It's natural curiosity that makes us want to learn more about the things we like. That's why we like DVD extras and behind-the-scenes looks at our favorite films. We don't just want to experience the story, we want to know what goes into creating the story; we want to know how it came to be. Similarly, we like to understand more about the types of things we like. Fans of horror films, for example, like retrospectives about the genre that namedrop familiar titles ("I saw that!") and hint at other films we might like ("I gotta see that!").

It's the same thing with books. As more-than-casual readers, we yearn to know more about the stories we read and the genre spaces they occupy. I've known for a long time that I don't just like reading speculative fiction, I like reading about speculative fiction. Fortunately, there are books to satisfy that hunger. Here's a look at some recent nonfiction books about speculative fiction that feed the mind….

Alien Imaginations edited by Ulrike Küchler, Silja Maehl, and Graeme Stout

Aliens are one of the oldest tropes in science fiction. And why not? From the perspective of a writer, aliens provide an opportunity for a wide variety of story ideas. Aliens may be technologically advanced invaders, or they may be benefactors, bestowing upon humanity technology that's decades ahead of our time. Aliens may be allies in an interstellar war, or they may be refugees from a dying world. Just the thought of intelligent beings from another world can evoke feelings ranging from fear to wonder. That's why alien stories are a great window into understanding "The Other," a term generically used to mean someone different than ourselves.

These literary opportunities do not go unnoticed by academics. Alien Imaginations: Science Fiction and Tales of Transnationalism, edited by Ulrike Küchler, Silja Maehl, and Graeme Stout, explores the ideas of alien fiction in fascinating depth. One of the main focuses of the book is the exploration of interactions between different cultures and the "transgressive force of travel over geographical, cultural or linguistic borders". It also looks at issues of immigration and globalization through a science-fiction lens. It examines fiction originating in both Europe and North America, using works by H.G. Wells, Eleanor Arnason, Philip K. Dick, and others, to examine current real-world issues of relevance. The editors are a mix of Ph.D. candidates and professors and contributions to the book include essays like "The Interplanetary Logic of Late Capitalism: Global Warming, Forced Migration and Cyborg Futures in Philip K. Dick's The Three Stigmata of Palmer Eldritch" and "Alienated Labor: William Gibson's Girls." You want to get neck-deep in science fiction? This is the book for you.

The Globe: The Science of Discworld II by Terry Pratchett, Ian Stewart, and Jack Cohen

Terry Pratchett will forever be known as the creator of Discworld, one of the most popular, funny fantasy settings. Like its name implies, Discworld is a disc-shaped world that is resting on the backs of four huge elephants who are, in turn, standing on the back of a gigantic turtle. Right from the start, you can see the author was going for silly and fun, but at the same time, it's also an endearing world that's heavily influenced by magic and populated with a huge cast of memorable characters. Pratchett's brand of humor has ensured the series' success, spinning the idea into dozens of novels, stories, spinoff books, and even television, film, and stage adaptations.

Last year's U.S. release of The Science of Discworld was a different beast, however. It combined both fiction and fact by telling an original Discworld story that is interspersed with factual science related to the story. That idea continues in the new U.S. release of The Globe: The Science of Discworld II in which Terry Pratchett again provides a fictional story and popular writers Ian Stewart and Jack Cohen explain the real scientific principles present in the fictional story. While the first book in the series played with the ideas of the origins of the universe and the beginnings of life, the second book in the series follows a parallel course as the modern history of Earth while the fictional story is about wizards rewriting human history.

The Cambridge Companion to American Science Fiction edited by Gerry Canavan and Professor Eric Link

It's no secret that literature is a product of the surrounding times. Current events and culture affect everyone—including writers—who then incorporate their observations into their writing. History has proven this to be true. In the area of science fiction, for example, short fiction took a significantly darker and more apocalyptic tone in the years following the 1945 bombing of Hiroshima, or more recently, think of the art that emerged following the September 11th attacks. Literature—even fiction—is a reflection of the real world.

Cambridge University Press has a new volume out that explores the relationship between fiction and culture. The Cambridge Companion to American Science Fiction, edited by Gerry Canavan and Professor Eric Link, examinesthe relationship between American science fiction and the American culture. It holds up examples from the world of books, film, television, gaming, and even fandom itself. Gary Westfahl, for example, looks at the development of American science fiction from the 1920s to the 1960s. There are essays about new-wave and post-new-wave science fiction, Afrofuturism, Feminist and queer science, slipstream, Hollywood sci-fi, weird sci-fi, and yes, even American science fiction after 9/11.

The Cambridge Companion to Fairy Tales edited by Professor Maria Tatar

Reading literature is fun. You know what else is fun? Discussing literature, and specifically talking about a certain type of literature that you like to read. Exploring literature in depth gives reads a deeper understanding of the stories, how they are created, what influences them, and how they affect us.

If you like exploring literature in depth and you read fairy tales, then you may want to check out The Cambridge Companion to Fairy Tales, edited by Professor Maria Tatar, also from Cambridge University Press. In this intriguing collection of essays, people from a wide-ranging variety of disciplines discuss the historic origins of fairy tales, how they are interpreted by different cultures, and the psychological impact of them. Specific topics include female tricksters, fairy-tale adaptations and economies of desire, symbolism in fairy tales, and media-hype, among others. It's a must-have for lovers of fairy tales.

John DeNardo is the editor of SF Signal, the Hugo Award-winning group science-fiction and fantasy blog featuring news, reviews and interviews. You can follow him on Twitter as @sfsignal.