The Physics of Superheroes: Spectacular Second Edition

by Kakalios, James

  Pym’s first accidental exposure (and you would not be far wrong to conclude that nearly all superheroes are fairly accident-prone, at least when it comes to gaining their powers) to his shrinking potion led to a harrowing adventure inside an ant hill, reminiscent of the 1954 science-fiction story The Incredible Shrinking Man. At the end of this story, Pym regains his original height through the application of the growth potion, and, once normal size, pours them both down the sink. Realizing that the potions are “far too dangerous to ever be used by any human again!” he vows, “From now on I’ll stick to practical projects!” What Pym considers more practical than developing a reversible miniaturization process is left to the reader’s imagination.

  Fig. 12. The opening page of “The Return of the Ant-Man” from Tales to Astonish # 35, in which we meet the costumed superhero alter-ego of Dr. Henry Pym for the first time.

  Dr. Pym’s vow remained unbroken until the sales figures came in for Tales to Astonish # 27. As shown in fig. 12, by Tales to Astonish # 35, the good doctor was back in “The Return of the Ant-Man” (though in the prior story in Tales to Astonish # 27, he had never referred to himself by that title), having replicated his shrinking potion and designed a snazzy red-and-black jumpsuit and a “cybernetic” helmet that enabled him to electronically communicate with ants. Given that ants actually communicate with one another by excreting pheromone chemicals, we won’t look too closely into how Pym’s helmet might actually function. So arrayed, scientist Henry Pym fought common criminals, Communist spies (it was the early 1960s, after all), invading aliens, and bizarre supervillains such as the Porcupine and Egghead as the astonishing Ant Man. It seemed as if no evildoer could win in a face-off (though not a literal one given the size differential) with a crimefighter whose superpower was that he was only a quarter-inch tall.

  Adventures involving characters reduced to the size of insects have been a staple of science-fiction movies and comic books for at least fifty years. Yet here we are in the twenty-first century and we’ve still not achieved this radical form of weight reduction. What’s the holdup?

  After all, it truly seems that every other day brings a news report confirming the equation: Science fact equals science fiction plus time. Robots assemble automobiles or vacuum your apartment; a computer has beaten the world champion in a chess tournament; and therapeutic cloning promises to alleviate many devastating diseases and medical conditions. Man has gone to the moon, walked upon its surface, and returned safely to Earth—not just once but several times—and travel to other planets, at least within our own solar system, has been accomplished, if only by unmanned craft so far. Scientific papers have even been published in prestigious physics journals discussing the construction of “time machines,” whose operation involves the concept of “negative energy.” (The “negative energy” is necessary to prevent the collapse of wormholes—a concept developed in the General Theory of Relativity—which has been postulated as providing a theoretical mechanism for warp speed; that is, faster-than- light travel.)20

  On the technology end of futuristic projections, the handheld communicators from Star Trek are now an everyday item—current cell phones, with digital cameras, image storage and transmission, and Internet access, exceed the imaginations of Star Trek writers from the 1960s. Star Trek’s “tricorders”—handheld devices the size of a hardcover book that enable chemical and biological analysis—may soon be available for purchase: PDAs such as the iPhone are already common, and the technology to perform “DNA analysis on a chip” and other functions is in development. From flat-panel television screens to microwave ovens and magnetic resonance imaging that provides three-dimensional views of the human interior, we are indeed living in the World of Tomorrow, even if we still lack portable jet packs and android butlers.

  Yet despite all the fantastic marvels and concepts that are either already here or seem within our grasp, we still can’t shrink or enlarge people at will. Compared with miniaturization, warp drives and time travel are right around the corner. However, back in the 1960s, it was shrink rays that were promised by our comic books and movies, coming soon to a top-secret underground military scientific laboratory near you.

  The 1966 science-fiction film Fantastic Voyage described the adventures of a surgical team and a mini-sub that is miniaturized to the size of a bacterium and injected into a scientist’s bloodstream to remove a blood clot in his brain that is inoperable from the outside. Before the movie begins, a title card appears, reading: THIS FILM WILL TAKE YOU WHERE NO ONE HAS EVER BEEN BEFORE. NO EYE-WITNESS HAS ACTUALLY SEEN WHAT YOU ARE ABOUT TO SEE. BUT IN THIS WORLD OF OURS WHERE GOING TO THE MOON WILL SOON BE UPON US AND WHERE THE MOST INCREDIBLE THINGS ARE HAPPENING ALL AROUND US, SOMEDAY, PERHAPS TOMORROW, THE FANTASTIC EVENTS YOU ARE ABOUT TO SEE CAN AND WILL TAKE PLACE. Three years later, man did indeed walk on the moon, and it is certainly true that compared with thirty years ago, the most incredible things are indeed happening all around us. Yet we have much longer to wait before a team of doctors can make this ultimate house call. What is the insurmountable barrier that prevents an aspiring Dr. Henry Pym from radically changing size?

  The reason that miniaturization is physically impossible (as far as we know) is that matter is made of atoms, and the size of an atom is a fundamental length scale of nature, not open to continuous adjustment. As discussed in Isaac Asimov’s novelization of Fantastic Voyage, to make something smaller requires either (1) making the atoms themselves smaller, (2) removing some (large) fraction of its atoms, or (3) pushing the atoms closer together.

