Physical Constants¶
CO Contents¶
CO Introduction¶
The constants from GSL are reworked with the type const double
and
placed in namespaces called o2scl_mks,
o2scl_cgs, and o2scl_mksa. The GSL MKSA constants are identical to the
MKS constants and thus are not duplicated here. The numerical
constants from gsl_num
and some other additional constants are
given in the namespace o2scl_const,
Some of the numerical values have been updated from recently released data. Electron, neutron, proton, and atomic mass have been updated with CODATA 2018 values. Also electron charge, gravitational constant, plancks_constant_hbar, are updated. The astronomical unit has been updated with the result from ref [Luzum11] (and possibly other values need updating as well).
These physical constants are often used to create unit conversion factors, described in Unit Conversions.
Namespace o2scl_const¶
-
namespace o2scl_const¶
Constants.
CODATA 2014 values were from [Mohr16] and previous versions contained constants from [Luzum11] and [Mohr12] .
CODATA 2018 values are from physics.nist.gov/constants. IAU 2015 values are the nominal values from arXiv:1510.07674 and arXiv:1605.09788 .
Squared electron charge
-
const double e2_gaussian = o2scl_const::hc_mev_fm * o2scl_const::fine_structure¶
Electron charge squared in Gaussian units (derived)
In Gaussian Units:
\[\begin{split}\begin{eqnarray*} &\vec{\nabla} \cdot \vec{E} = 4 \pi \rho \, , \quad \vec{E}=-\vec{\nabla} \Phi \, , \quad \nabla^2 \Phi = - 4 \pi \rho \, , &\\& F=\frac{q_1 q_2}{r^2} \, , \quad W=\frac{1}{2} \int \rho V d^3 x =\frac{1}{8 \pi} \int | \vec{E} |^2 d^3 x \, , \quad \alpha=\frac{e^2}{\hbar c}=\frac{1}{137}& \end{eqnarray*}\end{split}\]
-
const double e2_hlorentz = o2scl_const::fine_structure * 4.0 * pi¶
Electron charge sqaured in Heaviside-Lorentz units where \(\hbar=c=1\) (derived)
In Heaviside-Lorentz units:
\[\begin{split}\begin{eqnarray*} &\vec{\nabla} \cdot \vec{E} = \rho \, , \quad \vec{E}=-\vec{\nabla} \Phi \, , \quad \nabla^2 \Phi = - \rho \, , &\\& F=\frac{q_1 q_2}{4 \pi r^2} \, , \quad W=\frac{1}{2} \int \rho V d^3 x =\frac{1}{2} \int | \vec{E} |^2 d^3 x \, , \quad \alpha=\frac{e^2}{4 \pi}=\frac{1}{137}& \end{eqnarray*}\end{split}\]
-
const double e2_mks = o2scl_mks::electron_charge¶
Electron charge squared in SI(MKS) units (derived)
In MKS units:
\[\begin{split}\begin{eqnarray*} &\vec{\nabla} \cdot \vec{E} = \rho \, , \quad \vec{E}=-\vec{\nabla} \Phi \, , \quad \nabla^2 \Phi = - \rho \, , &\\& F=\frac{1}{4 \pi \varepsilon_0}\frac{q_1 q_2}{r^2} \, , \quad W=\frac{1}{2} \int \rho V d^3 x =\frac{\varepsilon_0}{2} \int | \vec{E} |^2 d^3 x \, , \quad \alpha=\frac{e^2}{4 \pi \varepsilon_0 \hbar c}=\frac{1}{137}& \end{eqnarray*}\end{split}\]Note the conversion formulas
\[ q_HL=\sqrt{4 \pi} q_G = \frac{1}{\sqrt{\varepsilon_0}} q_{SI} \]as mentioned, e.g. in pg. 13 of D. Griffiths Intro to Elem. Particles.
-
const double ec_gauss_fm2 = o2scl_mks::electron_charge * 1.0e-34 / o2scl_mks::plancks_constant_hbar¶
1 \(\mathrm{Gauss}\) times the electron charge in Gaussian units in \(\mathrm{fm}^{-2}\)
-
const double gauss2_fm4 = ec_gauss_fm2 * ec_gauss_fm2 / o2scl_const::fine_structure¶
Conversion factor from \( \mathrm{Gauss}^2 \) to \(\mathrm{fm}^{-4}\) in Gaussian units.
This is useful, e.g. in converting magnetic field squared to an energy density.
