One by one, she inserts extra delays to slow the paths that have become too fast. Click. Insert. Clack. Insert. She can only repair the skunkworks in the moment when the pipes are settled. It never halts. The skunkworks that lives in the innermost universe generates the outermost universe, whatever “innermost” and “outermost” mean when the universes are arranged in a loop.
Stopping one skunkworks stops all of them.
How you start them back up again is something she hopes she never has to figure out.
She dismisses the gauze and the skunkworks sharpen. The pipes grow and shrink in sync with the clacking of valves. Data no longer skids through paths causing pipes to expand or contract when they should be still.
“OK, Daniel, show me where to go. We need to flush out any speculative state before it’s committed, or we’re stuck with the results of a faulty skunkworks.”
The skunkworks is constantly speculating multiple possible futures. Ideally, only the correct one is committed to become the present, which becomes the past and what the skunkworks uses to speculate possible futures. The rest are all flushed away. Those futures never happen.
They, of course, are already stuck. Some mistakes of a faulty skunkworks have already been committed. Say a bug in the skunkworks causes fundamental constants to go out of whack. As a result, a beach ball tunneling through a brick wall is committed as the present instead of being flushed out. That’s now the state of the universe. Within the universe, whoever was looking at the beach ball saw it glitch from one side of the wall to the other. There’sno point to letting those errors compound, though. The universe should be generated correctly from as early as possible.
Daniel shifts his T-shirt across his back and ties it around his neck. It might look like a cape except it’s way too short. He appraises her, his face pensive.
“Anyone else might declare it close enough and leave. You really are Aunt Vera’s child.”
Ellie rolls her eyes. Mom’s reputation precedes her. “Considering how long you lived with us, you might as well be, too.”
Daniel looks annoyed again. “No, I mean her attitude about the skunkworks and the generated universe… Never mind. You have to see it yourself. Come on. Follow me.”
He leaps to a thick pipe way overhead. From there, he swings to a swath of mesh, he bounces, and off he goes.
“Hold up, you big lunk. You have over a foot of wingspan on me.” Ellie sighs too loudly, then follows him.
CHAPTER 3
Whether or not it’s truly hotter, the skunkworks’ interior is definitely more humid. Rust covers every pipe. Sometimes, it flakes off as the pipes grow and shrink. The farther in Ellie and Daniel go, the faster the skunkworks expand and contract. The transparent mesh that spans pipes goes taut and slack. It’s as though the skunkworks is breathing. A faint hiss precedes the near-unison clack of reservoir valves.
Daniel points out which valves she needs to wedge open and for how long. That will force the skunkworks to flush out its speculative state, then regenerate the universe anew from what has already been committed. By now, that’s not error-free. She’s already missed that first train arriving at South Station, but nothing left to do about that. He looks up for a moment, nods, then leaps for a pipe above him.
“Now that you’ve finally made changes to the skunkworks by yourself, you may be marked. Some people might assume you take after your mom.” Daniel treats the pipe as a high bar and executes several one-arm giants, swinging all the way around each time. “Guess I should have said something earlier, but I don’t see the big deal in this case. A straightforward fix that makes the universe behave correctly is literally what we’re supposed to do.”
Mom repaired the skunkworks quickly. At some point when Ellie was a kid—she doesn’t remember when—Mom started dragging Ellie into the skunkworks with her. Chris, already halfwayout the door to university, always demanded to be brought along anyway. Mom always put her off, saying she and Ellie would only be gone for a moment and they wouldn’t be doing anything Chris hadn’t already mastered. Ellie’s presence slowed things down a bit, though.
On these short trips, Ellie had two jobs: pay attention to Mom’s lecture-demonstration and keep an eye out for anyone coming for them. Mom always dodged the question of who. Ellie had to resort to asking Chris, who told her they were the isolationists she was always warning her about.
“Daniel, have I ever told you that when I was a kid, Chris used to ambush me in my sleep to see whether I’d wake up in time?”
Ellie climbs onto a pipe and stops, for a moment, to get her bearings. She has no idea where she is.
“No, you don’t talk about Chris much.” He hesitates for a beat before continuing. “Ambushing you sounds excessive and in your sleep seems utterly unreasonable, by the way, if you don’t mind me saying.”
It feels like every couple of months, Daniel tests Ellie to see whether she’s ready to talk about Chris yet. That Ellie became an adult before she stopped defending Chris to him is so embarrassing that Ellie doesn’t know whether she will ever be able to admit it to anyone, even him.
“She told me that she was trying to prepare me for attacks in the skunkworks and, you know, eight-year-old me didn’t know any better. She didn’t use real knives back then, of course.”
“But, like two decades later, you know better now, right?” Daniel hangs still on the pipe. “She doesn’t ambush you anymore, much less use real knives, right?”
“Not exactly. It’s complicated.”
Daniel looks at her, expectant. She’s wrong about being ready for this conversation, it turns out, so she doesn’t elaborate. There’sstill some tiny part of her that believes Chris will change. She has to hold on to that hope or else she’ll fall into pieces. After an uncomfortable silence, he shrugs and sighs.
“It’s funny. No one except me thinks of Chris as a black sheep. She’s so nice to everyone. Maybe a little too nice. She was even nice to me, once upon a time. Everyone thinks of me as a black sheep, though. Maybe I deserve it.” Daniel swings around the pipe again, releases it, flips through the air in a layout position, then bounces off the mesh toward another pipe. “In theory, I’ll verify that any design will work as intended as long as it’s well-specified and backward-compatible. Not only bug fixes.”
“Architects must really love you.” She projects where Daniel is about to land and jumps after him. “One look at you and I’m sure they all ask very nicely. Isn’t it better in the long run if we all implement the correct physics correctly?”
“Hey, I have my standards. Change the laws of physics, no. Discover a more general formulation of what we already know, as long as there are no unexpected side effects, why not?”
