| Constant |
Value |
Dimension |
Alias |
Definition & Notes |
| Universal constants used in too many categories to constrain their scope |
| Speed of light c |
2.997 924 580 e+8 |
m.s-1 |
m/s |
Assigned (see SI units) |
| Permeability of vacuum μ0 |
12.566 370 614 359 ... e-7 |
kg.m.s-2.A-2 |
H/m | N/A2 |
= 4π.10-7. Assigned. |
| Permittivity of vacuum ε0 |
8.854 187 817 620 ... e-12 |
kg-1.m-3.s4.A2 |
F/m |
= 1 / (c2 μ0). Assigned. |
| Gravitation constant G |
6.673 84[80] e-11 |
kg-1.m3.s-2 |
|
force = G M1M2 / r122 |
| Planck constant h |
6.626 069 57[29] e-34 |
kg.m2.s-1 |
J.s |
= (energy transfer quantum)/(channel frequency) |
| Angular Planck constant |
1.054 571 726[47] e-34 |
kg.m2.s-1 |
J.s |
= h/2π, the angular momentum quantum |
| Charge/Quantum ratio |
2.417 989 348[53] e+14 |
kg-1.m-2.s2.A |
A/J |
= e / h |
| Elementary charge e |
1.602 176 565[35] e-19 |
s.A |
C |
|
| Quantum/Charge ratio |
4.135 667 52[10] e-15 |
kg.m2.s-2.A-1 |
J/A |
= h / e |
| Fine structure constant α |
7.297 352 5698[24] e-3 |
Dimensionless |
|
= μ0 c e2 / 2h. |
| Inverse of fine structure constant |
137.035 999 074[45] |
Dimensionless |
|
= 1/α = 2h / (μ0 c e2). See ref.[1]. |
| Boltzmann constant k |
1.380 6488[13] e-23 |
kg.m2.s-2.K-1 |
J/K |
Sets thermodynamic temperature |
| Planck mass mp |
2.176 51[13] e-8 |
kg |
|
mp2 = (h/2π) c / G |
| Planck time tp |
5.391 06[32] e-44 |
s |
|
= (h/2π) / (mpc2) |
| Planck length lp |
1.616 199[97] e-35 |
m |
|
= ctp |
| Planck temperature |
1.416 833[85] e+32 |
K |
|
= mpc2 / k |
| Electromagnetic constants other than those already listed |
| Impedance of vacuum Z0 |
376.730 313 461 ... |
kg.m2.s-3.A-2 |
Ω |
Derived from assigned's: Z02 = μ0/ε0. |
| Magnetic flux quantum Φ0 |
2.067 833 758[46] e-15 |
kg.m2.s-2.A-1 |
Wb |
= h / 2e |
| Josephson constant KJ |
4.835 978 70[11] e14 |
kg-1.m-2.s2.A |
Hz/V |
= 2e / h . Conventional: 483597.9 GHz/V |
| von Klitzing constant RK |
2.581 280 744 34[84] e+4 |
kg.m2.s-3.A-2 |
Ω |
= h / e2. Conventional: 25812.807 Ω |
| Conductance quantum G0 |
7.748 091 7346[25] e-5 |
kg-1.m-2.s3.A2 |
S |
= 2e2 / h = 2 / RK |
| Inverse of conductance quantum |
1.290 640 372 17[42] e+4 |
kg.m2.s-3.A-2 |
Ω |
= RK / 2 |
| Electromagnetic radiation constants. For solar constant, see solar system |
| Stefan-Boltzmann const. σ |
5.670 373[21] e-8 |
kg.s-3.K-4 |
W/m2.K4 |
= 2 π5 k4 / 15 h3 c2 |
| 1st radiation constant c1 |
3.741 771 53[17] e-16 |
kg.m4.s-3 |
W.m2 |
= 2 π h c2 |
| 2nd radiation constant c2 |
1.438 7770[13] e-2 |
m.K |
|
= h c / k |
| Wien λ displacement constant λmaxT |
2.897 7721[26] e-3 |
m.K |
|
= c2 / 4.9651423... |
| Wien f displacement constant f/T |
5.878 9254[53] e+10 |
s-1.K-1 |
Hz/K |
|
| Max. luminous efficacy: absolute |
683 |
cd.sr.kg-1.m-1.s3 |
lm/W |
100% efficient, ideal 555 nm light source. |
| Max. luminous efficacy: black-body |
95 |
cd.sr.kg-1.m-1.s3 |
lm/W |
Achieved at 7000 °K |
| Solar luminous efficacy |
93 |
cd.sr.kg-1.m-1.s3 |
lm/W |
see Wikipedia |
| Solar illuminance |
1.280[10] e5 |
cd.sr.m-2 |
lx |
in the brightest sunlight, on Earth |
| Electron and atomic physics constants |
| Rydberg constant R∞ |
1.097 373 156 8539[55] e+7 |
m-1 |
m-1 |
= c α2 me / 2h |
| Hartree energy EH |
4.359 744 34[19] e-18 |
kg.m2.s-2 |
J |
= α2 me c2 = 2h c R∞ |
| Bohr radius |
5.291 772 1092[17] e-11 |
m |
m |
= α / (4π R∞) |
| Bohr magneton μB |
9.274 009 68[20] e-24 |
m2.A |
J/T |
= (1/2)(h/2π)(e/me) |
| Bohr magneton in Hz/T |
1.399624555[31] e+10 |
kg-1.s.A |
Hz/T |
= μB/h = [Larmor frequency]/[g-factor]; ~ 14 GHz/T |
| Quantum of circulation |
3.636 947 5520[24] e-4 |
m2.s-1 |
m2/s |
= h / 2me |
| Richardson constant |
1.20173 e+6 |
A.m-2.K-2 |
|
= 4πemek2 / h3; arises in thermionic emission |
| Electron (stable lepton, charge -1, spin 1/2, fermion, its antiparticle positron has positive charge) |
| Electron rest mass me |
9.109 382 91[40] e-31 |
kg |
|
= 5.485 799 0946[22] e-4 u |
| Electron rest energy (mec2) |
8.187 105 06[36] e-14 |
kg.m2.s-2 |
J |
= 0.510 998 928[11] MeV |
| Electron charge/mass ratio |
- 1.758 820 088[39] e11 |
kg-1.s.A |
C/kg |
= e / me |
| Compton wavelength of electron λC,e |
2.426 310 2389[16] e-12 |
m |
|
= h / c me |
| Classical electron radius re |
2.817 940 3267[27] e-15 |
m |
|
= e2 / (4πε0mec2 ) |
| Thomson cross section σe |
0.665 245 8734[13] e-28 |
m2 |
|
= (8π/3) re2 |
| Electron magnetic moment μe |
- 9.284 764 30[21] e-24 |
m2.A |
J/T |
|
| Electron g-factor ge |
- 2.002 319 304 361 53[53] |
