There are two main types of fluid flow - laminar flow, in which the fluid flows smoothly in layers, and turbulent flow, which is characterised by chaotic motion and large amounts of mixing. In this ...

From Quanta Magazine (find original story here). Spaghetti-thin shoelaces, sturdy hawsers, silk cravats—all are routinely tied in knots. So too, physicists believe, are water, air and the liquid iron ...