of course, there’s another thought to process.
ever since man wanted to transport things... he has forever tried to improve that process, thereby making life easier. so when the guys dragging things around on sticks ran into the first guy using a wheel and axle... we’ve been looking to improve transport ever since. as long as the usage, and possibly replication, of the transport system is within the capabilities of the people to use it... it would continue to be used long after the village (or world) that created it, died off.
realizing that, and combining it with the current theory of stable worm holes bouncing around physics... we come to an interesting prospect.
you see, any society advanced enough to develop a stable worm hole would also be advanced enough to create a rudimentary AI. as such, it would be possible they would send out robotic drones (doesn’t have to be a full blown AI) to place worm hole receivers. this would quickly evolve into the drones building these portals, or gates, using materials found at the remote site. they would also most likely program the drone to replicate itself first, then the gate, dialing back to the home world to announce the location and conditions of the new gate, then speeding off in opposite directions to repeat the process.
forever ... into deep space.
if such a thing were possible in the universe... EVEN ONCE... then it MUST exist at this point in time -somewhere- out there. robots flying between star systems, scouting for suitable planets, replicating themselves and a gate, then flying on. spreading this interstellar network of roads across the heavens ... long after originating society dies out.
such a system would be so infinitely useful ... it would have to continue to exist, once created.
such a system could easily spread life throughout the universe.
the question is... is there such a gate nearby and have we already found it?
Here's a thought that relates to Mathematical Induction. Let's accept that mankind is near to having the ability to terraform another planet, and make it suitable for human colonization. And that in time, civilization will develop in such terraformed entities, and some will themselves develop the abilities to terraform and colonize. It takes so long they will have no cultural memory of their beginnings, perhaps some ancient lore or mysterious aritifacts.
Let's go back one step instead of forward. Isn't there a very high probability that we are the result of terraforming and colonization?