# Planck constant

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Related to Planck constant: Joule, electron volt

## Planck con·stant (h),

(plahnk),
a constant, 6.6260755 × 10-34 J · s or 6.6260755 × 10-27 erg-seconds = 6.6260755 × 10-34 J Hz-1.
[Max Planck]

## Planck con·stant

(h) (plahngk kon'stănt)
A constant, 6.6260755 × 10-34 J · s (joule-seconds) or 6.6260755 × 10-27 erg-seconds = 6.6260755 × 10-34 J Hz-1 (joule per hertz).
[Max Planck]

## Planck,

Max, German physicist and Nobel laureate, 1858-1947.
Planck constant - a natural constant occurring in many physical formulas.
Planck theory - that energy can be emitted, transmitted, and absorbed only in discrete quantities. Synonym(s): quantum theory
References in periodicals archive ?
The result, a measurement of the Avogadro constant, can then be used to calculate the Planck constant, using precise measurements of other fundamental constants--including the Rydberg constant, which is related to the energy needed to ionize a hydrogen atom.
Smallness of Planck constant and vanishingly small value of information-entropy interaction force has negligibly small size, about [10.sup.-33] cm.
The kilogram, symbol kg, is the unit of mass; its magnitude is set by fixing the numerical value of the Planck constant to be equal to exactly 6.626 069 ...
Like the other electron models discussed above, the Helical Solenoid Electron Model postulates that the tangential velocity of the electric charge matches the speed of light and that the electron's angular momentum matches the reduced Planck constant.
Because of the quantum electrical standards involved, the ratio of the two power values results in a direct measurement of h, the Planck constant. In September 1998, the National Institute of Standards and Technology completed a new evaluation of the watt and reported the corresponding value for h.
The lead article in the annual Buyer's Guide of the American Institute of Physics features five pages of values of the fundamental physical constants, such as the speed of light, the Newtonian constant of gravitation, the Planck constant, the fine-structure constant, and energy-unit conversion factors.
where c is the speed of light, [??] is the reduced Planck constant, and m is the electron mass.
The NIST watt balance experiment is being completely rebuilt after its 1998 determination of the Planck constant. That measurement yielded a result with an approximately 1 X [10.sup.-7] relative standard uncertainty.
The invariability of Planck constant is a consequence of the fact that, although individually Planck energy and Planck time change in time, their product remains constant:
where [A.sub.S] and [A.sub.D] are the dipole hyperfine constants, [g.sub.J](S) and [g.sub.J](D) are the electronic g-factors, [g'.sub.I] is the nuclear g-factor, h is the Planck constant, and [[micro].sub.B] is the Bohr magneton.
where h is the Planck constant. Then Einstein applied the idea to the light and proposed that light was made of quanta, inseparable entities, with the energy [member of] in terms of the frequency being given in Eq.
for the electron ([r.sub.e][m.sub.e]) and proton ([r.sub.p][m.sub.p]), and the (reduced) Planck constant [??] = [e.sup.2.sub.*]/c.

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