rising from the ashes of our own, it's time arrow at right angles to our own.