After my debut-post disclosure that I write hard SF, you will be unsurprised to know that bad science in stories can annoy me.
It’s not that I’m looking for a Ph.D. dissertation in each story. It’s not that I limit my interests to stories that revolve around known science. What makes me testy—and, on occasion, has had me tossing a book across the room—is absurd deviations from (what should be, anyway) very basic science.
To be clear, my hobby horse is bad science, not the quantity of science, in stories. If a piece of SF illustrates a bit of science without injury to the story, that’s great—but it’s far from necessary. Many a fine SF story uses science or technology merely as backdrop. Many a fine SF story presumes a technological breakthrough and explores its implications without attempting to predict how the thing might actual work. And many an otherwise fine story bogs down in an excessive transfer of background information.
On to nanotechnology. Briefly, for those unfamiliar with the topic, nanotech deals with manufactured objects on the scale of nanometers (trillionth billionths of a meter). That’s smaller than the individual cells in the human body and bigger than atoms. The goal of nanotech is to manufacture things by precisely controlling the placement of individual atoms.
Nanotech is most definitely real—although still emerging—science. In fact, I’ve written a couple of popular-science articles on the subject. Once engineers learn to build with atomic precision, it will mean such neat things as super-strong materials (space elevator, anyone?) and really tiny machines (like a Roto-Router for the arteries).
A common SFnal premise is nanotech-built, nanoscale robots—nanobots—with the ability to make other things. Including more of themselves. Fictional replicators tend to run amok and remake the world in their image. In a phrase, this is the “grey goo” scenario. But even when fictional nanobots are better behaved, they show the wondrous ability to produce pretty much anything on demand, and in very short time frames.
Clarke’s Law posits that any sufficiently advanced technology is indistinguishable from magic. It does not say that a technology we have yet to invent can produce any desired magical outcome. And so we come to my gripe of the day.
One of the bedrock principles of physics is the conservation of energy. In this universe, energy can be neither created nor destroyed. (Why the caveat? Because maybe our universe began in an eruption of energy from a higher-order universe. Cosmology is just weird. Maybe in another post.) Energy can only change forms, as from the kinetic energy of flowing water into electromagnetic energy—electricity—when the flow (which slows down in the process) turns a dynamo at a hydroelectric dam. Matter is a form of energy, too—hence, the energy released by matter-to-energy conversion in nuclear bombs and reactors (including stars).
The biggest fatal flaw in most fictional portrayals of nanotech—what sends those books arcing across the room—is ignoring that the nanobots need energy to do anything. So how do nanobots get power? From sunlight? Explain why those nanobots will out-compete photosynthesizing algae. Chemicals in the environment? If nanobots forage for their “food,” I see no reason they would be more efficient at it than bacteria. (In both those cases, the living organisms have had myriads of generations to fine-tune and optimize their techniques.) How about beaming energy to the nanobots as radio waves? Matching antenna size to wavelength, it would take X-rays to power nanobots. Powering our nanobots that way wouldn’t be terribly eco-friendly.
A related problem is controlling the bots. Again, radio waves don’t work. Because of their size, nanobots can only transmit or receive X-rays or even shorter wavelength (i.e., higher-energy) signals. Nor is a flood of X-rays an acceptable way to control the Roto-Routers unplugging my arteries! Chemical signaling between nanobots certainly can work—that’s how biology controls activities within and between cells—but messenger molecules take time to get around.
As you can see, I got curious how nanobots, and especially medical nanobots, might really operate. (There are lots more issues, but I’ve run on long enough for one post.) So: I went to a major nanotech conference to meet the experts. I talked to specialists in biology, neurology, biophysics, and medicine. The result is my latest novel, a near-future medical-nanotech thriller, Small Miracles.
If anyone gets struck by a copy of SM thrown across the room, I want to know why. 
Edward M. Lerner worked in high tech for thirty years, as everything from engineer to senior vice president. He writes near-future techno-thrillers, most recently Fools’ Experiments and Small Miracles, and far-future space epics like the Fleet of Worlds series with colleague Larry Niven. Ed blogs regularly at SF and Nonsense.
