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.Dimensionless;
6 import org.djunits.value.vdouble.scalar.ElectricalCharge;
7 import org.djunits.value.vdouble.scalar.Frequency;
8 import org.djunits.value.vdouble.scalar.Mass;
9 import org.djunits.value.vdouble.scalar.SIScalar;
10 import org.djunits.value.vdouble.scalar.Speed;
11
12 /**
13 * Various physical constants. For many, see
14 * <a href="https://en.wikipedia.org/wiki/2019_redefinition_of_the_SI_base_units">Wikipedia 2019 redefinition of the SI base
15 * units</a>
16 * @author <a href="https://www.tudelft.nl/staff/p.knoppers">Peter Knoppers</a>
17 */
18 public final class FloatConstants
19 {
20 /** Utility class. */
21 private FloatConstants()
22 {
23 // utility class
24 }
25
26 /**
27 * Number of constituent particles in a Mole; a.k.a. Avogadro's number. This value is exact since the 2019 redefinition of
28 * the SI base units.
29 */
30 public static final SIScalar AVOGADRO = SIScalar.of(6.02214076e23, "1/mol");
31
32 /**
33 * Boltzmann constant in Joule per Kelvin (this value is exact since the 2019 redefinition of SI base units). See
34 * <a href="https://en.wikipedia.org/wiki/Boltzmann_constant">Wikipedia: Boltzmann constant</a>
35 */
36 public static final SIScalar BOLTZMANN = SIScalar.of(1.380649e-23, "kgm2/s2K");
37
38 /**
39 * The Cesium 133 ground state hyperfine structure transition frequency. This value is exact since the 2006 redefinition of
40 * the SI base units.
41 */
42 public static final Frequency CESIUM133_FREQUENCY = Frequency.of(9192631770d, "1/s");
43
44 /** Electrical charge of one electron. This value is exact since the 2019 redefinition of the SI base units. */
45 public static final ElectricalChargecalCharge.html#ElectricalCharge">ElectricalCharge ELECTRONCHARGE = new ElectricalCharge(-1, ElectricalChargeUnit.ATOMIC_UNIT);
46
47 /**
48 * Mass of an electron. See <a href="https://en.wikipedia.org/wiki/Physical_constant">Wikipedia Physical constant</a>. This
49 * value of this physical constant has an uncertainty of 2.8e-40 kg.
50 */
51 public static final Mass ELECTRONMASS = Mass.of(9.1093837015e-31, "kg");
52
53 /** ElectricalCharge of one proton. */
54 public static final ElectricalChargericalCharge.html#ElectricalCharge">ElectricalCharge PROTONCHARGE = new ElectricalCharge(1, ElectricalChargeUnit.ATOMIC_UNIT);
55
56 /**
57 * Mass of a neutron. See <a href="https://en.wikipedia.org/wiki/List_of_physical_constants">Wikipedia List of physical
58 * constants</a>. This value of this physical constant has an uncertainty of 9.5e-37 kg.
59 */
60 public static final Mass NEUTRONMASS = Mass.of(1.6749274714e-27, "kg");
61
62 /**
63 * Mass of a proton. See <a href="https://en.wikipedia.org/wiki/Physical_constant">Wikipedia Physical constant</a>. This
64 * value of this physical constant has an uncertainty of 5.1e-37.
65 */
66 public static final Mass PROTONMASS = Mass.of(1.67262192369e-27, "kg");
67
68 /**
69 * Gravitational constant, a.k.a. Newtonian constant of gravitation. This is the 2018 best known approximation, which has an
70 * uncertainty 1.5e-15 m^3/kgs^2
71 */
72 public static final SIScalar G = SIScalar.of(6.67430e-11, "m3/kgs2");
73
74 /** Speed of light in vacuum. This value is exact (since the 2006 redefinition of the SI base units). */
75 public static final Speed LIGHTSPEED = Speed.of(299792458, "m/s");
76
77 /**
78 * Permeability of vacuum. See <a href="https://en.wikipedia.org/wiki/Vacuum_permeability">Wikipedia, Vacuum
79 * permeability</a>. The uncertainty of this value is 1.9e-16N/A^2.
80 */
81 public static final SIScalar VACUUMPERMEABILITY = SIScalar.of(1.25663706212e-6, "kgm/s2A2");
82
83 /**
84 * Permittivity of vacuum. See <a href="https://en.wikipedia.org/wiki/Vacuum_permittivity">Wikipedia Vacuum
85 * permittivity</a>. The uncertainty of this value is 1.3e-21 F/m.
86 */
87 public static final SIScalar VACUUMPERMITTIVITY = SIScalar.of(8.8541878128e-12, "s4A2/kgm3");
88
89 /** Impedance of vacuum. */
90 public static final SIScalar VACUUMIMPEDANCE = VACUUMPERMEABILITY.times(LIGHTSPEED);
91
92 /**
93 * Planck constant; ratio of a photon's energy and its frequency. This value is exact since the 2019 redefinition of the SI
94 * base units.
95 */
96 public static final SIScalar PLANCK = SIScalar.of(6.62607015e-34, "kgm2/s");
97
98 /**
99 * The luminous efficacy Kcd of monochromatic radiation of frequency 540×10^12 Hz (540 THz). This is the frequency of a
100 * green-colored light at approximately the peak sensitivity of the human eye. This value is exact since the 2006
101 * redefinition of the SI base units.
102 */
103 public static final SIScalar LUMINOUS_EFFICACY_540THZ = SIScalar.of(683d, "cdsrs3/kg");
104
105 /** Ratio of circumference of circle and its radius. */
106 public static final Dimensionlessscalar/Dimensionless.html#Dimensionless">Dimensionless TAU = new Dimensionless(Math.PI * 2, DimensionlessUnit.SI);
107
108 /** Reduced Planck constant, a.k.a. angular Planck constant; Planck constant divided by 2 pi. */
109 public static final SIScalar PLANKREDUCED = PLANCK.divide(TAU);
110
111 }