Get the details behind our redesign

1.

the fundamental constant of quantum mechanics, expressing the ratio of the energy of one quantum of radiation to the frequency of the radiation and approximately equal to 6.624 × 10− ^{27} erg-seconds. Symbol: h.

Also, Planck constant.

Origin

Dictionary.com Unabridged

Based on the Random House Dictionary, © Random House, Inc. 2014.

Cite This Source

Based on the Random House Dictionary, © Random House, Inc. 2014.

Cite This Source

British Dictionary definitions for planck constant

noun

1.

a fundamental constant equal to the energy of any quantum of radiation divided by its frequency. It has a value of 6.62606876 × 10–34 joule seconds h See also Dirac constant

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition

© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins

Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Cite This Source

© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins

Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Cite This Source

planck constant in Medicine

**Planck's constant** (plängks)*n.* *Symbol ***h** The constant of proportionality relating the energy of a photon to the frequency of that photon. Its value is approximately 6.626 × 10-^{34} joule-second.

The American Heritage® Stedman's Medical Dictionary

Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Cite This Source

Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Cite This Source

planck constant in Science

Planck's constant (plängks) A physical constant that is used extensively in quantum mechanics and fixes the scale of quantization of many phenomena, such as the relation between the energy of a photon (a quantum of light) and its wavelength. Its value is approximately 6.626 × 10 ^{-34} joule-seconds (equivalent to units of angular momentum). Planck's constant is fundamental to phenomena as the quantization of angular momentum and is used in Heisenberg's Uncertainty Principle. See also Dirac's constant, quantize. |

The American Heritage® Science Dictionary

Copyright © 2002. Published by Houghton Mifflin. All rights reserved.

Cite This Source

Copyright © 2002. Published by Houghton Mifflin. All rights reserved.

Cite This Source

planck constant in Culture

A universal constant, first discovered by Max Planck, that states the mathematical relationship between the frequency of an electromagnetic wave and the energy in that wave. Planck's discovery unifies the seemingly contradictory observations that energy sometimes acts like a wave and at other times acts as if it is made up of particles.

: Knowing Planck's constant sets the scale of energy for events in which the atom and subatomic particles take part.Note

The American Heritage® New Dictionary of Cultural Literacy, Third Edition

Copyright © 2005 by Houghton Mifflin Company.

Published by Houghton Mifflin Company. All rights reserved.

Cite This Source

Copyright © 2005 by Houghton Mifflin Company.

Published by Houghton Mifflin Company. All rights reserved.

Cite This Source

Encyclopedia Article for planck constant

(symbol h), fundamental physical constant characteristic of the mathematical formulations of quantum mechanics, which describes the behaviour of particles and waves on the atomic scale, including the particle aspect of light. The German physicist Max Planck introduced the constant in 1900 in his accurate formulation of the distribution of the radiation emitted by a blackbody, or perfect absorber of radiant energy (see Planck's radiation law). The significance of Planck's constant in this context is that radiation, such as light, is emitted, transmitted, and absorbed in discrete energy packets, or quanta, determined by the frequency of the radiation and the value of Planck's constant. The energy E of each quantum, or each photon, equals Planck's constant h times the radiation frequency symbolized by the Greek letter nu, nu, or simply E=hnu. A modified form of Planck's constant called h-bar (), or Dirac h, frequently appears in the formulations of quantum mechanics, in which equals h divided by 2pi.

Learn more about Planck's constant with a free trial on Britannica.com

Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.

Cite This Source

Cite This Source

0

0

Scrabble
Words With Friends