Encyclopedia > Plancks constant

  Article Content

Planck's constant

Redirected from Plancks constant

Planck's constant, denoted h, named after the physicist Max Planck, is a physical constant which appears in all quantum mechanical equations. Its value is approximately

h = 6.6261 × 10-34 Js

Planck's constant can be seen as a conversion factor between frequency and energy, especially for photons. The unicode symbol ℎ (ℎ) can be used for Planck's constant.

The abbreviation

<math>\hbar = \frac{h}{2\pi}</math>

where π is Pi, is commonly encountered. It is pronounced as "h-bar". The constant <math>\hbar</math> is sometimes referred to as Dirac's constant after Paul Dirac. The unicode symbol &#8463; (ℏ) can be used for this on some browsers.

<math>\hbar</math> is the quantum of angular momentum, including spin. The angular momentum of any system, measured against any particular choice of axis, is always an integer multiple of this value. <math>\hbar</math> also occurs in Heisenberg's uncertainty principle. It has therefore been argued that <math>\hbar</math> is more fundamental than h. <math>\hbar</math> is used to define the Planck units.

see also: Electromagnetic radiation, Schrödinger equation, Heisenberg's uncertainty principle, Wave-particle duality, Quantum Hall effect



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Digital Rights Management

... device), hence the 'digital' in DRM. In contrast to existing legal restrictions which copyright status imposes on the owner of a copy of such data, DRM would allow ...

 
 
 
This page was created in 34.9 ms