Dimensionless |
|
= (μe / μB) / Se |
| Electron magnetic moment anomaly |
1.159 652 180 76[27] e-3 |
Dimensionless |
|
= (abs(ge) - 2) / 2 |
| Electron gyromagnetic ratio γe/2π |
28.024 952 66[62] e+9 |
kg-1.s.A |
Hz/T |
= μe / (hSe); ~ 28 GHz/T |
| Electron/Proton mass ratio |
5.446 170 2178[22] e-4 |
Dimensionless |
|
|
| Electron/Proton magnetic moments ratio |
- 658.210 6848[54] |
Dimensionless |
|
|
| Electron/Proton magnetic moments ratio |
- 658.227 597 1[72] |
Dimensionless |
|
Shielded in water; standard conditions |
| Physico-chemical constants |
| Atomic mass constant u |
1.660 538 921[73] e-27 |
kg |
|
Mass of 12C nuclide / 12 |
| Molar mass of 12C |
12 e-3 |
kg |
|
Assigned |
| Molar mass constant |
1.0 e-3 |
kg.mol-1 |
kg/mol |
Assigned |
| Boltzmann constant k |
1.380 6488[13] e-23 |
kg.m2.s-2.K-1 |
J/K |
Sets thermodynamic temperature |
| Boltzmann constant in eV/K |
8.617 3324[78] e-5 |
kg.m2.s-3.A-1.K-1 |
V/K |
= k/e. Electrochemical potential ~ (k/e)T ln(c1/c2) |
| Avogadro's number NA |
6.022 141 29[27] e+23 |
mol-1 |
count/mol |
~ 602 Z (Zetta) particles in a mole of substance |
| Molar Planck constant |
3.990 312 7176[28] e-10 |
kg.m2.s-1.mol-1 |
J.s/mol |
= h NA |
| Molar Planck constant by c |
0.119 626 565 779[84] |
kg.m3.s-2.mol-1 |
J.m/mol |
= h c NA |
| Electron molar mass |
5.485 799 0946[22] e-7 |
kg.mol-1 |
kg/mol |
= me NA |
| Electron molar charge |
- 9.648 533 65[21] e+4 |
s.A.mol-1 |
C/mol |
= e NA. |
| Faraday constant F |
+9.648 533 65[21] e+4 |
s.A.mol-1 |
C/mol |
= |electron molar charge|. |
| Molar gas constant R |
8.314 4621[75] |
kg.m2.s-2.K-1.mol-1 |
J/K.mol |
= k NA |
| Molar volume of ideal gas Vm |
22.413 968[20] e-3 |
m3.mol-1 |
m3/mol |
= (RT/p) at T=273.15 K, p=101325 Pa |
| Loschmidt constant n0 |
2.686 7805[24] e+25 |
m-3 |
count/m3 |
= NA / Vm at T=273.15 K, p=101325 Pa |
| Sackur-Tetrode constant S0/R |
- 1.164 8708[23] |
Dimensionless |
|
(5/2)+ln[(2πmukT/h2)(kT/p)] at T=1K, p=101325 Pa. |
| Basic nuclear physics data (those listed in CODATA) |
| Fermi coupling GF/(hc/2π)3 |
3.670 336[31] e+48 |
kg-2 |
|
= (1.026 8365[88] e-5) / mp2 |
| Fermi coupling in eV-2 |
1.166 364[5] e+4 |
eV-2 |
|
|
| Weak mixing angle sin2θW |
0.2223[21] |
Dimensionless |
|
= 1- (mW/mZ)2 |
| Nuclear magneton μN |
5.050 783 53[11] e-27 |
m2.A |
J/T |
= (1/2)(h/2π)(e/mp) |
| Nuclear magneton in Hz/T |
7.622 593 57[17] e+6 |
kg-1.s.A |
Hz/T |
= μN/h = [Larmor frequency]/[g-factor]; ~ 7.6 MHz/T |
| Proton (stable baryon, nucleon, hadron, charge +1, spin 1/2, fermion, parity +, isospin 1/2, its anti-particle antiproton has opposite charge) |
| Proton rest mass mp |
1.672 621 777[74] e-27 |
kg |
|
1.007 276 466 812[90] u |
| Proton rest energy (mc2) |
1.503 277 484[66] e-10 |
kg.m2.s-2 |
J |
938.272 046[21] MeV; quarks composition: uud |
| Proton / electron mass ratio |
1836.15267245[75] |
Dimensionless |
|
inverse: 5.4461702178[22]e-4 |
| Compton wavelength of proton λC,p |
1.321 409 856 23[94] e-15 |
m |
|
λC,p = h / c mp |
| Proton rms charge radius |
0.8775[51] e-15 |
m |
|
|
| Proton magnetic moment |
1.410 606 743[33] e-26 |
m2.A |
J/T |
μp |
| Proton g-factor |
5.585 694 713[46] |
Dimensionless |
|
= μp / (Sp μN) |
| Proton gyromagnetic ratio |
42.577 4806[10] e+6 |
kg-1.s.A |
Hz/T |
γp = μp / h Sp. |
| Proton gyromagnetic ratio shielded |
42.576 388 1[12] e+6 |
kg-1.s.A |
Hz/T |
In H2O, standard conditions |
| Proton magnetic shielding |
25.694[14] e-6 |
Dimensionless |
|
Relative value for pure water at 25 °C |
| Electric dipole moment |
< 8.7 e-45 |
m.s.A |
C.m |
< 5.4 e-24 e.cm; existence not confirmed |
| Electric polarizibility |
1.20[6] e-48 |
m3 |
|
|
| Magnetic polarizibility |
1.9[5] e-49 |
m3 |
|
|
| Neutron (baryon, nucleon, hadron, charge 0, spin 1/2, fermion, parity +, isospin 1/2, its anti-particle is antineutron) |
| Neutron rest mass mn |
1.674 927 351[74] e-27 |
kg |
|
1.008 664 916 00[43] u |
| Neutron rest energy (mc2) |
1.505 349 631[66] e-10 |
kg.m2.s-2 |
J |
939.565 379[21] MeV; quarks composition udd |
| Compton wavelength of neutron λC,n |
1.319 590 9068[11] e-15 |
m |
|
λC,n = h / c mn |
| Neutron half-life time |
881.5[15] |
s |
|
Beta-decay into proton + e- + νe |
| Neutron magnetic moment |
- 0.966 236 47[23] e-26 |
m2.A |
J/T |
μn |
| Neutron g-factor |
- 3.826 085 45[90] |
Dimensionless |
|
= μn / (Sn μN) |
| Neutron gyromagnetic ratio |
29.164 6943[69] e+6 |
kg-1.s.A |
Hz/T |
γn = μn / h Sn |
| Electric dipole moment |
< 4.6 e-47 |
