Constants (scipy.constants)#
Physical and mathematical constants and units.
Mathematical constants#
| Pi |
| Golden ratio |
| Golden ratio |
Physical constants#
The following physical constants are available as attributes ofscipy.constants.All units areSI.
Attribute | Quantity | Units |
|---|---|---|
| speed of light in vacuum | m s^-1 |
| speed of light in vacuum | m s^-1 |
| the magnetic constant\(\mu_0\) | N A^-2 |
| the electric constant (vacuum permittivity),\(\epsilon_0\) | F m^-1 |
| the Planck constant\(h\) | J Hz^-1 |
| the Planck constant\(h\) | J Hz^-1 |
| the reduced Planck constant,\(\hbar = h/(2\pi)\) | J s |
| Newtonian constant of gravitation | m^3 kg^-1 s^-2 |
| Newtonian constant of gravitation | m^3 kg^-1 s^-2 |
| standard acceleration of gravity | m s^-2 |
| elementary charge | C |
| elementary charge | C |
| molar gas constant | J mol^-1 K^-1 |
| molar gas constant | J mol^-1 K^-1 |
| fine-structure constant | (unitless) |
| fine-structure constant | (unitless) |
| Avogadro constant | mol^-1 |
| Avogadro constant | mol^-1 |
| Boltzmann constant | J K^-1 |
| Boltzmann constant | J K^-1 |
| Stefan-Boltzmann constant\(\sigma\) | W m^-2 K^-4 |
| Stefan-Boltzmann constant\(\sigma\) | W m^-2 K^-4 |
| Wien wavelength displacement law constant | m K |
| Rydberg constant | m^-1 |
| electron mass | kg |
| electron mass | kg |
| proton mass | kg |
| proton mass | kg |
| neutron mass | kg |
| neutron mass | kg |
Constants database#
In addition to the above variables,scipy.constants also contains the2022 CODATA recommended values[CODATA2022] database containing more physicalconstants.
| Value in physical_constants indexed by key |
| Unit in physical_constants indexed by key |
| Relative precision in physical_constants indexed by key |
| Return list of physical_constant keys containing a given string. |
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).The CODATA database uses ellipses to indicate that a value is defined(exactly) in terms of others but cannot be represented exactly with theallocated number of digits. In these cases, SciPy calculates the derivedvalue and reports it to the full precision of a Pythonfloat. Althoughphysical_constantslists the uncertainty as0.0to indicate thatthe CODATA value is exact, the value inphysical_constantsis stillsubject to the truncation error inherent in double-precision representation.
Available constants:
| 6.644657345e-27 kg |
| 5.9719201997e-10 J |
| 3727.3794118 MeV |
| 4.001506179129 u |
| 0.0040015061833 kg mol^-1 |
| 4.001506179129 |
| 1.6785e-15 m |
| 7294.29954171 |
| 3.972599690252 |
| 1.00001495e-10 m |
| 1.66053906892e-27 kg |
| 1.49241808768e-10 J |
| 931.49410372 MeV |
| 931494103.72 eV |
| 34231776.922 E_h |
| 2.25234272185e+23 Hz |
| 751300662090000.0 m^-1 |
| 1.49241808768e-10 J |
| 10809540206700.0 K |
| 1.66053906892e-27 kg |
| 3.2063612996e-53 C^3 m^3 J^-2 |
| 6.2353799735e-65 C^4 m^4 J^-3 |
