Planck's constant

noun

ˈpläŋ(k)s-  ˈplaŋ(k)s- 

variants or less commonly Planck constant

: a constant that gives the unvarying ratio of the energy of a quantum of radiation to its frequency and that has an exact value of 6.62607015 × 10⁻³⁴ joule seconds

—symbol h

Word History

Etymology

Max K. E. L. Planck

First Known Use

1910, in the meaning defined above

Rhymes for Planck's constant

• inconstant

Medical Definition

Planck's constant

noun

ˈplaŋ(k)s-  ˈpläŋ(k)s- 

: a constant that gives the unvarying ratio of the energy of a quantum of radiation to its frequency and that has an approximate value of 6.626 × 10⁻³⁴ joule second

—symbol h