WOLFRAM SYSTEM MODELER

# 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: 0.57721566490153286061 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: 6.67430e-11 Type: Real (m³/(kg⋅s²)) Description: Newtonian constant of gravitation Value: 1.602176634e-19 Type: ElectricCharge (C) Description: Elementary charge Value: q * N_A Type: FaradayConstant (C/mol) Description: Faraday constant, C/mol Value: 6.62607015e-34 Type: Real (J⋅s) Description: Planck constant Value: 1.380649e-23 Type: Real (J/K) Description: Boltzmann constant Value: k * N_A Type: Real (J/(mol⋅K)) Description: Molar gas constant Value: 2 * pi ^ 5 * k ^ 4 / (15 * h ^ 3 * c ^ 2) Type: Real (W/(m²⋅K⁴)) Description: Stefan-Boltzmann constant Value: 6.02214076e23 Type: Real (1/mol) Description: Avogadro constant Value: 4 * pi * 1.00000000055e-7 Type: Real (N/A²) Description: Magnetic constant Value: 1 / (mu_0 * c * c) Type: Real (F/m) Description: Electric constant 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 (based on the second source):

Michael Stock, Richard Davis, Estefanía de Mirandés and Martin J T Milton:
The revision of the SI-the result of three decades of progress in metrology in Metrologia, Volume 56, Number 2. https://iopscience.iop.org/article/10.1088/1681-7575/ab0013/pdf, 2019.
D B Newell, F Cabiati, J Fischer, K Fujii, S G Karshenboim, H S Margolis , E de Mirandés, P J Mohr, F Nez, K Pachucki, T J Quinn, B N Taylor, M Wang, B M Wood and Z Zhang:
The CODATA 2017 values of h, e, k, and NA for the revision of the SI in Metrologia, Volume 55, Number 1. https://iopscience.iop.org/article/10.1088/1681-7575/aa950a/pdf, 2017.

BIPM is Bureau International des Poids et Mesures (they publish the SI-standard).

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

# Wolfram Language

In[1]:=
SystemModel["Modelica.Constants"]
Out[1]:=

# Revisions

• Dec 4, 2019 by Thomas Beutlich:
Constant G updated according to 2018 CODATA value.
• Mar 25, 2019 by Hans Olsson:
Constants updated according to 2017 CODATA values and new SI-standard.
• Nov 4, 2015 by Thomas Beutlich:
Constants updated according to 2014 CODATA values.
• Nov 8, 2004 by Christian Schweiger:
Constants updated according to 2002 CODATA values.
• Dec 9, 1999 by Martin Otter:
Constants updated according to 1998 CODATA values. Using names, values and description text from this source. Included magnetic and electric constant.
• Sep 18, 1999 by Martin Otter:
Constants eps, inf, small introduced.
• Nov 15, 1997 by Martin Otter:
Realized.