(cosmology) the ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer; the Hubble constant is not actually a constant, but is regarded as measuring the expansion rate today

an oriental tobacco pipe with a long flexible tube connected to a container where the smoke is cooled by passing through water

a constant in the equation of a curve that can be varied to yield a family of similar curves

any factor that defines a system and determines (or limits) its performance

(computer science) a reference or value that is passed to a function, procedure, subroutine, command, or program

a quantity (such as the mean or variance) that characterizes a statistical population and that can be estimated by calculations from sample data

United States astronomer who discovered that (as the universe expands) the speed with which nebulae recede increases with their distance from the observer (1889-1953)