Writing Sci-Fi? First Understand How Elephants Aren't Dragonflies (Op-Ed)

Animals come in all different sizes, but the laws of physics mean that you can't just arbitrarily scale up a dragonfly to the size of an elephant and expect the body plan to result in a functioning creature. 

For one thing, mass increases much faster than other qualities like strength or surface area as you scale up a body, and so the legs and wings of an elephant-size dragonfly would have to be proportionately much larger to support the extra weight — and it's doubtful muscle power could be sufficient to propel such a creature into flight.

Moreover, insects are generally small because they rely on diffusion to distribute oxygen to interior cells instead of the active oxygen-pumping systems found in animals like mammals. This imposes an upper limit on just how big an insect can get. It's true that there were gigantic dragonflies — still not the size of elephants, however — during the Carboniferous period (as well as housecat-size cockroaches and other horrors), but the oxygen level in the atmosphere at the time was much higher, and that likely played a role in making such bodies viable.

Let's pause for a moment and give thanks for the fact that we don't have to live in a world of pet-size cockroaches and meter-long scorpions.

All of this presents an analogy for fiction. It's tempting to think of novels (the elephants) as scaled-up short stories, or short stories (the dragonflies) as miniaturized novels. But having written both 100-word drabbles as well as 200,000-word epic fantasies, I can assure you that's not the case.

To read the full article on space.com, click here