The Physics of Superheroes: Spectacular Second Edition (54 page)

When Roy Thomas took over the writing duties of the Marvel comic book
The Avengers
in the mid 1960s, he would frequently reintroduce Golden Age characters with a new Silver Age twist, just as DC Comics had done when they initiated the Silver Age. One of the more popular characters created by Thomas and artist John Buscema is the Vision. Originally a supernatural costumed crime-fighter in the 1940s, the new Vision introduced in
Avengers # 57
is an android
⁸⁶
created by Ultron, another android. Ultron is one of the Avengers’ most dangerous foes, and the Vision was initially intended to infiltrate the superteam in order to destroy them from within. Rebelling against his programming, the Vision saved the lives of the Avengers and went on to become a valued member of the team.

In addition to laser vision, the power of flight, and the mind of a computer, the Vision possessed the superpower of total independent control of his body’s density. He could make his body, or any part thereof, as hard as diamond or so insubstantial that he could pass through solid objects. Kitty Pryde of the X-Men walks through walls using her mutant ability to vary her quantum-mechanical tunneling probability, but the Vision should stick to using the door when he wants to enter a room.

The density of any object is defined as the mass per volume, and can be altered either by changing the mass or varying the volume. The volume is governed by the average spacing between atoms. Any solid typically has its atoms packed fairly closely, so the atoms can be considered to be touching (they have to be this close in order to form chemical bonds, which are what hold the atoms together in a solid after all). Very roughly, all solids have the same density, within a factor of ten or so.

Even if the Vision could control his density at will and could maintain the structural integrity of his body, he could not pass through walls. A gas, such as the air in your room, is comparatively dilute, with the average spacing between atoms being roughly ten times larger than the size of an atom. Yet the fact that the air in your room is less dense than the walls does not mean that the air can pass through the solid walls. Good thing, too, otherwise the air in an airplane would leak out through the fuselage and make air travel an even more unpleasant experience. We must therefore conclude that Ultron made a second error when he constructed the density-altering Vision (the first was believing that such a noble android would betray the mighty Avengers).

The DC superhero the Atom has appeared throughout this book, and his ability to reduce his size and mass independently have provided excellent illustrations of a wide range of physical phenomena. Of course, occasionally his shrinking would take him to ridiculous extremes, such as whenever he visited other worlds that contained civilizations, cities, and advanced technology all residing within an atom. Given that there are nearly a trillion trillion atoms in a cubic centimeter of a typical solid, it’s amazing that the Atom ever managed to find these nanoworlds, unless they are a routine feature of every element in the periodic table. The implausibility of the Atom’s powers was slyly acknowledged in 1989, in a scene in his second regular series,
The Power of the Atom # 12
. In this story, the Atom shrinks both himself and a colleague in order to escape a supervillain’s death trap, and they wind up decreasing to subatomic lengths in order to pass through the empty spaces in the floor’s atoms. Pausing in their miniaturization, they discuss the events of the past few issues while sitting on an electron. The Atom’s friend suddenly notes that they are smaller than oxygen molecules and wonders, “How are we even breathing?” To which the Atom honestly replies, “I’m not sure.”

Superman can fly, the Flash can run really fast, Hawkman has his wings and antigravity belt, Storm rides on thermally generated air currents, but how do you get around when you’re very, very tiny? Ant Man uses flying carpenter ants as his personal taxi service, the Wasp has wings that grow out of her back when she shrinks, but the Atom has Bell Telephone. In his Silver Age debut issue,
Showcase # 34
, the Atom employs a unique mode of transportation. In this story he needs to confront a small-time crook named Carl Ballard who is clear across town. Presumably, after looking up Ballard in the phone book, the Atom dials his number while setting up a metronome near the receiver, which creates a “tick-tock” sound. Shrinking himself smaller and smaller, the Mighty Mite jumps into one of the holes on the speaker of his telephone, and in the next panel we see him flying out of the receiver of Carl Ballard’s phone.

The “explanation” for this trick is revealed on a text page in the back of the comic.
⁸⁷
By dialing Ballard’s phone number, the Atom causes an electrical impulse to travel from his phone to the central telephone exchange, which then forwards the signal to Ballard’s phone. When the circuit is completed once Ballard answers the ringing phone, the signal—i n this case the ticking metronome—is transmitted from the Atom’s phone to Ballard’s. At this point the Atom jumps into his speaker, shrinking down to the size of an electron, and rides these electrical impulses from his phone to Ballard’s.

The writer of this text page, DC Comics editor Julie Schwartz, correctly describes how a telephone transfers sound into electrical impulses. A thin diaphragm vibrates when sound waves strike it, which in turn compress or dilate carbon granules that are adjacent to the membrane. The electrical conduction through the carbon grains is very sensitive to how tightly they press against one another. As you speak, the interconnections between the grains alternately contract or expand, and the electrical signal down the wire is appropriately modified. At the other end of the telephone connection, the electrical signal causes other carbon grains to undergo equivalent vibrations that are transferred to another diaphragm. The diaphragm’s vibrations create pressure waves in the air that are then detected by the ear of the person receiving the call. All of this Julie Schwartz got right. Where he goofed is in assuming that the Atom could hitch a ride on the electrical impulses propagated down the wire.

