unyt.physical_constants module¶
Predefined useful physical constants
Note that all of these names can be imported from the top-level unyt namespace. For example:
>>> from unyt.physical_constants import gravitational_constant, solar_mass
>>> from unyt import AU
>>> from math import pi
>>>
>>> period = 2 * pi * ((1 * AU)**3 / (gravitational_constant * solar_mass))**0.5
>>> period.in_units('day')
unyt_quantity(365.26236846, 'day')
Constant Name |
Value |
Alternate Names |
---|---|---|
me |
9.1094e-31 kg |
mass_electron, electron_mass |
Na |
1.000000020023999 dimensionless |
Avogadros_number, avogadros_number |
mp |
1.6726e-27 kg |
proton_mass, mass_proton |
mh |
1.6737e-27 kg |
hydrogen_mass, mass_hydrogen |
c |
2.9979e+08 m/s |
clight, speed_of_light |
σ_T |
6.6525e-29 m**2 |
sigma_thompson, thompson_cross_section, cross_section_thompson, sigma_thomson, thomson_cross_section, cross_section_thomson |
qp |
1.6022e-19 C |
proton_charge, elementary_charge, charge_proton |
qe |
-1.6022e-19 C |
electron_charge, charge_electron |
kb |
1.3806e-23 kg*m**2/(K*s**2) |
kboltz, boltzmann_constant |
G |
6.6741e-11 m**3/(kg*s**2) |
newtons_constant, gravitational_constant |
h |
6.6261e-34 kg*m**2/s |
planck_constant |
hbar |
1.0546e-34 kg*m**2/s |
reduced_planck_constant |
σ |
5.6704e-08 kg/(K**4*s**3) |
stefan_boltzmann_constant |
Tcmb |
2.726 K |
CMB_temperature |
Msun |
1.9884e+30 kg |
msun, m_sun, m_Sun, M_sun, M_Sun, solar_mass, mass_sun |
Mjup |
1.8985e+27 kg |
mjup, jupiter_mass, mass_jupiter |
mercury_mass |
3.3010e+23 kg |
mass_mercury |
venus_mass |
4.8673e+24 kg |
mass_venus |
Mearth |
6.0456e+24 kg |
mearth, earth_mass, mass_earth |
mars_mass |
6.4169e+23 kg |
mass_mars |
saturn_mass |
5.6846e+26 kg |
mass_saturn |
uranus_mass |
8.6819e+25 kg |
mass_uranus |
neptune_mass |
1.0243e+26 kg |
mass_neptune |
m_pl |
2.1765e-08 kg |
planck_mass |
l_pl |
1.6162e-35 m |
planck_length |
t_pl |
5.3912e-44 s |
planck_time |
E_pl |
1.9561e+09 J |
planck_energy |
q_pl |
1.8755e-18 C |
planck_charge |
T_pl |
1.4168e+32 K |
planck_temperature |
mu_0 |
1.2566e-06 kg*m/(A**2*s**2) |
vacuum_permeability, magnetic_constant, μ_0 |
eps_0 |
8.8542e-12 A**2*s**4/(kg*m**3) |
vacuum_permittivity, electric_constant, ε_0, epsilon_0 |
R_inf |
1.0974e+07 1/m |
rydberg_constant, R_∞ |
standard_gravity |
9.80665 m/s**2 |