A Comb for Magnetic Waves
Waves in magnets resemble the vibrations of a string: if you pluck a string, it sounds a single note, but with a strong pluck, overtones appear — sounds at multiple frequencies.
How Connectivity Percolates Through Dimensions
A handful of matches falls on the table. Each lies however it lands, but in our minds we turn each into an arrow — from one end to the other. Now ask: can you get from one point to another by moving only in the direction of the arrows? A group of points where you can reach any one from any other is called a strongly connected cluster.