In algebraic geometry, a lemniscate may refer to any of several figure-eight or ∞-shaped curves. or alternatively may refer to the wool from which the ribbons were made.
Although the name "lemniscate" dates to the late 17th century, the consideration of curves with a figure eight shape can be traced back to Proclus, a Greek Neoplatonist philosopher and mathematician who lived in the 5th century AD. Proclus considered the cross-sections of a torus by a plane parallel to the axis of the torus. As he observed, for most such sections the cross section consists of either one or two ovals; howe...