When you speak, complex sound waves can convey all sorts of information. The sound waves can be detected by another membrane (such as an eardrum), causing it to vibrate in accordance with the amplitude, wavelength, and even phase information encoded in the message you spoke. But it is the wave that carries that information—not the air you expelled from your mouth. By speaking, you set up alternating regions of less-dense and more-dense air (equivalently you can think about the density variations as pressure modulations—a reasonable approximation at a constant temperature) that move away from the speaker. It is not the air coming from your mouth that reaches the listener; otherwise you would never have to worry about noisy neighbors in the apartment next door.

Similarly, the information encoded in electrical impulses in a telephone wire is transmitted by means of density waves of electrons, rather than having the electrons move down the wire. What happens is that a region of electrons of higher-than-normal density is unstable (as the negatively charged electrons repel each other) and expands into the adjacent regions, causing a buildup of electron density in the next spatial location, which in turn causes a bulge farther down the line, and so on. The speed of this transmission is determined by the electrostatic repulsion that pushes the electrons away from each other. That is, if I shake one electron, how long will it take a second electron some distance away to respond to the first electron’s motion? Pretty quickly, as it turns out, as the electrical interaction between two charges in the wire is communicated at roughly one third of the speed of light. Depending on the distance, there will be a barely perceptible time lag between moving the first charge and it being noticed by the second charge. The speed of light is so fast—186,000 miles per second—that this time lag will be less than a billionth of a second over a distance of 12 inches. If the Atom were riding on one electron carrying the electrical impulse signal along the telephone wire, he would have to jump to the next bunch of electrons with the speed of light in order to “ride the wave” all the way to the receiver.

It’s a good thing that the information in a telephone wire is in fact transmitted at the speed of light, as the average speed that an electron moves along a wire in response to an external electric field is less than a millimeter per second, nearly a trillion times slower. If you had to wait for the electrons to physically travel along the telephone wires before your message could be sent, it would be quicker to just walk to the house of the person you’re calling and speak to her face-to-face.

When not fighting crime as the Atom, Ray Palmer’s civilian identity is equally heroic, for he is a physics professor at Ivy University. As mentioned in Chapter 13, it was the late-night discovery of a strange meteorite that led to the research breakthrough that enabled Palmer to develop a second career as a costumed crime fighter. As shown in fig. 43, Palmer discovers that the meteor is in fact a chunk of white-dwarf-star matter that will enable him to miniaturize himself and independently control his mass. Ray strains to lift and carry the meteorite, which is roughly twelve inches in diameter, over to his car. We are privy to Prof. Palmer’s thoughts as he struggles with the great weight. “So heavy—I can hardly lift it! Puff! I don’t know the odds against one white dwarf hitting another out in space—Puff—but it could happen—and when it did, this piece drifted until it landed in this field.” (By the way, as also shown in fig. 43, in the mid 1960s, physics professors typically drove Cadillac convertibles.)

Fig. 43.
Physics Professor Ray Palmer discovers the white-dwarf-star fragment that will turn out to be the key missing ingredient in his miniaturization device and eventually lead to his moonlighting as the superhero the Atom (from
Showcase # 34
). © 1961 National Periodical Publications, Inc. (DC)

Ray’s reasoning here is sound. When a low-mass star of a certain size has exhausted most of its elemental fuel, the energy released by fusion reactions is insufficient to counteract the gravitational pull of the star’s core. The large force at the center of the star leads to a massive compression, until its density is three million grams per cubic centimeter, in which case we call the remnant a white dwarf. The pull of gravity on the remaining core of a white dwarf star is so great that only a cataclysmic explosion would generate sufficient energy to enable a small chunk of the core to break away from the rest of the star and float through space. Some astrophysicists have suggested that white-dwarf collisions occur roughly once a month.

As Ray reminds himself while struggling with the meteor fragment, the rock he is holding is heavy because it is composed of “degenerate” matter. The electrons are termed “degenerate” because they are all in the lowest energy quantum states, unlike in a normal star, where the electrons would be distributed over many quantum states, some at higher energies. The interior of the white dwarf is composed of carbon and oxygen nuclei and a sea of electrons packed as closely as they can be. The core of white dwarfs cannot be easily compressed further, for all the electrons are already in the lowest possible energy state. This is what Ray means when, as he nears his car, he thinks to himself that white-dwarf stars are composed of “degenerate matter from which the electrons have been stripped, greatly compressing them.” The electrons are still in there, but are not associated with any particular atomic ions.

Ray is certainly correct that this “degeneracy” is why the white-dwarf star is so dense. The rock Ray is carrying appears to have a radius of 6 inches. Assuming a spherical white-dwarf fragment, the volume would be (4π/3)× (radius)
³
. In this case the volume of the rock is (4π/3) × (6 inches)
³
= 905 inches
³
—equivalent to nearly 15,000 cm
³
since 1 inch equals 2.54 centimeters. To find the mass of the rock we multiply the density of white-dwarf-star matter (3 million grams/cm
³
) by this volume (15,000 cm
³
), which gives us 45 billion grams, equal to 45 million kilograms. Converting this mass to weight, we multiply the mass by the acceleration due to gravity (W= mg), and find that the meteorite in fig. 43 weighs one hundred million pounds. No wonder Prof. Palmer, physics professor at Ivy University, is huffing and puffing as he struggles with his find—that little rock weighs 50,000 tons!

But it turns out that this is, technically, not actually a blooper. Despite appearances, there is nothing wrong with the scene depicted in fig. 43. And that is because we physics professors are Just. That. Strong. Remember this the next time you’re tempted to kick sand in someone’s face at the beach. You never know if that seemingly ninety-eight-pound weakling actually has an advanced degree in physics.