This is obviously not getting stickied, but imagine how beautiful it would be if we had one collective thread for all of this stuff. I really hope this is not a repost...
Anyways, I was thinking about eternity. I know that technically the idea of eternity initially makes people of a really long (limitless) time. Actually, it's the absence of time, the omnipresence of all occurrences, or something along those lines. But for this idea, imagine eternity being an endless timeline. With that notion, everything that can happen will happen. For example, some rock formation in some desert will be eroded by wind and water so that it has the exact resemblance of Mount Rushmore.
Now let's suppose time travel. I don't think it is possible, but our minds our incredible finite and perhaps it is. Now, suppose that time travel has to be created by humans. Obviously at this point in time our technologies are not sophisticated enough to produce time travel. But suppose that 1000 years from now, we really got our shit together and created time travel. Furthermore suppose, we've already been to 3012 and we've time-traveled back. That could have happened, but we lost evidence of creating time travel when the Tartus (Dr. Who time machine) disappeared. But even if that did happen, we would eventually really get our shit together and create time travel that was able to preserve evidence of the creation/existence of time travel. And even if we got really sophisticated and had the ability to prove time travel in the past but said we would vow not to tell the past we would create time travel, somebody would eventually fuck up and let the cat out of the back. That is, if time travel is possible, we would have created it in the future by now and proved it's existence.
One (or more) can come from this.
1. We haven't been to 3012 for the first time yet.
2. Time travel isn't possible.
3. Eternity doesn't exist because time travel didn't happen.
4. we REALLY got our shit together and became expert secret-keepers.