What I love is that this is simultaneously preposterous and erudite. It's an accurate-while-ridiculous animation of the way the computer algorithm known as "quicksort" works. The logic behind quicksort is to put a list of items into order through a recursive series of "greater than / less than" tests. You could read all about it here or here. Or you could just watch the video.
I also love this comment on the YouTube version: "It would have been cool if it was multithreaded." That's true -- you would have had dancers on both sides doing simultaneous "pivot" tests after the first partition -- but it's a full success as is. My admiration goes to whoever had the weird imagination to think this was worth the effort. It was.
PS The video itself is recursive, so you get the point pretty quickly. It just repeats the sorting process all the way to the end.
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