physical constant
physical quantity that is generally believed to be both universal in nature and constant in time
Planck length
very small-scale unit of length
solar constant
intensity of sunlight
cryoscopic constant
material property relating molality to freezing point depression
Gaussian gravitational constant
constant used in orbital mechanics of the solar system
magnetic constant
physical constant; ratio between the magnetic H-field and the magnetic B-field in classical vacuum
reduced Planck constant
physical constant, Dirac's constant: the Planck constant divided by 2 π; mathematical symbol h-bar ‹ℏ› (U+210F)
magnetic flux quantum
quantized unit of magnetic flux threading a loop in a bulk superconductor
astronomical constant
type of constant
electron mass
mass of a stationary electron
pion decay constant
physical constant
elementary charge
the electric charge carried by a single proton or a single positron
standard atmosphere
unit of pressure defined as 101325 Pa
Faraday constant
physical constant: electric charge of one mole of electrons
Wien wavelength displacement law constant
constant in Wien's displacement law
Einstein's constant
physical constant occurring in Einstein's equations (c^2 convention)
electron magnetic dipole moment
spin of an electron
light-year
unit of astronomical length, defined as the distance that light travels in the vacuum in one year
gravitational constant
physical constant relating the gravitational force between objects to their mass and distance
speed of gravity
physical constant equal to the speed of light
Planck mass
unit of mass in the system of Planck units
Planck energy
unit of energy in the system of Planck units
coupling constant
parameter describing the strength of a force
dimensionless physical constant
physical constant with no units
neutron magnetic dipole moment
intrinsic magnetic dipole moment of neutrons
Coulomb's constant
proportionality constant in electrodynamics equations
Rydberg energy
physical constant equal to the ionization energy of the hydrogen atom in a simplified Bohr model
Josephson constant
the inverse of the flux quantum
permittivity of vacuum
physical constant defining the capability of an electric field to permeate a vacuum
Stefan-Boltzmann constant
ratio between the radiative power of a black body to the fourth power of its temperature
impedance of vacuum
physical constant relating the magnitudes of the electric and magnetic fields of electromagnetic radiation travelling through free space
Planck temperature
very large unit of temperature
Avogadro constant
fundamental physical constant (symbols: L, Nᴀ) representing the molar number of entities
cosmological constant
constant representing stress-energy density of the vacuum in Einstein's equation and accounts for the rate of expansion of the universe
Planck constant
physical constant representing the quantum of action ; mathematical italic small h (U+210E), mathematical symbol ‹ℎ›
proton-to-electron mass ratio
physical constant
conductance quantum
quantized unit of electrical conductance
Avogadro number
dimensionless number corresponding to Avogadro's constant (which has units of inverse mole)
Boltzmann constant
physical constant relating energy at the individual particle level with temperature
electronvolt
unit of energy
molar gas constant
physical constant; the molar equivalent to the Boltzmann constant
Planck time
smallest describable unit of time
Bohr radius
physical constant; the most probable distance between an electron and the nucleus in a nonrelativistic model of the hydrogen atom with infinitely heavy nucleus
Rydberg constant
physical constant
Carter constant
constant of motion in the Kerr-Newman spacetime
unified atomic mass constant
a twelfth of the mass of a carbon-12 atom in its ground state