Welcome to Number 12 of 13 posts regarding the Ghost Drive Setting. If you came to the party late you can check out the other posts on my Ghost Drive Page (see sidebar)!
Against all odds mankind seems to be one of the first and most advanced races in the Milky Way Galaxy. There are several reasons for this.
The Milky Way suffers from periodic eruptions of gamma rays that sterilized a number of areas in the past. That activity seems to have settled down. Add to that intelligent life takes a long time to evolve, on average ten billion years.
Sol is only four billion years old or so which has many xenologists scratching their heads there are currently two theories on why we are advanced enough to ponder that question rather than be concerned with breaking carbon dioxide down into carbon and oxygen. The first theory is that Sol is a fairly unique star system with enough giant planets to keep cometary impacts that destroy most life down to a reasonable level and enough asteroids to provide near extinction events and drive evolution faster than most worlds. The may be so. It isn't like the xenologists were around to watch all this stuff. But there are enough star system similar to Sol's to make that theory a little shaky.
The second theory, no one likes. While the Milky Way is barely old enough and only recently hospitable enough to evolve intelligent life there are older more hospitable regions, the Halo Stars (most are old enough but lack the right chemical mix) and some globular clusters.
One of those clusters was the Omega Centauri Cluster (OOC). The OOC may in fact be the heart of a smaller galaxy the Milky Way devoured. Its hospitable stars might have developed life before and seeded our galaxy with life.
The xenologists don't expect the seeding to take the form of god like elder aliens jumping into rockets and having picnics on prebiotic Earth next to the primordial ooze. Meteor impacts and other cosmic disasters could carry cosmic debris with advanced microbes to other younger worlds. The sub sentient and semi sentient life humans found and their eco systems all have many features in common. that may show a common ancestry or that there are laws to biology and evolutions we are just learning.
Some very unpopular theories hold the the Non-Biological Entities are the Milky Way's native life and we are in effect invaders from the OOC. Some critics of the theory wonder where the other advanced life forms descended from the OOC are. Could we be the only intelligent life descended from the older stars?
Now there have been ruins, old artifacts found on some worlds. These are incredibly old, in most cases fossilized on terrestrial planets or in very rare are cases mostly intact or vacuum worlds. In most cases again these are found around stars from the OOC or that were close to them at some point, millions of years in the past.
There is still the possibility of far off starfaring races. The old stars fell into the galaxy a long time ago and could have been carried far away in their orbits around the galaxy.
Maybe the ghosts got them. The OOC invasion failed and fell to the NBE retaliation. There are no gods to meet us. We are the gods for al that is worth.
The ghosts, spirits, NBEs, and what have you may be native to the Milky Way. They may be entities from the Omega Centauri Cluster who transcended their physical forms. They might be the pets of those long ago beings.
For all the worlds humanity has found and settled we still move into the galaxy like a child who found their way into the attic. It is silent, deserted and feels like someone else was just there a moment before.