The Physics of Superheroes: Spectacular Second Edition (2 page)

Now, I don’t want you to think that I bring up comic books and popular misconceptions in the same paragraph because I want to denigrate the former. Far from it! Indeed, the comics sometimes actually get it right, and as James Kakalios describes in his introduction to this far-reaching journey from the gravity of Krypton to the quantum mechanics of the X Men, students often seem to grumble about how the standard examples from his introductory physics class have nothing to do with the real world they will encounter upon graduation. But when they are instead introduced to the physics of superheroes, this complaint never arises!

One might initially wonder whether Superman might seem more real to students than pulleys, ropes, and inclined planes. But the real reason students don’t complain is undoubtedly that the comic-book examples are fun, while inclined planes aren’t. And that is perhaps one of the most useful reasons for thinking about the physics of superheroes. Not only can you imagine, and be introduced to, lots of interesting physics, from everyday phenomena to esoteric modern subjects, but it is actually fun to think about. Moreover, while subjects like quantum mechanics might seem intimidating, who could be intimidated by cute Kitty Pryde?

Some who remember the comic books that enthralled them as young people might also recall a sense of wistfulness in pondering whether our own world could ever capture the excitement and drama of the worlds of comic-book superheroes. In truth, however, it is far more interesting and exciting to open up our minds to the hidden wonders of nature that science has revealed to us over the past four hundred or so years. Truth is far stranger than fiction, even comic-book fiction. And finding out why is all part of the fun.

 

Lawrence M. Krauss
Cleveland, Ohio

I WAS A COMIC-BOOK FAN as a kid, but like many who have come before and after me, I abandoned the hobby in high school upon discovering girls. My mother, following the standard script, used this opportunity to throw my collection away. I renewed my comic-book reading habit years later, in graduate school, as a way to relieve the stress of working on my dissertation. Now, as an adult, I’ve rebuilt much of my comic-book collection (or, as my wife refers to it, “the fire hazard”), but as a precaution, my mother is not allowed near it.

Back in 1998, the University of Minnesota, where I am a physics professor, introduced a new type of class termed “freshman seminars.” These are small, seminar-type classes open to entering students, and while they are for credit, they are not tied to any particular curriculum. Professors are encouraged to develop classes on unconventional topics, and freshman seminars on Bio-Ethics and the Human Genome; The Color Red (a chemistry class); Trade and the Global Economy; and Complex Systems: From Sandpiles to Wall Street, are among the many offered. In 2001 I introduced a class originally entitled Everything I Know About Physics I Learned from Reading Comic Books. This is an actual physics class, covering most of the topics traditionally covered in an introductory course, but rather than employing illustrations of masses on springs, or blocks sliding down inclined planes, all of the examples came from the four-color adventures of costumed superheroes, and focused in particular on those situations where the comic books got their physics right.

The present book, while inspired by this class, is not a textbook per se. It is written for the nonspecialist who is interested in a relatively pain-free way to learn about the basic physics concepts underlying our modern technological lifestyle. Topics such as forces and motion, conservation of energy, thermodynamics, electricity and magnetism, quantum mechanics, solid-state physics and materials science are discussed, and real-world applications such as automobile airbags, transistors, and microwave ovens are explained. I hope you will be so busy enjoying this superhero ice-cream sundae that you won’t realize that I am sneakily getting you to eat your spinach at the same time.

This book is intended for both longtime comic-book fans and those who can’t tell Batman from Man Bat. In order to describe the physics connected with certain superheroes or story lines, I have had to summarize key plot points in various comic books. Therefore, for those who have not yet read these classics, the following two words apply to this entire book: “Spoiler Alert.”

Readers interested in consulting the source materials considered here will find citations of the comic books discussed in the text at the end of the book. I have listed the original comic-book information and, whenever possible, where the issue can be found in a reprint volume. The dates listed for a given comic book, printed on its cover, are not when the issue first appeared on the newsstands. To extend shelf life, the date listed indicated when the comic was to be returned to the publisher for credit, and not when it became available for purchase. In an effort to attract new readers who desire first issues as collectors’ items, comic books will occasionally restart their numbering scheme while keeping the name of the comic unchanged. If not otherwise noted, issue numbers refer to the first volume of a comic. I have listed, where known, the writer and artist for each comic listed in the endnotes. My omission of the inkers should not be construed as denigrating their contribution to the finished comic (I most certainly do not believe that such a job is equivalent to “tracing”), but rather a reflection of the fact that the artist, along with the writer, typically have the primary responsibility for the physics in a given comic-book scene.

Any discussion of physics in comic books naturally invites the scrutiny of physicists as well as comic-book fans, both of whom are known for their, let us say, attention to detail. Each of the incidents I’ve selected illustrates a particular physics principle. Sometimes the very next issue would contain a scene contradicting the physically plausible manifestation of a superpower described here. When considering characters that have starred in multiple comic books for more than half a century, it is a sure bet that there will be counter-examples for any statement I make. Consequently, while examining the physics associated with a superhero’s powers will, in many cases, provide a better appreciation for their talents, my comrades in fandom are advised that this book is not intended to provide definitive accounts of any character’s power or adventures.

