coordinate axes
71Parallel universe (fiction) — A parallel universe or alternative reality is a hypothetical self contained separate reality coexisting with one s own. A specific group of parallel universes is called a multiverse , although this term can also be used to describe the possible… …
72Orthogonal matrix — In linear algebra, an orthogonal matrix (less commonly called orthonormal matrix[1]), is a square matrix with real entries whose columns and rows are orthogonal unit vectors (i.e., orthonormal vectors). Equivalently, a matrix Q is orthogonal if… …
73Pseudoscalar — In physics, a pseudoscalar is a quantity that behaves like a scalar, except that it changes sign under a parity inversion such as improper rotations while true scalar does not.The prototypical example of a pseudoscalar is the scalar triple… …
74Octahedral symmetry — The cube is the most common shape with octahedral symmetry A regular octahedron has 24 rotational (or orientation preserving) symmetries, and a symmetry order of 48 including transformations that combine a reflection and a rotation. A cube has… …
75Squircle — is a portmanteau word used to refer to a mathematical shape with properties between those of a square and those of a circle. It is a special case of superellipse.EquationIn a Cartesian coordinate system, the squircle centered on the point ( a , b …
76Direct manipulation interface — In computer science, direct manipulation is a human computer interaction style which involves continuous representation of objects of interest, and rapid, reversible, incremental actions and feedback. The intention is to allow a user to directly… …
77Relativity priority dispute — Albert Einstein presented the theories of Special Relativity and General Relativity in groundbreaking publications that either contained no formal references to previous literature, or referred only to a small number of his predecessors for… …
78Crystal optics — is the branch of optics that describes the behaviour of light in anisotropic media, that is, media (such as crystals) in which light behaves differently depending on which direction the light is propagating. The index of refraction depends on… …
79Derivative — This article is an overview of the term as used in calculus. For a less technical overview of the subject, see Differential calculus. For other uses, see Derivative (disambiguation) …
80Rational normal curve — In mathematics, the rational normal curve is a smooth, rational curve C of degree n in projective n space mathbb{P}^n. It is a simple example of a projective variety. The twisted cubic is the special case of n =3.DefinitionThe rational normal… …
