1 package org.djunits.value.vfloat.scalar.base;
2
3 import org.djunits.unit.DimensionlessUnit;
4 import org.djunits.unit.ElectricalChargeUnit;
5 import org.djunits.value.vdouble.scalar.ElectricalCharge;
6 import org.djunits.value.vfloat.scalar.FloatDimensionless;
7 import org.djunits.value.vfloat.scalar.FloatElectricalCharge;
8 import org.djunits.value.vfloat.scalar.FloatFrequency;
9 import org.djunits.value.vfloat.scalar.FloatMass;
10 import org.djunits.value.vfloat.scalar.FloatSIScalar;
11 import org.djunits.value.vfloat.scalar.FloatSpeed;
12
13 /**
14 * Various physical constants. For many, see
15 * <a href="https://en.wikipedia.org/wiki/2019_redefinition_of_the_SI_base_units">Wikipedia 2019 redefinition of the SI base
16 * units</a>
17 * @author <a href="https://www.tudelft.nl/staff/p.knoppers">Peter Knoppers</a>
18 */
19 public final class FloatConstants
20 {
21 /** Utility class. */
22 private FloatConstants()
23 {
24 // utility class
25 }
26
27 /**
28 * Number of constituent particles in a Mole; a.k.a. Avogadro's number. This value is exact since the 2019 redefinition of
29 * the SI base units.
30 */
31 public static final FloatSIScalar AVOGADRO = FloatSIScalar.of(6.02214076e23f, "1/mol");
32
33 /**
34 * Boltzmann constant in Joule per Kelvin (this value is exact since the 2019 redefinition of SI base units). See
35 * <a href="https://en.wikipedia.org/wiki/Boltzmann_constant">Wikipedia: Boltzmann constant</a>
36 */
37 public static final FloatSIScalar BOLTZMANN = FloatSIScalar.of(1.380649e-23f, "kgm2/s2K");
38
39 /**
40 * The Cesium 133 ground state hyperfine structure transition frequency. This value is exact since the 2006 redefinition of
41 * the SI base units.
42 */
43 public static final FloatFrequency CESIUM133_FREQUENCY = FloatFrequency.of(9192631770f, "1/s");
44
45 /** Electrical charge of one electron. This value is exact since the 2019 redefinition of the SI base units. */
46 public static final FloatElectricalCharge ELECTRONCHARGE = new FloatElectricalCharge(-1.0f, ElectricalChargeUnit.ATOMIC_UNIT);
47
48 /**
49 * Mass of an electron. See <a href="https://en.wikipedia.org/wiki/Physical_constant">Wikipedia Physical constant</a>. This
50 * value of this physical constant has an uncertainty of 2.8e-40 kg.
51 */
52 public static final FloatMass ELECTRONMASS = FloatMass.of(9.1093837015e-31f, "kg");
53
54 /** ElectricalCharge of one proton. */
55 public static final ElectricalCharge PROTONCHARGE = new ElectricalCharge(1, ElectricalChargeUnit.ATOMIC_UNIT);
56
57 /**
58 * Mass of a neutron. See <a href="https://en.wikipedia.org/wiki/List_of_physical_constants">Wikipedia List of physical
59 * constants</a>. This value of this physical constant has an uncertainty of 9.5e-37 kg.
60 */
61 public static final FloatMass NEUTRONMASS = FloatMass.of(1.6749274714e-27f, "kg");
62
63 /**
64 * Mass of a proton. See <a href="https://en.wikipedia.org/wiki/Physical_constant">Wikipedia Physical constant</a>. This
65 * value of this physical constant has an uncertainty of 5.1e-37.
66 */
67 public static final FloatMass PROTONMASS = FloatMass.of(1.67262192369e-27f, "kg");
68
69 /**
70 * Gravitational constant, a.k.a. Newtonian constant of gravitation. This is the 2018 best known approximation, which has an
71 * uncertainty 1.5e-15 m^3/kgs^2
72 */
73 public static final FloatSIScalar G = FloatSIScalar.of(6.67430e-11f, "m3/kgs2");
74
75 /** Speed of light in vacuum. This value is exact (since the 2006 redefinition of the SI base units). */
76 public static final FloatSpeed LIGHTSPEED = FloatSpeed.of(299792458f, "m/s");
77
78 /**
79 * Permeability of vacuum. See <a href="https://en.wikipedia.org/wiki/Vacuum_permeability">Wikipedia, Vacuum
80 * permeability</a>. The uncertainty of this value is 1.9e-16N/A^2.
81 */
82 public static final FloatSIScalar VACUUMPERMEABILITY = FloatSIScalar.of(1.25663706212e-6f, "kgm/s2A2");
83
84 /**
85 * Permittivity of vacuum. See <a href="https://en.wikipedia.org/wiki/Vacuum_permittivity">Wikipedia Vacuum
86 * permittivity</a>. The uncertainty of this value is 1.3e-21 F/m.
87 */
88 public static final FloatSIScalar VACUUMPERMITTIVITY = FloatSIScalar.of(8.8541878128e-12f, "s4A2/kgm3");
89
90 /** Impedance of vacuum. */
91 public static final FloatSIScalar VACUUMIMPEDANCE = VACUUMPERMEABILITY.times(LIGHTSPEED);
92
93 /**
94 * Planck constant; ratio of a photon's energy and its frequency. This value is exact since the 2019 redefinition of the SI
95 * base units.
96 */
97 public static final FloatSIScalar PLANCK = FloatSIScalar.of(6.62607015e-34f, "kgm2/s");
98
99 /**
100 * The luminous efficacy Kcd of monochromatic radiation of frequency 540×10^12 Hz (540 THz). This is the frequency of a
101 * green-colored light at approximately the peak sensitivity of the human eye. This value is exact since the 2006
102 * redefinition of the SI base units.
103 */
104 public static final FloatSIScalar LUMINOUS_EFFICACY_540THZ = FloatSIScalar.of(683f, "cdsrs3/kg");
105
106 /** Ratio of a half circumference of a circle and its radius. */
107 public static final FloatDimensionless PI = new FloatDimensionless(Math.PI, DimensionlessUnit.SI);
108
109 /** Ratio of circumference of circle and its radius. */
110 public static final FloatDimensionless TAU = new FloatDimensionless(Math.PI * 2, DimensionlessUnit.SI);
111
112 /** Euler's constant. */
113 public static final FloatDimensionless E = new FloatDimensionless(Math.E, DimensionlessUnit.SI);
114
115 /** Golden ratio. */
116 public static final FloatDimensionless PHI = new FloatDimensionless(0.5 + 0.5 * Math.sqrt(5.0), DimensionlessUnit.SI);
117
118
119 /** Reduced Planck constant, a.k.a. angular Planck constant; Planck constant divided by 2 pi. */
120 public static final FloatSIScalar PLANCKREDUCED = PLANCK.divide(TAU);
121
122 }