Similarly, my physics colleagues are warned that this book is for a nonexpert audience. I have attempted to keep things simple, while acknowledging the rough edges and complications of the real world. A complete discussion of many of the topics considered here could easily expand to fill several volumes and would provide a concrete illustration of Dr. Manhattan’s final words at the conclusion of Alan Moore’s and Dave Gibbons’
Watchmen
: “Nothing ends, Adrian. Nothing ever ends.”

The language that describes the physical world is mathematical in nature. Why this should be so is a deep, philosophical question (the physicist Eugene Wigner referred to the “unreasonable effectiveness of mathematics” in accounting for nature’s properties) that has puzzled and stirred all those who have studied it. It is tempting, in a book involving comic-book superheroes, to avoid even the slightest whiff of mathematics. However, that would be a cheat, worse than omitting any reproductions of artwork in a book about Picasso, or not providing a CD of recordings for a book about the history of jazz, because mathematics is necessary in any thorough discussion of physics.

The reader may protest that they do not understand math, or cannot think mathematically. But for this book, all that is required is that one recognizes that ½ + ½ = 1. That’s it, that two halves equal a whole. If you are comfortable with ½ + ½ = 1, then writing it as 2 × (½) =
= 1 (that is, two multiplied by one half) should cause no concern, because obviously two halves equal one. It seems so simple that you may be surprised to discover that we have already been doing algebra (and you thought you’d never use that again after high school!).

As many students have long suspected, there is a trick to algebra, and the trick is the following: If one has an equation describing a true statement, such as 1 = 1, then one can add, subtract, multiply, or divide (excepting division by zero) the equation by any number we wish, and as long as we do it to both the left and right sides of the equation, the correctness of the equation is unchanged. So if we add 2 to both sides of 1 = 1, we obtain 1 + 2 = 1 + 2 or 3 = 3, which is still a true statement. Dividing both sides of 1 = 1 by 2 gives us ½ = ½. Since 1 = 1, then ½ + ½ = 1, which in turn can be written as
= 1. I’ll make a deal with you, Fearless Reader: I won’t use any mathematics more sophisticated than what’s described in this paragraph if you’ll refrain from panicking when a mathematical equation appears. You can always glide right by the math, and your understanding will be no worse for it. But if you take a notion to calculate a velocity or a force for a situation other than considered here, you’ll have the tools to do so. In any event, I promise you that there will be no quizzes at the end of the book!

IN GRADUATE SCHOOL, as the writing of my physics dissertation neared completion, my thesis adviser impressed upon me that no scientific research is ever “finished.” Regardless of the answers you have obtained to your problem, there are always at least a few open questions—loose threads waiting to be pulled. Having written
The Physics of Superheroes,
I have discovered that, similarly, no book is ever finished. The manuscript is delivered to the editor, galley proofs are checked (though the typographical errors that inevitably slip through are guaranteed to be the first thing the proud author spots upon cracking open the newly published book), the book shows up on the shelves of bookstores, and yet threads remain loose. There is always more that could be said, or said better.

Consequently, I was pleased when Gotham Books offered me the opportunity to revise
Superheroes
for a second edition. The feedback I received from readers on the 2005 first edition suggested many topics that warranted additional attention. My estimation of the time Superman would spend pushing his weight down against the ground as he prepared to leap a tall building in a single bound in particular provoked many friendly discussions with readers, and I am happy to have a chance to elaborate on this point in this second edition.

Additionally, soon after publication, I came across superhero illustrations of various physics principles that, had I been aware of earlier, I certainly would have included. This second edition also includes new chapters on fluid mechanics, angular momentum, and materials science, as reflected in discussions of the heroes and villains Aquaman, the Top, and Whirlwind; and the entire Justice League of America and Avengers, respectively. Some chapters in the Mechanics section have been reordered, in order to improve the flow of the topics discussed. Every chapter has been edited, some extensively. Moreover, mathematical analysis indicates that in this second edition, the jokes are now 12.7 percent cornier, in some cases by the utilization of the anti ”rule of three” (two punch lines followed by a straight line). I hope that you will find this second edition to be a fun and accessible way to learn the basic principles of physics.

In addition to all of those I thanked in the first edition, there are a few new names whose assistance with the second edition I wish to acknowledge. Patrick Mulligan at Gotham Books has been a wonderful and insightful editor of this edition. I am proud to thank my son Thomas for his careful reading of the new chapters and his suggestions for improvement and clarification. Laura Gjo vaag, who runs The Unofficial Aquaman website, and Rob Kelly at The Aquaman Shrine website, were both great resources for all things Aquaman-related and provided indispensable information and images of the Aquatic Ace. I appreciate their generous time and effort. Once again, Jenny Allen’s assistance preparing the new figures for the second edition is greatly appreciated.