Fermat's spiral

The spiral of Fermat is a kind of Archimedean spiral.
Because of its parabolic formula the curve is also called the parabolic spiral.

It was the great mathematician Fermat (1636) who started investigating the curve, so that the curve has been given his name.
Sometimes the curve is called the dual Fermat's spiral when both both negative and positive values are accepted.

The people who practice omphaloskepsis adopted the curve as their symbol. Omphaloskepsis is a way of life, around the act of contemplating one's navel as a method of achieving higher meditation.

The inverse of the curve is the lituus.