I had created two fantasy worlds, and wanted to do a science fictional one. But I kept having problems. I could build a science fictional universe around a story (see Black Flag for an example of a universe built around a specific story) but to just build one that stood on it's own was for some reason giving me trouble. I finally realized that it was because I was tripping over the fact that science fiction universes are often seen as a continuation of ours: a possible future. My imagination was choking over my conviction that I was incapable of guessing what the future would be.

So instead of creating a possible future, I created an impossible one.

As soon as I had detached the universe I was building from the real world and real life, by centering it on a concept that was scientificly impossible, I was free to be as scientificly rigorous as I wanted to be in everything else. At the same time I remained free to ignore scientific realities when I thought they were getting in the way of a good yarn. The best aspects of both worlds were mine to play with.