“The suburban mind cannot comprehend the emergent complexity of a New York sidewalk.”

“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.”

“The thinnest tendrils of dawn are creeping in from the east. People in New York are softly starting to tweet.”

“Kat bought a New York Times but couldn’t figure out how to operate it, so now she’s fiddling with her phone.”

“I sit up straight and do the first thing a person is supposed to do in an emergency, which is send a text message.”

“...I can’t stop squirming. If fidgets were Wikipedia edits, I would have completely revamped the entry on guilt by now, and translated it into five new languages.”

“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.”