Note: This entry includes spoilers for my book Redshirts, so if you haven’t read it and want some elements to be a surprise, go ahead and stop reading now.
— John Scalzi (@scalzi) February 7, 2016
As you can see from the above embedded tweet and picture, a reader (who also appears to be a NASA scientist) asked me a question about the atoms in the pizza eaten in Redshirts, consumed by the heroes of the story, who had also traveled back in time.
Why would this matter? Because as a plot point in the book, time travelers had about six days to get back to their own time before they began to disintegrate — the atoms of their bodies from the future also existed in the past they’re visiting, and the atoms (eventually) can’t be two places at the same time and would choose to “exist” in the positions where they were in the current frame of reference.
Which is fine as long as you don’t mix atom eras. But when the characters ate pizza, they were commingling atoms from the book’s 2012 with their own atoms several centuries later — and what happens to those atoms from the pizza when the characters return to their own time? Because the atoms gained from the pizza would simultaneously be present elsewhere, and, as already noted, the atoms default to where they were supposed to be in their then-current frame of reference. Right?
As you can see from the tweet above I avoided the answer by giving a completely bullshit response (and then bragging about it). I’m delighted to say I was immediately called on it by another NASA scientist, and I responded appropriately, i.e., by running away. I’m the Brave Sir Robin of science, I am.
But it is actually an interesting question, both for itself and for what it says about my writing process. So now let me try to answer it more fully, because why not.
First, here are the some of the options for what happened to the pizza atoms:
1. After six days they were pooed out and that was the end of it (so to speak). This is a glib answer, and immediately brings up other questions like: So, people from the future don’t absorb atoms from the past at all? Wouldn’t they get hungry? Or thirsty, because presumably it would work the same for liquids? How would they respire? Wouldn’t it be the case in this scenario that everyone from the future would be dead in five minutes from lack of oxygen? These are all reasonable questions, and if correct would have made for a shorter and rather more tragic book, so let’s assume this scenario is not in fact the correct one.
2. After six days the atoms do what they do and revert to their then current locations. What does this mean for each individual? I suspect in the long term not too much. One, a fair number of the atoms will no longer be in the body anyway; they’ll have left through excretion, both through the alimentary canal and respiration. As for the rest, some of them would still be in the body as waste product (i.e., in the process of being expelled but not yet), while the ones that were in the body would be roughly evenly distributed so their sudden disappearance would… probably… not be substantially noticed or cause great disruption to body systems. But it’s certainly possible (depending on how much you eat and/or the positions of these atoms in one’s body) there might be side effects. In this scenario, time travel carries risk analogous to exposure to high radiation levels: Probably fine in small doses, but the more you do it, the more problems potentially crop up. This scenario is logical, given the rules of the particular universe in the book.
3. But wait! At the very end it was revealed there was yet another layer of reality, maybe, and also, maybe, a prime mover of the story independent of the story itself, an author, if you will, who probably could, at their whim, decide that the pizza atoms would just stay where they were, or at least not cause any damage as they left because the author had promised the readers that everyone in the book lived happily ever, so he wouldn’t, like, have them die stupidly from vaporizing atoms, what kind of bullshit is that. This scenario is not outside the realm of possibility, given the rules of the particular universe in the book, but it is kind of slapdash and lazy. Or is it? (Yes.) (Maybe.)
So what’s the actual answer? The actual answer is as the writer I didn’t give the pizza atom scenario any thought whatsoever — it just didn’t come up at all while I was writing — so when this fellow asked the question, I had no idea what the actual answer was, aside from “I don’t know, I didn’t think about it at the time, or really ever, until just now.”
Why didn’t I think of it? For one thing it wasn’t directly material to story at hand, either immediately or long term, so as a plotting consideration it wouldn’t have been anything I would have spent time on. For another thing I was writing quickly and even if I had thought about it at the time, my answer would have likely been “it doesn’t matter to the story, keep going.”
For a third thing, and this is the most relevant thing, I think, writing fiction isn’t about necessarily about so thoroughly developing your world that you as an author have an immediate answer for every possible consequence of the development of your universe. What you are often going for is sufficiency — that the world is logical enough to play in for the purposes of your story — and direction — moving people along in the story quickly enough that they don’t have time or the interest to question your worldbuilding or story-telling choices, at least until the story is done and you’ve bundled them back out into the real world, waving and smiling.
This doesn’t mean you settle for bad or sloppy worldbuilding, on the idea that you’ll just move readers along quickly enough that they don’t see the seams. No, you still attempt to make the universe you’re creating sound. If you set up rules for the universe, you have to follow them as a writer. What it means, however, is that once you’ve made up the rules for the universe, you don’t necessarily have to have an answer for every single question that might come up later. If you’ve built the universe soundly, when previously unanswered questions come up, you can create plausible answers based on the rules of the world you’ve built. Or, more likely, others can, in fan forums and blog posts and Twitter streams, while you sit back and every once in a while say “This is a very interesting theory you have! It might even be true!”
The point is that authors are often an interesting combination of god and tour guide: We create worlds, but then only let readers see the parts of the worlds that suit our own needs — that tell the story we want to tell. What that means is sometimes there are parts to our world that we haven’t seen either, that we only see when or if a reader gets away from us and asks a question we didn’t think to ask ourselves. Sometimes, that question is about pizza.