Particle masses from PDG 2020
-
const double mass_lambda_MeV = 1115.683¶
\( \Lambda \) hyperon mass in \( \mathrm{MeV} \) (used value labeled “OUR FIT”)
-
const double mass_sigma_minus_MeV = 1197.449¶
\( \Sigma^{-} \) hyperon mass in \( \mathrm{MeV} \) (used value labeled “OUR FIT”)
-
const double mass_sigma_zero_MeV = 1192.642¶
\( \Sigma^{0} \) hyperon mass in \( \mathrm{MeV} \) (used value labeled “OUR FIT”)
-
const double mass_sigma_plus_MeV = 1189.37¶
\( \Sigma^{+} \) hyperon mass in \( \mathrm{MeV} \) (used value labeled “OUR FIT”)
-
const double mass_cascade_zero_MeV = 1314.86¶
\( \Xi^{0} \) hyperon mass in \( \mathrm{MeV} \) (used value labeled “OUR FIT”)
-
const double mass_cascade_minus_MeV = 1321.71¶
\( \Xi^{-} \) hyperon mass in \( \mathrm{MeV} \) (used value labeled “OUR FIT”)
-
const double mass_up_MeV = 2.16¶
Up quark mass in \( \mathrm{MeV} \) (used value labeled “OUR EVALUATION”)
-
const double mass_down_MeV = 4.67¶
Down quark mass in \( \mathrm{MeV} \) (used value labeled “OUR EVALUATION”)
-
const double mass_strange_MeV = 93.0¶
Strange quark mass in \( \mathrm{MeV} \) (used value labeled “OUR EVALUATION”)
Functions
Variables
-
const double yotta = 1e24¶
-
const double zetta = 1e21¶
-
const double exa = 1e18¶
-
const double peta = 1e15¶
-
const double tera = 1e12¶
-
const double giga = 1e9¶
-
const double mega = 1e6¶
-
const double kilo = 1e3¶
-
const double milli = 1e-3¶
-
const double micro = 1e-6¶
-
const double nano = 1e-9¶
-
const double pico = 1e-12¶
-
const double femto = 1e-15¶
-
const double atto = 1e-18¶
-
const double zepto = 1e-21¶
-
const double yocto = 1e-24¶
-
const double fine_structure = 7.2973525693e-3¶
Fine structure constant (CODATA 2018 value)
-
const double avogadro = 6.02214076e23¶
Avogadro’s number (CODATA 2018 value; exact)
-
const double pi = boost::math::constants::pi<double>()¶
\( \pi \)
-
const double pi2 = boost::math::constants::pi_sqr<double>()¶
\( \pi^2 \)
-
const double root_pi = boost::math::constants::root_pi<double>()¶
\( \sqrt{\pi} \)
-
const double zeta32 = 2.6123753486854883433¶
\( \zeta(3/2) \)
-
const double zeta2 = boost::math::constants::zeta_two<double>()¶
\( \zeta(2) \)
-
const double zeta52 = 1.3414872572509171798¶
\( \zeta(5/2) \)
-
const double zeta3 = boost::math::constants::zeta_three<double>()¶
\( \zeta(3) \)
-
const double zeta5 = 1.0369277551433699263¶
\( \zeta(5) \)
-
const double zeta7 = 1.0083492773819228268¶
\( \zeta(7) \)
-
const double euler_mascheroni = 0.57721566490153286060¶
The Euler-Mascheroni constant.
-
const double sin2_theta_weak = 0.23121¶
\( \sin^2 \theta_W \) (PDG 2020 value)
-
const double gfermi_gev2 = 1.1663787e-5¶
Fermi coupling constant in \( \mathrm{GeV}^{-2} \) (CODATA 2018 value)
-
static const size_t o2scl_mks = 1¶
MKS units.
-
static const size_t o2scl_cgs = 2¶
CGS units.
-
const double hc_mev_fm = hc_mev_fm_f<double>()¶
\( \hbar c \) in MeV fm (exact)
-
const double e2_gaussian = o2scl_const::hc_mev_fm * o2scl_const::fine_structure¶
Namespace o2scl_mks¶
-
namespace o2scl_mks¶
Constants in MKS units.
Where possible, constants here are defined in terms of the values in o2scl_cgs, in order to make it easier to update these values. See also the documentation at o2scl_cgs .
Fundamental constants
-
const double speed_of_light = o2scl_cgs::speed_of_light / 1.0e2¶
Speed of light in m / s.
-
const double gravitational_constant = o2scl_cgs::gravitational_constant / 1.0e3¶
Newtonian constant of gravitation in m^3 / kg s^2.
-
const double plancks_constant_h = o2scl_cgs::plancks_constant_h / 1.0e7¶
Planck constant in kg m^2 / s.
-
const double plancks_constant_hbar = o2scl_cgs::plancks_constant_hbar / 1.0e7¶
Planck constant divided by 2 pi in kg m^2 / s.
-
const double electron_volt = o2scl_cgs::electron_volt / 1.0e7¶
Electron volt in kg m^2 / s^2.
-
const double bohr_radius = o2scl_cgs::bohr_radius / 1.0e2¶
Bohr radius in m.
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const double stefan_boltzmann_constant = o2scl_cgs::stefan_boltzmann_constant / 1.0e3¶
Stefan-Boltzmann constant in kg / K^4 s^3.
-
const double thomson_cross_section = o2scl_cgs::thomson_cross_section / 1.0e4¶
Thomson cross section in m^2.
Solar system properties
-
const double solar_mass_parameter = o2scl_cgs::solar_mass_parameter¶
Solar mass times gravitational constant in km^3 / s^2.
-
const double solar_mass = o2scl_cgs::solar_mass / 1.0e3¶
Mass of the sun in kg.
-
const double solar_radius = o2scl_cgs::solar_radius / 1.0e2¶
Radius of the sun in m.
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const double solar_temperature = o2scl_cgs::solar_temperature¶
Temperature of the sun’s photosphere in K.
-
const double solar_luminosity = o2scl_cgs::solar_luminosity¶
Luminosity of sun in erg/s.
