PLAYING THE GAME

Dear Roger,

(XXX) and I have been exchanging letters for some time. As a fan,he's strange; he likes the science better than the fiction. Wants me toquit futzing with the plot and characters and get on with the strangeenvironments. He plays The Game: finds the holes in the science andwrites in. I like him....

—LETTER FROM LARRY NIVEN TO ROGER ZELAZNY, JANUARY 3,1974

1.1 THE PURPOSE OF THE BOOK

When I was young, back in the 1970s and 80s, I read a lot of sciencefiction. I read a lot of other stuff, as well, but science fiction (andfantasy) filled a need that other literature simply didn't. I tended toread "hard" science fiction, that is, stories plotted around hard science:physics, astrophysics, giant engineering projects, and the like. Theworlds these stories portrayed, where space travel was common, humanproblems such as poverty were nearly eliminated, and conflicts centeredon larger-than-life issues, always seemed to me more compelling thanhuman dramas that revolved around why someone didn't love someoneelse.

My tastes have changed since then, but the initial thrill of these storieshas never really left me. I am a scientist because of my initial love ofthese tales. A chill still runs down my spine whenever I look at a HubbleTelescope photo or learn of a new exoplanet discovered. I live in hopethat I will be alive when life on other planets is discovered. I still want totake a vacation to the Moon or to an orbiting satellite. These thrills aretempered by my adult realization that much of what goes into sciencefiction is quite unrealistic. This book is written for my fifteen-year-oldself, and other readers like him, who would like to know which partsof science fiction are based on real science, and therefore in some wayplausible, and which parts are unrealistic. This is the book I would havewanted to read when I was young. Just as for Niven's correspondent,my interest in science fiction was mostly in the strange environments,the new worlds, the alien life, the superscience it portrayed. I wanted toknow which parts were (potentially) real and which weren't. To a largeextent, that is why I eventually became a physicist.

Almost any science fiction story has a lot of incorrect science. Thisdoesn't make the story bad or invalid. Some authors, like Larry Niven,are almost obsessive in trying to get the science right; most are more lackadaisicalabout it. However, the standards for the profession are prettyhigh: no science fiction writer can be really esteemed accomplishedunless he or she has a thorough knowledge of basic physics, chemistry,biology, astrophysics, history (ancient and modern), sociology, and militarytactics; and besides all this, must possess a certain something in theirair and manner of writing, or their profession will be but half-deserved.(Improvement of their minds by extensive reading goes without saying.)Science fiction writers do not have the same opportunities as researchscientists do to stay up-to-date in their research fields, and writingscience fiction involves a lot more fields than most research scientistscan keep up with.

This book is one physicist's attempt to discuss the science, particularlythe physics and mathematics, that goes into writing hard sciencefiction. As an added bonus, I also take a look at physics in fantasy writing:there's more in it than meets the eye. This is not an attempt to predict thefuture: as G. K. Chesterton pointed out, most of the fun in predicting thefuture comes from burying the people who attempt to do it. Rather,I stick to the science used in crafting the stories. There are many booksdedicated to the literary criticism of science fiction; this book is devotedto its scientific critique. As such, my choice of which literature to use isdictated both by my own reading and by the needs of the book. I tend toavoid writers who don't make much use of science in their stories, exceptoccasionally to comment on their errors. I also tend to stick to literature,that is, novels and short stories, although I occasionally comment onscience fiction movies or television shows as well.

Many have gone down this path before me, scientists and writers alike(and a few who were both). The preeminent standout among sciencefiction writers is Poul Anderson, to whom this book is dedicated, for hisessays "How to Build a Planet" and "On Thud and Blunder." I read bothwhen I was a teen; this book would not have been written but for hisexample. Isaac Asimov and Arthur C. Clarke both wrote many essays onscience. Larry Niven has written several essays on the scientific aspectsof teleportation, time travel, and other science fiction themes. Almostfrom the beginning of the modern era, scientists have written essays onscience fictiony ideas, and I reference them where appropriate. This bookis mainly synthetic rather than original, although I think there are a fewnew things in it, such as the discussion of candlelight in the Harry Potterseries in chapter 3.

1.2 THE ASSUMPTIONS I MAKE

David Gerrold has written that science fiction authors by necessityalmost always involve bits in their work that defy the laws of scienceas we know them. He refers to places where this happens as instances of"baloneyum." His advice is that beginning authors limit themselves toonly one piece of baloneyum per story, experienced authors perhaps asmany as two, and only grandmasters put in three instances. It's agood rule.

In this book I have followed a similarly conservative path. In analyzingscience fiction my assumptions are that the laws of physics aswe understand them now are pretty much correct. They are incomplete;we don't know all of them, but the incompleteness doesn't really affectmost science fiction stories. In particular, I assume that Newton's lawsof motion are good enough to describe things larger than atoms, thatEinstein's theory of relativity is correct, and that quantum mechanicsis the correct description of nature on the microscopic scale. The oneexample of baloneyum I indulge in is in the consideration of faster-than-lighttravel and, equivalently, time travel, which appear to be impossiblefrom almost everything we know about...