EMILY: You know what it's like? I was just reading about this this morning. It's like a Fermi problem.
JASON: What's that?
EMILY: It's named after this guy named Fermi, Enrico Fermi. He was this famous mathematician, and he would ask questions, like the big one was, "how many piano tuners are there in Chicago?"
JASON: Huh.
EMILY: So how do you answer that without actually going and counting, right? Well, you ask a lot of little questions that kind of hack away at the answer. Questions like, okay, first off, how many pianos do you think there are in Chicago? And then it's like, well, what percentage of people actually own a piano? So you estimate the number of people who, you know, you've been to their house and you know they have a piano. And then divide that by the total number of peoples' houses you've been to.
JASON: Hmm ... I'm gonna say one in ... let's just keep it easy. One in a hundred homes has a piano in it.
EMILY: Sure, we'll use that. And the population of Chicago is like three billion.
JASON: Three billion?
EMILY: Million. Three million.
JASON: You said billion. I swear you said billion.
EMILY: Well whatever, you know I meant million. So that would mean there are ...
JASON: 30,000 pianos in Chicago.
EMILY: Uh uh uhhhhh! There are three million people in Chicago. Not three million homes. You're probably looking at, I don't know, one million homes maybe? That's like three people per home.
JASON: But then you have to think about the number of Chicago homes that could actually accommodate a piano. Probably fewer than usual.
EMILY: There you go! Now you're getting the game!
JASON: Man, where did you read about that?
EMILY: Wikipedia.
JASON: You rabbit-holing again?
EMILY: Yep.
JASON: God, I can't believe I didn't know about that until now. It basically describes exactly what I've spent all these years doing.
EMILY: I swear, I'll never get to the bottom of Wikipedia. Or at least, it'll take a long time. You know they've started putting in entries for apartment histories? Lori was telling me about it.
JASON: What do you mean?
EMILY: Like, the history of an apartment. Like you can type in "123 whatever street, apartment 3" and it'll be this enormous history of everything that ever happened in that apartment.
JASON: Ah.
EMILY: I thought it was kinda cool.