FOOLING AROUND WITH SCIENTIFIC IDEAS
Science Fiction Story
Technical ErrorArthur C. Clarke
Read the story HERE.
Hold your right hand up to a mirror, and you will see a left hand reflected back at you. Now think of your two hands as mirror images, and try to superimpose them, thumb on thumb, pinky on pinky, front on front, back on back. You can either do front on front, or thumb on thumb, but not both. Your hands are, roughly, mirror images that cannot be superimposed. Chemists call objects like this enantiomers, which is a mouthful, but it’s still easier than calling them non-superimposable mirror images.
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| Molecules can be left-handed, too. Left- and right-handed forms of the amino acid threonine |
In Clarke’s tale, Technical Error, Nelson, an electric-power engineer, is inside the stator—the nonmoving part, in which a rotor spins—of a first-generation, high-technology generator, when a huge power surge occurs. There is a hint that he vanished briefly but reappeared, and at first, all seems normal. But it turns out that he has been transformed into his own mirror image as a result of the surge. He and everything he carried with him, including coins and the handwritten notes in his notebook, are reversed in such a way that they appear normal when viewed in a mirror. This seems exceedingly odd, but not too serious at first, until we realize that such a true inversion would also turn asymmetric molecules into their enantiomers, or mirror-image structures.
As any student of biochemistry knows, many biomolecules are asymmetric, having two forms that, roughly speaking, are left- and right-handed. Look at yourself in the mirror. When real-you lifts your right hand, mirror-you lifts mirror-your left. In nature, usually only one form of an asymmetric molecule is present and functional. For sugars, it’s the right-handed form, for amino acids, which build proteins, it’s the left. Left and right, in such matters, are defined in a manner that is somewhat arbitrary, but is consistent across all types of asymmetrical molecules. A longstanding mystery of life science is how asymmetry arose, and how each “choice” of handedness was made, either by accident or by natural selection.
Organic chemistry, a prerequisite for a course in biochemistry, teaches us that mirror-image molecules are chemically identical except when interacting with other asymmetric molecules. In living organisms, enzymes control the courses and rates of nearly all chemical reactions, such as those that extract usable energy from sugars. Most enzymes are proteins made of left-handed amino acids, so they are asymmetric. So are sugars. So natural sugars and other essential molecules like vitamins are non-nutritious to Nelson, whose enzymes are inverted. With plenty to eat, he is starving.
One solution to this problem is to try re-inverting Nelson by recreating the conditions that flipped him in the first place. Clarke takes us through what seems like a neat little teaching aside about how inversion of an object requires flipping it over in a dimension higher than that of the object. To invert an asymmetric two-dimensional object requires rotation in a third dimension. (What operation is needed to reverse the direction of a one-dimensional arrow?) Discussion of the solution among the engineers includes a reminder that physicists think of time as the fourth dimension in our universe, but everyone in the story provisionally accepts the notion that Nelson was rotated in a fourth spatial dimension. This notion turns out to be their most serious error. Most of the engineers were unaware that Nelson disappeared briefly during his inversion, which might have tipped them off that his rotation involved time instead of a purely space-like fourth dimension.
So when they try the re-flip, he disappears, and they are puzzled. Only after the generator is reassembled and in operation does Dr. Hughes realize the meaning of his disappearance, and by then it is too late: Nelson has apparently reappeared in the guts of the now-assembled and functioning generator, with disastrous results.
In literary circles, science fiction is sort of like an unwashed relative. Common and often justified complaints about it include poor or merely serviceable writing, flat characters, and of course, the lack of the grueling or exalting explorations of the human condition that we expect from literature.
But many a budding scientist, yielding only to the force of course requirements to subject themselves to Shakespeare or Joyce Carol Oates, has sat for hours with nose in book—paper, or more recently, electronic—absorbing stories in which vivid, three-dimensional human characters and their joys and agonies are displaced from center stage by space travel, futuristic gadgets, and even basic scientific concepts like stereoisomerism.
In younger days, I was not exactly a voracious reader, but my favorite elected reading materials were science fact and science fiction. Looking back, I see now that in reading science fact, I was learning about the world and the universe around me, glimpsing what scientists knew in realms of science beyond my high-school courses. In reading fiction, I was being entertained by science, that same subject I was studying because I liked it best, but also in hopes that it would make me a living.
In my favorite stories, well-understood scientific concepts, sometimes new to me, were often the solution to whodunnit-style mysteries. “Technical Error” was just my kind of thing, an example of “hard” science fiction, in which the science is pretty rigorous. At the other, “soft,” end of the science fiction spectrum, authors do not allow scientific accuracy to constrain them. Soft sci-fi is somewhere on the spectrum between science fiction and fantasy, that genre in which spirits and magical forces hold sway—along with the obligatory strange and precious names. In fantasy, no one is named Nelson.
From my favorite writers, I often came away with a better understanding, and sometimes with vivid examples, of neat concepts like multidimensional geometry—build a house like the three-dimensional projection of a four-dimensional cube (a tesseract), then have it collapse into a true tesseract (read the story HERE); gravity gradients—move in orbit above a neutron star, where the strength of gravity increases dramatically with each meter of distance toward its incredible mass, and be pulled apart by the difference in gravitational pull at your feet and at your head—or more precisely, by the tendency of your head and feet to travel at different orbital velocity, the same “force” that causes tides (read the story HERE); and natural selection in strange environments—meet massive jellyfish-like organisms living in the atmosphere of the gas giant, Jupiter (see if you can find Meeting with Medusa, by Arthur C. Clarke, with a Google search; today, I could not.). Later on, I used some of these ideas in my teaching. I credit science fiction with allowing my imagination to encompass distances from the atomic to the cosmic, and to span time from the nanoseconds of chemistry to the eons of star lifetimes.
I also learned many interesting facts from science fiction. For example, did you know that, at certain times, you can see the planet Venus in broad daylight.? You need to know just where to look (consult SpaceWeather.com to learn when planets are at their brightest), and you need to trick your eyes to focus on a distant object while looking at a blank blue sky (align the top of a tall tree or building with the desired line of sight). Authors like Clarke were careful about these details; if he described an eclipse in the year 3058, you could bet that his date and location would correspond to a real eclipse.
People read for many reasons, which are revealed in their reading material. Among those reasons: to savor skilled, powerful, moving use of language; to escape to other lives; to better understand people, including themselves; to travel without leaving home, or to prepare for—or re-experience—real travels; to be challenged by puzzles or mysteries; or to play with interesting ideas.
I realized long ago that most of the really interesting people in my life have something in common: they read.
