“To be honest, my life has exhibited many strange and sometimes troubling characteristics, but shortness is not one of them. It feels like an eternity since I started school and a techno-social epoch since I moved to San Francisco. My phone couldn't even connect to the internet back then.”

“This girl has the spark of life. This is my primary filter for new friends (girl- and otherwise) and the highest compliment I can pay. I've tried many times to figure out exactly what ignites it -- what cocktail of characteristics come together in the cold, dark cosmos to form a star. I know it's mostly in the face -- not just the eyes, but the brow, the cheeks, the mouth, and the micromuscles that connect them all.Kat's micromuscles are very attractive.”

“But I kept at it with the help-wanted ads. My standards were sliding swiftly. At first I had insisted I would only work at a company with a mission I believed in. Then I thought maybe it would be fine as long as I was learning something new. After that I decided it just couldn't be evil. Now I was carefully delineating my personal definition of evil.”

“Then: I google "time-series visualization" and start work on a new version of my model, thinking that maybe I can impress her with a prototype. I am really into the kind of girl you can impress with a prototype.”

“Neel cuts in: "Where'd you grow up?""Palo Alto," she says. From there to Stanford to Google: for a girl obsessed with the outer limits of human potential, Kat has stayed pretty close to home. Neel nods knowingly. "The suburban mind cannot comprehend the emergent complexity of a New York sidewalk.""I don't know about that," Kat says, narrowing her eyes. "I'm pretty good with complexity.""See, I know what you're thinking," Neel says, shaking his head."You're thinking it's just an agent-based simulation, and everybody out here follows a pretty simple set of rules"-- Kat is nodding--"and if you can figure out those rules, you can model it. You can simulate the street, then the neighborhood, then the whole city. Right?""Exactly. I mean, sure, I don't know what the rules are yet, but I could experiment and figure them out, and then it would be trivial--" "Wrong," Neel says, honking like a game-show buzzer. "You can't do it. Even if you know the rules-- and by the way, there are no rules--but even if there were, you can't model it. You know why?"My best friend and my girlfriend are sparring over simulations. I can only sit back and listen. Kat frowns. "Why?""You don't have enough memory.""Oh, come on--""Nope. You could never hold it all in memory. No computer's big enough. Not even your what's-it-called--""The Big Box.""That's the one. It's not big enough. This box--" Neel stretches out his hands, encompasses the sidewalk, the park, the streets beyond--"is bigger."The snaking crowd surges forward.”

“So I switch to my MacBook and make my rounds: news sites, blogs, tweets. I scroll back to find the conversations that happened without me during the day. When every single piece of media you consume is time-shifted, does that mean it’s actually you that’s time-shifted?”

“Neel takes a sharp breath and I know exactly what it means. It means: I have waited my whole life to walk through a secret passage built into a bookshelf.”