| 1.0545718176461565e-34 J s |
| 1.602176634e-19 C |
| 1081202386770.0 C m^-3 |
| 0.0066236182375082 A |
| 8.4783536198e-30 C m |
| 514220675112.0 V m^-1 |
| 9.7173624424e+21 V m^-2 |
| 1.64877727212e-41 C^2 m^2 J^-1 |
| 27.211386245981 V |
| 4.4865515185e-40 C m^2 |
| 4.359744722206e-18 J |
| 8.2387235038e-08 N |
| 5.29177210544e-11 m |
| 1.85480201315e-23 J T^-1 |
| 235051.757077 T |
| 7.8910365794e-29 J T^-2 |
| 9.1093837139e-31 kg |
| 1.99285191545e-24 kg m s^-1 |
| 1.1126500562e-10 F m^-1 |
| 2.4188843265864e-17 s |
| 2187691.26216 m s^-1 |
| 6.02214076e+23 mol^-1 |
| 9.2740100657e-24 J T^-1 |
| 5.7883817982e-05 eV T^-1 |
| 13996244917.1 Hz T^-1 |
| 46.686447719 m^-1 T^-1 |
| 0.67171381472 K T^-1 |
| 5.29177210544e-11 m |
| 1.380649e-23 J K^-1 |
| 8.617333262145179e-05 eV K^-1 |
| 20836619123.327576 Hz K^-1 |
| 69.50348004861274 m^-1 K^-1 |
| 376.730313412 ohm |
| 2.8179403205e-15 m |
| 2.42631023538e-12 m |
| 7.748091729863649e-05 S |
| 1.0000000888714378 A |
| 1.0000000888714378 C |
| 0.9999999822063325 F |
| 1.0000000177936679 H |
| 483597900000000.0 Hz V^-1 |
| 1.0000000177936679 ohm |
| 1.0000001066651072 V |
| 25812.807 ohm |
| 1.0000001955365543 W |
| 1.00207697e-13 m |
| 0.8574382335 |
| 4.330735087e-27 J T^-1 |
| 0.0004669754568 |
| 0.8574382335 |
| 3.3435837768e-27 kg |
| 3.00506323491e-10 J |
| 1875.612945 MeV |
| 2.013553212544 u |
| 0.00201355321466 kg mol^-1 |
| 2.013553212544 |
| 2.12778e-15 m |
| -0.000466434555 |
| 3670.482967655 |
| -0.44820652 |
| 0.3070122093 |
| 1.9990075012699 |
| -175882000838.0 C kg^-1 |
| -2.00231930436092 |
| 176085962784.0 s^-1 T^-1 |
| 28024.9513861 MHz T^-1 |
| -9.2847646917e-24 J T^-1 |
| 0.00115965218046 |
| -1.00115965218046 |
| -1838.281971877 |
| 9.1093837139e-31 kg |
| 8.187105788e-14 J |
| 0.51099895069 MeV |
| 0.0005485799090441 u |
| 5.4857990962e-07 kg mol^-1 |
| 0.0005485799090441 |
| 0.0001370933554733 |
| 864.05823986 |
| -658.2275856 |
| 1.602176634e-19 J |
| 1.07354410083e-09 u |
| 0.036749322175665 E_h |
| 241798924208491.8 Hz |
| 806554.3937349211 m^-1 |
| 1.602176634e-19 J |
| 11604.518121550082 K |
| 1.7826619216278975e-36 kg |
| -2143.9234921 |
| 0.0002724437107629 |
| 0.0001819543074649 |
| 206.7669881 |
| 0.0048363317 |
| 960.92048 |
| 0.00054386734416 |
| -658.21068789 |
| 0.0005446170214889 |
| 0.000287585 |
| 0.0001819200062327 |
| 1.602176634e-19 C |
| 1519267447878626.0 A J^-1 |
| 96485.33212331001 C mol^-1 |
| 1.1663787e-05 GeV^-2 |
| 0.0072973525643 |
| 3.7417718521927573e-16 W m^2 |
| 1.1910429723971884e-16 W m^2 sr^-1 |
| 4.359744722206e-18 J |
| 27.211386245981 eV |
| 2.92126231797e-08 u |
| 27.211386245981 eV |
| 6579683920499900.0 Hz |
| 21947463.136314 m^-1 |
| 4.359744722206e-18 J |
| 315775.02480398 K |
| 4.8508702095419e-35 kg |
| -4.2552506995 |
| -1.07461755198e-26 J T^-1 |
| -0.00115874098083 |
| -2.1276253498 |
| 5.0064127862e-27 kg |
| 4.4995394185e-10 J |
