# Constants

Library of mathematical constants and constants of nature (e.g., pi, eps, R, sigma)

# Package Constants (22)

e Value: Modelica.Math.exp(1.0) Type: Real Value: 2 * Modelica.Math.asin(1.0) Type: Real Value: pi / 180 Type: Real Description: Degree to Radian Value: 180 / pi Type: Real Description: Radian to Degree Value: 0.57721566490153286060 Type: Real Description: see http://en.wikipedia.org/wiki/Euler_constant Value: ModelicaServices.Machine.eps Type: Real Description: Biggest number such that 1.0 + eps = 1.0 Value: ModelicaServices.Machine.small Type: Real Description: Smallest number such that small and -small are representable on the machine Value: ModelicaServices.Machine.inf Type: Real Description: Biggest Real number such that inf and -inf are representable on the machine Value: ModelicaServices.Machine.Integer_inf Type: Integer Description: Biggest Integer number such that Integer_inf and -Integer_inf are representable on the machine Value: 299792458 Type: Velocity (m/s) Description: Speed of light in vacuum Value: 9.80665 Type: Acceleration (m/s²) Description: Standard acceleration of gravity on earth Value: 6.67408e-11 Type: Real (m³/(kg·s²)) Description: Newtonian constant of gravitation (previous value: 6.6742e-11) Value: 9.648533289e4 Type: FaradayConstant (C/mol) Description: Faraday constant, C/mol (previous value: 9.64853399e4) Value: 6.626070040e-34 Type: Real (J·s) Description: Planck constant (previous value: 6.6260693e-34) Value: 1.38064852e-23 Type: Real (J/K) Description: Boltzmann constant (previous value: 1.3806505e-23) Value: 8.3144598 Type: Real (J/(mol·K)) Description: Molar gas constant (previous value: 8.314472) Value: 5.670367e-8 Type: Real (W/(m²·K⁴)) Description: Stefan-Boltzmann constant (previous value: 5.670400e-8) Value: 6.022140857e23 Type: Real (¹/mol) Description: Avogadro constant (previous value: 6.0221415e23) Value: 4 * pi * 1.e-7 Type: Real (N/A²) Description: Magnetic constant Value: 1 / (mue_0 * c * c) Type: Real (F/m) Description: Electric constant Value: Modelica.Constants.F / Modelica.Constants.N_A Type: ElectricCharge (C) Description: Elementary charge (electron charge without sign) = 1.602177e-19 C Value: -273.15 Type: Temperature_degC (°C) Description: Absolute zero temperature

# Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

This package provides often needed constants from mathematics, machine dependent constants and constants from nature. The latter constants (name, value, description) are from the following source:

Peter J. Mohr, David B. Newell, and Barry N. Taylor:
CODATA Recommended Values of the Fundamental Physical Constants: 2014. http://dx.doi.org/10.5281/zenodo.22826, 2015. See also http://physics.nist.gov/cuu/Constants/index.html

CODATA is the Committee on Data for Science and Technology.

Main Author:
Martin Otter
Deutsches Zentrum für Luft und Raumfahrt e. V. (DLR)
Oberpfaffenhofen
Postfach 1116
D-82230 Weßling
email: Martin.Otter@dlr.de

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