|
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.. index::
|
|
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single: physical constants
|
|
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single: constants, physical
|
|
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single: conversion of units
|
|
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single: units, conversion of
|
|
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|
|
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******************
|
|
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Physical Constants
|
|
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******************
|
|
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|
|
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This chapter describes macros for the values of physical constants, such
|
|
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as the speed of light, :math:`c`, and gravitational constant, :math:`G`.
|
|
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The values are available in different unit systems, including the
|
|
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standard MKSA system (meters, kilograms, seconds, amperes) and the CGSM
|
|
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system (centimeters, grams, seconds, gauss), which is commonly used in
|
|
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Astronomy.
|
|
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|
|
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The definitions of constants in the MKSA system are available in the file
|
|
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:file:`gsl_const_mksa.h`. The constants in the CGSM system are defined in
|
|
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:file:`gsl_const_cgsm.h`. Dimensionless constants, such as the fine
|
|
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structure constant, which are pure numbers are defined in
|
|
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:file:`gsl_const_num.h`.
|
|
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|
|
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The full list of constants is described briefly below. Consult the
|
|
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header files themselves for the values of the constants used in the
|
|
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library.
|
|
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|
|
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.. index::
|
|
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single: fundamental constants
|
|
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single: constants, fundamental
|
|
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|
|
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Fundamental Constants
|
|
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=====================
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_SPEED_OF_LIGHT
|
|
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|
|
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The speed of light in vacuum, :math:`c`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_VACUUM_PERMEABILITY
|
|
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|
|
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The permeability of free space, :math:`\mu_0`. This constant is defined
|
|
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in the MKSA system only.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_VACUUM_PERMITTIVITY
|
|
Packit |
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|
|
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The permittivity of free space, :math:`\epsilon_0`. This constant is
|
|
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defined in the MKSA system only.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_PLANCKS_CONSTANT_H
|
|
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|
|
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Planck's constant, :math:`h`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_PLANCKS_CONSTANT_HBAR
|
|
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|
|
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Planck's constant divided by :math:`2\pi`, :math:`\hbar`.
|
|
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|
|
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.. macro:: GSL_CONST_NUM_AVOGADRO
|
|
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|
|
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Avogadro's number, :math:`N_a`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_FARADAY
|
|
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|
|
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The molar charge of 1 Faraday.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_BOLTZMANN
|
|
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|
|
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The Boltzmann constant, :math:`k`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_MOLAR_GAS
|
|
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|
|
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The molar gas constant, :math:`R_0`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_STANDARD_GAS_VOLUME
|
|
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|
|
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The standard gas volume, :math:`V_0`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_STEFAN_BOLTZMANN_CONSTANT
|
|
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|
|
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The Stefan-Boltzmann radiation constant, :math:`\sigma`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_GAUSS
|
|
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|
|
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The magnetic field of 1 Gauss.
|
|
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|
|
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.. index:: astronomical constants
|
|
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|
|
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Astronomy and Astrophysics
|
|
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==========================
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_ASTRONOMICAL_UNIT
|
|
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|
|
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The length of 1 astronomical unit (mean earth-sun distance), :math:`au`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_GRAVITATIONAL_CONSTANT
|
|
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|
|
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The gravitational constant, :math:`G`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_LIGHT_YEAR
|
|
Packit |
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|
|
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The distance of 1 light-year, :math:`ly`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_PARSEC
|
|
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|
|
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The distance of 1 parsec, :math:`pc`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_GRAV_ACCEL
|
|
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|
|
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The standard gravitational acceleration on Earth, :math:`g`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_SOLAR_MASS
|
|
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|
|
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The mass of the Sun.
|
|
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|
|
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.. index::
|
|
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single: atomic physics, constants
|
|
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single: nuclear physics, constants
|
|
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|
|
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Atomic and Nuclear Physics
|
|
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==========================
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_ELECTRON_CHARGE
|
|
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|
|
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The charge of the electron, :math:`e`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_ELECTRON_VOLT
|
|
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|
|
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The energy of 1 electron volt, :math:`eV`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_UNIFIED_ATOMIC_MASS
|
|
Packit |
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|
|
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The unified atomic mass, :math:`amu`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_MASS_ELECTRON
|
|
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|
|
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The mass of the electron, :math:`m_e`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_MASS_MUON
|
|
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|
|
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The mass of the muon, :math:`m_\mu`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_MASS_PROTON
|
|
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|
|
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The mass of the proton, :math:`m_p`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_MASS_NEUTRON
|
|
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|
|
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The mass of the neutron, :math:`m_n`.
