Constants (scipy.constants)

Physical and mathematical constants and units.

Mathematical constants

pi	Pi
golden	Golden ratio
golden_ratio	Golden ratio

Physical constants

c	speed of light in vacuum
speed_of_light	speed of light in vacuum
mu_0	the magnetic constant \(\mu_0\)
epsilon_0	the electric constant (vacuum permittivity), \(\epsilon_0\)
h	the Planck constant \(h\)
Planck	the Planck constant \(h\)
hbar	\(\hbar = h/(2\pi)\)
G	Newtonian constant of gravitation
gravitational_constant	Newtonian constant of gravitation
g	standard acceleration of gravity
e	elementary charge
elementary_charge	elementary charge
R	molar gas constant
gas_constant	molar gas constant
alpha	fine-structure constant
fine_structure	fine-structure constant
N_A	Avogadro constant
Avogadro	Avogadro constant
k	Boltzmann constant
Boltzmann	Boltzmann constant
sigma	Stefan-Boltzmann constant \(\sigma\)
Stefan_Boltzmann	Stefan-Boltzmann constant \(\sigma\)
Wien	Wien displacement law constant
Rydberg	Rydberg constant
m_e	electron mass
electron_mass	electron mass
m_p	proton mass
proton_mass	proton mass
m_n	neutron mass
neutron_mass	neutron mass

Constants database

In addition to the above variables, scipy.constants also contains the 2014 CODATA recommended values [CODATA2014] database containing more physical constants.

value(key)	Value in physical_constants indexed by key
unit(key)	Unit in physical_constants indexed by key
precision(key)	Relative precision in physical_constants indexed by key
find([sub, disp])	Return list of physical_constant keys containing a given string.
ConstantWarning	Accessing a constant no longer in current CODATA data set

scipy.constants.physical_constants

Dictionary of physical constants, of the format physical_constants[name] = (value, unit, uncertainty).

Available constants:

alpha particle mass	6.64465723e-27 kg
alpha particle mass energy equivalent	5.971920097e-10 J
alpha particle mass energy equivalent in MeV	3727.379378 MeV
alpha particle mass in u	4.001506179127 u
alpha particle molar mass	0.004001506179127 kg mol^-1
alpha particle-electron mass ratio	7294.29954136
alpha particle-proton mass ratio	3.97259968907
Angstrom star	1.00001495e-10 m
atomic mass constant	1.66053904e-27 kg
atomic mass constant energy equivalent	1.492418062e-10 J
atomic mass constant energy equivalent in MeV	931.4940954 MeV
atomic mass unit-electron volt relationship	931494095.4 eV
atomic mass unit-hartree relationship	34231776.902 E_h
atomic mass unit-hertz relationship	2.2523427206e+23 Hz
atomic mass unit-inverse meter relationship	751300661660000.0 m^-1
atomic mass unit-joule relationship	1.492418062e-10 J
atomic mass unit-kelvin relationship	10809543800000.0 K
atomic mass unit-kilogram relationship	1.66053904e-27 kg
atomic unit of 1st hyperpolarizability	3.206361329e-53 C^3 m^3 J^-2
atomic unit of 2nd hyperpolarizability	6.235380085e-65 C^4 m^4 J^-3
atomic unit of action	1.0545718e-34 J s
atomic unit of charge	1.6021766208e-19 C
atomic unit of charge density	1081202377000.0 C m^-3
atomic unit of current	0.006623618183 A
atomic unit of electric dipole mom.	8.478353552e-30 C m
atomic unit of electric field	514220670700.0 V m^-1
atomic unit of electric field gradient	9.717362356e+21 V m^-2
atomic unit of electric polarizability	1.6487772731e-41 C^2 m^2 J^-1
atomic unit of electric potential	27.21138602 V
atomic unit of electric quadrupole mom.	4.486551484e-40 C m^2
atomic unit of energy	4.35974465e-18 J
atomic unit of force	8.23872336e-08 N
atomic unit of length	5.2917721067e-11 m
atomic unit of mag. dipole mom.	1.854801999e-23 J T^-1
atomic unit of mag. flux density	235051.755 T
atomic unit of magnetizability	7.8910365886e-29 J T^-2
atomic unit of mass	9.10938356e-31 kg
atomic unit of mom.um	1.992851882e-24 kg m s^-1
atomic unit of permittivity	1.1126500560536183e-10 F m^-1
atomic unit of time	2.418884326509e-17 s
atomic unit of velocity	2187691.26277 m s^-1
Avogadro constant	6.022140857e+23 mol^-1
Bohr magneton	9.274009994e-24 J T^-1
Bohr magneton in eV/T	5.7883818012e-05 eV T^-1
Bohr magneton in Hz/T	13996245042.0 Hz T^-1
Bohr magneton in inverse meters per tesla	46.68644814 m^-1 T^-1
Bohr magneton in K/T	0.67171405 K T^-1
Bohr radius	5.2917721067e-11 m
Boltzmann constant	1.38064852e-23 J K^-1
Boltzmann constant in eV/K	8.6173303e-05 eV K^-1
Boltzmann constant in Hz/K	20836612000.0 Hz K^-1
Boltzmann constant in inverse meters per kelvin	69.503457 m^-1 K^-1
characteristic impedance of vacuum	376.73031346177066 ohm
classical electron radius	2.8179403227e-15 m
Compton wavelength	2.4263102367e-12 m
Compton wavelength over 2 pi	3.8615926764e-13 m
conductance quantum	7.748091731e-05 S
conventional value of Josephson constant	483597900000000.0 Hz V^-1
conventional value of von Klitzing constant	25812.807 ohm
Cu x unit	1.00207697e-13 m
deuteron g factor	0.8574382311
deuteron mag. mom.	4.33073504e-27 J T^-1
deuteron mag. mom. to Bohr magneton ratio	0.0004669754554
deuteron mag. mom. to nuclear magneton ratio	0.8574382311
deuteron mass	3.343583719e-27 kg
deuteron mass energy equivalent	3.005063183e-10 J
deuteron mass energy equivalent in MeV	1875.612928 MeV
deuteron mass in u	2.013553212745 u
deuteron molar mass	0.002013553212745 kg mol^-1
deuteron rms charge radius	2.1413e-15 m
deuteron-electron mag. mom. ratio	-0.0004664345535
deuteron-electron mass ratio	3670.48296785
deuteron-neutron mag. mom. ratio	-0.44820652
deuteron-proton mag. mom. ratio	0.3070122077
deuteron-proton mass ratio	1.99900750087
electric constant	8.854187817620389e-12 F m^-1
electron charge to mass quotient	-175882002400.0 C kg^-1
electron g factor	-2.00231930436182
electron gyromag. ratio	176085964400.0 s^-1 T^-1
electron gyromag. ratio over 2 pi	28024.95164 MHz T^-1
electron mag. mom.	-9.28476462e-24 J T^-1
