Wizards, Aliens, and Starships – Physics and Math in Fantasy and Science Fiction - Hardcover

Adler, Charles L.

Hardcover

ISBN 10: 0691147159 ISBN 13: 9780691147154

Publisher: Princeton University Press, 2014

Synopsis

From teleportation and space elevators to alien contact and interstellar travel, science fiction and fantasy writers have come up with some brilliant and innovative ideas. Yet how plausible are these ideas--for instance, could Mr. Weasley's flying car in the Harry Potter books really exist? Which concepts might actually happen, and which ones wouldn't work at all? Wizards, Aliens, and Starships delves into the most extraordinary details in science fiction and fantasy--such as time warps, shape changing, rocket launches, and illumination by floating candle--and shows readers the physics and math behind the phenomena. With simple mathematical models, and in most cases using no more than high school algebra, Charles Adler ranges across a plethora of remarkable imaginings, from the works of Ursula K. Le Guin to Star Trek and Avatar, to explore what might become reality. Adler explains why fantasy in the Harry Potter and Dresden Files novels cannot adhere strictly to scientific laws, and when magic might make scientific sense in the muggle world. He examines space travel and wonders why it isn't cheaper and more common today. Adler also discusses exoplanets and how the search for alien life has shifted from radio communications to space-based telescopes. He concludes by investigating the future survival of humanity and other intelligent races. Throughout, he cites an abundance of science fiction and fantasy authors, and includes concise descriptions of stories as well as an appendix on Newton's laws of motion. Wizards, Aliens, and Starships will speak to anyone wanting to know about the correct--and incorrect--science of science fiction and fantasy.

About this title

About the Author

Charles L. Adler is professor of physics at St. Mary's College of Maryland.

From the Back Cover

"To only call Wizards, Aliens, and Starships engaging would be a real understatement--it is a delightful, funny, and immensely interesting romp through science and fiction. From candlepower to teleportation, all the way to the fate of the cosmos in the span of a googol years, this is a cornucopia of teachable material. It is also a reminder of the simple thrill of applying science to the world around us, real or imagined. A new classic."--Caleb Scharf, author of Gravity's Engines and The Copernicus Complex

"This terrific book analyzes the romantic ideas of science fiction using the hard-nosed reality of the laws of physics. It will interest all readers, from Star Trek enthusiasts to astrophysicists."--Paul Nahin, author of The Logician and the Engineer

"Wizards, Aliens, and Starships rigorously applies the principles of physics to concepts, plot devices, and other features of science fiction and fantasy books, films, and television series. Readers who follow Adler's carefully developed analyses will learn a great deal about familiar science fiction tropes, physics, and how scientists think about the world. An exceptional book."--A. Bowdoin Van Riper, author of Science in Popular Culture

From the Inside Flap

"To only call Wizards, Aliens, and Starships engaging would be a real understatement--it is a delightful, funny, and immensely interesting romp through scienceand fiction. From candlepower to teleportation, all the way to the fate of the cosmos in the span of a googol years, this is a cornucopia of teachable material. It is also a reminder of the simple thrill of applying science to the world around us, real or imagined. A new classic."--Caleb Scharf, author of Gravity's Engines andThe Copernicus Complex

"This terrific book analyzes the romantic ideas of science fiction using the hard-nosed reality of the laws of physics. It will interest all readers, fromStar Trek enthusiasts to astrophysicists."--Paul Nahin, author of The Logician and the Engineer

"Wizards, Aliens, and Starships rigorously applies the principles of physics to concepts, plot devices, and other features of science fiction and fantasy books, films, and television series. Readers who follow Adler's carefully developed analyses will learn a great deal about familiar science fiction tropes, physics, and how scientists think about the world. An exceptional book."--A. Bowdoin Van Riper, author ofScience in Popular Culture

Excerpt. © Reprinted by permission. All rights reserved.

WIZARDS, ALIENS, AND STARSHIPS

PHYSICS AND MATH IN FANTASY AND SCIENCE FICTION

By CHARLES L. ADLER

PRINCETON UNIVERSITY PRESS

Copyright © 2014 Princeton University Press
All rights reserved.