| 2808.39161112 MeV |
| 3.014932246932 u |
| 0.0030149322501 kg mol^-1 |
| 3.014932246932 |
| 5.9967029e-05 |
| 5495.88527984 |
| 2.993152671552 |
| 4.439821659e-24 u |
| 4.135667696923859e-15 eV |
| 1.5198298460574e-16 E_h |
| 3.3356409519815204e-09 m^-1 |
| 6.62607015e-34 J |
| 4.799243073366221e-11 K |
| 7.372497323812708e-51 kg |
| 9192631770.0 Hz |
| 137.035999177 |
| 1.33102504824e-15 u |
| 1.2398419843320026e-06 eV |
| 4.5563352529132e-08 E_h |
| 299792458.0 Hz |
| 1.9864458571489286e-25 J |
| 0.014387768775039337 K |
| 2.2102190943042335e-42 kg |
| 12906.403729652257 ohm |
| 483597848416983.6 Hz V^-1 |
| 6700535247.1 u |
| 6.241509074460763e+18 eV |
| 2.2937122783969e+17 E_h |
| 1.5091901796421518e+33 Hz |
| 5.03411656754271e+24 m^-1 |
| 7.24297051603992e+22 K |
| 1.1126500560536185e-17 kg |
| 9.2510872884e-14 u |
| 8.617333262145179e-05 eV |
| 3.1668115634564e-06 E_h |
| 20836619123.327576 Hz |
| 69.50348004861274 m^-1 |
| 1.380649e-23 J |
| 1.5361791872403723e-40 kg |
| 6.0221407537e+26 u |
| 5.609588603804452e+35 eV |
| 2.0614857887415e+34 E_h |
| 1.3563924896521321e+50 Hz |
| 4.524438335443823e+41 m^-1 |
| 8.987551787368176e+16 J |
| 6.509657260728958e+39 K |
| 5.431020511e-10 m |
| 1.920155716e-10 m |
| 2.6516458048837345e+25 m^-3 |
| 2.686780111798444e+25 m^-3 |
| 683.0 lm W^-1 |
| 2.0678338484619295e-15 Wb |
| 8.31446261815324 J mol^-1 K^-1 |
| 0.00100000000105 kg mol^-1 |
| 0.0120000000126 kg mol^-1 |
| 3.990312712893431e-10 J Hz^-1 mol^-1 |
| 0.02271095464148557 m^3 mol^-1 |
| 0.022413969545014137 m^3 mol^-1 |
| 1.205883199e-05 m^3 mol^-1 |
| 1.00209952e-13 m |
| 1.17344411e-14 m |
| -2.00233184123 |
| -4.4904483e-26 J T^-1 |
| 0.00116592062 |
| -0.00484197048 |
| -8.89059704 |
| 1.883531627e-28 kg |
| 1.692833804e-11 J |
| 105.6583755 MeV |
| 0.1134289257 u |
| 0.0001134289258 kg mol^-1 |
| 206.7682827 |
| 0.1124545168 |
| -3.183345146 |
| 0.1126095262 |
| 0.0594635 |
| 1.0545718176461565e-34 J s |
| 6.582119569509067e-16 eV s |
| 8.187105788e-14 J |
| 0.51099895069 MeV |
| 3.8615926744e-13 m |
| 9.1093837139e-31 kg |
| 2.730924488e-22 kg m s^-1 |
| 0.5109989461 MeV/c |
| 1.28808866644e-21 s |
| 299792458.0 m s^-1 |
| 1.31959090382e-15 m |
| -3.82608552 |
| 183247174.0 s^-1 T^-1 |
| 29.1646935 MHz T^-1 |
| -9.6623653e-27 J T^-1 |
| -0.00104187565 |
| -1.91304276 |
| 1.67492750056e-27 kg |
| 1.50534976514e-10 J |
| 939.56542194 MeV |
| 1.00866491606 u |
| 0.00100866491712 kg mol^-1 |
| 1.00866491606 |
| -0.68499694 |
| 0.00104066884 |
| 1838.683662 |
| 8.89248408 |
| -0.68497935 |
| 2.30557461e-30 kg |
| 2.07214712e-13 J |
| 1.29333251 MeV |
| 0.00138844948 u |
| 1.00137841946 |
| 0.528779 |
| 6.6743e-11 m^3 kg^-1 s^-2 |
| 6.70883e-39 (GeV/c^2)^-2 |
| 5.0507837393e-27 J T^-1 |
| 3.15245125417e-08 eV T^-1 |
| 0.0254262341009 m^-1 T^-1 |
| 0.00036582677706 K T^-1 |
| 7.6225932188 MHz T^-1 |
| 6.62607015e-34 J Hz^-1 |