-
const double earth_mass_parameter = o2scl_cgs::earth_mass_parameter¶
Earth mass times gravitational constant in m^3 / s^2.
-
const double earth_mass = o2scl_cgs::earth_mass / 1.0e3¶
Mass of the earth in kg.
-
const double earth_radius_equatorial = o2scl_cgs::earth_radius_equatorial / 1.0e2¶
Equatorial radius of earth in m.
-
const double earth_radius_polar = o2scl_cgs::earth_radius_polar / 1.0e2¶
Polar radius of earth in m.
-
const double jupiter_mass_parameter = o2scl_cgs::jupiter_mass_parameter¶
Jupter mass times gravitational constant in m^3 / s^2.
-
const double jupiter_mass = o2scl_cgs::jupiter_mass / 1.0e3 / 1.0e2¶
Mass of jupiter in kg.
-
const double jupiter_radius_equatorial = o2scl_cgs::jupiter_radius_equatorial¶
Equatorial radius of jupiter in m.
-
const double jupiter_radius_polar = o2scl_cgs::jupiter_radius_polar / 1.0e2¶
Polar radius of jupiter in m.
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const double mercury_mass = o2scl_cgs::mercury_mass / 1.0e3¶
Mass of mercury in kg.
-
const double mercury_radius = o2scl_cgs::mercury_radius / 1.0e2¶
Radius of mercury in m.
-
const double venus_mass = o2scl_cgs::venus_mass / 1.0e3¶
Mass of venus in kg.
-
const double venus_radius = o2scl_cgs::venus_radius / 1.0e2¶
Radius of venus in m.
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const double mars_radius_equatorial = o2scl_cgs::mars_radius_equatorial / 1.0e2¶
Equatorial radius of mars in m.
-
const double mars_radius_polar = o2scl_cgs::mars_radius_polar / 1.0e2¶
Polar radius of mars in m.
-
const double saturn_mass = o2scl_cgs::saturn_mass / 1.0e3¶
Mass of saturn in kg.
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const double saturn_radius_equatorial = o2scl_cgs::saturn_radius_equatorial / 1.0e2¶
Equatorial radius of saturn in m.
-
const double saturn_radius_polar = o2scl_cgs::saturn_radius_polar / 1.0e2¶
Polar radius of saturn in m.
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const double uranus_mass = o2scl_cgs::uranus_mass / 1.0e3¶
Mass of uranus in kg.
-
const double uranus_radius_equatorial = o2scl_cgs::uranus_radius_equatorial / 1.0e2¶
Equatorial radius of uranus in m.
-
const double uranus_radius_polar = o2scl_cgs::uranus_radius_polar / 1.0e2¶
Polar radius of uranus in m.
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const double neptune_mass = o2scl_cgs::neptune_mass / 1.0e3¶
Mass of neptune in kg.
-
const double neptune_radius_equatorial = o2scl_cgs::neptune_radius_equatorial / 1.0e2¶
Equatorial radius of neptune in m.
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const double neptune_radius_polar = o2scl_cgs::neptune_radius_polar / 1.0e2¶
Polar radius of neptune in m.
-
const double pluto_mass = o2scl_cgs::pluto_mass / 1.0e3¶
Mass of pluto in kg.
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const double pluto_radius = o2scl_cgs::pluto_radius / 1.0e2¶
Radius of pluto in m.
Astrophysical constants
-
const double astronomical_unit = o2scl_cgs::astronomical_unit / 1.0e2¶
Astronomical unit in m.
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const double grav_accel = o2scl_cgs::grav_accel / 1.0e2¶
Acccleration due to gravity in m / s^2.
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const double schwarzchild_radius = o2scl_cgs::schwarzchild_radius / 1.0e2¶
Schwarzchild radius in m.
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const double sidereal_year = o2scl_cgs::sidereal_year¶
Sidereal year in s (from https://pdg.lbl.gov/2021/reviews/contents_sports.html)
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const double tropical_year = o2scl_cgs::tropical_year¶
Tropical year in s (from https://pdg.lbl.gov/2021/reviews/contents_sports.html)
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const double julian_year = o2scl_cgs::julian_year¶
Julian year in s.
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const double light_year = o2scl_cgs::light_year / 1.0e2¶
Light year in \( \mathrm{m} \).
Particle masses
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const double mass_electron = o2scl_cgs::mass_electron / 1.0e3¶
Electron mass in kg.
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const double mass_proton = o2scl_cgs::mass_proton / 1.0e3¶
Proton mass in kg.
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const double mass_neutron = o2scl_cgs::mass_neutron / 1.0e3¶
Neutron mass in kg.
Nuclear masses
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const double mass_deuteron = o2scl_cgs::mass_deuteron / 1.0e3¶
Deuteron mass in kg.
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const double mass_triton = o2scl_cgs::mass_triton / 1.0e3¶
Triton mass in kg.
-
const double mass_helion = o2scl_cgs::mass_helion / 1.0e3¶
Helion mass in kg.
-
const double mass_alpha = o2scl_cgs::mass_alpha / 1.0e3¶
Alpha particle mass in kg.
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const double unified_atomic_mass = o2scl_cgs::unified_atomic_mass / 1.0e3¶
Atomic mass constant in kg.
