Dilation is the act of expanding something. This term is usually used in the context of "dialating the eyes".
In mathematics, a dilation is a function f from a metric space into itself that satisfies the identity
- <math>d(f(x),f(y))=rd(x,y)</math>
where
d(
x,
y) is the distance from
x to
y and
r is some
real number. A dilation of a
Euclidean space is called a
similarity.