Systolic geometry

Systolic geometry is like a big, grownup version of hopscotch. It's a way that mathematicians use to measure shapes. In systolic geometry, you measure shapes by counting the number of squares that you have to cross when you hop from one corner of the shape to another. So if your shape has four corners and you can hop from one corner to the other without crossing any other squares, then it's a four-square systole. The more squares you have to cross, the more complicated the shape is.