Chemical constants
-
const double standard_gas_volume = o2scl_cgs::standard_gas_volume / 1.0e6¶
m^3 / mol
Unit conversions
-
const double nautical_mile = o2scl_cgs::nautical_mile * 1.0e-2¶
m
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const double fluid_ounce = o2scl_cgs::fluid_ounce * 1.0e-6¶
m^3
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const double tablespoon = o2scl_cgs::tablespoon * 1.0e-6¶
m^3
-
const double canadian_gallon = o2scl_cgs::canadian_gallon * 1.0e-6¶
m^3
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const double miles_per_hour = o2scl_cgs::miles_per_hour * 1.0e-2¶
m / s
-
const double kilometers_per_hour = o2scl_cgs::kilometers_per_hour * 1.0e-2¶
m / s
-
const double pound_mass = o2scl_cgs::pound_mass * 1.0e-3¶
kg
-
const double ounce_mass = o2scl_cgs::ounce_mass * 1.0e-3¶
kg
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const double metric_ton = o2scl_cgs::metric_ton * 1.0e-3¶
kg
-
const double troy_ounce = o2scl_cgs::troy_ounce * 1.0e-3¶
kg
-
const double gram_force = o2scl_cgs::gram_force * 1.0e-5¶
kg m / s^2
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const double pound_force = o2scl_cgs::pound_force * 1.0e-5¶
kg m / s^2
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const double kilopound_force = o2scl_cgs::kilopound_force * 1.0e-5¶
kg m / s^2
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const double horsepower = o2scl_cgs::horsepower * 1.0e-7¶
kg m^2 / s^3
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const double std_atmosphere = o2scl_cgs::std_atmosphere * 1.0e-1¶
kg / m s^2
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const double meter_of_mercury = o2scl_cgs::meter_of_mercury * 1.0e-1¶
kg / m s^2
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const double inch_of_mercury = o2scl_cgs::inch_of_mercury * 1.0e-1¶
kg / m s^2
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const double inch_of_water = o2scl_cgs::inch_of_water * 1.0e-1¶
kg / m s^2
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const double gauss = 1.0e-4¶
kg / A s^2
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const double footcandle = o2scl_cgs::footcandle * 1.0e4¶
cd sr / m^2
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const double footlambert = o2scl_cgs::footlambert * 1.0e4¶
cd sr / m^2
ELectromagnetic constants
-
const double electron_magnetic_moment = o2scl_cgsm::electron_magnetic_moment / 1.0e3¶
A m^2.
-
const double proton_magnetic_moment = o2scl_cgsm::proton_magnetic_moment / 1.0e3¶
A m^2.
-
const double bohr_magneton = o2scl_cgsm::bohr_magneton / 1.0e3¶
Bohr magneton in A m^2.
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const double nuclear_magneton = o2scl_cgsm::nuclear_magneton / 1.0e3¶
A m^2.
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const double vacuum_permittivity = 1.0 / o2scl_mks::speed_of_light / o2scl_mks::speed_of_light / 4.0e-7 / o2scl_const::pi¶
A^2 s^4 / kg m^3 (derived)
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const double vacuum_permeability = 4.0 * o2scl_const::pi * 1.00000000082e-7¶
Vacuum permeability in kg m / A^2 s^2 (being redefined as of 5/20, this value is from Wikipedia)
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const double faraday = o2scl_cgsm::faraday * 10.0¶
A s / mol.
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const double electron_charge = o2scl_cgsm::electron_charge * 1.0e1¶
A s (derived)
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const double speed_of_light = o2scl_cgs::speed_of_light / 1.0e2¶
Namespace o2scl_cgs¶
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namespace o2scl_cgs¶
Constants in CGS units.
CODATA 2014 values were from [Mohr16]. CODATA 2018 values are from physics.nist.gov/constants. IAU 2015 values are the nominal values from arXiv:1510.07674 and arXiv:1605.09788 .
Fundamental constants
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const double speed_of_light = 2.99792458e10¶
Speed of light in \( \mathrm{cm}/\mathrm{s} \) (exact)
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const double gravitational_constant = 6.67430e-8¶
Newtonian constant of gravitation in cm^3 / g s^2 (CODATA 2018 value)
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const double plancks_constant_h = 6.62607015e-27¶
Planck constant in g cm^2 / s (CODATA 2018 value; exact)
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const double plancks_constant_hbar = o2scl_cgs::plancks_constant_h / 2.0 / o2scl_const::pi¶
Planck constant divided by 2 pi in g cm^2 / s (derived)
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const double electron_volt = 1.602176634e-12¶
Electron volt in g cm^2 / s^2 (CODATA 2018; exact)
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const double boltzmann = 1.380649e-16¶
Boltzmann constant in g cm^2 / K s^2 (CODATA 2018; exact)
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const double bohr_radius = 5.29177210903e-9¶
Bohr radius in cm (CODATA 2018 value)
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const double stefan_boltzmann_constant = o2scl_const::pi * o2scl_const::pi * o2scl_cgs::boltzmann * o2scl_cgs::boltzmann * o2scl_cgs::boltzmann * o2scl_cgs::boltzmann / 60.0 / o2scl_cgs::plancks_constant_hbar / o2scl_cgs::plancks_constant_hbar / o2scl_cgs::plancks_constant_hbar / o2scl_cgs::speed_of_light / o2scl_cgs::speed_of_light¶
Stefan-Boltzmann constant in g / K^4 s^3 (CODATA 2018; derived; exact)
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const double thomson_cross_section = 6.6524587321e-25¶
Thomson cross section in cm^2 (CODATA 2018 value)
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const double gfermi = o2scl_const::gfermi_gev2 * 1.0e-18 / o2scl_cgs::electron_volt / o2scl_cgs::electron_volt¶
Fermi coupling constant in s^4 / cm^4 g^2 (derived from CODATA 2018 value)
Solar system properties
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const double solar_mass_parameter = 1.3271244e26¶
Solar mass times gravitational constant in cm^3 / s^2 (IAU 2015 value, see https://arxiv.org/abs/1510.07674)
Note that this value differs slightly in Barycentric Coordinate Time and Barycentric Dynamical Time. This is the IAU’s nominal value.
