Spiral

In mathematics, a spiral is a curve which emanates from a central point, getting progressively farther away as it revolves around the point.

Spirals and helices

Two major definitions of "spiral" in a respected American dictionary are:

Definition a describes a planar curve, that extends in both of the perpendicular directions within its plane; the groove on one side of a record closely approximates a plane spiral (and it is by the finite width and depth of the groove, but not by the wider spacing between than within tracks, that it falls short of being a perfect example); note that successive loops differ in diameter. In another example, the "center lines" of the arms of a spiral galaxy trace logarithmic spirals.

Definition b includes two kinds of 3-dimensional relatives of spirals:

Spiral (disambiguation)

A spiral is a curve which emanates from a central point, getting progressively farther away as it revolves around the point.

Spiral may also refer to:

Science, mathematics and art

Computer science

Transport

Film and television

Spiral (TV series)

Spiral (French: Engrenages, pronounced: [ɑ̃ɡʁəˈnaʒ]) is a French television police and legal drama series set in Paris. The show follows the lives and work of Paris police officers and the lawyers and judges who work at the Palais de Justice. It was created by the TV production company Son et Lumière.

The first series of eight-episodes started on Canal+ in France on 13 December 2005. The series was shown in the UK on BBC Four during the summer of 2006. It was the channel's first French-language drama series, attracting a modest but loyal audience (around 200,000) and firm critical approval. On 13 September 2009, BBC Four started showing the second series – another eight-part series, partly funded by the BBC – was broadcast from 12 May 2008. The third series was shown from 2 April 2011, and the fourth series from 9 February 2013 – both consisting of twelve episodes.

Series 5 was filmed in 2013 and broadcast in France in late 2014, and in the UK on BBC Four from 10 January 2015. The sixth series has been ordered.