## Limaçon pendulum

#### Geege Schuman stashed this in Gifs of Glory

**Stashed in:** gifs, Math!, Perfect GIFs!!!, Mathy, Oddly Satisfying, Snails!

Mathy:

In geometry, a **limaçon** or **limacon** /ˈlɪməsɒn/, also known as a **limaçon of Pascal**, is defined as a roulette formed when a circle rolls around the outside of a circle of equal radius. It can also be defined as the roulette formed when a circle rolls around a circle with half its radius so that the smaller circle is inside the larger circle. Thus, they belong to the family of curves called centered trochoids; more specifically, they are epitrochoids. The **cardioid** is the special case in which the point generating the roulette lies on the rolling circle; the resulting curve has a cusp.

The term derives from the French word *limaçon*, which refers to small snails (Latin *limax*). Depending on the position of the point generating the curve, it may have inner and outer loops (giving the family its name), it may be heart-shaped, or it may be oval.

A limaçon is a bicircular rational plane algebraic curve of degree 4.

So full of Maths! And it does look like snails!

7:55 AM Jul 15 2015