|
|
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|
|
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.. macro:: GSL_CONST_NUM_FINE_STRUCTURE
|
|
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|
|
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The electromagnetic fine structure constant :math:`\alpha`.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_RYDBERG
|
|
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|
|
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The Rydberg constant, :math:`Ry`, in units of energy. This is related to
|
|
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the Rydberg inverse wavelength :math:`R_\infty` by :math:`Ry = h c R_\infty`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_BOHR_RADIUS
|
|
Packit |
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|
|
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The Bohr radius, :math:`a_0`.
|
|
Packit |
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|
|
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.. macro:: GSL_CONST_MKSA_ANGSTROM
|
|
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|
|
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The length of 1 angstrom.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_BARN
|
|
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|
|
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The area of 1 barn.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_BOHR_MAGNETON
|
|
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|
|
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The Bohr Magneton, :math:`\mu_B`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_NUCLEAR_MAGNETON
|
|
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|
|
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The Nuclear Magneton, :math:`\mu_N`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_ELECTRON_MAGNETIC_MOMENT
|
|
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|
|
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The absolute value of the magnetic moment of the electron, :math:`\mu_e`.
|
|
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The physical magnetic moment of the electron is negative.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_PROTON_MAGNETIC_MOMENT
|
|
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|
|
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The magnetic moment of the proton, :math:`\mu_p`.
|
|
Packit |
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|
|
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.. macro:: GSL_CONST_MKSA_THOMSON_CROSS_SECTION
|
|
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|
|
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The Thomson cross section, :math:`\sigma_T`.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_DEBYE
|
|
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|
|
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The electric dipole moment of 1 Debye, :math:`D`.
|
|
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|
|
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.. index:: time units
|
|
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|
|
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Measurement of Time
|
|
Packit |
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===================
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_MINUTE
|
|
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|
|
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The number of seconds in 1 minute.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_HOUR
|
|
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|
|
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The number of seconds in 1 hour.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_DAY
|
|
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|
|
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The number of seconds in 1 day.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_WEEK
|
|
Packit |
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|
|
Packit |
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The number of seconds in 1 week.
|
|
Packit |
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|
|
Packit |
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.. index::
|
|
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single: imperial units
|
|
Packit |
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single: units, imperial
|
|
Packit |
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|
|
Packit |
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Imperial Units
|
|
Packit |
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==============
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_INCH
|
|
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|
|
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The length of 1 inch.
|
|
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_FOOT
|
|
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|
|
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The length of 1 foot.
|
|
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_YARD
|
|
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|
|
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The length of 1 yard.
|
|
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_MILE
|
|
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|
|
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The length of 1 mile.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_MIL
|
|
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|
|
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The length of 1 mil (1/1000th of an inch).
|
|
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|
|
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.. index:: nautical units
|
|
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|
|
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Speed and Nautical Units
|
|
Packit |
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========================
|
|
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_KILOMETERS_PER_HOUR
|
|
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|
|
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The speed of 1 kilometer per hour.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_MILES_PER_HOUR
|
|
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|
|
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The speed of 1 mile per hour.
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_NAUTICAL_MILE
|
|
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|
|
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The length of 1 nautical mile.
|
|
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_FATHOM
|
|
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|
|
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The length of 1 fathom.
|
|
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_KNOT
|
|
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|
|
Packit |
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The speed of 1 knot.
|
|
Packit |
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|
|
Packit |
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.. index:: printers units
|
|
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|
|
Packit |
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Printers Units
|
|
Packit |
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==============
|
|
Packit |
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|
|
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.. macro:: GSL_CONST_MKSA_POINT
|
|
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|
|
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The length of 1 printer's point (1/72 inch).
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_TEXPOINT
|
|
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|
|
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The length of 1 TeX point (1/72.27 inch).
|
|
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|
|
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.. index:: volume units
|
|
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|
|
Packit |
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Volume, Area and Length
|
|
Packit |
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=======================
|
|
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|
|
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.. macro:: GSL_CONST_MKSA_MICRON
|
|
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|
|
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The length of 1 micron.
|
|
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_HECTARE
|
|
Packit |
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|
|
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The area of 1 hectare.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_ACRE
|
|
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|
|
Packit |
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The area of 1 acre.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_LITER
|
|
Packit |
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|
|
Packit |
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The volume of 1 liter.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_US_GALLON
|
|
Packit |
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|
|
Packit |
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The volume of 1 US gallon.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_CANADIAN_GALLON
|
|
Packit |
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|
|
Packit |
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The volume of 1 Canadian gallon.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_UK_GALLON
|
|
Packit |
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|
|
Packit |
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The volume of 1 UK gallon.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_QUART
|
|
Packit |
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|
|
Packit |
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The volume of 1 quart.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_PINT
|
|
Packit |
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|
|
Packit |
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The volume of 1 pint.
