Physical Constants
Reference
| symbol | name | value | unit | ||||
|---|---|---|---|---|---|---|---|
| c | speed of light in a vacuum |
299,792,458 | m/s | ||||
| G | gravitational constant |
6.67430 | × 10−11 | N m2/kg2 | |||
| h | Planck constant |
6.62607015 4.135667696 |
× 10−34 × 10−15 |
J s eV s |
|||
| hc | h c |
1.986445857 1239.841984 |
× 10−25 |
J m eV nm |
|||
|
h bar reduced Planck constant Dirac constant |
1.054571817 6.582119569 |
× 10−34 × 10−16 |
J s eV s |
|||
| fCs |
hyperfine transition of 133Cs | 9,192,631,770 | Hz | ||||
| e | elementary charge |
1.602176634 | × 10−19 | C | |||
| ε0 | electric constant permitivitty of free space vacuum permitivitty |
8.8541878128 | × 10−12 | C2/N m2 | |||
| μ0 | magnetic constant permeability of free space vacuum permeability |
1.25663706212 | × 10−6 | T m/A | |||
| NA |
Avogadro constant |
6.02214076 | × 1023 | 1/mol | |||
| k | Boltzmann constant |
1.380649 | × 10−23 | J/K | |||
| R = NAk |
gas constant |
8.314462618 | J/mol K | ||||
|
Stefan-Boltzmann constant |
5.670374419 | × 10−8 | W/m2K4 | |||
| b | Wien displacement constant |
2.897771955 58.78925757 |
mm K GHz/K |
||||
| mu | atomic mass constant |
1.66053906660 931.49410242 1 |
× 10−27 |
kg MeV/c2 u |
|||
| me | electron mass |
9.1093837015 0.51099895000 5.48579909065 |
× 10−31 × 10−4 |
kg MeV/c2 u |
|||
| mp | proton mass |
1.67262192369 938.27208816 1.007276466621 |
× 10−27 |
kg MeV/c2 u |
|||
| mn | neutron mass |
1.67492749804 939.56542052 1.00866491595 |
× 10−27 |
kg MeV/c2 u |
|||
| Kcd |
luminous efficacy |
683 | lm/W |
||||
| H0 | hubble constant* |
69.3 2.25 |
× 10−18 |
km/s/Mpc 1/s |
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