m.s.A |
C.m |
< 2.9 e-26 e.cm; existence not confirmed |
| Electric polarizibility |
1.16[15] e-48 |
m3 |
|
|
| Magnetic polarizibility |
3.7[20] e-49 |
m3 |
|
|
| Deuteron (stable nuclide, protons 1, neutrons 1, charge +1, spin 1, boson) |
| Deuteron rest mass |
3.343 583 48[15] e-27 |
kg |
|
2.013 553 212 712[77] u |
| Deuteron rest energy (mc2) |
3.005 062 97[13] e-10 |
kg.m2.s-2 |
J |
1875.612 859[41] MeV |
| Deuteron rms charge radius |
2.1424[21] e-15 |
m |
|
|
| Deuteron magnetic moment |
0.433 073 489[10] e-26 |
m2.A |
J/T |
|
| Deuteron g-factor |
0.857 438 2308[72] |
Dimensionless |
|
|
| Deuteron gyromagnetic ratio |
6.535 903 381 41 e+6 |
kg-1.s.A |
Hz/T |
|
| Deuteron quadrupole moment |
4.581 e-50 |
m2.s.A |
C.m2 |
0.2859 e(fm)2 |
| Triton (stable nuclide, protons 1, neutrons 2, charge +1, spin 1/2, fermion) |
| Triton rest mass |
5.007 356 30[22] e-27 |
kg |
|
3.015 500 7134[25] u |
| Triton rest energy (mc2) |
4.500 387 41[20] e-10 |
kg.m2.s-2 |
J |
2808.921 005[62] MeV |
| Triton half-life time |
3.888[70] e+8 |
s |
|
= 12.32 years; beta-decay into 3He + e- + νe |
| Triton magnetic moment |
1.504 609 447[38] e-26 |
m2.A |
J/T |
|
| Triton g-factor |
5.957 924 896[76] |
Dimensionless |
|
|
| Triton gyromagnetic ratio |
45.413 674 6[13] e+6 |
kg-1.s.A |
Hz/T |
|
| Helion (stable nuclide, protons 2, neutrons 1, charge +2, spin 1/2, fermion, nuclide) |
| Helion rest mass |
5.006 412 34[22] e-27 |
kg |
|
3.014 932 2468[25] u |
| Helion rest energy (mc2) |
4.499 539 02[20] e-10 |
kg.m2.s-2 |
J |
2808.391 482[62] MeV |
| Helion magnetic moment |
- 1.074 617 486[27] e-26 |
m2.A |
J/T |
Shielded |
| Helion g-factor |
- 4.255 250 613[50] |
Dimensionless |
|
|
| Helion gyromagnetic ratio |
32.434 101 98[90] e+6 |
kg-1.s.A |
Hz/T |
Shielded |
| Alpha particle (stable nuclide, protons 2, neutrons 2, charge +2, spin 0, magnetic moment 0, boson) |
| α-particle rest mass |
6.644 656 75[29] e-27 |
kg |
|
4.001 506 179 125[62] u |
| α-particle rest energy (mc2) |
5.971 919 67[26] e-10 |
kg.m2.s-2 |
J |
3727.379 240[82] MeV |
| Particle physics data (source: Particle Data Group) |
| Neutrinos ν (stable leptons, charge 0, exist in e,μ,τ flavors, each has matter / anti-matter version with opposite chirality, spin 1/2, fermions) |
| Electron neutrino νe rest energy (mc2) |
max 3.5 e-13 |
kg.m2.s-2 |
J |
0 to 2.2 eV |
| Muon neutrino νμ rest energy (mc2) |
max 0.27 e-13 |
kg.m2.s-2 |
J |
0 to 0.17 MeV |
| Tau neutrino ντ rest energy (mc2) |
max 24.8 e-13 |
kg.m2.s-2 |
J |
0 to 15.5 MeV |
| Muon μ± (lepton, charge ±1, matter μ-, antimatter μ+, spin 1/2, fermion) |
| Muon rest energy (mc2) |
1.692 833 667[86] e-11 |
kg.m2.s-2 |
J |
105.658 3715[35] MeV |
| Muon rest mass |
1.883 531 475[96] e-28 |
kg |
|
0.113 428 9267[29] u |
| Muon magnetic moment |
- 4.490 448 07[15] e-26 |
m2.A |
J/T |
|
| Muon g-factor gμ |
- 2.002 331 8418[13] |
Dimensionless |
|
(μ / μB) * (m / me) / spin |
| Muon magnetic moment anomaly |
1.165 920 91[63] e-3 |
Dimensionless |
|
(abs(gμ) - 2) / 2 |
| Muon gyromagnetic ratio |
135.538 817[12] e+6 |
kg-1.s.A |
Hz/T |
= μn / h Sn |
| Muon half-life time |
1.52 e-6 |
s |
|
|
| Tau τ± (lepton, charge ±1, matter τ-, antimatter τ+, spin 1/2, fermion) |
| Tau rest energy (mc2) |
2.846 78[26] e-10 |
kg.m2.s-2 |
J |
1776.82[16] MeV |
| Tau rest mass |
3.167 47[29] e-27 |
kg |
|
1.907 49[17] u |
| Tau half-life time |
2.9 e-13 |
s |
|
|
| Quarks with charge +2/3 (baryon number 1/3, exist in u,c,t flavors, each has matter / anti-matter versions with some property flipped, spin 1/2, fermions) |
| u (up) quark rest energy (mc2) |
3.8 e-13 |
kg.m2.s-2 |
J |
2.4 MeV, stable |
| c (charm) quark rest energy (mc2) |
2.03 e-10 |
kg.m2.s-2 |
J |
1.27 GeV, unstable |
| t (top) quark rest energy (mc2) |
2.743 e-8 |
kg.m2.s-2 |
J |
171.2 GeV, terribly unstable |
| Quarks with charge -1/3 (baryon number 1/3, exist in d,s,b flavors, each has matter / anti-matter versions with some property flipped, spin 1/2, fermions) |
| d (down) quark rest energy (mc2) |
7.7 e-13 |
kg.m2.s-2 |
J |
4.8 MeV, stable |
| s (strange) quark rest energy (mc2) |
1.67 e-11 |
kg.m2.s-2 |
J |
104 MeV, unstable |
| b (bottom) quark rest energy (mc2) |
6.7 e-10 |
kg.m2.s-2 |
J |
4.2 GeV, unstable |
| Pions π± (mesons, hadrons, charge ±1, anti-particles of each other, spin 0, boson, parity -, isospin 1) |
| Pions π± rest energy (mc2) |
2.236 1607[56] e-11 |
kg.m2.s-2 |
J |
139.570 18[35] MeV |
| Pions π± rest mass |
2.488 0643[62] e-28 |
kg |
