Search results
Results from the WOW.Com Content Network
The Planck constant, or Planck's constant, denoted by , [1] is a fundamental physical constant [1] of foundational importance in quantum mechanics: a photon's energy is equal to its frequency multiplied by the Planck constant, and the wavelength of a matter wave equals the Planck constant divided by the associated particle momentum.
Constant Value Relative standard uncertainty ... reduced Planck constant in eV⋅s ... atomic unit of electric charge density e/a 0 3 = ...
The constants listed here are known values of physical constants expressed in SI units; that is, physical quantities that are generally believed to be universal in nature and thus are independent of the unit system in which they are measured. Many of these are redundant, in the sense that they obey a known relationship with other physical ...
This equation is known as the Planck relation. Additionally, using equation f = c/λ, = where E is the photon's energy; λ is the photon's wavelength; c is the speed of light in vacuum; h is the Planck constant; The photon energy at 1 Hz is equal to 6.626 070 15 × 10 −34 J, which is equal to 4.135 667 697 × 10 −15 eV.
In other natural unit systems, the unit of charge is defined as , with the result that =, where α is the fine-structure constant, c is the speed of light, ε 0 is the electric constant, and ħ is the reduced Planck constant.
In particle physics and physical cosmology, the Planck scale is an energy scale around 1.22 × 10 28 eV (the Planck energy, corresponding to the energy equivalent of the Planck mass, 2.176 45 × 10 −8 kg) at which quantum effects of gravity become significant.
A fundamental physical constant occurring in quantum mechanics is the Planck constant, h. A common abbreviation is ħ = h /2 π , also known as the reduced Planck constant or Dirac constant . Quantity (common name/s)
The Planck relation [1] [2] [3] (referred to as Planck's energy–frequency relation, [4] the Planck–Einstein relation, [5] Planck equation, [6] and Planck formula, [7] though the latter might also refer to Planck's law [8] [9]) is a fundamental equation in quantum mechanics which states that the energy E of a photon, known as photon energy, is proportional to its frequency ν: =.