AgeOfUniverse is the age of the universe, a physical constant.
BohrRadius is the Bohr radius, an atomic constant.
BoltzmannConstant is the ratio of the universal gas constant (MolarGasConstant) to Avogadro's number (AvogadroConstant).
ClassicalElectronRadius is the classical electron radius, an atomic constant.
CosmicBackgroundTemperature is the temperature of the cosmic background radiation.
DeuteronMagneticMoment is the deuteron magnetic moment.
DeuteronMass is the mass of a deuteron.
EarthMass
(Physical Constants Package Symbol) EarthMass is the mass of Earth, a physical constant.
EarthRadius is the radius of Earth, a physical constant.
ElectronCharge is the elementary charge on the electron, an electromagnetic constant.