  First let’s consider the size of the atoms. In cartoon representations of atoms, in DANGER! RADIOACTIVITY! warning signs for example, the orbits of electrons around the nucleus are represented as elliptical trajectories, like those the planets make about the sun in our solar system. We would mark the “size” of our solar system as the distance from the sun at its center to the outer boundaries of the orbits of the planets, and similarly the “diameter” of an atom would be determined by the range over which the electrons buzzed around the nucleus. The typical size of an atom is about a third of a nanometer, where one nanometer is one billionth of a meter (a meter is roughly 39 inches long). This seems small, and it is: Looking along the cross section of an average human hair, about 300,000 atoms lie end to end across its width.

  Every atom has a nucleus consisting of a number of positively charged protons and a comparable number of uncharged neutrons. In addition to the positively charged protons, the atom contains an equal number of negatively charged electrons. If oppositely charged objects attract one another, then why don’t the positively charged protons pull the negatively charged electrons toward them until the electrons sit on the nucleus? Well, they would, if the electrons were standing still. After all, as discussed in Chapter 2, the Earth and moon pull toward each other through their mutual gravitational attraction, and the moon’s orbit is such that its distance from the Earth and its speed exactly balance the inward gravitational pull. Similarly, the electrons reside in “orbits” around the nucleus at the center of the atom. Interestingly enough, all atoms are roughly the same size, to within a factor of three. The number of protons in the nucleus is countered by an equal number of “orbiting” electrons. Heavier atoms have more protons that pull the electrons more strongly toward the nucleus, but more electrons mean there is more repulsion between the negatively charged electrons trying to get away from each other. This balancing act results in a “size” of the atom that is roughly twenty or thirty billionths of a centimeter.

  I must note, for reasons that we will get into in Section 3, that this picture of electrons moving in precise elliptical orbits around the nucleus is not correct. Rather, quantum mechanics tells us not where the electrons are, but provides a mechanism for calculating the probability of finding an electron at a certain distance from the nucleus. It is the largest distance for which the probability of finding an electron is appreciable (the extent of the “probability cloud”) that is referred to as
the “radius” of the atom. The diameter of the atom (twice its radius) can also be thought of as the atom’s size. The expression for the most probable radius of the atom depends only on such terms as the mass of the electron, its electric charge, the number of positive charges in the nucleus, and a fundamental constant of the universe represented by the letter h, known as Planck’s constant (the value of which determines the magnitude of all quantum phenomena). We will discuss h in more detail in Section 3, but for now, all we need worry about is that h is a fixed number, just as the mass of an electron or the magnitude of its electric charge is in the expression for the atomic radius. Once the number of positive charges in the nucleus (the quantity that determines which element we are dealing with) is set, there’s nothing to change. The size of an atom is determined by a collection of fundamental constants and is not open to adjustment.

  In Isaac Asimov’s follow-up to his novelization of Fantastic Voyage, titled Fantastic Voyage II: Destination Brain, the mechanism proposed to enable miniaturization involve the creation of a “local distortion field” that somehow manages to change the value of Planck’s constant. If h becomes a tunable parameter, a factor-of-ten reduction in its value would shrink the size of an atom to one hundredth of its present size. Needless to say, we have no idea how to begin to accomplish this in the real world, which is, after all, why h is considered an invariable constant. Our lives would be profoundly different if we ever discovered a way to change the fundamental constants of nature so that the speed of light or the charge of an electron becomes open for our adjustment. Until that day comes, these constants are just that, and because the radius of an atom is described by said constants, the size of an atom cannot be changed. We therefore cannot make atoms themselves smaller—at least not without also changing the type of universe we live in.

  What about the second suggestion for size reduction—that is, removing a fraction of the atoms in an object? Everything is made of atoms; consequently, removing some of them should make an object smaller. Certainly the reduction in the size of electronic devices suggests that some objects can be made with less material and still retain their functionality. Problems arise, however, with complex, living things, for which the removal of a significant number of atoms would have serious consequences. To go from a height of six feet to six inches is a reduction in height by a factor of twelve. Of course, people are three-dimensional, and a factor-of-twelve reduction in the width and breadth would be required as well. To accomplish this by removing atoms (assuming that one could do this, had a safe place to store them, and could replace them later when you wanted to regain your original height) means that you would get to keep only one atom for every 1,728 atoms subtracted. Even assuming that this removal is performed uniformly—such that the same fraction of atoms is removed from all of your cells—biological functionality would be lost or at least severely compromised.

  Consider the neurons in your brain. It is a myth that man uses only 10 percent of present brain capacity; evolution theory argues against such a monumental waste of available resources. If neurons could be smaller and still fulfill their role in the brain, then there would be a strong competitive advantage to any mutation in this direction. Not only would it require fewer atoms to build a person (so the demands for raw materials through food would be greatly reduced), but one could have many more neurons and hence synaptic connections if our brains retained their current size. The typical neuron has a width of approximately one thousandth of a centimeter, and this is true whether one is considering an ant’s neuron or a human’s. People are smarter than ants (on average—I’m sure we can all think of a counterexample from our personal experiences) because we possess roughly four hundred thousand times more neurons, not because our neurons are a thousand times bigger. Remove 99 percent of the atoms, and you can make your body’s cells 99 percent smaller, but they won’t work as intended.

