The point at infinity, also called ideal point, of the real number line is a point which, when added to the number line yields a closed curve called the real projective line, . The real projective line is not equivalent to the extended real number line, which has two different points at infinity.
The point at infinity can also be added to the complex plane, thereby turning it into a closed surface (i.e., complex algebraic curve) known as the complex projective line, also called the Riemann sphere.
The concept of infinity point admits several generalizations for various multi-dimensional constructions.
Read more about Point At Infinity: Projective Geometry, Hyperbolic Geometry, Other Generalisations
Famous quotes containing the words point and/or infinity:
“The modern mind is in complete disarray. Knowledge has streched itself to the point where neither the world nor our intelligence can find any foot-hold. It is a fact that we are suffering from nihilism.”
—Albert Camus (1913–1960)
“The poetic notion of infinity is far greater than that which is sponsored by any creed.”
—Joseph Brodsky (b. 1940)