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 |
| amu | 1.6605e-27 kg | atomic_mass_unit |
| 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 |