electron mag. mom. anomaly	0.00115965218091
electron mag. mom. to Bohr magneton ratio	-1.00115965218091
electron mag. mom. to nuclear magneton ratio	-1838.28197234
electron mass	9.10938356e-31 kg
electron mass energy equivalent	8.18710565e-14 J
electron mass energy equivalent in MeV	0.5109989461 MeV
electron mass in u	0.00054857990907 u
electron molar mass	5.4857990907e-07 kg mol^-1
electron to alpha particle mass ratio	0.0001370933554798
electron to shielded helion mag. mom. ratio	864.058257
electron to shielded proton mag. mom. ratio	-658.2275971
electron volt	1.6021766208e-19 J
electron volt-atomic mass unit relationship	1.0735441105e-09 u
electron volt-hartree relationship	0.03674932248 E_h
electron volt-hertz relationship	241798926200000.0 Hz
electron volt-inverse meter relationship	806554.4005 m^-1
electron volt-joule relationship	1.6021766208e-19 J
electron volt-kelvin relationship	11604.5221 K
electron volt-kilogram relationship	1.782661907e-36 kg
electron-deuteron mag. mom. ratio	-2143.923499
electron-deuteron mass ratio	0.0002724437107484
electron-helion mass ratio	0.0001819543074854
electron-muon mag. mom. ratio	206.766988
electron-muon mass ratio	0.0048363317
electron-neutron mag. mom. ratio	960.9205
electron-neutron mass ratio	0.00054386734428
electron-proton mag. mom. ratio	-658.2106866
electron-proton mass ratio	0.000544617021352
electron-tau mass ratio	0.000287592
electron-triton mass ratio	0.0001819200062203
elementary charge	1.6021766208e-19 C
elementary charge over h	241798926200000.0 A J^-1
Faraday constant	96485.33289 C mol^-1
Faraday constant for conventional electric current	96485.3251 C_90 mol^-1
Fermi coupling constant	1.1663787e-05 GeV^-2
fine-structure constant	0.0072973525664
first radiation constant	3.74177179e-16 W m^2
first radiation constant for spectral radiance	1.191042953e-16 W m^2 sr^-1
Hartree energy	4.35974465e-18 J
Hartree energy in eV	27.21138602 eV
hartree-atomic mass unit relationship	2.9212623197e-08 u
hartree-electron volt relationship	27.21138602 eV
hartree-hertz relationship	6579683920711000.0 Hz
hartree-inverse meter relationship	21947463.13702 m^-1
hartree-joule relationship	4.35974465e-18 J
hartree-kelvin relationship	315775.13 K
hartree-kilogram relationship	4.850870129e-35 kg
helion g factor	-4.255250616
helion mag. mom.	-1.074617522e-26 J T^-1
helion mag. mom. to Bohr magneton ratio	-0.001158740958
helion mag. mom. to nuclear magneton ratio	-2.127625308
helion mass	5.0064127e-27 kg
helion mass energy equivalent	4.499539341e-10 J
helion mass energy equivalent in MeV	2808.391586 MeV
helion mass in u	3.01493224673 u
helion molar mass	0.00301493224673 kg mol^-1
helion-electron mass ratio	5495.88527922
helion-proton mass ratio	2.99315267046
hertz-atomic mass unit relationship	4.4398216616e-24 u
hertz-electron volt relationship	4.135667662e-15 eV
hertz-hartree relationship	1.5198298460088e-16 E_h
hertz-inverse meter relationship	3.3356409519815204e-09 m^-1
hertz-joule relationship	6.62607004e-34 J
hertz-kelvin relationship	4.7992447e-11 K
hertz-kilogram relationship	7.372497201e-51 kg
inverse fine-structure constant	137.035999139
inverse meter-atomic mass unit relationship	1.331025049e-15 u
inverse meter-electron volt relationship	1.2398419739e-06 eV
inverse meter-hartree relationship	4.556335252767e-08 E_h
inverse meter-hertz relationship	299792458.0 Hz
inverse meter-joule relationship	1.986445824e-25 J
inverse meter-kelvin relationship	0.0143877736 K
inverse meter-kilogram relationship	2.210219057e-42 kg
inverse of conductance quantum	12906.4037278 ohm
Josephson constant	483597852500000.0 Hz V^-1
joule-atomic mass unit relationship	6700535363.0 u
joule-electron volt relationship	6.241509126e+18 eV
joule-hartree relationship	2.293712317e+17 E_h
joule-hertz relationship	1.509190205e+33 Hz
joule-inverse meter relationship	5.034116651e+24 m^-1
joule-kelvin relationship	7.2429731e+22 K
joule-kilogram relationship	1.1126500560536185e-17 kg