| 4.135667696923859e-15 eV Hz^-1 |
| 1.616255e-35 m |
| 2.176434e-08 kg |
| 1.22089e+19 GeV |
| 1.416784e+32 K |
| 5.391247e-44 s |
| 95788331.43 C kg^-1 |
| 1.3214098536e-15 m |
| 5.5856946893 |
| 267522187.08 s^-1 T^-1 |
| 42.577478461 MHz T^-1 |
| 1.41060679545e-26 J T^-1 |
| 0.0015210322023 |
| 2.79284734463 |
| 2.56715e-05 |
| 1.67262192595e-27 kg |
| 1.50327761802e-10 J |
| 938.27208943 MeV |
| 1.0072764665789 u |
| 0.00100727646764 kg mol^-1 |
| 1.0072764665789 |
| 8.4075e-16 m |
| 1836.152673426 |
| 8.88024338 |
| -1.45989802 |
| 0.99862347797 |
| 0.528051 |
| 0.00036369475467 m^2 s^-1 |
| 0.00072738950934 m^2 s^-1 |
| 3.8615926744e-13 m |
| 1.867594306e-15 m |
| 2.100194152e-16 m |
| 1.0545718176461565e-34 J s |
| 6.582119569509067e-16 eV s |
| 197.3269804593025 MeV fm |
| 2.10308910051e-16 m |
| 1.110538e-16 m |
| 10973731.568157 m^-1 |
| 3289841960250000.0 Hz |
| 13.60569312299 eV |
| 2.179872361103e-18 J |
| -1.15170753496 |
| -1.16487052149 |
| 0.014387768775039337 m K |
| 203789460.78 s^-1 T^-1 |
| 32.434100033 MHz T^-1 |
| -1.07455311035e-26 J T^-1 |
| -0.00115867149457 |
| -2.1274977624 |
| -0.76176657721 |
| -0.7617861334 |
| 267515319.4 s^-1 T^-1 |
| 42.57638543 MHz T^-1 |
| 1.410570583e-26 J T^-1 |
| 0.0015209931551 |
| 2.792775648 |
| 1.9877e-08 |
| 2.3945e-08 |
| 299792458.0 m s^-1 |
| 9.80665 m s^-2 |
| 101325.0 Pa |
| 100000.0 Pa |
| 5.6703744191844314e-08 W m^-2 K^-4 |
| 6.97771e-16 m |
| 1776.86 MeV |
| 3.16754e-27 kg |
| 2.84684e-10 J |
| 1.90754 u |
| 0.00190754 kg mol^-1 |
| 3477.23 |
| 16.817 |
| 1.89115 |
| 1.89376 |
| 6.6524587051e-29 m^2 |
| 5.95792493 |
| 1.5046095178e-26 J T^-1 |
| 0.0016223936648 |
| 2.978962465 |
| 5.0073567512e-27 kg |
| 4.5003878119e-10 J |
| 2808.92113668 MeV |
| 3.01550071597 u |
| 0.00301550071913 kg mol^-1 |
| 3.01550071597 |
| 1.0666399189 |
| 5496.92153551 |
| 2.99371703403 |
| 1.66053906892e-27 kg |
| 8.8541878188e-12 F m^-1 |
| 1.25663706127e-06 N A^-2 |
| 25812.807459304513 ohm |
| 0.88145 |
| 0.22305 |
| 58789257576.468254 Hz K^-1 |
| 0.0028977719551851727 m K |
Units#
SI prefixes#
| \(10^{30}\) |
| \(10^{27}\) |
| \(10^{24}\) |
| \(10^{21}\) |
| \(10^{18}\) |
| \(10^{15}\) |
| \(10^{12}\) |
| \(10^{9}\) |
| \(10^{6}\) |
| \(10^{3}\) |
| \(10^{2}\) |
| \(10^{1}\) |
| \(10^{-1}\) |
| \(10^{-2}\) |
| \(10^{-3}\) |
| \(10^{-6}\) |
| \(10^{-9}\) |
| \(10^{-12}\) |
| \(10^{-15}\) |
| \(10^{-18}\) |
| \(10^{-21}\) |
| \(10^{-24}\) |
| \(10^{-27}\) |
| \(10^{-30}\) |
Binary prefixes#
| \(2^{10}\) |
| \(2^{20}\) |
| \(2^{30}\) |
| \(2^{40}\) |
| \(2^{50}\) |
| \(2^{60}\) |
| \(2^{70}\) |
| \(2^{80}\) |
Mass#
| \(10^{-3}\) kg |
| \(10^{3}\) kg |
| one grain in kg |
| one pound (avoirdupous) in kg |
| one pound (avoirdupous) in kg |
| one inch version of a slug in kg (added in 1.0.0) |
| one inch version of a slug in kg (added in 1.0.0) |
| one slug in kg (added in 1.0.0) |
| one ounce in kg |
| one ounce in kg |