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const double solar_mass = solar_mass_parameter / gravitational_constant¶
Mass of the sun in g (derived)
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const double solar_radius = 6.957e10¶
Radius of the sun in cm (IAU 2015 nominal value)
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const double solar_temperature = 5772.0¶
Temperature of the sun’s photosphere in K (IAU 2015 nominal value)
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const double solar_luminosity = 3.828e40¶
Luminosity of sun in erg/s (IAU 2015 nominal value)
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const double solar_irradiance = 1361.0¶
Solar total irradiance in W/m^2 (IAU 2015 nominal value)
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const double earth_mass_parameter = 3.986004e20¶
Earth mass times gravitational constant in cm^3 / s^2 (IAU 2015 nominal values)
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const double earth_mass = earth_mass_parameter / gravitational_constant¶
Mass of the earth in g (derived)
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const double earth_radius_equatorial = 6.3781e8¶
Equatorial radius of earth in cm (IAU 2015 value)
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const double earth_radius_polar = 6.3568e8¶
Polar radius of earth in cm (IAU 2015 value)
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const double jupiter_mass_parameter = 1.2668653e23¶
Jupter mass times gravitational constant in cm^3 / s^2 (IAU 2015 nominal values)
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const double jupiter_mass = jupiter_mass_parameter / gravitational_constant¶
Mass of jupiter in g (derived)
-
const double jupiter_radius_equatorial = 7.1492e9¶
Equatorial radius of jupiter in cm (IAU 2015 value)
-
const double jupiter_radius_polar = 6.6854e9¶
Polar radius of jupiter in cm (IAU 2015 value)
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const double mercury_mass = 3.3011e26¶
Mass of mercury in g.
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const double mercury_radius = 2.4397e8¶
Radius of mercury in cm.
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const double venus_mass = 7.8675e27¶
Mass of venus in g.
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const double venus_radius = 6.0518e8¶
Radius of venus in cm.
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const double mars_mass = 6.4171e26¶
Mass of mars in g.
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const double mars_radius_equatorial = 3.3962e8¶
Equatorial radius of mars in cm.
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const double mars_radius_polar = 3.3762e8¶
Polar radius of mars in cm.
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const double saturn_mass = 5.6834e29¶
Mass of saturn in g.
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const double saturn_radius_equatorial = 6.0268e9¶
Equatorial radius of saturn in cm.
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const double saturn_radius_polar = 5.4364e9¶
Polar radius of saturn in cm.
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const double uranus_mass = 8.6810e28¶
Mass of uranus in g.
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const double uranus_radius_equatorial = 2.5559e9¶
Equatorial radius of uranus in cm.
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const double uranus_radius_polar = 2.4973e9¶
Polar radius of uranus in cm.
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const double neptune_mass = 1.02413e29¶
Mass of neptune in g.
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const double neptune_radius_equatorial = 2.4764e9¶
Equatorial radius of neptune in cm.
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const double neptune_radius_polar = 2.4341e9¶
Polar radius of neptune in cm.
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const double pluto_mass = 1.303e25¶
Mass of pluto in g.
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const double pluto_radius = 1.1883e8¶
Radius of pluto in cm.
