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Planck length

Planck length noun: a unit of length, believed to be the scale at which quantum gravity effects become significant, that is defined in terms of the speed of light, the gravitational constant and the reduced Planck's constant, namely: ℓ_P=√hbar Gc³≈1.616 252(81)×10⁻³⁵ mbox m.

Noun

Planck length (plural Planck lengths)

  1. A unit of length, believed to be the scale at which quantum gravity effects become significant, that is defined in terms of the speed of light, the gravitational constant and the reduced Planck's constant, namely: ℓ_P=√hbar Gc³≈1.616 252(81)×10⁻³⁵ mbox m
    • As Dr. Feynman noted, there are still shorter scales of time and distance to go before we reach the ultimate limits imposed by quantum physics: the Planck length, 10^-33 of a centimeter, and the Planck time, 10^-43 of a second. Both are named for the German physicist Max Planck, who made the...2023 October 9, Dennis Overbye, “The Science Nobel Winners Were Short and Fast”, in The New York Times, archived from the original on 12 Oct 2023

Forms of Planck length

pluralPlanck lengths

Origin of Planck length

Named after Max Planck, who defined it.

Questions about Planck length

What does Planck length mean?
Planck length means a unit of length, believed to be the scale at which quantum gravity effects become significant, that is defined in terms of the speed of light, the gravitational constant and the reduced Planck's constant, namely: ℓ_P=√hbar Gc³≈1.616 252(81)×10⁻³⁵ mbox m.
What part of speech is Planck length?
Planck length is a noun.
What is the plural of Planck length?
The plural of Planck length is Planck lengths.

Words near Planck length in the dictionary

  1. Planck era
  2. Planck force
  3. Planck forces
  4. Planck frequencies
  5. Planck frequency
  6. Planck length
  7. Planck lengths
  8. Planck mass
  9. Planck masses
  10. Planck momentum
  11. Planck momentums

Source and license

Adapted from Wiktionary: Planck length (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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