ISBN: 978-0-691-14715-4

Contents

1 PLAYING THE GAME, 1, 
I POTTER PHYSICS, 11, 
2 HARRY POTTER AND THE GREAT CONSERVATION LAWS, 13, 
3 WHY HOGWARTS IS SO DARK, 27, 
4 FANTASTIC BEASTS AND HOW TO DISPROVE THEM, 38, 
II SPACE TRAVEL, 57, 
5 WHY COMPUTERS GET BETTER AND CARS CAN'T (MUCH), 59, 
6 VACATIONS IN SPACE, 71, 
7 SPACE COLONIES, 86, 
8 THE SPACE ELEVATOR, 115, 
9 MANNED INTERPLANETARY TRAVEL, 130, 
10 ADVANCED PROPULSION SYSTEMS, 145, 
11 SPECULATIVE PROPULSION SYSTEMS, 157, 
12 INTERSTELLAR TRAVEL AND RELATIVITY, 176, 
13 FASTER-THAN-LIGHT TRAVEL AND TIME TRAVEL, 188, 
III WORLDS AND ALIENS, 215, 
14 DESIGNING A HABITABLE PLANET, 217, 
15 THE SCIENTIFIC SEARCH FOR SPOCK, 242, 
16 THE MATHEMATICS OF TALKING WITH ALIENS, 255, 
IV YEAR GOOGOL, 273, 
17 THE SHORT-TERM SURVIVAL OF HUMANITY, 275, 
18 WORLD-BUILDING, 292, 
19 DYSON SPHERES AND RINGWORLDS, 303, 
20 ADVANCED CIVILIZATIONS AND THE KARDASHEV SCALE, 326, 
21 A GOOGOL YEARS, 336, 
Acknowledgments, 351, 
Appendix: Newton's Three Laws of Motion, 353, 
Bibliography, 359, 
Index, 371, 

CHAPTER 1

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 physics—but perhaps not quite.

1.3 ORGANIZATION

There are four large sections of the book. Each of them contains severalchapters centered on a given theme. The sections are:

1. "Potter Physics." This first section explores physics as used and abusedin fantasy novels and series. I've chosen two examples of "urban fantasy"novels to focus on, the Harry Potter series by J. K. Rowling and theDresden Files novels by Jim Butcher. The issues here are different fromthose in the rest of the book, for fantasy, by its very nature, cannot adherestrictly to scientific laws. However, we can ask whether the series are atleast internally consistent, and whether the magic used in the series makessense when in contact with the muggle world.

2. "Space Travel." This is the largest single section, consisting of ninechapters, as befits the subject. Space travel is perhaps the theme of sciencefiction, to the point that it almost defined the genre from the 1930s to the1980s. One goal of this section is to examine not only the scientific issuesinvolved in space travel but also the economic ones. The big question is,why isn't space travel cheap and common now, as it was certainly foretoldto be in almost all of "golden age" science fiction?

3. "Worlds and Aliens." This section consists of four chapters exploring theother major theme of science fiction, the possibility of life on other worldsin our Solar System and elsewhere.

4. "Year Googol." This part explores the potential survival of humanity (orother intelligent species) into the far distant future, along lines laid downoriginally by the writer Olaf Stapledon and the physicist Freeman Dyson.

My choice of subject matter, like the organization of the book, isidiosyncratic. The book is a loose collection of essays more than a unifiedtext. I write about those aspects of science fiction and fantasy that mostinterest me. My hope is that my readers are similarly interested. Bynecessity, I concentrate on those writers whom I know the best, meaningAmerican and British science fiction writers. Since I know the "goldenage," New Wave, and early cyberpunk literature best, this may give thebook an antiquated feel. I try to include ample description of these storiesso that anyone reading the book can understand the scientific points I amtrying to make.

A set of problems has been prepared for instructors intendingto use this book as a class text. For space reasons, we have placedthese problems, organized by chapter, on a website (press.princeton.edu/titles/10070.html). I've also included solutions and hints for theproblems. This book cannot be used to replace a physics textbook, butit could be used in a specialized course.

1.4 THE MATHEMATICS AND PHYSICS YOU NEED

I expect the readers of this book to be able to read and use algebraicequations, and to understand them on some level. I intend the book as aworking book for science fiction enthusiasts who have at least a decentknowledge of algebra and know what calculus means.

The equations I introduce don't exist in a vacuum; they are mostlydrawn from physics, and represent physical quantities. That is, unlikepure mathematics, there is always some connection with the real (or,at least, science fiction) world that is expressed by them. In most casesI explain the equations in detail but do not derive them from basicprinciples. This is unlike what happens in most physics courses, wherethe emphasis is as much on deriving the equations as on using them.Since most of my readers aren't physicists, I will explain how theequations are used and why they make sense. I also want my readers tohave a conceptual understanding of calculus. There are only a few placeswhere this will crop up, so it isn't essential, but it is useful to know whatis meant when I use the terms "derivative" and "integral."

Physics is the science central to this book. Appendix 1 at the endof the book reviews Newton's laws of motion, which are central to anyunderstanding of physics. Just as a knowledge of grammar and spelling isneeded for reading and writing, a knowledge of Newton's laws is neededfor any understanding of physics. Newton's laws describe how thingsmove on the macroscopic scale; that is, they are a good description ofthings larger than atomic size. However, they are only approximations tothe truth. The laws of quantum mechanics are the real way things work.It is characteristic of physics that the underlying laws are difficult to seedirectly. Why this is so, and why Newton's laws are good approximationsto the true fundamental laws of nature, are questions beyond the scopeof this book to answer. If readers are interested in this, there are dozensof good books that examine these questions. I strongly recommend twobooks by Richard Feynman, The Character of Physical Law and (forthose who have a physics background) The Feynman Lectures on Physics,particularly book 2, chapter 20.

