مارپیچ ِ کورنو mârpic-e Cornu (#)
*Fr.: spirale de Cornu*
A plane curve whose Cartesian
coordinates are given in parametric form by the → *Fresnel integrals*.
Cornu's spiral is an auxiliary tool for calculating the Fresnel integrals. It is
particularly used for the calculation of the diffraction of light at the straight edge
of a flat screen or at a straight slit. It is characterized by the fact that the angle it
makes with the abscissa axis is proportional to the square of
the distance along the curve from the origin of coordinates.
Cornu's spiral comprises two branches, symmetrical with respect to the origin and
winding asymptotically on the points (0.5,0.5) and (-0.5,-0.5) respectively.
Also known as the → *clothoid* or *Euler's spiral*. Named after the French physicist Alfred Cornu (1841-1902); → *spiral*. |