|
0.149 834 75[37] u |
| Pions π± half-life time |
2.6 e-8 |
s |
|
quarks composition: π+: ud', π-: du' |
| Pion π0 (meson, hadron, charge 0, its own antiparticle, spin 0, boson, parity -,C-parity +, isospin 1) |
| Pion π0 rest energy (mc2) |
2.162 5634[96] e-11 |
kg.m2.s-2 |
J |
134.976 60[60] MeV |
| Pion π0 rest mass |
2.406 176[11] e-28 |
kg |
|
0.144 903 34[64] u |
| Pion π0 half-life time |
8.4 e-17 |
s |
|
quarks composition: (uu'-dd')/&radiv;2 |
| Kaons K± ('strange' mesons, hadrons, charge ±1, anti-particles of each other, spin 0, boson, parity -, isospin 1/2) |
| Kaons K± rest energy (mc2) |
7.909 58[26] e-11 |
kg.m2.s-2 |
J |
493.677[16] MeV |
| Kaons K± rest mass |
8.800 591[29] e-28 |
kg |
|
0.529 984[17] u |
| Kaons K± half-life time |
1.2380[21] e-8 |
s |
|
quarks composition: K+: us', K-: su' |
| Kaon K0 ('strange' meson, hadron, charge 0, self-antiparticle, spin 0, boson, isospin 1/2, parity -) |
| Kaon K0 rest energy (mc2) |
7.972 65[38] e-11 |
kg.m2.s-2 |
J |
497.614[24] MeV; quarks: see below |
| Kaon K0 rest mass |
8.870 77[42] e-28 |
kg |
|
0.534 211[26] u |
| Kaon K0L half-life time (long) |
5.116[20] e-8 |
s |
|
quarks composition: (ds'+sd')/√2 |
| Kaon K0S half-life time (short) |
8.953[5] e-11 |
s |
|
quarks composition: (ds'-sd')/√2 |
| Eta mesons η and η' (hadrons, charge 0, antiparticles of each other, spin integer, bosons, |
| η rest energy (mc2) |
8.777 57[38] e-11 |
kg.m2.s-2 |
J |
547.853[24] MeV |
| η rest mass |
9.766 36[42] e-28 |
kg |
|
0.588 144[25] u |
| η half-life time |
5.0[3] e-19 |
s |
|
quarks composition: (uu'+dd'-2ss')/√6 |
| η' rest energy (mc2) |
1.53434[38] e-10 |
kg.m2.s-2 |
J |
957.66[24] MeV |
| η' rest mass |
1.70718[43] e-27 |
kg |
|
1.02809[26] u |
| η' half-life time |
3.2[2] e-21 |
s |
|
quarks composition: (uu'+dd'+ss')/√3 |
| Lambda hyperons (baryons, charge 0 or +1, spin 1/2, fermions, parity +; predicted only: top Λt+, quarks udt, but t-quark decays before it hadronizes) |
| Λ0 rest energy (mc2) |
1.7875211[96] e-10 |
kg.m2.s-2 |
J |
1.1156830[60] GeV; charge 0 |
| Λ0 rest mass |
1.988885[11] e-27 |
kg |
|
1.1977349[64] u |
| Λ0 half-life time |
2.631[20] e-10 |
s |
|
quarks composition: uds |
| Bottom Λ0b rest energy (mc2) |
9.0046[26] e-10 |
kg.m2.s-2 |
J |
5.6202[16] GeV; charge 0 |
| Bottom Λ0b rest mass |
1.00189[29] e-26 |
kg |
|
6.0335[17] u |
| Bottom Λ0b half-life time |
1.409[55] e-12 |
s |
|
quarks composition: udb |
| Charmed Λ+c rest energy (mc2) |
3.66331[22] e-10 |
kg.m2.s-2 |
J |
2.28646[14] GeV; charge +1 |
| Charmed Λ+c rest mass |
4.07599[25] e-27 |
kg |
|
2.45462[15] u |
| Charmed Λ+c half-life time |
2.000[60] e-13 |
s |
|
quarks composition: udc |
| Sigma hyperons with spin 1/2 (barions, charge -1, 0, +1 or +2, fermions, parity +; predicted only: udb, uut, udt, ddt) |
| Σ+ rest energy (mc2) |
1.90558[11] e-10 |
kg.m2.s-2 |
J |
1.189370[70] GeV; charge +1 |
| Σ+ rest mass |
2.12024[12] e-27 |
kg |
|
1.276841[75] u |
| Σ+ half-life time |
8.018[26] e-11 |
s |
|
quarks composition: uus |
| Σ0 rest energy (mc2) |
1.910823[38] e-10 |
kg.m2.s-2 |
J |
1.192642[24] GeV; charge 0 |
| Σ0 rest mass |
2.126077[43] e-27 |
kg |
|
1.280353[26] u |
| Σ0 half-life time |
7.40[70] e-20 |
s |
|
quarks composition: uds |
| Σ- rest energy (mc2) |
1.918525[48] e-10 |
kg.m2.s-2 |
J |
1.197449[30] GeV; charge -1 |
| Σ- rest mass |
2.13465[53] e-27 |
kg |
|
1.285514[32] u |
| Σ- half-life time |
1.479[11] e-10 |
s |
|
quarks composition: dds |
| Charmed Σc++ rest energy (mc2) |
3.93177[29] e-10 |
kg.m2.s-2 |
J |
2.45402[18] GeV; charge +2 |
| Charmed Σc++ rest mass |
4.37469[32] e-27 |
kg |
|
2.63450[19] u |
| Charmed Σc++ half-life time |
3.00[40] e-22 |
s |
|
quarks composition: uuc |
| Charmed Σc+ rest energy (mc2) |
3.92998[64] e-10 |
kg.m2.s-2 |
J |
2.45290[40] GeV; charge +1 |
| Charmed Σc+ rest mass |
4.37269[71] e-27 |
kg |
|
2.63330[43] u |
| Charmed Σc+ half-life time |
>1.4 e-22 |
s |
|
quarks composition: udc |
| Charmed Σc0 rest energy (mc2) |
3.93136[29] e-10 |
kg.m2.s-2 |
J |
2.45376[18] GeV; charge 0 |
| Charmed Σc0 rest mass |
4.37422[32] e-27 |
kg |
|
2.63422[19] u |
| Charmed Σc0 half-life time |
3.0 e-22 |
s |
|
quarks composition: ddc |
| Bottom Σb+ rest energy (mc2) |
9.3051[62] e-10 |
kg.m2.s-2 |
J |
5.8078[39] GeV; charge +1 |
| Bottom Σb+ rest mass |
1.03533[69] e-26 |
kg |
|
6.2349[42] u |
| Bottom Σb+ half-life time |
? |
s |
|
quarks composition: uub |
| Bottom Σb- rest energy (mc2) |
9.3170[43] e-10 |
kg.m2.s-2 |
