Reaching the Nearest Star, and Lighting Hogwarts Castle

Equations aside, a physicist presents an approachable and informal survey of science and technology according to contemporary science fiction and fantasy.

Wizards, Aliens, and Starships: Physics and Math in Fantasy and Science Fiction. Charles L. Adler. 378 pages. Princeton University Press.

Photo of Hogwarts Castle model by Robert Clarke, via Wikimedia Commons.

You just know that a book whose title includes wizards and starships is going to cover a range of topics. Charles Adler’s Wizards, Aliens, and Starships doesn’t disappoint. Adler, a physics professor at St. Mary’s College of Maryland, has written a book about the physics and math behind many of the most widely used ideas in science fiction and fantasy.

The book’s inclusion of fantasy is unusual. Traditionally, there’s a boundary between the two genres:  fantasy allows magic; science fiction does not. But the science in science fiction can be inaccurate, so scientific critiques of the style abound. And while fantasy isn’t about science, TV shows and big-ticket films like Star Trek and the Harry Potter series have nonetheless catapulted both classes into popular culture. That gives new opportunities to convey science—even when it is expressed incorrectly or implicitly on screen—to new audiences, especially young people who love these films and so may be open to learning and inspiration.

Still, science fiction offers more science than does fantasy, so the book is mostly about the former genre. The “Space Travel” section covers nearly every fictional possibility ever presented, from travel within our solar system, to space colonies and the space elevator, to the speculative prospects of interstellar and faster-than-light travel. “Worlds and Aliens” also treats a big science fiction theme, describing the physical requirements for life to exist elsewhere and introducing the Drake equation to explore the possibility of hearing from aliens. This section also discusses the search for exoplanets, and Adler gets credit for including this exciting contemporary quest. A third part, “Year Googol,” poses a question also considered in science fiction: How long can humanity last? It considers looming threats like global warming and depletion of resources and discusses speculative solutions such as terraforming.

These three parts add up to a survey of subjects in basic physics, planetary science and astrophysics, and technology. Adler presents all this in generally clear and informal prose pitched at non-specialists. He mingles the science with examples of how it appears in literary science fiction written by such authors as Robert Heinlein, Arthur C. Clarke, Poul Anderson, Larry Niven and Greg Bear. But some examples from film and television, such as 2001: A Space Odyssey and Babylon 5, also appear. Much of the scientific discussion is quite detailed, and Adler supplements it with numerous, carefully explained equations.

Though fantasy is the junior partner, Adler opens the book with it in “Potter Physics.” He notes that some fantasy authors, like Ursula LeGuin in her Earthsea series, write semi-scientifically, using magical laws that are at least internally consistent. Others, like J.K. Rowling, use magic in inconsistent ways that also are scientifically incorrect, as Adler illustrates by teasing out the basic principles magical events may violate.

As one example, he asks this: When a 60 kilogram character in Harry Potter and the Goblet of Fire is magically changed into a ferret weighing 2 kilograms, where does the missing mass go? That question leads to a discussion of conservation of mass. This approach also lets Adler introduce, through fantasy, conservation of momentum and the second law of thermodynamics. And his question about whether candlelight could possibly illuminate all of Hogwarts Castle sparks a discussion of the nature of light and illumination. The conclusion is that the Hogwarts Great Hall is poorly lit, at around 30 lumens per square meter—not enough for simple tasks, let alone reading. Even at that inadequate level, the yearly budget for candles would be $1 million!

Like the sections on science fiction, these discussions also use a fair number of equations. Adler’s extensive use of math made me wonder: Who are his intended readers? The cover blurb says, “Anyone who wants to know about the correct—and incorrect—science of science fiction and fantasy.”  Presumably that includes people with science backgrounds and fans of both genres.

Scientists and hard science fiction enthusiasts (who often also know real science) will grasp and enjoy both the words and the math. But from my own experience in covering science in the media, I’ve learned that science fiction and fantasy can be lumped together in popular culture simply as escapist entertainment. You can see this blurring in the highly successful film The Avengers (2012), where Ironman’s wondrous high-tech powered armor seamlessly coexists with magical, not to say divine, powers wielded by Norse gods. Along similar lines, some people tell me what they want to experience is imagination unfettered, whether in a magical castle or aboard a spacecraft, and not constrained by quantitative fact. That isn’t what scientists want to hear, but it’s part of the evolution of science fiction and fantasy in the mass media and must be recognized as we try to convey science to non-scientists.

So I wonder if, with its mathematical content, this book will reach its widest possible readership. Its reliance on literary science fiction, mostly from earlier generations of writers, also may limit its impact on younger readers. But for those who want to learn the hard facts about the realities of space travel or the chances for alien life, and as an engaging supplemental text for physics and astronomy courses, Wizards, Aliens, and Starships would be an admirable choice.

Sidney Perkowitz, Candler Professor of Physics Emeritus, Emory University, writes often about science and science fiction in the media. His latest book is Hollywood Chemistry (American Chemical Society). His website: On Twitter @physp.

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