Shortest Distance

The old saying goes that the shortest distance between two points is a straight line. That's clear the way we usually picture it, with a line linking two points on a flat surface or map.

And it's true on weird shapes as well, as this post at Curiosa Mathematica indicates.

If you were to find yourself on a shape like the above, you should probably first stop doing drugs. But if it turns out that you really were standing on this strange surface and you started walking straight ahead at 0º, you would wind up following the orange line. After which you might need some drugs, specifically dramamine.