How not to teach recursion, Sergey Brin and Larry Page edition. (From an 2003 interview on NPR's Fresh Air.) http://www.npr.org/2003/10/14/167643282/google-fou

How not to teach recursion, Sergey Brin and Larry Page edition. (From an 2003 interview on NPR's Fresh Air.) http://www.npr.org/2003/10/14/167643282/google-founders-larry-page-and-sergey-brin-part-2 http://www.npr.org/2003/10/14/167643282/google-founders-larr... Starting at 13:45 it goes like this: Terry Gross: Now I'll tell you, in preparing for this, I decided, let me Google Google, so I typed in "Google" into the Google search, and I came up with a lot of Google things in the regular search, but in the "Are you feeling lucky?" search, I got nothing. Larry Page: Well you just got Google itself. TG: Yeah, I just got Google itself. Oh, I see, Google was giving me itself. LP: Yeah. TG: Oh. LP: In computer science, we call that recursion. [laugh]. TG: Oh, you even have a name for it. [laugh]. I didn't quite get that. I kept thinking it was just repeating itself. I didn't realize it was giving me itself. [laugh]. LP: [laugh] TG: And what's the name for it? LP: Uh, recursion. It's... kind of... Sergey is giving me a dirty look. TG: Why? LP: It's a loose definition. [laugh] TG: Lighten up Sergey. [laugh] LP: It's a loose interpretation of... [laugh]... recursion. TG: Sergey, what's the more literal interpretation? Sergey Brin: The technical term is you got itself back. TG: Right? SB: There's not really much beyond that. [laugh] TG: Okay. SB: Idempotence. How about that? TG: Say it again. SB: Idempotence. TG: What is it? SB: That's when you uh... [laugh]... Maybe I should stop while I'm ahead... TG: ...You're just making this up, aren't you... SB: ...Before I dig a deeper hole. Idempotence is when you do something and you get the original thing back. TG: Oh, so that's a real word? LP: It's a mathematical term. SB: Yeah, yeah, but it's also just as loose an interpretation as Larry's was of recursion.