Worlds of David Darling
Encyclopedia of Science
Home > Encyclopedia of Science

uncountable set

A set of numbers that can't be put in a definite order from smallest to largest and so can't be counted. All uncountable sets are infinite, but not all infinite sets are uncountable. The best known uncountable set is the set of all real numbers. By contrast the set of all natural numbers, which represents the "smallest" type of infinity, is countable.

Related category