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

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

Secondary caustics are orthotomic curves having the reflected or refracted rays as normals, and consequently the proper caustic curve, being the envelope of the normals, is their evolute.

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

That is, the soul, being absolute, eternal, and subject to no development, is itself neither the evolvent nor the evolute of aught beside.

From The Sarva-Darsana-Samgraha Review of the Different Systems of Hindu Philosophy by Acharya, Madhava

The balustrade of the platform consists of a simple diaper pattern of intersecting arcs with the familiar evolute band above and below.

From The Colonial Architecture of Philadelphia by Cousins, Frank