The Light Horizon

No, I'm not talking about Event Horizon, that super-creepy movie from the 1997. I'm not even talking about the event horizon, the edge of a black hole past which there's no escaping its gravity no matter how fast you're going. I'm talking about something much, much bigger than that, something I'd never heard of until recently.  And it's trippy.

The Light Horizon is the absolute farthest we can see. As you probably know, when we look into the sky, we're looking into the past. Well, there's only so much "past" to see - the Big Bang happened 13.7 billion years ago, so we can only see 13.7 billion light-years away from us, in all directions.

(The quickest among us would take this moment to ask, "Wait a second - how can things exist 13.7 billion light-years away in all directions? Does that mean we're the center of the universe?" The quick answer is "No." The long answer? You'll have to wait until the end of the post. Back to the Light Horizon.)

This idea means that we're at the center of our sort of "Sphere of Existence" - there can't be anything outside of it, since that sphere IS the time of the Big Bang and nothing existed before that apart from an incredibly uniform field of "Cosmic Background Radiation."

(If this idea doesn't really make sense, read my post on Spacetime.)

The Trippy Part:

What if we could somehow warp instantly to the edge of our Sphere? What would we see when we look away from Earth? Would it be emptiness, or would we then be at the center of an entirely new Sphere of Existence, in which the Milky Way Galaxy is so far away that the Earth won't form for another 10 billion years or so?

And then what if we move to the edge of that new Sphere? And the edge of that one? How far does it go? Does it loop back at some point, or just keep on going (in which case, what happens if we go the other way?)?

And here's the super-trippy part: What if we warped to the edge of Earth's sphere, saw the Milky Way as it was 13.7 billion years ago, and then warped back again. Would we end up in the same existence? Or might we be in a wholly different dimension, where different things happened over the last 13.7 billion years, leading to an entirely different set of present circumstances???