When playing in the surf, it’s easy to imagine that the incoming waves are a wall of water crashing into the shore. And, in a way they are, but probably less so than you imagine. Waves travel through a medium, whether it’s solid or fluid, but for the most part, they’re not translating the medium itself. You can see that in the animation above by watching the dye beneath the surface. The passing waves don’t cause much mixing in the dye, and though their passage distorts the underlying water, we see that everything returns more or less to its starting position once the wave has passed. (Image credit: S. Morris, source)
How Waves Travel
