Conversation

Visa ✈️ SF (Aug 2-14)
@visakanv
i'm going to bed but let's try and set up a game 1. reply with an interest, a picture, a quote, whatever  – something random that you'd like to talk about with someone. ask a question, state an observation 2. reply to someone else in the replies enjoy your new friends
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QC (in Berlin 7/29-??? w/ COVID 😷)
@QiaochuYuan
anyone wanna talk about how applying the central limit theorem to a random walk in 2D reproduces the euclidean metric starting from a *grid* it’s fucked up and wrong and i’m still trying to figure out what it means
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QC (in Berlin 7/29-??? w/ COVID 😷)
@QiaochuYuan
idk a place where this is spelled out but like okay take a random walk on a 2D square grid where you go up, down, left or right with probability 1/4 each. sample the walk a bunch of times and make a plot of where you end up after like a million steps. you’ll get a 2D gaussian
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QC (in Berlin 7/29-??? w/ COVID 😷)
@QiaochuYuan
which has radial symmetry: the probability that you end up in a certain small region depends only on how far you are from the origin, in the *euclidean* metric. this is despite the fact that the random walk itself is only defined knowing what up, down, left, and right are
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QC (in Berlin 7/29-??? w/ COVID 😷)
@QiaochuYuan
yeah exactly it’s super weird i’m starting to realize in this discussion also that like... okay i vaguely expected people to be kinda familiar with CLT from hearing about bell curves but now i’m starting to realize probably way fewer people have seen CLT in multiple variables
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