|
|
Packit |
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|
|
Packit |
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.. @node Cookery
|
|
Packit |
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.. @section Cookery
|
|
Packit |
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.. @commentindex cookery units
|
|
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|
|
Packit |
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.. @table @commentode
|
|
Packit |
67cb25 |
.. @item GSL_CONST_MKSA_CUP
|
|
Packit |
67cb25 |
.. The volume of 1 cup.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. @item GSL_CONST_MKSA_FLUID_OUNCE
|
|
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67cb25 |
.. The volume of 1 fluid ounce.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. @item GSL_CONST_MKSA_TABLESPOON
|
|
Packit |
67cb25 |
.. The volume of 1 tablespoon.
|
|
Packit |
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|
|
Packit |
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.. @item GSL_CONST_MKSA_TEASPOON
|
|
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.. The volume of 1 teaspoon.
|
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.. @end table
|
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.. index::
|
|
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single: mass, units of
|
|
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single: weight, units of
|
|
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|
|
Packit |
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Mass and Weight
|
|
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===============
|
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|
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.. macro:: GSL_CONST_MKSA_POUND_MASS
|
|
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|
|
Packit |
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The mass of 1 pound.
|
|
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_OUNCE_MASS
|
|
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|
|
Packit |
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The mass of 1 ounce.
|
|
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|
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Packit |
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.. macro:: GSL_CONST_MKSA_TON
|
|
Packit |
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|
|
Packit |
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The mass of 1 ton.
|
|
Packit |
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|
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Packit |
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.. macro:: GSL_CONST_MKSA_METRIC_TON
|
|
Packit |
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|
|
Packit |
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The mass of 1 metric ton (1000 kg).
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_UK_TON
|
|
Packit |
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|
|
Packit |
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The mass of 1 UK ton.
|
|
Packit |
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|
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Packit |
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.. macro:: GSL_CONST_MKSA_TROY_OUNCE
|
|
Packit |
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|
|
Packit |
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The mass of 1 troy ounce.
|
|
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|
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Packit |
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.. macro:: GSL_CONST_MKSA_CARAT
|
|
Packit |
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|
|
Packit |
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The mass of 1 carat.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_GRAM_FORCE
|
|
Packit |
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|
|
Packit |
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The force of 1 gram weight.
|
|
Packit |
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|
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Packit |
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.. macro:: GSL_CONST_MKSA_POUND_FORCE
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Packit |
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|
Packit |
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The force of 1 pound weight.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_KILOPOUND_FORCE
|
|
Packit |
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|
|
Packit |
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The force of 1 kilopound weight.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_POUNDAL
|
|
Packit |
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|
|
Packit |
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The force of 1 poundal.
|
|
Packit |
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|
|
Packit |
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.. index::
|
|
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single: energy, units of
|
|
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single: power, units of
|
|
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single: thermal energy, units of
|
|
Packit |
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|
|
Packit |
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Thermal Energy and Power
|
|
Packit |
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========================
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_CALORIE
|
|
Packit |
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|
|
Packit |
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The energy of 1 calorie.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_BTU
|
|
Packit |
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|
|
Packit |
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The energy of 1 British Thermal Unit, :math:`btu`.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_THERM
|
|
Packit |
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|
|
Packit |
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The energy of 1 Therm.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_HORSEPOWER
|
|
Packit |
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|
|
Packit |
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The power of 1 horsepower.
|
|
Packit |
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|
|
Packit |
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.. index:: pressure, units of
|
|
Packit |
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|
|
Packit |
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Pressure
|
|
Packit |
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========
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_BAR
|
|
Packit |
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|
|
Packit |
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The pressure of 1 bar.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_STD_ATMOSPHERE
|
|
Packit |
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|
|
Packit |
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The pressure of 1 standard atmosphere.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_TORR
|
|
Packit |
67cb25 |
|
|
Packit |
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The pressure of 1 torr.
|
|
Packit |
67cb25 |
|
|
Packit |
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.. macro:: GSL_CONST_MKSA_METER_OF_MERCURY
|
|
Packit |
67cb25 |
|
|
Packit |
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The pressure of 1 meter of mercury.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_INCH_OF_MERCURY
|
|
Packit |
67cb25 |
|
|
Packit |
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The pressure of 1 inch of mercury.
|
|
Packit |
67cb25 |
|
|
Packit |
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.. macro:: GSL_CONST_MKSA_INCH_OF_WATER
|
|
Packit |
67cb25 |
|
|
Packit |
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The pressure of 1 inch of water.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_PSI
|
|
Packit |
67cb25 |
|
|
Packit |
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The pressure of 1 pound per square inch.
|
|
Packit |
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|
|
Packit |
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.. index:: viscosity, units of
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
Viscosity
|
|
Packit |
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=========
|
|
Packit |
67cb25 |
|
|
Packit |
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.. macro:: GSL_CONST_MKSA_POISE
|
|
Packit |
67cb25 |
|
|
Packit |
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The dynamic viscosity of 1 poise.
