I kind of like the idea of something like a Star Trek universe. That is to say a universe filled with lots of basically human people. At its most extreme, this is kind of the polynesian idea of James T. Kirk pickin’ up pretty green chicks at the starport bar. Actually, that’s less extreme than Planet of the Nazis and Planet of the Roman Empire and even, um… Yangs and Kohms.
There are a lot of ways of doing this at various levels. Some of the ways are better suited to the pretty green girls and less well suited to the Planets of Convenient Historical Costumes.
One idea is the Foundation and Empire method: start with an empty universe, let humanity spread out across the universe, wait awhile, then you have a lot of nice alien humans out there. Now let them interact.
Another variation on that is the Transhumanist method, which is to put the genetic engineers to work splitting humanity into a lot of different kinds of folks with different strengths and weaknesses. Make your aliens, and see how they work together.
Both of these have what I call the Deep Time problem. Obviously, in the first case, this means that the story needs to be set so far in the future that it might become difficult to find a protagonist that you can emphasize with or get a reader to emphasize with as an author. An analogous problem exists with the Transhumanist method. You might be working in the much nearer future than even a more conventional space opera story, but the density of change is so great that characters are still existing in a completely different world of the mind. This gives an author the same problem with the creation of a sympathetic character as you would using the Deep Time method. Clearly, some authors could handle this better than others.
Another concept that came to me while taking Doctor Who far too seriously, was the Time Wars concept. Basically, good old humans from Earth spread out into the universe, having adventures, getting into scrapes with genuinely alien critters and generally just doing their human thing for eons on end. Then in the distant future a greatly evolved human culture on some distant planet, let’s call it Gallifrey, discover the arcane secrets of time travel. These Timelords from the future travel through time, generally leaving things alone till something goes seriously wrong: time travel falls into the hands of a fairly malignant human culture on a planet we’ll call Skaro. The Time Wars between Gallifrey and Skaro tear up the fabric of timespace itself and leave little groups of people from all kinds of eras scattered like islands in the sea of time(ISOT) all over the timeline of the universe. This idea, or some variation on it gives lots of opportunities for fun. It does allow for Romans or Nazis o whatever in space. Heck, you could even arrange to have Elvis, Shakespeare, Newton, and Einstein stranded together on some alien planet with the unknown survivors of the Titanic. Or Vesuvius. Or whatever…
Another idea is the Friendly Aliens method. Like the name says, some group of aliens took an unwholesome interest in the human race and decided to seed cowboy-movie indians and other hollywood-ethnic-stereotype humans all over the universe. I’ve used this idea, and I kind of liked it, but the more I think seriously about it the more problems I see in it. For one, if you’re going to say that some powerful alien species decided they really liked humans and decided to drop them all over the place, what about the other aliens they might encounter? Seems like you either have to have an ET-poor environment or things get really crowded. Especially if you start throwing in uplifted kitties and doggies and dinosaurs(Which I would definitely do). Or… they just liked humans and said, “never mind all those other things.” If you’re going to say humans are special like that, why don’t you just say we’re the supreme master race and the Almighty God just likes us better? Yeah, I’m just finding the idea increasingly unappealing, though I’ll always have a soft mushy place for the Vilani.
The notebook entry I’m going to share with you is based on a variation of the Islands in the Sea of Time mentioned earlier. Sometime in the distant future, scientists on an Earth which was not exactly our own Earth did something which caused little copies of their world, which I call Oikos, for home, from various points in their history to pop up all over the universe. Dinosaur planets, planets of the wooly mammoths, planets with various proto-human races? Sure. Planet of the Nazis, world where Charlemagne still rules? Not in this case, but depends on the point of divergence. You could set it up so that there are echoes of everything up to the Martian Pantechnicron of 2108. I also had all the echoes come into existence about 7,000 years ago. Plenty of time for lots of cultural variation, but you aren’t going to have intelligent critters evolve on dinosaur planet. It’s easy enough to take the same idea and have the times at which these planets appear somewhat scattered. You could even postulate a sort of collision of Earths from multiple timelines instead of or in addition to the multiple times idea. Imagine, coming upon an Earth where the Aztecs had just conquered medieval Europe.
The Broken Strand is a little alternate world history I created for Oikos, the world, an echo of which would become Earth. Aspects of the history allow me to play with both Deep Time and Islands in the Sea of Time, depending on where I set an adventure. The idea for it came to me largely while I was physically busy, but clearly not too mentally engaged with work. For me, that sort of time is a treasury of creativity, though not a good time for writing.
Unfortunately, I was at about 3400 words and nearing the middle of my notes. So I think it needs to be a post of it’s own.