J |
5.8152[27] GeV; charge -1 |
| Bottom Σb- rest mass |
1.03665[48] e-26 |
kg |
|
6.2429[30] u |
| Bottom Σb- half-life time |
? |
s |
|
quarks composition: ddb |
| Sigma* hyperons with spin 3/2 (barions, charge -1, 0, +1 or +2, fermions, parity +; predicted only: uub, udb, ddb, uut, udt, ddt) |
| Σ*+ rest energy (mc2) |
2.21549[64] e-10 |
kg.m2.s-2 |
J |
1.38280[40] GeV; charge +1 |
| Σ*+ rest mass |
2.46506[71] e-27 |
kg |
|
1.48450[43] u |
| Σ*+ half-life time |
1.840[40] e-23 |
s |
|
quarks composition: uus |
| Σ*0 rest energy (mc2) |
2.21693[16] e-10 |
kg.m2.s-2 |
J |
1.38370[10] GeV; charge 0 |
| Σ*0 rest mass |
2.46667[18] e-27 |
kg |
|
1.48546[11] u |
| Σ*0 half-life time |
1.80[30] e-23 |
s |
|
quarks composition: uds |
| Σ*- rest energy (mc2) |
2.22254[80] e-10 |
kg.m2.s-2 |
J |
1.38720[50] GeV; charge -1 |
| Σ*- rest mass |
2.47291[89] e-27 |
kg |
|
1.48922[54] u |
| Σ*- half-life time |
1.670[90] e-23 |
s |
|
quarks composition: dds |
| Charmed Σ*++c rest energy (mc2) |
4.03492[96] e-10 |
kg.m2.s-2 |
J |
2.51840[60] GeV; charge +2 |
| Charmed Σ*++c rest mass |
4.4894[11] e-27 |
kg |
|
2.70361[64] u |
| Charmed Σ*++c half-life time |
4.40[60] e-23 |
s |
|
quarks composition: uuc |
| Charmed Σ*+c rest energy (mc2) |
4.0335[37] e-10 |
kg.m2.s-2 |
J |
2.5175[23] GeV; charge +1 |
| Charmed Σ*+c rest mass |
4.4879[41] e-27 |
kg |
|
2.7026[25] u |
| Charmed Σ*+c half-life time |
> 3.9 e-23 |
s |
|
quarks composition: udc |
| Charmed Σ*0c rest energy (mc2) |
4.03428[80] e-10 |
kg.m2.s-2 |
J |
2.518 GeV; charge 0 |
| Charmed Σ*0c rest mass |
4.48874[89] e-27 |
kg |
|
2.70318[54] u |
| Charmed Σ*0c half-life time |
4.10[50] e-23 |
s |
|
quarks composition: ddc |
| Xi hyperons (barions, charge -1, 0, +1, spin 1/2, fermions, parity +; predicted only: ucc, ubb, dbb, ucb, dcb) |
| Ξ0 rest energy (mc2) |
2.106638[32] e-10 |
kg.m2.s-2 |
J |
1.31486[20] GeV; charge 0 |
| Ξ0 rest mass |
2.34395[35] e-27 |
kg |
|
1.41156[21] u |
| Ξ0 half-life time |
2.900[90] e-10 |
s |
|
quarks composition: uss |
| Ξ- rest energy (mc2) |
2.11697[21] e-10 |
kg.m2.s-2 |
J |
1.32131[13] GeV; charge -1 |
| Ξ- rest mass |
2.35544[23] e-27 |
kg |
|
1.41848[14] u |
| Ξ- half-life time |
1.639[15] e-10 |
s |
|
quarks composition: dss |
| Charmed Ξc+ rest energy (mc2) |
3.95401[64] e-10 |
kg.m2.s-2 |
J |
2.46790[40] GeV; charge +1 |
| Charmed Ξc+ rest mass |
4.39943[71] e-27 |
kg |
|
2.64940[43] u |
| Charmed Ξc+ half-life time |
4.42[26] e-13 |
s |
|
quarks composition: usc |
| Charmed Ξc0 rest energy (mc2) |
3.95898[64] e-10 |
kg.m2.s-2 |
J |
2.47100[40] GeV; charge 0 |
| Charmed Ξc0 rest mass |
4.40496[71] e-27 |
kg |
|
2.65273[43] u |
| Charmed Ξc0 half-life time |
1.12[13] e-13 |
s |
|
quarks composition: dsc |
| Double charmed Ξcc+ rest energy (mc2) |
5.6379[14] e-10 |
kg.m2.s-2 |
J |
3.51890[90] GeV; charge +1 |
| Double charmed Ξcc+ rest mass |
6.2730[16] e-27 |
kg |
|
3.77769[97] u |
| Double charmed Ξcc+ half-life time |
< 3.3 e-14 |
s |
|
quarks composition: dcc |
| Bottom Ξb0 rest energy (mc2) |
9.2798[48] e-10 |
kg.m2.s-2 |
J |
5.7920[30] GeV; charge 0 |
| Bottom Ξb0 rest mass |
1.0325[53] e-26 |
kg |
|
6.2180[32] u |
| Bottom Ξb0 half-life time |
1.42[28] e-12 |
s |
|
quarks composition: usb |
| Bottom Ξb- rest energy (mc2) |
9.2815[48] e-10 |
kg.m2.s-2 |
J |
5.7929[30] GeV; charge -1 |
| Bottom Ξb- rest mass |
1.0335[53] e-26 |
kg |
|
6.2191[32] u |
| Bottom Ξb- half-life time |
1.42[28] e-12 |
s |
|
quarks composition: dsb |
| Ξ resonances:
{uss, S=3/2, 1.53180[32] GeV},
{dss, S=3/2, 1.53500[60] GeV},
{usc, S=1/2, 2.57570[31] GeV},
{dsc, S=1/2, 2.57800[29] GeV, 1.1e-13 s},
|
| Omega hyperons (barions, charge -1 or 0, spin 1/2 or 3/2, fermions, parity +; predicted only: scc, scb, sbb, ccc, ccb, cbb, bbb) |
| Ω- rest energy (mc2) |
2.67956[46] e-10 |
kg.m2.s-2 |
J |
1.67245[29] GeV; charge -1, spin 3/2 |
| Ω- rest mass |
2.98141[52] e-27 |
kg |
|
1.79544[31] u |
| Ω- half-life time |
8.21[11] e-11 |
s |
|
quarks composition: sss |
| Charmed Ω0c rest energy (mc2) |
4.3219[41] e-10 |
kg.m2.s-2 |
J |
2.6975[26] GeV; charge 0, spin 1/2 |
| Charmed Ω0c rest mass |
4.8087[28] e-27 |
kg |
|
2.8959[28] u |
| Charmed Ω0c half-life time |
6.9[12] e-14 |
s |
|
quarks composition: ssc |
| Bottom Ω-b rest energy (mc2) |
9.700[11] e-10 |
kg.m2.s-2 |
J |
6.0544[68] GeV; charge -1, spin 1/2 |
| Bottom Ω-b rest mass |
1.0793[12] e-26 |
kg |
|
6.49967[73] u |
| Bottom Ω-b half-life time |
1.13[53] e-12 |
s |
|
quarks composition: ssb |