1.5 ENERGY AND POWER

Energy and power, which is the rate at which energy is converted fromone form to another, are the key points to understand for this book.Energy is useful because it is conserved: it can be transformed from oneform to another, but not created or destroyed. I use energy conservation,either implicitly or explicitly, in almost every chapter of the book. A fewof the forms that energy can take are the following:

• Gravitational potential energy: This is the energy that pairs of objectspossess by virtue of the gravitational attraction between the members ofthe pair. This form of energy is very important for any discussion of spacetravel.

• Chemical potential energy: This is the energy resulting from the spacing,composition, and shape of chemical bonds within a molecule. Chemicalreactions involve changes in these properties, which usually meanschanges in chemical potential energy. In an exothermic reaction, thechemical potential energy is less after the reaction than before it. Energy is"released" during the course of the reaction, usually in the form of heat. Anendothermic reaction is the opposite: energy must be added to the reactionto make it proceed.

• Nuclear energy: This is the energy resulting from the structure andcomposition of the atomic nucleus, the part of the atom containing theprotons and neutrons. Transformations of nuclei either require or releaseenergy in the same way that chemical reactions do, except on an energyscale about one million times higher.

• Mass: Mass is a form of energy. The amount of energy equivalent to massis given by Einstein's famous formula

E = Mc2, (1.1)

where E is the energy content of mass M and c is a constant, the speed oflight (3×108 m/s, in metric units). This is the ultimate amount of energyavailable from any form of mass.

• Kinetic energy: This is the energy of motion. Newton's formula for kineticenergy is

K = 1/2 Mv2, (1.2)

where K is the kinetic energy, M is the mass of the object, and v is its speed.This formula doesn't take relativity into account, but it is good enough forspeeds less than about 10% the speed of light. If an object slows down, itloses kinetic energy, and this energy must be turned into another form. Ifit speeds up, energy must be converted from some other form into kineticenergy.

• Heat: Heat is energy resulting from the random motion of the atoms ormolecules making up any object. In a gas at room temperature, this is thekinetic energy of the gas molecules as they move every which way, plus theenergy resulting from their rotation as they spin about their centers. Forsolids or liquids, the energy picture is more complicated, but we won't getinto that in this book.

• Radiation: Light, in other words. Light carries both energy and force,although the force is almost immeasurable under most circumstances.Most light is invisible to the eye, as it is at wavelengths that the eye isinsensitive to.

In the units most often used in this book, energy is expressed in joules(J). The joule is the unit of energy used in the metric system. To geta feel for what a joule means, take a liter water bottle in your hand.Raise it 10 cm in the air (about 4 inches). You have just increased thepotential energy of the water bottle by 1 J. Other units are also used; inparticular, the food calorie, or kilocalorie (kcal), will be used in severalchapters. The kilocalorie is the amount of energy required to increasethe temperature of 1 kg of water by 1°C (Celsius). It is equivalentto 4,190 J. Other units are defined as they come up in the chapterdiscussions.

Power is the rate at which energy is transformed from one form toanother. The unit of power is the watt (W), which is 1 J transformed persecond from one form of energy to another form. For example, if wehave a 60W light bulb, 60 J is being transformed from the kinetic energyof electrons moving through the tungsten filament in the light bulb intoradiation, every second.

The different forms of energy and their transformations are the mostimportant things you need to know to read this book. With this briefintroduction to the subject, we are ready to start.

CHAPTER 2

HARRY POTTER AND THE GREATCONSERVATION LAWS

2.1 THE TAXONOMY OF FANTASY

The "physics of fantasy" seems like an oxymoron: by definition, fantasydoesn't concern itself with science but with magic. However, a lotof fantasy writers follow in the tradition of science fiction writers intrying to set up consistent rules by which their fantasy worlds operate.This is because many fantasy writers are science fiction writers as well.It is almost a universal trait: those who write quasi-realistic sciencefiction will also write quasi-realistic, rules-based fantasy; those who don'tgenerally won't set up rules by which magic works.

Among the former is Ursula K. Le Guin, whose Earthsea trilogy haslong descriptions of the "rule of names" underlying all magic. Her booksinclude several lectures by magicians on exactly how this works. Manywriters have found her works compelling enough to copy her rules intheir own stories. Others base their magic rules on outdated scientific orphilosophical ideas, as Heinlein did in his novella, Magic, Incorporated.Magicians in that book use the "laws" of similarity and so forth, toperform their magic. Randall Garrett in his Lord Darcy stories writesof a world in which magic (following these laws) has developed insteadof science. The stories are full of descriptions of how the magic worksand is used in solving crimes.

(Continues...)

Excerpted from WIZARDS, ALIENS, AND STARSHIPS by CHARLES L. ADLER. Copyright © 2014 Princeton University Press. Excerpted by permission of PRINCETON UNIVERSITY PRESS.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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Edition details

• Publisher: Princeton University Press
• Publication date: 2014
• Language: English
• ISBN 10: 0691147159
• ISBN 13: 9780691147154
• Binding: Hardcover
• Number of pages: 392