If the universe is expanding does that mean that the point of origin of the big bang, that original dot where it all began, is now a void that is expanding also?
And as that void grows so does the distance between the galaxies as they speed outward from that original point, much like the debris of a softball if you were to put an explosive device in its center.
If that is true then all the outward bound galaxies will eventually be spread out so far from each other that any physical effects they may have on each other will fade away. Will these galaxies just die out, disintegrate and fade away or pass thru an "invisible boundary" that makes them disappear and eventually lead to a universe devoid of matter entirely?
But back to the point of origin of the big bang. If we could locate that exact location and observe it, would we see it producing ensuing big bangs, much like the faucet in your sink that produces an endless stream of water when you turn it on?
I'm not being facetious in any way, it's just a thought that came to my simple human brain that is incapable of grasping the thought of infinity......
There is no one point of origin, or ‘center’, of the expansion. Everywhere is said to be the center. But it is true that objects can drift apart so much that they cannot possibly communicate anymore, even at the speed of light. See “Horizon Problem”. It relates to the Big Bang, and is one of the fundamental problems with the theory.
However, they (certain objects) MAY still communicate within the mysterious realm of quantum physics, where once quantum-entangled particles somehow remain in instantaneous communication with each other despite of the current distance between them. In theory, they can be on opposite ends of the universe. The phenomenon is called non-locality, “spooky action at a distance”(Einstein), EPR thought experiment(Einstein, Podolsky and Rosen), Belle’s Theorem.
Here’s a good explanation (w/ animation) of why there is no center of the universe’s expansion. That everywhere can be considered the center —this link is for real :)
http://www.youtube.com/watch?v=i1UC6HpxY28
To your second point, no one knows since our big bang created our space-time and it not thought to be possible to observe another space time even if one existed. So maybe there was just one big bang or maybe there is a never ending series of big bangs. Right now we don't know and finding out if other big bangs happen will not be an easy thing to do. There is much to learn yet.