| W ± gauge boson (charge ±1, matter W -, antimatter W+, spin 1) |
| W boson rest energy (mc2) |
1.28791[24] e-8 |
kg.m2.s-2 |
J |
80.385[15] GeV |
| W boson rest mass |
1.432993[25] e-25 |
kg |
|
86.296[16] u |
| Z gauge boson (charge 0, spin 1) |
| Z boson rest energy (mc2) |
1.460986[33] e-8 |
kg.m2.s-2 |
J |
91.1876[21] GeV |
| Z boson rest mass |
1.625566[37] e-25 |
kg |
|
97.8939[23] u |
| Higgs boson H0 (charge 0, spin 0, predicted only, not found) |
| H0 rest energy (mc2) |
2.0042[34] e-8 |
kg.m2.s-2 |
J |
125.09[21] GeV; ATLAS/CMS 26 Mar 2015 |
| H0 rest mass |
2.2299[37] e-25 |
kg |
|
134.29[23] u |
| H0 half-life time |
1.56 e-22 |
s |
|
h/(2πΓ), predicted Γ = 4.21 MeV |
| Cosmic microwave background (CMB) |
| Mean apparent CMB temperature |
2.72548[57] |
K |
Kelvin |
From CMB black-body radiation spectrum |
| rms variations of CMB temperature |
1.8 e-7 |
K |
|
18 μK; deviations from perfect isotropy |
| Peak frequency density νmax |
1.6023 e+11 |
Hz |
|
160.23 GHz, corresponding to λ = 1.871 mm |
| Peak wavelength density λmax |
1.063 e-3 |
m |
|
1.063 mm, corresponding to 318.7 GHz |
| Metrics of the known Universe (for the prefixes M (Mega), G (Giga), Z (Zetta), and Y (Yocto), click here)
|
| Diameter visible by Hubble telescope |
8.80[10] e+26 |
m |
|
~ 93 G light-years |
| Volume of the visible sphere |
3.60[10] e+80 |
m3 |
|
~ 420 MY light-years3 (Mega-Yocta) |
| Mass contained therein |
3.56[10] e+54 |
kg |
|
~ 3.56 MYY kg; mostly dark energy & matter |
| Mean density |
9.90[20] e-27 |
kg.m-1 |
kg/m |
~ 9.9 e-30 g/ml |
| Age, assuming Big Bang theory |
4.366[54] e+17 |
s |
|
~ 13.75±0.17 G years |
| Mean expansion rate |
2.29[13] e-18 |
s-1 |
|
~ 70.8±4.0 (km/s)/Mpc (km/s per Megaparsec) |
| Number of stars |
3.0[10] e+23 |
Dimensionless |
|
~ 300 Z , or 0.5 mols of stars |
| Number of galaxies |
1.25[20] e+11 |
Dimensionless |
|
~ 125 G, or 0.2 pico-mols of galaxies |
| Number of fundamental particles |
1.00[25] e+80 |
Dimensionless |
|
~ 100 MYYY (Mega-Yocto-Yocto-Yocto) |
| Mean concentration of particles |
0.28[10] |
m-3 |
counts/m3 |
~ 4.5e-28 molar "solution" |
| Milky Way galaxy. Type BSc (barred spiral), lentil-shaped, 9 arms, center in the direction of Sagittarius constellation |
| Diameter |
1.04[10] e+21 |
m |
|
100000 - 120000 light-years (30 - 37 Kpc) |
| Thickness |
1.00[10] e+19 |
m |
|
~1000 light-years (~300 pc) |
| Mass |
2.50[50] e+42 |
kg |
|
1.25[25] e+12 solar masses |
| Number of stars |
3.0[10] e+11 |
Dimensionless |
count |
~300 e+9 |
| Oldest known star |
4.156[50] e+17 |
s |
|
13.2 e+9 years |
| Speed with respect to CMB |
5.520[60] e+5 |
m.s-1 |
|
552 ± 6 km/s; the absolute galaxy motion |
| Angle between galactic plane and the ecliptic |
1.05[10] |
rad |
|
~60 degrees |
| Milky Way arms look like logarithmic-spirals; galaxy is a kind of vortex and its apparent features keep changing faster than the motions of its stars |
| Arms pattern rotation (apparent) |
1.58[15] e+15 |
s |
|
~50 million years; move like ripple patterns |
| Milky Way central bar |
| Bar pattern rotation period (apparent) |
5.20[47] e+14 |
s |
|
15-18 million years; moves like a ripple pattern |
| Solar system data; see also NASA Planetary Fact Sheets |
| Distance to Milky Way galaxy center |
2.57[10] e+20 |
m |
|
27200 ±1100 light-years |
| Rotation around galaxy center: period |
7.49[39] e+15 |
s |
|
225 - 250 million years |
| Rotation around galaxy center: orbital speed |
2.20 e+5 |
m.s-1 |
m/s |
approximately opposed to absolute galaxy motion |
| Absolute speed with respect to CMB |
3.7 e+5 |
m.s-1 |
m/s |
370 km/s; 0.123% of the speed of light |
| Extension (max.aphelion of a minor planet) |
1.598 e+14 |
m |
|
over 1068 au; planetoid (87269) 2000 OO67 |
| Distance to nearest-neighbour system |
3.970[50] e+16 |
m |
|
4.2 light-years; Proxima Centauri |
| The Sun; spectral class G2V, main sequence (V) yellow dearf (G2). Composition: 73.46% H, 24.85% He, 0.77% O, 0.29 C, 0.16% Fe, 0.12% Ne, 0.09% N |
| Mass |
1.98910[20] e+30 |
kg |
|
330'000 times that of Earth |
| Mean radius |
6.9550[50] e+8 |
m |
|
109.2 times that of Earth |
| Flattening |
9 e-6 |
Dimensionless |
|
(equatorial - polar)/equatorial radii |
| Volume |
1.41226[50] e+27 |
m3 |
|
1'304'000 times that of Earth |
| Mean density |
1.408 e+3 |
kg.m-3 |
kg/m3 |
0.255 times that of Earth |
| Surface gravity on equator |
2.74 e+2 |
m.s-2 |
m/s2 |
27.94 g |
| Escape velocity |
6.176 e+2 |
m.s-1 |
m/s |
55.2 times that of Earth |