| one stone in kg |
| one grain in kg |
| one long ton in kg |
| one short ton in kg |
| one Troy ounce in kg |
| one Troy pound in kg |
| one carat in kg |
| atomic mass constant (in kg) |
| atomic mass constant (in kg) |
| atomic mass constant (in kg) |
Angle#
| degree in radians |
| arc minute in radians |
| arc minute in radians |
| arc second in radians |
| arc second in radians |
Time#
| one minute in seconds |
| one hour in seconds |
| one day in seconds |
| one week in seconds |
| one year (365 days) in seconds |
| one Julian year (365.25 days) in seconds |
Length#
| one inch in meters |
| one foot in meters |
| one yard in meters |
| one mile in meters |
| one mil in meters |
| one point in meters |
| one point in meters |
| one survey foot in meters |
| one survey mile in meters |
| one nautical mile in meters |
| one Fermi in meters |
| one Angstrom in meters |
| one micron in meters |
| one astronomical unit in meters |
| one astronomical unit in meters |
| one light year in meters |
| one parsec in meters |
Pressure#
| standard atmosphere in pascals |
| standard atmosphere in pascals |
| one bar in pascals |
| one torr (mmHg) in pascals |
| one torr (mmHg) in pascals |
| one psi in pascals |
Area#
| one hectare in square meters |
| one acre in square meters |
Volume#
| one liter in cubic meters |
| one liter in cubic meters |
| one gallon (US) in cubic meters |
| one gallon (US) in cubic meters |
| one gallon (UK) in cubic meters |
| one fluid ounce (US) in cubic meters |
| one fluid ounce (US) in cubic meters |
| one fluid ounce (UK) in cubic meters |
| one barrel in cubic meters |
| one barrel in cubic meters |
Speed#
| kilometers per hour in meters per second |
| miles per hour in meters per second |
| one Mach (approx., at 15 C, 1 atm) in meters per second |
| one Mach (approx., at 15 C, 1 atm) in meters per second |
| one knot in meters per second |
Temperature#
| zero of Celsius scale in Kelvin |
| one Fahrenheit (only differences) in Kelvins |
| Convert from a temperature scale to another one among Celsius, Kelvin, Fahrenheit, and Rankine scales. |
Energy#
| one electron volt in Joules |
| one electron volt in Joules |
| one calorie (thermochemical) in Joules |
| one calorie (thermochemical) in Joules |
| one calorie (International Steam Table calorie, 1956) in Joules |
| one erg in Joules |
| one British thermal unit (International Steam Table) in Joules |
| one British thermal unit (International Steam Table) in Joules |
| one British thermal unit (thermochemical) in Joules |
| one ton of TNT in Joules |
Power#
| one horsepower in watts |
| one horsepower in watts |
Force#
| one dyne in newtons |
| one dyne in newtons |
| one pound force in newtons |
| one pound force in newtons |
| one kilogram force in newtons |
| one kilogram force in newtons |
Optics#
References#
CODATA Recommended Values of the FundamentalPhysical Constants 2022.