Package org.djunits.util

Class Constants

java.lang.Object
org.djunits.util.Constants
public final class Constants extends Object

Various physical constants. For many, see Wikipedia 2019 redefinition of the SI base units

Author:
Peter Knoppers

  • Field Details

    • AVOGADRO

      public static final SIQuantity AVOGADRO
      Number of constituent particles in a Mole; a.k.a. Avogadro's number. This value is exact since the 2019 redefinition of the SI base units.

    • BOLTZMANN

      public static final SIQuantity BOLTZMANN
      Boltzmann constant in Joule per Kelvin (this value is exact since the 2019 redefinition of SI base units). See Wikipedia: Boltzmann constant

    • CESIUM133_FREQUENCY

      public static final Frequency CESIUM133_FREQUENCY
      The Cesium 133 ground state hyperfine structure transition frequency. This value is exact since the 2006 redefinition of the SI base units.

    • ELECTRONCHARGE

      public static final ElectricCharge ELECTRONCHARGE
      Electric charge of one electron. This value is exact since the 2019 redefinition of the SI base units.

    • ELECTRONMASS

      public static final Mass ELECTRONMASS
      Mass of an electron. See Wikipedia Physical constant. This value of this physical constant has an uncertainty of 2.8e-40 kg.

    • PROTONCHARGE

      public static final ElectricCharge PROTONCHARGE
      ElectricCharge of one proton.

    • NEUTRONMASS

      public static final Mass NEUTRONMASS
      Mass of a neutron. See Wikipedia List of physical constants. This value of this physical constant has an uncertainty of 9.5e-37 kg.

    • PROTONMASS

      public static final Mass PROTONMASS
      Mass of a proton. See Wikipedia Physical constant. This value of this physical constant has an uncertainty of 5.1e-37.

    • G

      public static final SIQuantity G
      Gravitational constant, a.k.a. Newtonian constant of gravitation. This is the 2018 best known approximation, which has an uncertainty 1.5e-15 m^3/kgs^2

    • LIGHTSPEED

      public static final Speed LIGHTSPEED
      Speed of light in vacuum. This value is exact (since the 2006 redefinition of the SI base units).

    • VACUUMPERMEABILITY

      public static final SIQuantity VACUUMPERMEABILITY
      Permeability of vacuum. See Wikipedia, Vacuum permeability. The uncertainty of this value is 1.9e-16N/A^2.

    • VACUUMPERMITTIVITY

      public static final SIQuantity VACUUMPERMITTIVITY
      Permittivity of vacuum. See Wikipedia Vacuum permittivity. The uncertainty of this value is 1.3e-21 F/m.

    • VACUUMIMPEDANCE

      public static final SIQuantity VACUUMIMPEDANCE
      Impedance of vacuum.

    • PLANCK

      public static final SIQuantity PLANCK
      Planck constant; ratio of a photon's energy and its frequency. This value is exact since the 2019 redefinition of the SI base units.

    • LUMINOUS_EFFICACY_540THZ

      public static final SIQuantity LUMINOUS_EFFICACY_540THZ
      The luminous efficacy Kcd of monochromatic radiation of frequency 540x10^12 Hz (540 THz). This is the frequency of a green-colored light at approximately the peak sensitivity of the human eye. This value is exact since the 2006 redefinition of the SI base units.

    • PI

      public static final Dimensionless PI
      Ratio of a half circumference of a circle and its radius.

    • TAU

      public static final Dimensionless TAU
      Ratio of circumference of circle and its radius.

    • E

      public static final Dimensionless E
      Euler's constant.

    • PHI

      public static final Dimensionless PHI
      Golden ratio.

    • PLANCKREDUCED

      public static final SIQuantity PLANCKREDUCED
      Reduced Planck constant, a.k.a. angular Planck constant; Planck constant divided by 2 pi.