| Photosphere temperature |
5778 |
K |
|
In the layer emitting the light we see |
| Absolute visual magnitude |
+4.83 |
Dimensionless |
|
see stellar magnitudes (Conventional constants) |
| Radiance Isol |
2.009 e+7 |
W.m2.sr-1 |
|
total from the layer emitting the light we see |
| Luminose efficacy |
98 |
lm.kg-1.m-2.s3 |
lm/W |
see "Electromagnetic radiation constants" |
| Luminosity Lsol |
3.841[14] e+26 |
kg.m2.s-3 |
W |
~3.75 e+28 lm |
| Loss of mass due to elmag radiation |
4.273[16] e+9 |
kg.s-1 |
kg/s |
<electromagnetic power output> / c2 |
| Total neutrino emissions |
1.830[50] e+38 |
s-1 |
count/s |
Mean value (very variable) |
| Age |
1.4420[14] e+17 |
s |
|
4.57 e+9 years |
| Planet Earth in relation to the Sun and the Solar system. The orbit of Earth defines the ecliptic plane. |
| Earth aphelion, largest distance from Sun |
1.52098232 e+11 |
m |
|
1.01671388 au |
| Earth perihelion, smallest distance from Sun |
1.47098290 e+11 |
m |
|
0.98329134 au |
| Longitude of ascending node |
6.08665006 |
rad |
|
348.73936 degrees |
| Argument of perihelion |
1.9933026 |
rad |
|
114.20783 degrees |
| Semi-major orbital axis |
1.49598261 e+11 |
m |
|
1.00000261 au |
| Earth orbit inclination to Sun equator |
0.1249 |
rad |
|
7.155 degrees |
| Earth orbit inclination to invariable plane |
0.0275533 |
rad |
|
1.57869 degrees |
| Earth orbital excentricity |
0.01671123 |
Dimensionless |
|
will be about 0.015 after 5000 years |
| Mean anomaly of Earth orbit |
3.5751716 e+2 |
Dimensionless |
|
|
| Earth mean orbital velocity |
2.9780 e+4 |
m.s-1 |
m/s |
107200 km/h |
| Sun visual brightess from the Earth |
-26.74 |
Dimensionless |
|
see stellar magnitudes (Conventional constants) |
| Sun angular diameter seen from the Earth |
0.00919 - 0.00951 |
rad |
|
Varies between 0.527 and 0.545 degrees |
| Solar constant (mean value for Earth) |
1.36594[48] e3 |
kg.s-3 |
W/m2 |
Elmag irradiation from Sun at 1 AU distance |
| Solar neutrinos flux on Earth surface |
6.50[10] e+14 |
m-2.s-1 |
|
Mean count per m2 per second; very variable |
| Satellites count |
1 natural |
Dimesionless |
|
994 artificial (December 2011) |
| Planets: see the PDF document SOLAR SYSTEM PLANETS AT A GLANCE and the NASA Planetary Fact Sheets |
| Number of planets |
8 |
Dimensionless |
count |
Planetary data table |
| Minor planets; see also NASA Facts Sheets:
Pluto,
Chiron,
Asteroids,
Comets,
|
| Registered, with known orbits |
583'767 |
Dimensionless |
count |
Apr 2012; ~3000 are added every month |
| Numbered minor planets |
326'266 |
Dimensionless |
count |
Apr 2012 |
| Named minor planets |
17'055 |
Dimensionless |
count |
Apr 2012 |
| Planet Earth (Terra) data, other than those listed above; see also NASA Earth Fact Sheet |
| Age |
1.4327[14] e+17 |
s |
|
4.54 e+9 years |
| Global composition in weight % |
Fe 32.1, O 30.1, Si 15.1, Mg 13.9, S 2.9, Ni 1.8, Ca 1.5, Al 1.4, the rest: 1.2 |
| Atmospheric composition in weight % |
N2 78.08, O2 20.95, Ar 0.93, CO2 0.038, the rest: 0.002; extra: 1% of H2O wapor (variable) |
| Mass |
5.9736 e+24 |
kg |
|
|
| Volume |
1.08321 e+21 |
m3 |
|
108.321 km3 |
| Mean density |
5.515 e+3 |
kg.m-3 |
kg/m3 |
5.515 g/cm3 |
| Mean radius |
6.3710 e+6 |
m |
|
this is volumetric mean |
| Equatorial radius |
6.3781 e+6 |
m |
|
6378.1 km; circumpherence 40075.017 km |
| Polar radius |
6.3568 e+6 |
m |
|
6356.8 km; circumpherence 40007.860 km |
| Flattening |
0.00335 |
Dimensionless |
|
f = (a-b)/a; a = equatorial, b = polar radius |
| Surface area |
5.100720 e+14 |
m2 |
|
5.100720 e+8 km2 |
| Dry land surface area |
1.48940 e+14 |
m2 |
|
1.48940 e+8 km (29.200 %)2 |
| Surface temperature, mean |
287.2 |
K |
|
14.0 °C; range 184 to 331 K (-90 to 58 °C)) |
| Surface pressure, mean |
1.01325 e+5 |
kg.m-1.s-2 |
Pa |
1 atm = 101325 Pa |
| Equatorial surface gravity |
9.780327 |
m.s-2 |
m/s2 |
0.99732 g |
| Escape velocity |
1.1186 e+4 |
m.s-1 |
m/s |
11.186 km/s |
| Albedo, geometric |
0.367 |
Dimensionless |
|
|
| Albedo, Bond |
0.306 |
Dimensionless |
|
|
| Sidereal rotation period |
8.616410 e+4 |
s |
|
0.99726968 days, or 23 h 56 m 4.100 s |
| Equatorial rotation speed |
465.1 |
m.s-1 |
m/s |
0.4651 km/s (4.1579 % of escape volocity)) |
| Axial tilt |
0.40763819 |
rad |
|
23.355948 °, or 23 ° 26' 21“.4119 |
| Radius of the core |
3.485 e+6 |
m |
|
3485 km |
| Average lunar month |
2.5514430[5] e+6 |
s |
|
29 days+ 12 hours+ 44 minutes+ 3 seconds |
| Conventional constants |
| Molar mass constant |
0.001 |
