What's The Difference?
Novel = Break open the moment.
Story = Collapse the moment.
And there you have it: a book on fiction writing in a nutshell.
"Breaking open the moment" is a phrase I picked up from the Green River Writers, and it means dispersing what's happening from a simple statement into an experience.
In any piece of fiction, there is a pivotal moment: an important thing happens, an important discovery is made, an important epiphany is experienced. That moment might be the climax of the action (the Ring of Power is destroyed) or it might be the result of the action (Boo Radley returns our friendship).
Novels take that moment and expand it with explorations of setting, multiple characters and characterization, emotions, senses, details, internal dialog, background, relevant subplots and dialog.
Short stories have all these things, but collapse them, trimming subplots and multiple characters down or out, suggesting rather than exploring. The pivotal moment is front and center, and the diffusion of that moment is minimal.
Flash fiction has been defined as from 300-1000 words, but I've seen "flash" as short as six words (Hemingway's "For sale. Baby shoes. Never used.") up to 2000. As you can see from the Hemingway example, flash fiction can be so collapsed that even the pivotal moment is only implied.
So there you have it. Love to write novels and want to write a short story? Get an idea for your novel's pivotal moment and collapse the surrounding elements. Distill them to their essences. Love to write short stories and want to write a novel? Write a short story and then break open the pivotal moment. Sound easy? No? Maybe or maybe not, but I assure you it's doable.
Go forth, ye writers! Go forth and have fun with it!
Marian Allen is the author of EEL'S REVERENCE, a fantasy