Astrophysical constants
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const double astronomical_unit = 1.495978707e13¶
Astronomical unit in cm (IAU 2009 value; now exact)
-
const double parsec = o2scl_cgs::astronomical_unit * 648000.0 / o2scl_const::pi¶
Parsec in \( \mathrm{cm} \) (derived; exact)
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const double grav_accel = 9.80665e2¶
Acccleration due to gravity in cm / s^2 (CODATA 2018; now exact)
-
const double schwarzchild_radius = 2.0 * o2scl_cgs::solar_mass_parameter / o2scl_cgs::speed_of_light / o2scl_cgs::speed_of_light¶
Schwarzchild radius in cm (derived)
-
const double sidereal_year = 31558149.8¶
Sidereal year in s (from https://pdg.lbl.gov/2021/reviews/contents_sports.html)
-
const double tropical_year = 31556925.1¶
Tropical year in s (from https://pdg.lbl.gov/2021/reviews/contents_sports.html)
-
const double julian_year = 365.25 * 8.64e4¶
Julian year in s (exact)
-
const double light_year = o2scl_cgs::julian_year * o2scl_cgs::speed_of_light¶
Light year in \( \mathrm{cm} \) (derived; exact)
Particle masses
-
const double mass_electron = 9.1093837015e-28¶
Electron mass in g (CODATA 2018 value)
-
const double mass_muon = 1.883531627e-25¶
Muon mass in g (CODATA 2018 value)
-
const double mass_tau = 3.16754e-24¶
Muon mass in g (CODATA 2018 value)
-
const double mass_proton = 1.67262192369e-24¶
Proton mass in g (CODATA 2018 value)
-
const double mass_neutron = 1.67492749804e-24¶
Neutron mass in g (CODATA 2018 value)
Nuclear masses
-
const double mass_deuteron = 3.3435837724e-24¶
Deuteron mass in kg (CODATA 2018 value)
-
const double mass_triton = 5.0073567446e-24¶
Triton mass in kg (CODATA 2018 value)
-
const double mass_helion = 5.0064127796e-24¶
Helion mass in kg (CODATA 2018 value)
-
const double mass_alpha = 6.6446573357e-24¶
Alpha particle mass in kg (CODATA 2018 value)
-
const double unified_atomic_mass = 1.6605390666e-24¶
Atomic mass constant in g (CODATA 2018 value)
Chemical constants
-
const double rydberg = 2.1798723611035e-11¶
Rydberg constant in g cm^2 / s^2 (CODATA 2018 value)
-
const double molar_gas = o2scl_const::avogadro * o2scl_cgs::boltzmann¶
Molar gas constant, “R”, in g cm^2 / K mol s^2 (CODATA 2018; exact; derived)
-
const double standard_gas_volume = 2.271095464e4¶
Molar volume of ideal gas at standard T and P in cm^3 / mol (CODATA 2018 value)
Unit conversions
-
const double minute = 6e1¶
s
-
const double hour = 3.6e3¶
s
-
const double day = 8.64e4¶
s
-
const double week = 6.048e5¶
s
-
const double inch = 2.54e0¶
cm
-
const double foot = 3.048e1¶
cm
-
const double yard = 9.144e1¶
cm
-
const double mile = 1.609344e5¶
cm
-
const double nautical_mile = 1.852e5¶
cm
-
const double fathom = 1.8288e2¶
cm
-
const double mil = 2.54e-3¶
cm
-
const double point = 3175.0 / 90000.0¶
cm
-
const double texpoint = 3.51459803515e-2¶
cm
-
const double micron = 1e-4¶
cm
-
const double angstrom = 1e-8¶
cm
-
const double hectare = 1e8¶
cm^2
-
const double acre = 4.04685642241e7¶
cm^2
-
const double barn = 1e-24¶
cm^2
-
const double liter = 1e3¶
cm^3
-
const double us_gallon = 3.78541178402e3¶
cm^3
-
const double quart = 9.46352946004e2¶
cm^3
-
const double pint = 4.73176473002e2¶
cm^3
-
const double cup = 2.36588236501e2¶
cm^3
-
const double fluid_ounce = 2.95735295626e1¶
cm^3
-
const double tablespoon = 1.47867647813e1¶
cm^3
-
const double teaspoon = 4.92892159375e0¶
cm^3
-
const double canadian_gallon = 4.54609e3¶
cm^3
-
const double uk_gallon = 4.546092e3¶
cm^3
-
const double miles_per_hour = 4.4704e1¶
cm / s
-
const double kilometers_per_hour = 250.0 / 9.0¶
cm / s
-
const double knot = 463.0 / 9.0¶
cm / s
-
const double pound_mass = 4.5359237e2¶
g
-
const double ounce_mass = 2.8349523125e1¶
g
-
const double ton = 9.0718474e5¶
g
-
const double metric_ton = 1e6¶
g
-
const double uk_ton = 1.0160469088e6¶
g
-
const double troy_ounce = 3.1103475e1¶
g
-
const double carat = 2e-1¶
g
-
const double gram_force = 9.80665e2¶
cm g / s^2
-
const double pound_force = 4.44822161526e5¶
cm g / s^2
-
const double kilopound_force = 4.44822161526e8¶
cm g / s^2
-
const double poundal = 1.38255e4¶
cm g / s^2
-
const double calorie = 4.1868e7¶
g cm^2 / s^2
-
const double btu = 1.05505585262e10¶
g cm^2 / s^2
-
const double therm = 1.05506e15¶
g cm^2 / s^2
-
const double horsepower = 7.457e9¶
g cm^2 / s^3
-
const double bar = 1e6¶
g / cm s^2
-
const double std_atmosphere = 1.01325e6¶
g / cm s^2
-
const double torr = 1.33322368421e3¶
g / cm s^2
-
const double meter_of_mercury = 1.33322368421e6¶
g / cm s^2
-
const double inch_of_mercury = 3.38638815789e4¶
g / cm s^2
-
const double inch_of_water = 2.490889e3¶
g / cm s^2
-
const double psi = 6.89475729317e4¶
g / cm s^2
-
const double poise = 1e0¶
g / cm s
-
const double stokes = 1e0¶
cm^2 / s
-
const double stilb = 1e0¶
cd / cm^2
-
const double lumen = 1e0¶
cd sr
-
const double lux = 1e-4¶
cd sr / cm^2
-
const double phot = 1e0¶
cd sr / cm^2
-
const double footcandle = 1.076e-3¶
cd sr / cm^2
-
const double lambert = 1e0¶
cd sr / cm^2
-
const double footlambert = 1.07639104e-3¶
cd sr / cm^2
-
const double curie = 3.7e10¶
1 / s
-
const double rad = 1e2¶
cm^2 / s^2
-
const double newton = 1e5¶
cm g / s^2
-
const double dyne = 1e0¶
cm g / s^2
-
const double joule = 1e7¶
g cm^2 / s^2
-
const double erg = 1e0¶
g cm^2 / s^2
Electromagnetic constants
-
const double roentgen = 2.58e-7¶
A s / g.
