I haven’t written or shared a ton about my current project, but if you’re a regular reader, you know it’s sci-fi.

Which I love.

Two of my top five movies of all time are science fiction (The Matrix and Back to the Future, in no particular order), so writing in the same genre, even if it were never to come to the light of day, sends thrills up the spine of my nerdy secret (yeah, not so secret) self. But film sci-fi and novel sci-fi are two different beasts, aren’t they? Because with the one you get to see everything as a director envisions it, but in the other you must create the images yourself based on what the author describes.

And there are pros and cons. Star Wars is what it is because of the dramatic and impressive visuals that linger forever in the minds of its devotees. (I’m talking about a starship that seems to go on forever, a space station the size of a moon, a battle with swords made out of fargoing light). And I’ve read a Star Wars novel or two, and they’re good, but they’re different. They don’t have to describe a lightsaber because we know what it looks like.

So, in my novel, there’s time travel. And there are robots. And there is other vaguely sciencey stuff floating around in the background.

And at every turn, I find myself wondering: how much do I need to describe this thing?

I picture the story unfolding in my own mind, and I see the characters and the places a certain way, but part of the magic of a book is that you get to decide for yourself to an extent what everything looks like. You get a sense of the whole, for example, in a book like Harry Potter: you can picture Hogwarts and its main features, but you don’t get into the grainy bits of detail. You don’t see the scorch marks on the brick from thousands of misfired spells, but you can imagine them. You don’t smell the faint musty funk on the community brooms in flying class, but you can make it up for yourself.

So as I’m writing my book, I keep crashing into this problem. Because description slows down storytelling, my usual tendency is to eschew it as much as possible. (See any of my Flash Fiction offerings.) But I also know how powerful it can be, and how much a good description helps to ground the reader in time and place. So, when the protagonist is picking through the long-abandoned house of the deranged and vanished eccentric who lived on the edge of town, how much do I need to describe the cobwebs on the walls, the countless volumes on physics and quantum theory scattered in all rooms of the house, the closets full of discarded, half-fused mechanical bits, the strange humming structure on the roof? Is it enough to say that the robot looks like half a tractor with a head like the front of a 1978 Buick, or do you want to see its feet like cinder blocks, its clumsy crab-claws-in-oven-mitt hands, its sparkling unstainable not-exactly-chrome finish? Do you want me to tell you about the faint whiff of burning hair that trails in its wake, or the fact that the ground trembles ever so slightly at its every plodding step?

And, given that it’s sci-fi and some funky pseudo-science-ish things are happening, how much should I try to describe that not-actually-science? Have the inventor hit my protagonists with a stream of technobabble and invented vaguely scientific terminology to give the concepts more depth or believability? Or just skim over the explanations of how any of this stuff works, throw any grounding in plausibility to the wind and, Sharknado-like, just expect my readers to get over it and get on for the ride?

Where’s the freaking line, in other words? How much description does a reader really need? How much is too much?