  Finally, what about the third possibility—shrinking a person by making him denser by pushing the atoms closer together? Unfortunately, this is not a successful strategy for miniaturization either, for the same reasons that the planet Krypton could not simply be fifteen times denser than Earth. Atoms in most solids are already tightly packed, with each atom essentially in direct physical contact with its neighbors. Moreover, thanks to the repulsion of negatively charged electron probability clouds around each atom, they are fairly rigid objects and resist being squeezed together. When a box is filled to the top with a child’s collection of marbles, nearly all of the container’s available space is taken up by the marbles. With few exceptions, every marble is in physical contact with several of its neighbors. Certainly there are open gaps between the marbles, but these spaces are not big enough for us to add more than possibly a few percent more marbles. If the marbles are hard spheres and not compressible, then squeezing on the walls of the container will not lead to a significant reduction in its volume. Reducing the size of the container by a factor of ten would require pressures that would significantly deform or crush the marbles. Trying to shrink a person by applying similar pressures would result in comic-book stories that would be both brief and messy and almost certainly would not garner approval by the Comics Code Authority.

  Well, if miniaturization is so difficult, how does biochemist Dr. Henry Pym, also known as the Ant-Man, accomplish it? In Tales to Astonish # 27, Pym had devoted years to discovering a potion that would shrink any object, until treated with an antidote growth serum. Later, he would convert his shrinking potion into an easy-to-swallow pill form. When it eventually became necessary to explain how he was able to shrink other objects, such as his costume, helmet, and weapons that he carried, it was revealed that he had developed a small generator of “Pym particles” that were able to increase or decrease an object’s size. No explanation has ever been put forth for how these potions or Pym particles actually work, and their physical basis must fall under the “miracle exemption” we frequently invoke when considering the source of a hero’s superpowers.

  6

  SO HE TALKS TO FISHES. WANT TO MAKE SOMETHING OF IT?—FLUID MECHANICS

  WHILE SUPERMAN, Spider-Man, Batman, and the Hulk are considered A-list superheroes, there are those who fight the never-ending battle, yet seem to garner little respect. Despite facing world-shaking threats and being present at the creation of a variety of superhero teams, these heroes are, unfairly, I would say, relegated to the ranks of second-stringers or worse. I am here referring to such champions as Ant Man (a founding member of the Avengers), Bouncing Boy and Matter- Eater Lad (both early members of the Legion of Super-Heroes), as well as an original participant of the Justice League of America: the King of the Seven Seas, the Aquatic Ace, Aquaman.

  In Chapter 8 we will see how Henry Pym, despite being only a quarter of an inch tall when fighting for justice as the astonishing Ant Man, is still able to punch his way out of a paper bag (a minimum prerequisite in the superhero game). Bouncing Boy will make an (albeit brief) appearance later on, when we discuss electrostatics and grounding. Matter- Eater Lad, whose real name in Tenzil Kim, from the planet Bismoll, whose inhabitants have evolved the ability to chew and digest any and all types of solids, from stone to metal to plastic, is not really relevant to explain any important physics principles. Nevertheless, villainous foes of the Legion have discovered to their regret that no jail can hold Matter-Eater Lad (who always takes a bite out of crime). But we will see in this chapter that the most undeservedly underrated superhero is Aquaman.

  Fig. 13. Aquaman in his first comic adventure, in More Fun Comics # 73, punching a hole through the plates of a submarine, which is designed to withstand the pressures at the ocean’s floor.

  Making his debut in More Fun Comics # 73 back in November of 1941, Aquaman was created by artist Paul Norris and writer Mort Weisinger; the latter would go on to edit the Superman comic line in the 1950s. In this first story, a German U-boat mistakenly torpedoes a refugee ship, which had been granted immunity from harm. In order to cover up their mistak
e, the submarine crew prepares to sink the lifeboat carrying the passengers and crew from the refugee ship. However, the refugees are saved by the sudden appearance from beneath the ocean’s surface of a strange hero, wearing an orange top and green slacks, who then goes on to mete out justice to the German submariners. While he never achieved the popularity of Superman, Batman, or Wonder Woman, he did share with them the distinction of maintaining a monthly publication schedule even during the dark period of the mid 1950s, when nearly all of the other superhero titles went out of print. Not bad for a guy who talks to fish.

  From this very first appearance in 1941, it was clear that Aquaman could breathe underwater, possessed great strength, could swim at remarkable velocities, enjoyed keen vision that enabled him to see even in the murky ocean depth,21 and could communicate with fish (though in his first adventure he used plants as an intermediary to send a message to some porpoises—it would be four issues later when he gave direct orders to a sawfish). All of these skills are consistent with known properties of fluid mechanics (well, “fish telepathy” requires a little electromagnetic theory—we will hold off discussing this superpower until later on in Chapter 20).