kg.mol-1 |
kg/mol |
Assigned (exact) |
| Molar mass of 12C |
0.012 |
kg |
|
Assigned (exact) |
| Standard gravity acceleration |
9.806 65 |
m.s-2 |
m/s2 |
Assigned. Called 1 g (gee). |
| Standard atmosphere |
101 325 |
Pa |
|
Assigned. Called 1 atm . |
| Stellar magnitudes. Reference points: Apparent brightness: bolometric, initially Vega was 0 (now it is +0.03). Absolute: the Sun is 4.83 (used to be 4.75) |
| Stellar apparent magnitude unit |
2.511 886 431 509 580 ... |
Dimensionless |
a ratio |
1001/5 = 100.4; also stellar brightness |
| Stellar absolute magnitude unit |
2.511 886 431 509 580 ... |
Dimensionless |
a ratio |
Brightness of a star when distant 10 parsecs |
| Conventional engineering constants. See also Math constants pertinent to Engineering definitions |
| dBm |
| 0 dBm power |
0.001 |
kg.m2.s-3 |
Watts |
1 mW; assigned |
| 0 dBm potential |
0.774 596 669 241 483 ... |
kg.m2.s-3.A-1 |
Volts |
1 mW into 600 Ohm load |
| 0 dBm current |
0.001 290 994 448 736 ... |
A |
Amperes |
1 mW into 600 Ohm load |
| dBW |
| 0 dBW power |
1.0 |
kg.m2.s-3 |
Watts |
1 W; assigned |
| 0 dBW potential |
7.071 067 811 865 475 ... |
kg.m2.s-3.A-1 |
Volts |
sqrt(Z0); 1 W into 50 Ohm load Z0 |
| 0 dBW current |
0.141 421 356 237 310 ... |
A |
Amperes |
sqrt(1/Z0); 1 W into 50 Ohm load Z0 |
| Conversion of dBW into dBm (additive) |
+30 |
Dimensionless |
dB |
In terms of power |
| Relative luminance Y of RGB color primaries: Y = 0.2126.R + 0.7152.G + 0.0722.B. More info ... |
| Relative luminance of Red/RGB |
0.2126 |
Dimensionless |
a ratio |
|
| Relative luminance of Green/RGB |
0.7152 |
Dimensionless |
a ratio |
Human eye is most sensitive to green |
| Relative luminance of Blue/RGB |
0.0722 |
Dimensionless |
a ratio |
|
| Music and acoustics |
| Frequency of the A4 reference note |
440.0 |
s-1 |
Hz |
ISO 16 |
| Full-octave frequency ratio |
2.0 exact |
Dimensionless |
Ratio |
C,C#,D,D#,E,F,F#,G,G#,A,A#,B,...next C |
| Half-tone frequency ratio 21/12 |
1.059 463 094 359 295 ... |
Dimensionless |
Ratio |
12 half-tones per octave, each worth 100 cents |
| Conversion factors for entities tolerated by SI, as well as some others |
| Energy & its equivalents |
| Electron volt |
1.602 176 565[35] e-19 |
kg.m2.s-2 |
J |
Basic eV-to-SI conversion |
| Electron volt to mass |
1.782 661 845[39] e-36 |
kg |
|
mass = energy/c2 |
| Electron volt to atomic units u |
1.073 544 150[24] e-9 |
- |
u |
a mass equivalent |
| Electron volt to frequency |
2.417 989 348[53] e+14 |
s-1 |
Hz |
frequency = energy/h |
| Electron volt to half-life time |
6.582 119 28[22] e-16 |
s |
|
Inverse relationship: τ = h/(2πΓ) |
| Joul to eV |
6.241 509 34[14] e+18 |
- |
eV |
Basic SI-to-eV conversion |
| Mass to eV |
5.609 588 85[12] e+35 |
- |
eV |
energy = mass.c2 |
| Atomic unit u to eV |
931.494 061[21] e+6 |
- |
eV |
a bit less than 1 GeV/atomic_unit |
| Frequency (1 Hz) to eV |
4.135 667 516[91] e-15 |
- |
eV |
energy = frequency*h |
| Atomic mass constant u, mu |
1.660 538 921[73] e-27 |
kg |
|
Mass of 12C nuclide / 12 |
| Atomic mass energy (uc2) |
1.492 417 954[66] e-10 |
kg.m2.s-2 |
J |
931.494 061[21] MeV |
| Length / Distance |
| Astronomical unit ua, au |
1.49597870[30] e+11 |
m |
~150 Gm |
Mean Earth-to-Sun distance |
| Light-year ly |
9.4607304725808 e+15 |
m |
~9.5 Pm |
Exact: light covers it in one Julian year |
| Parsec pc (~ 32.6 ly) |
3.08567757[60] e+16 |
m |
~30 Pm |
Corresponds to au parallax of 1 second |
| Time |
| Hour |
3.600 e+3 |
s |
|
Exact: 3600 seconds |
| Day |
8.6400 e+4 |
s |
|
Exact: 24 hours |
| Julian year |
3.1557600 e+7 |
s |
|
Exact: 365.25 days |
| Gregorian year (mean) |
3.1556952 e+7 |
s |
|
Exact: 365.2425 days |
| Tropical year (drops ~0.53 s/century) |
3.155692518747072 e+7 |
s |
|
365.2421896698 days in year 2000 |
| Plane and solid angles |
| 1 radian in degrees |
5.729577951308232... e+1 |
Dimensionless |
°, degree |
180/π; planar angle; 57° 17' 44.806247...'' |
| 1° degree in radians |
1.745329251994330... e-2 |
Dimensionless |
rad |
π/180; planar angle |
| 1' minute in radians |
2.908882086657215 ... e-4 |
Dimensionless |
rad |
π/180/60; planar angle |
| 1'' second in radians |
4.848136811095359 ... e-6 |
Dimensionless |
rad |
π/180/60/60; planar angle |
| 1 steradian in degree2 |
3.282806350011744... e+3 |
Dimensionless |
degree2 |
(180/π)2; for solid angle infinitesimals |
| 1 degree2 in steradians |
3.046174197867086... e-4 |
Dimensionless |
sr |
(π/180)2; for solid angle infinitesimals |