constants.h

// Copyright 2020, the Aether Development Team (see doc/dev_team.md for members)
// Full license can be found in License.md
 
#ifndef INCLUDE_CONSTANTS_H_
#define INCLUDE_CONSTANTS_H_
 
#include <vector>
 
// -------------------------------------------------------------------------
// Physical Constants
//   - Naming standards:
//     - Names start with a "c" to indicate they are constants
//     - Names should be all CAPS (except for "c" at start)
//     - Should use common abbreviations for names and not whole names
// -------------------------------------------------------------------------
 
// avogadros_number (per mole)
const precision_t cNA = 6.02214086e23;
 
// boltzmanns_constant (m2 kg /s2 /K)
const precision_t cKB = 1.38064852e-23;
 
// Universal Gas Constant (J/K/mol)
const precision_t cR = cNA * cKB;
 
// Mass of a proton (kg)
const precision_t cMP = 1.6726219e-27;
 
// Atomic Mass Unit (kk)
const precision_t cAMU = cMP;
 
// Mass of an electron (kg)
const precision_t cME = 9.1094e-31;
 
// Plancks Constant (Js)
const precision_t cH = 6.6261e-34;
 
// Elemental Charge (C (J/eV))
const precision_t cE = 1.6022e-19;
 
// Speed of Light (m/s)
const precision_t cC = 2.9979e8;
 
// -------------------------------------------------------------------------
// Stellar constants:
// -------------------------------------------------------------------------
 
// gravitational_constant (m3/kg/s2)
const precision_t cG = 6.67408e-11;
 
// This is for our sun (solar mass in kg):
const precision_t cMSOL = 1.989e30;
 
// -------------------------------------------------------------------------
// Some constants for time
// -------------------------------------------------------------------------
 
const std::vector<int> cDAYS {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int cREFYEAR = 1965;
const double cREFJULIAN = 2438762.0;
const double cJULIAN2000 = 2451545.0;
 
// -------------------------------------------------------------------------
// Some Constants for Angles
// -------------------------------------------------------------------------
 
const precision_t cPI = 3.141592653589793;
const precision_t cTWOPI = 2*cPI;
 
// -------------------------------------------------------------------------
// Conversion Constants:
// - Naming standards:
//   - Names start with a "c" to indicate they are constants
//   - Names have a lower-case "to" in them to indicate conversion
//   - Names are all UPPER CASE otherwise
// -------------------------------------------------------------------------
 
const precision_t cDtoR = cPI/180.0;
const precision_t cRtoD = 180.0/cPI;
 
// -------------------------------------------------------------------------
// converting time between seconds and other units of time:
// -------------------------------------------------------------------------
 
// Years <-> Seconds:
const double cYtoS = 31536000.0;
const double cStoY = 1.0 / cYtoS;
 
// Days <-> Seconds:
const double cDtoS = 86400.0;
const double cStoD = 1.0 / cDtoS;
 
// Hours <-> Seconds:
const double cHtoS = 3600.0;
const double cStoH = 1.0 / cHtoS;
 
// Minutes <-> Seconds:
const double cMtoS = 60.0;
const double cStoM = 1.0 / cMtoS;
 
// MilliSeconds <-> Seconds:
const double cMStoS = 1.0/1000.0;
const double cStoMS = 1000.0;
 
// -------------------------------------------------------------------------
// converting lengths between meters and other units of measurement:
// -------------------------------------------------------------------------
 
// kilometer <-> meter:
const precision_t cKMtoM = 1000.0;
const precision_t cMtoKM = 1.0 / cKMtoM;
 
// Angstrom <-> Meter
const precision_t cAtoM = 1.0e-10;
 
// AU <-> Meter
const precision_t cAUtoM = 1.495978707e11;
 
const precision_t pcm3topm3 = 1e6;  // /cm3 to /m3
const precision_t pcm2topm2 = 1e4;  // /cm2 to /m2
const precision_t pcmtopm = 100.0;  // /cm to /m
 
// -------------------------------------------------------------------------
// B-Field
// -------------------------------------------------------------------------
 
const float cNTtoT = 1e-9;  // nT to T
 
#endif  // INCLUDE_CONSTANTS_H_