kelvin-atomic mass unit relationship	9.2510842e-14 u
kelvin-electron volt relationship	8.6173303e-05 eV
kelvin-hartree relationship	3.1668105e-06 E_h
kelvin-hertz relationship	20836612000.0 Hz
kelvin-inverse meter relationship	69.503457 m^-1
kelvin-joule relationship	1.38064852e-23 J
kelvin-kilogram relationship	1.53617865e-40 kg
kilogram-atomic mass unit relationship	6.022140857e+26 u
kilogram-electron volt relationship	5.60958865e+35 eV
kilogram-hartree relationship	2.061485823e+34 E_h
kilogram-hertz relationship	1.356392512e+50 Hz
kilogram-inverse meter relationship	4.524438411e+41 m^-1
kilogram-joule relationship	8.987551787368176e+16 J
kilogram-kelvin relationship	6.5096595e+39 K
lattice parameter of silicon	5.431020504e-10 m
Loschmidt constant (273.15 K, 100 kPa)	2.6516467e+25 m^-3
Loschmidt constant (273.15 K, 101.325 kPa)	2.6867811e+25 m^-3
mag. constant	1.2566370614359173e-06 N A^-2
mag. flux quantum	2.067833831e-15 Wb
Mo x unit	1.00209952e-13 m
molar gas constant	8.3144598 J mol^-1 K^-1
molar mass constant	0.001 kg mol^-1
molar mass of carbon-12	0.012 kg mol^-1
molar Planck constant	3.990312711e-10 J s mol^-1
molar Planck constant times c	0.119626565582 J m mol^-1
molar volume of ideal gas (273.15 K, 100 kPa)	0.022710947 m^3 mol^-1
molar volume of ideal gas (273.15 K, 101.325 kPa)	0.022413962 m^3 mol^-1
molar volume of silicon	1.205883214e-05 m^3 mol^-1
muon Compton wavelength	1.173444111e-14 m
muon Compton wavelength over 2 pi	1.867594308e-15 m
muon g factor	-2.0023318418
muon mag. mom.	-4.49044826e-26 J T^-1
muon mag. mom. anomaly	0.00116592089
muon mag. mom. to Bohr magneton ratio	-0.00484197048
muon mag. mom. to nuclear magneton ratio	-8.89059705
muon mass	1.883531594e-28 kg
muon mass energy equivalent	1.692833774e-11 J
muon mass energy equivalent in MeV	105.6583745 MeV
muon mass in u	0.1134289257 u
muon molar mass	0.0001134289257 kg mol^-1
muon-electron mass ratio	206.7682826
muon-neutron mass ratio	0.1124545167
muon-proton mag. mom. ratio	-3.183345142
muon-proton mass ratio	0.1126095262
muon-tau mass ratio	0.0594649
natural unit of action	1.0545718e-34 J s
natural unit of action in eV s	6.582119514e-16 eV s
natural unit of energy	8.18710565e-14 J
natural unit of energy in MeV	0.5109989461 MeV
natural unit of length	3.8615926764e-13 m
natural unit of mass	9.10938356e-31 kg
natural unit of mom.um	2.730924488e-22 kg m s^-1
natural unit of mom.um in MeV/c	0.5109989461 MeV/c
natural unit of time	1.28808866712e-21 s
natural unit of velocity	299792458.0 m s^-1
neutron Compton wavelength	1.31959090481e-15 m
neutron Compton wavelength over 2 pi	2.1001941536e-16 m
neutron g factor	-3.82608545
neutron gyromag. ratio	183247172.0 s^-1 T^-1
neutron gyromag. ratio over 2 pi	29.1646933 MHz T^-1
neutron mag. mom.	-9.662365e-27 J T^-1
neutron mag. mom. to Bohr magneton ratio	-0.00104187563
neutron mag. mom. to nuclear magneton ratio	-1.91304273
neutron mass	1.674927471e-27 kg
neutron mass energy equivalent	1.505349739e-10 J
neutron mass energy equivalent in MeV	939.5654133 MeV
neutron mass in u	1.00866491588 u
neutron molar mass	0.00100866491588 kg mol^-1
neutron to shielded proton mag. mom. ratio	-0.68499694
neutron-electron mag. mom. ratio	0.00104066882
neutron-electron mass ratio	1838.68366158
neutron-muon mass ratio	8.89248408
neutron-proton mag. mom. ratio	-0.68497934
neutron-proton mass difference	2.30557377e-30
neutron-proton mass difference energy equivalent	2.07214637e-13
neutron-proton mass difference energy equivalent in MeV	1.29333205
neutron-proton mass difference in u	0.001388449
neutron-proton mass ratio	1.00137841898
neutron-tau mass ratio	0.52879
Newtonian constant of gravitation	6.67408e-11 m^3 kg^-1 s^-2
Newtonian constant of gravitation over h-bar c	6.70861e-39 (GeV/c^2)^-2
nuclear magneton	5.050783699e-27 J T^-1
nuclear magneton in eV/T	3.152451255e-08 eV T^-1
nuclear magneton in inverse meters per tesla	0.02542623432 m^-1 T^-1
