Cosmologists seem to refer interchangeably both to a big-bang origin just beyond the limit of present observation, and to an observational horizon where the rate of expansion of the universe exceeds the speed of light. The notion that looking out in space entails looking back in time gives rise to the conception that the most distant observations are of a much shrunken early universe that is projected to have originated in a big bang some 13.75 billion years ago. In the meantime, expanding spacetime has stretched this observational bubble to about 25 billion light years in radius. Concurrently there are credible suggestions of a mega-universe that extends, perhaps infinitely, beyond the event horizon of local observation. This horizon occurs at the distance where the rate of expansion of the universe with respect to the observer exceeds the speed of light. At least these are my understandings. My question is, how are these two conceptions reconciled? A mega-universe would seem to imply that, if there were a big bang, it must have occurred beyond the local event horizon. On the other hand, a big-bang singularity that lies within the local event horizon, albeit at the de facto limit of observation, would seem to render the notion of a mega-universe moot. Perhaps more to the point, how is the observational event horizon related to the big-bang?