-
const double speed_of_light = 2.99792458e10¶
Namespace o2scl_cgsm¶
-
namespace o2scl_cgsm¶
Constants in CGSM units.
Where possible, constants here are defined in terms of the values in o2scl_cgs, in order to make it easier to update these values. See also the documentation at o2scl_cgs .
Fundamental constants
-
const double speed_of_light = o2scl_cgs::speed_of_light¶
Speed of light in cm / s.
-
const double gravitational_constant = o2scl_cgs::gravitational_constant¶
Newtonian constant of gravitation in cm^3 / g s^2.
-
const double plancks_constant_h = o2scl_cgs::plancks_constant_h¶
Planck constant in g cm^2 / s.
-
const double plancks_constant_hbar = o2scl_cgs::plancks_constant_hbar¶
Planck constant divided by 2 pi in g cm^2 / s.
-
const double electron_volt = o2scl_cgs::electron_volt¶
Electron volt in g cm^2 / s^2.
-
const double bohr_radius = o2scl_cgs::bohr_radius¶
Bohr radius in cm.
-
const double stefan_boltzmann_constant = o2scl_cgs::stefan_boltzmann_constant¶
Stefan-Boltzmann constant in g / K^4 s^3.
-
const double thomson_cross_section = o2scl_cgs::thomson_cross_section¶
Thomson cross section in cm^2.
Solar system properties
-
const double solar_mass_parameter = o2scl_cgs::solar_mass_parameter¶
Solar mass times gravitational constant in cm^3 / s^2 (IAU 2015 value)
Note that this value differs slightly in Barycentric Coordinate Time and Barycentric Dynamical Time. This is the IAU’s nominal value.
-
const double solar_mass = o2scl_cgs::solar_mass¶
Mass of the sun in g (derived)
-
const double solar_radius = o2scl_cgs::solar_radius¶
Radius of the sun in cm (IAU 2015 value)
-
const double solar_temperature = o2scl_cgs::solar_temperature¶
Temperature of the sun’s photosphere in K (IAU 2015 value)
-
const double solar_luminosity = o2scl_cgs::solar_luminosity¶
Luminosity of sun in erg/s (IAU 2015 value)
-
const double earth_mass_parameter = o2scl_cgs::earth_mass_parameter¶
Earth mass times gravitational constant in cm^3 / s^2 (IAU 2015 value)
-
const double earth_mass = o2scl_cgs::earth_mass¶
Mass of the earth in g (derived)
-
const double earth_radius_equatorial = o2scl_cgs::earth_radius_equatorial¶
Equatorial radius of earth in cm (IAU 2015 value)
-
const double earth_radius_polar = o2scl_cgs::earth_radius_polar¶
Polar radius of earth in cm (IAU 2015 value)
-
const double jupiter_mass_parameter = o2scl_cgs::jupiter_mass_parameter¶
Jupter mass times gravitational constant in cm^3 / s^2 (IAU 2015 value)
-
const double jupiter_mass = o2scl_cgs::jupiter_mass¶
Mass of jupiter in g (derived)
-
const double jupiter_radius_equatorial = o2scl_cgs::jupiter_radius_equatorial¶
Equatorial radius of jupiter in cm (IAU 2015 value)
-
const double jupiter_radius_polar = o2scl_cgs::jupiter_radius_polar¶
Polar radius of jupiter in cm (IAU 2015 value)
-
const double mercury_mass = o2scl_cgs::mercury_mass¶
Mass of mercury in g.
-
const double mercury_radius = o2scl_cgs::mercury_radius¶
Radius of mercury in cm.
-
const double venus_mass = o2scl_cgs::venus_mass¶
Mass of venus in g.
-
const double venus_radius = o2scl_cgs::venus_radius¶
Radius of venus in cm.
-
const double mars_radius_equatorial = o2scl_cgs::mars_radius_equatorial¶
Equatorial radius of mars in cm.
-
const double mars_radius_polar = o2scl_cgs::mars_radius_polar¶
Polar radius of mars in cm.
-
const double saturn_mass = o2scl_cgs::saturn_mass¶
Mass of saturn in g.
-
const double saturn_radius_equatorial = o2scl_cgs::saturn_radius_equatorial¶
Equatorial radius of saturn in cm.
-
const double saturn_radius_polar = o2scl_cgs::saturn_radius_polar¶
Polar radius of saturn in cm.
-
const double uranus_mass = o2scl_cgs::uranus_mass¶
Mass of uranus in g.
-
const double uranus_radius_equatorial = o2scl_cgs::uranus_radius_equatorial¶
Equatorial radius of uranus in cm.
-
const double uranus_radius_polar = o2scl_cgs::uranus_radius_polar¶
Polar radius of uranus in cm.