nuclear magneton in K/T	0.0003658269 K T^-1
nuclear magneton in MHz/T	7.622593285 MHz T^-1
Planck constant	6.62607004e-34 J s
Planck constant in eV s	4.135667662e-15 eV s
Planck constant over 2 pi	1.0545718e-34 J s
Planck constant over 2 pi in eV s	6.582119514e-16 eV s
Planck constant over 2 pi times c in MeV fm	197.3269788 MeV fm
Planck length	1.616229e-35 m
Planck mass	2.17647e-08 kg
Planck mass energy equivalent in GeV	1.22091e+19 GeV
Planck temperature	1.416808e+32 K
Planck time	5.39116e-44 s
proton charge to mass quotient	95788332.26 C kg^-1
proton Compton wavelength	1.32140985396e-15 m
proton Compton wavelength over 2 pi	2.10308910109e-16 m
proton g factor	5.585694702
proton gyromag. ratio	267522190.0 s^-1 T^-1
proton gyromag. ratio over 2 pi	42.57747892 MHz T^-1
proton mag. mom.	1.4106067873e-26 J T^-1
proton mag. mom. to Bohr magneton ratio	0.0015210322053
proton mag. mom. to nuclear magneton ratio	2.7928473508
proton mag. shielding correction	2.5691e-05
proton mass	1.672621898e-27 kg
proton mass energy equivalent	1.503277593e-10 J
proton mass energy equivalent in MeV	938.2720813 MeV
proton mass in u	1.007276466879 u
proton molar mass	0.001007276466879 kg mol^-1
proton rms charge radius	8.751e-16 m
proton-electron mass ratio	1836.15267389
proton-muon mass ratio	8.88024338
proton-neutron mag. mom. ratio	-1.45989805
proton-neutron mass ratio	0.99862347844
proton-tau mass ratio	0.528063
quantum of circulation	0.00036369475486 m^2 s^-1
quantum of circulation times 2	0.00072738950972 m^2 s^-1
Rydberg constant	10973731.568508 m^-1
Rydberg constant times c in Hz	3289841960355000.0 Hz
Rydberg constant times hc in eV	13.605693009 eV
Rydberg constant times hc in J	2.179872325e-18 J
Sackur-Tetrode constant (1 K, 100 kPa)	-1.1517084
Sackur-Tetrode constant (1 K, 101.325 kPa)	-1.1648714
second radiation constant	0.0143877736 m K
shielded helion gyromag. ratio	203789458.5 s^-1 T^-1
shielded helion gyromag. ratio over 2 pi	32.43409966 MHz T^-1
shielded helion mag. mom.	-1.07455308e-26 J T^-1
shielded helion mag. mom. to Bohr magneton ratio	-0.001158671471
shielded helion mag. mom. to nuclear magneton ratio	-2.12749772
shielded helion to proton mag. mom. ratio	-0.7617665603
shielded helion to shielded proton mag. mom. ratio	-0.7617861313
shielded proton gyromag. ratio	267515317.1 s^-1 T^-1
shielded proton gyromag. ratio over 2 pi	42.57638507 MHz T^-1
shielded proton mag. mom.	1.410570547e-26 J T^-1
shielded proton mag. mom. to Bohr magneton ratio	0.001520993128
shielded proton mag. mom. to nuclear magneton ratio	2.7927756
speed of light in vacuum	299792458.0 m s^-1
standard acceleration of gravity	9.80665 m s^-2
standard atmosphere	101325.0 Pa
standard-state pressure	100000.0 Pa
Stefan-Boltzmann constant	5.670367e-08 W m^-2 K^-4
tau Compton wavelength	6.97787e-16 m
tau Compton wavelength over 2 pi	1.11056e-16 m
tau mass	3.16747e-27 kg
tau mass energy equivalent	2.84678e-10 J
tau mass energy equivalent in MeV	1776.82 MeV
tau mass in u	1.90749 u
tau molar mass	0.00190749 kg mol^-1
tau-electron mass ratio	3477.15
tau-muon mass ratio	16.8167
tau-neutron mass ratio	1.89111
tau-proton mass ratio	1.89372
Thomson cross section	6.6524587158e-29 m^2
triton g factor	5.95792492
triton mag. mom.	1.504609503e-26 J T^-1
triton mag. mom. to Bohr magneton ratio	0.0016223936616
triton mag. mom. to nuclear magneton ratio	2.97896246
triton mass	5.007356665e-27 kg
triton mass energy equivalent	4.500387735e-10 J
triton mass energy equivalent in MeV	2808.921112 MeV
triton mass in u	3.01550071632 u
triton molar mass	0.00301550071632 kg mol^-1
triton-electron mass ratio	5496.92153588
triton-proton mass ratio	2.99371703348
unified atomic mass unit	1.66053904e-27 kg
von Klitzing constant	25812.8074555 ohm
weak mixing angle	0.2223
Wien frequency displacement law constant	58789238000.0 Hz K^-1
Wien wavelength displacement law constant	0.0028977729 m K
{220} lattice spacing of silicon	1.920155714e-10 m

