evolute

American  

[ev-uh-loot, ee-vuh-] / ˈɛv əˌlut, ˈi və- /

noun

Geometry.

1. the locus of the centers of curvature of, or the envelope of the normals to, another curve.

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evolute British  

/ ˈɛvəˌluːt /

noun

1. a geometric curve that describes the locus of the centres of curvature of another curve (the involute ). The tangents to the evolute are at right angles to the involute

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adjective

1. biology having the margins rolled outwards

Etymology

Origin of evolute

1720–30; < Latin ēvolūtus (past participle of ēvolvere to roll out, unfold, evolve )

Example Sentences

Both of these liquids have specific pericosities given by P = 2.5C.n^6-7 where n is the diathetical evolute of retrograde temperature phase disposition and C is Cholmondeley's annular grillage coefficient.

From Time Magazine Archive

When the refracting curve is a circle and the rays emanate from any point, the locus of the secondary caustic is a Cartesian oval, and the evolute of this curve is the required diacaustic.

From Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 5 "Cat" to "Celt" by Various

The evolute of a curve is the curve which is the envelope of all its normals or the locus of all its centres of curvature.

From The New Gresham Encyclopedia Volume 4, Part 3: Estremoz to Felspar by Various

The intrinsic equation is s = 4a sin ψ, and the equation to the evolute is s = 4a cos ψ, which proves the evolute to be a similar cycloid placed as in fig.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 8 "Cube" to "Daguerre, Louis" by Various

His enquiries into evolutes enabled him to prove that the evolute of a cycloid was an equal cycloid, and by utilizing this property he constructed the isochronal pendulum generally known as the cycloidal pendulum.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 8 "Cube" to "Daguerre, Louis" by Various