Falaco Solitons: Particles at the Pool

While the season for swimming has already passed in most of the country, it's still not too late in the year for some physics fun in the pool! If you've got a sunny day, a dinner plate, and access to a calm body of water, you can explore one of the coolest (and coolest-sounding) phenomena in fluid dynamics: vortical (or "Falaco") solitons. If it sounds like I'm making up words here, let's start with some definitions: a soliton is a kind of wave which moves without dispersing. When you cannonball...