What is the difference between science fiction, science fantasy, and speculative fiction, and do the differences even matter? I think they do.
When you write a novel that falls outside your area of expertise or educational background, it is a risky proposition. Science fiction writers, such as Asimov, Crichton, Sagan, and Clarke each drew from their substantial well of personal knowledge about physics, anthropology and other physical sciences in developing and fleshing out their story ideas. Very few successful science fiction writers lacked a background in the sciences. Oddly enough, some who are considered among the greatest sci-fi writers didn't even write science fiction. Ray Bradbury comes to mind first. Not only was he not a scientist, but he also had never attended college. Even so, many readers mistakenly identify him as a science fiction writer, when he himself states that he actually writes science fantasy. On the other hand, Robert Heinlein, often referred to as the "dean of science fiction writers", took graduate courses in physics and mathematics, which served him well during his writing career. If you're a hybrid-- non-scientist writing science fiction-- you have to immerse yourself in unfamiliar territory and research disciplines which often use terminology that is completely foreign to you. In that regard, writing "Purusha's Urn" was a significant challenge.
Despite the fact that "Purusha's Urn" draws from several scientific disciplines, I would actually prefer not to call it science fiction. I believe that designation can provoke an unhelpful expectation in many readers. My story is much closer to the kind of thing Bradbury, Harlan Ellison or Richard Matheson would write. Ellison, like Bradbury, had no education in the sciences and, in fact, had been expelled from college after only 18 months. The smart thing that Bradbury, Ellison and Matheson did was base their stories on broadly fantastic notions about the world and reality, avoiding the technological mine-field created by relying too much on hard science. I'm not saying that science fiction is any better or more difficult to write than speculative fiction. In fact, in some ways speculative fiction is more demanding on the writer. Science fiction necessarily involves an element of non-fiction and, as Tom Clancy said, writing non-fiction is less challenging because we accept reality for what it is, no matter how outlandish. Conversely, a fantastic story has to make sense and it is essential that your characters be as real as possible if you're going to sell the fantasy to your readers. When making "Superman: the Movie" in 1977, Richard Donner put a sign on the production office door that had one word: "Verisimilitude".
In terms of what to expect from "Purusha's Urn", it is more like an "Outer Limits" or old "Twilight Zone" episode that spans two generations. While the premise was inspired by cutting edge scientific theory, it simply uses that as a launching point into the realm of the truly fantastic. Because of the outlandish nature of the premise, I drew heavily from the disciplines of astronomy, anthropology (cultural and physical), ancient religion, physics and biology. Not having an advanced degree in any of those fields, I had to go back to school. One of the most surprising things I learned during the writing of "Purusha's Urn" was how willing experts in their field were to answer my questions. Whether I was corresponding with the director of the VLA in New Mexico or a linguistics professor at the University of London, I never encountered any resistance to sharing knowledge. The same thing happened whenever I reached out to established writers, whether I was asking questions about their writing process or how they went about finding their first literary agent. Gregory Benford, Dan Brown, and Douglas Preston were always encouraging and responsive.
An interesting side note about my contacts with Dr. Benford, a professor of physics at UC Irvine who has written more than 20 science fiction novels and is a two-time winner of the Nebula Award. When I first got the idea for my novel and needed to come up with a title, I wanted to create a single word which related to the story and did not appear in any dictionary or text book. The word I came up with was "COSM". I thought it would look great on a bookcover and I included it on a cover sheet on all my submissions to prospective literary agents. Then, one day, I received an email from a well-known agent in New York. In the process of kindly declining to represent my manuscript, he happened to mention that I would, of course, have to change the title. When I asked why, he told me that Gregory Benford's latest book was going to press with that title and that it has already been optioned as a film. I couldn't believe it. I had invented that word. What were the chances that another writer would come up with it at virtually the same time. I contacted Benford's publisher, Tor Books, and asked them to pass along a note to him which stated that my federally copyrighted manuscript had that title, and that I was curious as to how he came up with it. Benford sent me an email the next day, probably concerned that I was the litigious sort, which I was not. As it turned out, Benford and I had actually come up with "COSM" within months of each other and, while his novel was his usual hard-science fiction, his story had some interesting similarities to mine. The coincidence was dripping with Jungian 'synchronism'. Over the next few years, we exchanged a handful of emails and he was always willing to respond and offer encouragement. A good man.
Later on, my editor, Sasha Miller, convinced me that I had to let go of "COSM", and she suggested "The Urn of Purusha". Ultimately, it was modified to its current title and I'm satisfied that it works well on the bookcover. Of course, it's not "COSM", but it will do.