Posts in category #demo
Posts that include some interactive, magical, interesting or otherwise animated demo of whatever they're describing.

The IMO 2011 windmill problem
A recent video by 3Blue1Brown (previously seen generating Pi from bouncing blocks) introduced me to an interesting problem from the 2011 International Mathematical Olympiad. The problem (described below) describes a windmill process where a line rotates through a cloud of points, switching pivots whenever it hits a new point.
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Bouncing blocks gives you Pi
The YouTube channel 3Blue1Brown recently uploaded a video where they give the following situation: we have two sliding blocks and a wall on the left. The first block starts out motionless, and the second block comes in sliding from the right.
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