-
const double neptune_mass = o2scl_cgs::neptune_mass¶
Mass of neptune in g.
-
const double neptune_radius_equatorial = o2scl_cgs::neptune_radius_equatorial¶
Equatorial radius of neptune in cm.
-
const double neptune_radius_polar = o2scl_cgs::neptune_radius_polar¶
Polar radius of neptune in cm.
-
const double pluto_mass = o2scl_cgs::pluto_mass¶
Mass of pluto in g.
-
const double pluto_radius = o2scl_cgs::pluto_radius¶
Radius of pluto in cm.
Astrophysical constants
-
const double astronomical_unit = o2scl_cgs::astronomical_unit¶
Astronomical unit in cm (IAU 2009 value; now exact)
-
const double grav_accel = o2scl_cgs::grav_accel¶
Acccleration due to gravity in cm / s^2 (CODATA 2018; now exact)
-
const double schwarzchild_radius = o2scl_cgs::schwarzchild_radius¶
Schwarzchild radius in cm (derived)
-
const double sidereal_year = o2scl_cgs::sidereal_year¶
Sidereal year in s (from https://pdg.lbl.gov/2021/reviews/contents_sports.html)
-
const double tropical_year = o2scl_cgs::tropical_year¶
Tropical year in s (from https://pdg.lbl.gov/2021/reviews/contents_sports.html)
-
const double julian_year = o2scl_cgs::julian_year¶
Julian year in s (exact)
-
const double light_year = o2scl_cgs::light_year¶
Light year in \( \mathrm{cm} \) (derived; exact)
Particle masses
-
const double mass_electron = o2scl_cgs::mass_electron¶
Electron mass in g.
-
const double mass_proton = o2scl_cgs::mass_proton¶
Proton mass in g.
-
const double mass_neutron = o2scl_cgs::mass_neutron¶
Neutron mass in g.
Nuclear masses
-
const double mass_deuteron = o2scl_cgs::mass_deuteron¶
Deuteron mass in g.
-
const double mass_triton = o2scl_cgs::mass_triton¶
Triton mass in g.
-
const double mass_helion = o2scl_cgs::mass_helion¶
Helion mass in g.
-
const double mass_alpha = o2scl_cgs::mass_alpha¶
Alpha particle mass in g.
-
const double unified_atomic_mass = o2scl_cgs::unified_atomic_mass¶
Atomic mass constant in g.
Chemical constants
-
const double standard_gas_volume = o2scl_cgs::standard_gas_volume¶
Molar volume of ideal gas at standard T and P in cm^3 / mol.
Unit conversions
-
const double nautical_mile = o2scl_cgs::nautical_mile¶
cm
-
const double fluid_ounce = o2scl_cgs::fluid_ounce¶
cm^3
-
const double tablespoon = o2scl_cgs::tablespoon¶
cm^3
-
const double canadian_gallon = o2scl_cgs::canadian_gallon¶
cm^3
-
const double miles_per_hour = o2scl_cgs::miles_per_hour¶
cm / s
-
const double kilometers_per_hour = o2scl_cgs::kilometers_per_hour¶
cm / s
-
const double pound_mass = o2scl_cgs::pound_mass¶
g
-
const double ounce_mass = o2scl_cgs::ounce_mass¶
g
-
const double metric_ton = o2scl_cgs::metric_ton¶
g
-
const double troy_ounce = o2scl_cgs::troy_ounce¶
g
-
const double gram_force = o2scl_cgs::gram_force¶
cm g / s^2
-
const double pound_force = o2scl_cgs::pound_force¶
cm g / s^2
-
const double kilopound_force = o2scl_cgs::kilopound_force¶
cm g / s^2
-
const double horsepower = o2scl_cgs::horsepower¶
g cm^2 / s^3
-
const double std_atmosphere = o2scl_cgs::std_atmosphere¶
g / cm s^2
-
const double meter_of_mercury = o2scl_cgs::meter_of_mercury¶
g / cm s^2
-
const double inch_of_mercury = o2scl_cgs::inch_of_mercury¶
g / cm s^2
-
const double inch_of_water = o2scl_cgs::inch_of_water¶
g / cm s^2
-
const double footcandle = o2scl_cgs::footcandle¶
cd sr / cm^2
-
const double footlambert = o2scl_cgs::footlambert¶
cd sr / cm^2
Electromagnetic constants
-
const double electron_magnetic_moment = 9.2847647043e-21¶
Electron magnetic moment in abamp cm^2 (CODATA 2018 value)
-
const double proton_magnetic_moment = 1.41060679736e-23¶
Proton magnetic moment in abamp cm^2 (CODATA 2018 value)
-
const double bohr_magneton = 9.2740100783e-21¶
Bohr magneton in abamp cm^2 (CODATA 2018 value)
-
const double nuclear_magneton = 5.0507837461e-24¶
Nuclear magneton in abamp cm^2 (CODATA 2018 value)
-
const double faraday = o2scl_const::avogadro * o2scl_cgs::electron_volt / 1.0e8¶
Faraday constant in abamp s / mol (CODATA 2018 value; derived; exact)
-
const double electron_charge = electron_volt * 1.0e-8¶
Electron charge in abamp s (derived)
-
const double speed_of_light = o2scl_cgs::speed_of_light¶