It was definitely a dorky question, and a glaring sign of the interviewer's lack of maturity to blithely burn through your precious time in this manner.
But if you're going to play Google's game, this what you're going to get apparently. So what was your answer? One guesses that they weren't so much interested in a correct answer (since it's a bullshit question anyway) but that you were willing to give it a college try (and reference some concepts about limits, and perhaps the geometric layout of this "file system" in the Doctor Who universe they were apparently hoping to roll out this system in, the speed of light, etc).
Yes, I'm sure that's what they were looking for. I hadn't heard of it before but I improvised my way in that direction until the interview was over. :)
As if this what they do all day: ask each other fundamentally useless questions with no meaningful answer (that anyone would actually care about), and which you aren't expected to provide an actual working answer to, anyway. But which have a cute partial (shibboleth) answer embedded in them. Which if you manage to come up with (under interview time constraints and pressure) -- and most importantly: if you ignore the request to actually solve the problem as stated -- will tell the person asking "how you think".
But if you're going to play Google's game, this what you're going to get apparently. So what was your answer? One guesses that they weren't so much interested in a correct answer (since it's a bullshit question anyway) but that you were willing to give it a college try (and reference some concepts about limits, and perhaps the geometric layout of this "file system" in the Doctor Who universe they were apparently hoping to roll out this system in, the speed of light, etc).
In order to, you know, pass their dipshit filter.