|
|
Packit |
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|
|
Packit |
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.. macro:: GSL_CONST_MKSA_STOKES
|
|
Packit |
67cb25 |
|
|
Packit |
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The kinematic viscosity of 1 stokes.
|
|
Packit |
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|
|
Packit |
67cb25 |
.. index::
|
|
Packit |
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single: light, units of
|
|
Packit |
67cb25 |
single: illumination, units of
|
|
Packit |
67cb25 |
|
|
Packit |
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Light and Illumination
|
|
Packit |
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======================
|
|
Packit |
67cb25 |
|
|
Packit |
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.. macro:: GSL_CONST_MKSA_STILB
|
|
Packit |
67cb25 |
|
|
Packit |
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The luminance of 1 stilb.
|
|
Packit |
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|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_LUMEN
|
|
Packit |
67cb25 |
|
|
Packit |
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The luminous flux of 1 lumen.
|
|
Packit |
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|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_LUX
|
|
Packit |
67cb25 |
|
|
Packit |
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The illuminance of 1 lux.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_PHOT
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The illuminance of 1 phot.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_FOOTCANDLE
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The illuminance of 1 footcandle.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_LAMBERT
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The luminance of 1 lambert.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_FOOTLAMBERT
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The luminance of 1 footlambert.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. index:: radioactivity, units of
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
Radioactivity
|
|
Packit |
67cb25 |
=============
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_CURIE
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The activity of 1 curie.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_ROENTGEN
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The exposure of 1 roentgen.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_RAD
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The absorbed dose of 1 rad.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. index:: force and energy, units of
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
Force and Energy
|
|
Packit |
67cb25 |
================
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_NEWTON
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The SI unit of force, 1 Newton.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_DYNE
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The force of 1 Dyne = :math:`10^{-5}` Newton.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_JOULE
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The SI unit of energy, 1 Joule.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_MKSA_ERG
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The energy 1 erg = :math:`10^{-7}` Joule.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. index::
|
|
Packit |
67cb25 |
single: prefixes
|
|
Packit |
67cb25 |
single: constants, prefixes
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
Prefixes
|
|
Packit |
67cb25 |
========
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
These constants are dimensionless scaling factors.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_YOTTA
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{24}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_ZETTA
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{21}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_EXA
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{18}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_PETA
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{15}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_TERA
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{12}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_GIGA
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^9`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_MEGA
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^6`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_KILO
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^3`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_MILLI
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{-3}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_MICRO
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{-6}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_NANO
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{-9}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_PICO
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{-12}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_FEMTO
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{-15}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_ATTO
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{-18}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_ZEPTO
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{-21}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. macro:: GSL_CONST_NUM_YOCTO
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
:math:`10^{-24}`
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
Examples
|
|
Packit |
67cb25 |
========
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The following program demonstrates the use of the physical constants in
|
|
Packit |
67cb25 |
a calculation. In this case, the goal is to calculate the range of
|
|
Packit |
67cb25 |
light-travel times from Earth to Mars.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The required data is the average distance of each planet from the Sun in
|
|
Packit |
67cb25 |
astronomical units (the eccentricities and inclinations of the orbits
|
|
Packit |
67cb25 |
will be neglected for the purposes of this calculation). The average
|
|
Packit |
67cb25 |
radius of the orbit of Mars is 1.52 astronomical units, and for the
|
|
Packit |
67cb25 |
orbit of Earth it is 1 astronomical unit (by definition). These values
|
|
Packit |
67cb25 |
are combined with the MKSA values of the constants for the speed of
|
|
Packit |
67cb25 |
light and the length of an astronomical unit to produce a result for the
|
|
Packit |
67cb25 |
shortest and longest light-travel times in seconds. The figures are
|
|
Packit |
67cb25 |
converted into minutes before being displayed.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. include:: examples/const.c
|
|
Packit |
67cb25 |
:code:
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
Here is the output from the program,
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
.. include:: examples/const.txt
|
|
Packit |
67cb25 |
:code:
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
References and Further Reading
|
|
Packit |
67cb25 |
==============================
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
The authoritative sources for physical constants are the 2006 CODATA
|
|
Packit |
67cb25 |
recommended values, published in the article below. Further
|
|
Packit |
67cb25 |
information on the values of physical constants is also available from
|
|
Packit |
67cb25 |
the NIST website.
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
* P.J. Mohr, B.N. Taylor, D.B. Newell, "CODATA Recommended
|
|
Packit |
67cb25 |
Values of the Fundamental Physical Constants: 2006", Reviews of
|
|
Packit |
67cb25 |
Modern Physics, 80(2), pp. 633--730 (2008).
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
* http://www.physics.nist.gov/cuu/Constants/index.html
|
|
Packit |
67cb25 |
|
|
Packit |
67cb25 |
* http://physics.nist.gov/Pubs/SP811/appenB9.html
|