Need to let loose a primal scream without collecting footnotes first? Have a sneer percolating in your system but not enough time/energy to make a whole post about it? Go forth and be mid: Welcome to the Stubsack, your first port of call for learning fresh Awful you’ll near-instantly regret.
Any awful.systems sub may be subsneered in this subthread, techtakes or no.
If your sneer seems higher quality than you thought, feel free to cut’n’paste it into its own post — there’s no quota for posting and the bar really isn’t that high.
The post Xitter web has spawned soo many “esoteric” right wing freaks, but there’s no appropriate sneer-space for them. I’m talking redscare-ish, reality challenged “culture critics” who write about everything but understand nothing. I’m talking about reply-guys who make the same 6 tweets about the same 3 subjects. They’re inescapable at this point, yet I don’t see them mocked (as much as they should be)
Like, there was one dude a while back who insisted that women couldn’t be surgeons because they didn’t believe in the moon or in stars? I think each and every one of these guys is uniquely fucked up and if I can’t escape them, I would love to sneer at them.
(Semi-obligatory thanks to @dgerard for starting this.)
I aint clicking on LW links on my day off (ty for your service though). I am trying to reverse engineer wtf this poster is possibly saying though. My best guess: If we have a random walk in Z_2, with X_i being a random var with 2 outcomes, -1 or +1 (50% chance left at every step, 50% chance for a step to the right), then the expected squared distance from the origin after n steps E[ (Σ_{i=1}^n X_i)^2 ] = E[Σ_{i=1}^n X_i^2}] + E[Σ_{i not = j, i,j both in {1,2,…n}} X_i X_j}]. The expectation of any product E[X_i X_j] with i not = j is 0, (again 50% -1, 50% +1), so the 2nd expectation is 0, and (X_i)^2 is always 1, hence the whole expectation of the squared distance is equal to n => the expectation of the nonsquared distance should be on the order of root(n). (I confess this rather straightforward argument comes from the wikipedia page on simple random walks, though I swear I must have seen it before decades ago.)
Now of course, to actually get the expected 1-norm distance, we need to compute E[Σ_{i=1}^n |X_i| ]. More exciting discussion here if you are interested! https://mathworld.wolfram.com/RandomWalk1-Dimensional.html
But back to the original posters point… the whole point of this evaluation is that it is directionLESS, we are looking at expected distance from the origin without a preference for left or right. Like I kind of see what they are trying to say? If afterwards I ignored any intermediate steps of the walker and just looked at the final location (but why tho), I could say "the walker started at the origin and now is approx root(2n/pi) distance away in the minus direction, so only looking at the start and end of the walk I would say the average velocity is d(position)/(d(time)) = ( - root(2n/pi) - 0) /( n ) -> the walker had directional movement in the minus direction at a speed of root(2/(pi*n)) "
wait, so the “speed” would be O(1/root(n)), not root(n)… am I fucking crazy?
I think they took the rather elementary fact about random walks that the variance grows linearly with time and, in trying to make a profundity, got the math wrong and invented a silly meaning for “in retrospect”.
hundo p.