Units

SI prefixes

yotta	\(10^{24}\)
zetta	\(10^{21}\)
exa	\(10^{18}\)
peta	\(10^{15}\)
tera	\(10^{12}\)
giga	\(10^{9}\)
mega	\(10^{6}\)
kilo	\(10^{3}\)
hecto	\(10^{2}\)
deka	\(10^{1}\)
deci	\(10^{-1}\)
centi	\(10^{-2}\)
milli	\(10^{-3}\)
micro	\(10^{-6}\)
nano	\(10^{-9}\)
pico	\(10^{-12}\)
femto	\(10^{-15}\)
atto	\(10^{-18}\)
zepto	\(10^{-21}\)

Binary prefixes

kibi	\(2^{10}\)
mebi	\(2^{20}\)
gibi	\(2^{30}\)
tebi	\(2^{40}\)
pebi	\(2^{50}\)
exbi	\(2^{60}\)
zebi	\(2^{70}\)
yobi	\(2^{80}\)

Mass

gram	\(10^{-3}\) kg
metric_ton	\(10^{3}\) kg
grain	one grain in kg
lb	one pound (avoirdupous) in kg
pound	one pound (avoirdupous) in kg
blob	one inch version of a slug in kg (added in 1.0.0)
slinch	one inch version of a slug in kg (added in 1.0.0)
slug	one slug in kg (added in 1.0.0)
oz	one ounce in kg
ounce	one ounce in kg
stone	one stone in kg
grain	one grain in kg
long_ton	one long ton in kg
short_ton	one short ton in kg
troy_ounce	one Troy ounce in kg
troy_pound	one Troy pound in kg
carat	one carat in kg
m_u	atomic mass constant (in kg)
u	atomic mass constant (in kg)
atomic_mass	atomic mass constant (in kg)

Angle

degree	degree in radians
arcmin	arc minute in radians
arcminute	arc minute in radians
arcsec	arc second in radians
arcsecond	arc second in radians

Time

minute	one minute in seconds
hour	one hour in seconds
day	one day in seconds
week	one week in seconds
year	one year (365 days) in seconds
Julian_year	one Julian year (365.25 days) in seconds

Length

inch	one inch in meters
foot	one foot in meters
yard	one yard in meters
mile	one mile in meters
mil	one mil in meters
pt	one point in meters
point	one point in meters
survey_foot	one survey foot in meters
survey_mile	one survey mile in meters
nautical_mile	one nautical mile in meters
fermi	one Fermi in meters
angstrom	one Angstrom in meters
micron	one micron in meters
au	one astronomical unit in meters
astronomical_unit	one astronomical unit in meters
light_year	one light year in meters
parsec	one parsec in meters

Pressure

atm	standard atmosphere in pascals
atmosphere	standard atmosphere in pascals
bar	one bar in pascals
torr	one torr (mmHg) in pascals
mmHg	one torr (mmHg) in pascals
psi	one psi in pascals

Area

hectare	one hectare in square meters
acre	one acre in square meters

Volume

liter	one liter in cubic meters
litre	one liter in cubic meters
gallon	one gallon (US) in cubic meters
gallon_US	one gallon (US) in cubic meters
gallon_imp	one gallon (UK) in cubic meters
fluid_ounce	one fluid ounce (US) in cubic meters
fluid_ounce_US	one fluid ounce (US) in cubic meters
fluid_ounce_imp	one fluid ounce (UK) in cubic meters
bbl	one barrel in cubic meters
barrel	one barrel in cubic meters

Speed

kmh	kilometers per hour in meters per second
mph	miles per hour in meters per second
mach	one Mach (approx., at 15 C, 1 atm) in meters per second
speed_of_sound	one Mach (approx., at 15 C, 1 atm) in meters per second
knot	one knot in meters per second

Temperature

zero_Celsius	zero of Celsius scale in Kelvin
degree_Fahrenheit	one Fahrenheit (only differences) in Kelvins

convert_temperature(val, old_scale, new_scale)

Convert from a temperature scale to another one among Celsius, Kelvin, Fahrenheit and Rankine scales.

Energy

eV	one electron volt in Joules
electron_volt	one electron volt in Joules
calorie	one calorie (thermochemical) in Joules
calorie_th	one calorie (thermochemical) in Joules
calorie_IT	one calorie (International Steam Table calorie, 1956) in Joules
erg	one erg in Joules
Btu	one British thermal unit (International Steam Table) in Joules
Btu_IT	one British thermal unit (International Steam Table) in Joules
Btu_th	one British thermal unit (thermochemical) in Joules
ton_TNT	one ton of TNT in Joules

Power

hp	one horsepower in watts
horsepower	one horsepower in watts

Force

dyn	one dyne in newtons
dyne	one dyne in newtons
lbf	one pound force in newtons
pound_force	one pound force in newtons
kgf	one kilogram force in newtons
kilogram_force	one kilogram force in newtons

Optics

lambda2nu(lambda_)	Convert wavelength to optical frequency
nu2lambda(nu)	Convert optical frequency to wavelength.

References

[CODATA2014]

CODATA Recommended Values of the Fundamental Physical Constants 2014. http://physics.nist.gov/cuu/Constants/index.html