Robert Heinlein had this chart: a big piece of paper marked off into columns. One column was a timeline, starting in the not-to-distant future and going on a couple centuries beyond. In the others he had story titles, characters, inventions and technical developments and other important events. It was an outline of the Future, which he used as a consistent framework for many of his early short stories and which his editor Robert Campbell enthusiastically called Heinlein's "Future History".
Heinlein was not by any means the first writer of fantastic literature to engage in world-building, but perhaps he might have been the most methodical. Still, there is an impulse among many creators of Fantasy and Science Fiction to make not just stories, but entire worlds in which their stories shall be set. They don't just write novels; they create Universes.
Most writers don't exactly start out to build a universe. They start by writing a story or a novel. If that is successful, perhaps they write a sequel, and then maybe another. As novel grows into series, the chain of stories begin to accumulate backstory and characters and verisimilitude begins to accrete around it like cosmic dust around a gas giant's magnetosphere.
But a series is not exactly a Universe. A series generally has a single constistent element, usually the main protagonist, that provides the main thread of continuity. In a Universe, the world itself is the thread of continuity. Characters may recur now and then, but stories tend to be isolated and for the most part unrelated to each other.
Sometimes a writer will give a shout out to a previous story, mentioning characters, places or events that occurred before. Jules Verne would do this occasionally: in his novel The Clipper of the Clouds, he made reference to the artificial satellite inadvertantly launched by the villain of The Begum's Fortune. In The Mysterious Island he brings back not only Captain Nemo from Twenty Thousand Leagues Under the Sea, but also a character named Eyrton, who appeared in an earlier novel, Captain Grant's Children.
With enough of these links between stories, a web of connections begins to appear and something like a Universe begins to form. This is what happened in the works of H.P. Lovecraft. Elements such as the Necronomicon, the tome of eldrich lore scribed by a mad Arab; and Miskatonic University, the home of research into Things Man Was Not Meant to Know; appeared in several of his stories. This body of unrelated yet connected tales became known as the Cthulhu Mythos and he encouraged his friends to add to it. After Lovecraft's death, he friend August Derleth organized and greatly expanded the Mythos; but Lovecraft himself was much more casual about his "pseudomythology", regarding it as atmospheric background rather than a rigid pantheon of elemental beings.
Tolkien created his world in a peculiar order. At one point, he actually had the ambition of inventing an "English Mythology." To a certain extent, he succeeded -- his Middle Earth is extremely English -- but along the way he became sidetracked. A philologist, he was chiefly interested in languages. He started off by inventing his own language, Elvish, and then began coming up with stories that would go with it. The result was a huge ocean of legends and lore, and poetic fragments that his son Christopher eventually welded into The Silmarillion and which became the quarry out of which Tolkien built his own epic, The Lord of the Rings.
To a lesser extent, Tolkien's friend C.S. Lewis had the world-building bug too. As a child, Lewis wrote stories about talking animals in a place called "Animal-Land." Later on, he and his older brother Warnie developed their own "shared world" called Boxen. Lewis decided that Animal-Land and Boxen were actually the same place at different points in history and at one time attempted to create a history of Boxen from his early Medieval stories to the Modern Day. He later admitted, "...I never succeeded in bringing it down to modern time; centuries take a great deal of filling when all the events have to come out of the historian's head."
Tolkien, unfortunately, started a trend of Multi-Volume Fantasy Epics starting out with a Map and a Prologue describing cosmic events. But these later writers weren't creating worlds in the same way Tolkien did; they were creating settings for their epics. Very rarely did the maps on Page Four of the paperback become the setting for any other stories; and when they did, it was more frequently a continuation of the original epic with the original protagonists or descendants thereof.
It's said that late in life, Albert Einstein spent his final years trying to come up with a Unified Field Theory to explain all of physics. Isaac Asimov spent his final years doing something similar. Asimov wrote a number of successful series: his robot short stories, the R. Daneel Olivaw novels, and the thundering Foundation trilogy. In the 1980s, he began trying to tie them all together into a coherent Universe.
In some places, this was relatively easy: his three early novels, Pebble in the Sky, The Currents of Space and The Stars Like Dust, all take place against the backdrop of a Galactic Empire which could well be an earlier stage of the Empire from the Foundation series. The I, Robot stories and the R. Daneel novels share the Three Laws of Robotics and the Positronic Brain and fit fairly well together. But getting the Empire stories and the Robot stories to fit together proved more challenging.
In Pebble in the Sky, large portions of the Earth have been rendered radioactive -- presumably by nuclear war. In Currents of Space, most of the surface is unihabitable and natives of Earth tend to leave if at all possible; and by the time of Stars Like Dust, Earth is no longer inhabited. Yet in the Robot stories, which would be set chronologically before the Empire sequence, there is no mention of atomic war or radioactive deadlands at all. More significantly, the Robot stories are entirely about how humanity develops robots and comes to incorporate them into human society -- yet the Empire and Foundation novels have no robots at all!
So Asimov wrote a few additional novels to explain the discrepencies and tie everything together into a single timeline. Personally, I think he would have done better to leave the series seperate. His efforts to jam unrelated stories into a uniform framework by brute force to me are less appealing than the original stories themselves. But that's a matter of personal taste.
Sometimes having a Universe proves to be a straitjacket. Robert Heinlein had to publish his non-Future History short stories under a pseudonym; (although partly that was so that Campbell could run two Heinlein stories in an issue and still present the semblance of variety). In his juveniles, he was able to cut loose from strictly adhering to the timeline; (although there were occasional connections; In Space Cadet, for example, he refers back to the protagonist of his story "The Long Watch").
In an essay written in the 1960s, Heinlein described a few stories he intended to write for his Future History but never completed. One was to be about a revolution on the Moon that would take place during the interregnum of Nehemiah Scudder. He never wrote it, he said, because it would be doomed to failure and therefore too depressing. But he ultimately lifted the idea of the Lunar Revolution out of his timeline and it became one of his better novels.
Which brings us to NEXT WEEK: We're going to start a new book; and by amazing coincidence, it's going to be the very one I just mentioned. We have a lot of people here who love Heinlein -- or who love to hate him -- and so I'm going to Luna to see a guy about a sentient computer with a wacky sense of humor. Get ready for "Tea Parties in Space" or The Moon is a Harsh Mistress.