Lihat sumber Konstanta fisika

[[Berkas:17pml015 si-constants-card.jpg|jmpl|Berbagai konstanta fisika dasar]]
'''Konstanta fisika''' atau '''tetapan fisika''' adalah [[besaran fisika]] yang umumnya dipercaya secara universal di alam dan [[konstanta (matematika)|konstan]] terhadap waktu. Berkebalikan dengan [[konstanta matematika]] yang nilai numeriknya tetap namun tidak berhubungan dengan pengukuran fisika manapun.

Banyak konstanta fisika dalam ilmu sains, salah satu yang paling umum misalnya [[kecepatan cahaya]] dalam ruang vakum ''c'', [[konstanta gravitasi]] ''G'', [[konstanta Planck]] ''h'', [[konstanta listrik]] ε<sub>0</sub>, dan [[muatan elementer]] ''e''. Konstanta fisika dapat menjelaskan berbagai bentuk [[analisis dimensi]]onal: kecepatan cahaya meningkatkan drastis batas [[kecepatan]] maksimum [[alam semesta]] dan dinyatakan secara dimensional sebagai [[panjang]] dibagi [[waktu]]; sedangkan [[konstanta struktur-halus]] α yang mengkarakterisasikan kekuatan [[interaksi elektromagnetik]], adalah [[satuan tak berdimensi]].

== Tabel konstanta universal ==
{| class="wikitable"
|-
!{{tnavbar-header|Quantity|Template:Table of universal constants}}
!Simbol
!Nilai<ref name="concise"/><ref name="2014 CODATA">{{cite arXiv|last1=Mohr|first1=Peter J.|last2=Newell|first2=David B.|last3=Taylor|first3=Barry N.|title=CODATA Recommended Values of the Fundamental Physical Constants: 2014|eprint=1507.07956v1 |class=physics.atom-ph}}</ref>
!Ketidakpastian standar relatif
|- 
|[[kecepatan cahaya|kecepatan cahaya dalam vakum]]
|<math>c \,</math>
|299 792 458 m·s<sup>−1</sup>
|terdefinisi
|-
|[[konstanta gravitasi|konstanta gravitasi Newton]]
|<math>G \,</math>
|{{val|6.67408|(31)|e=-11|u=m<sup>3</sup>·kg<sup>−1</sup>·s<sup>−2</sup>}}
|4.7 × 10<sup>−5</sup>
|-
|[[konstanta Planck]]
|<math>h \,</math>
|6.626 070 040(81) × 10<sup>−34</sup> J·s
|1.2 × 10<sup>−8</sup>
|-
|[[konstanta Planck tereduksi]]
|<math>\hbar = h / (2 \pi)</math>
|1.054 571 800(13) × 10<sup>−34</sup> J·s
|1.2 × 10<sup>−8</sup>
|-
|}

== Tabel konstanta elektromagnetik ==
{| class="wikitable"
|-
!{{tnavbar-header|Quantity|Template:Table of electromagnetic constants}}
!Simbol
!Nilai<ref name="concise"/><ref name="2010 CODATA">P.J. Mohr, B.N. Taylor, and D.B. Newell (2011), "The 2010 CODATA Recommended Values of the Fundamental Physical Constants" (Web Version 6.0). This database was developed by J. Baker, M. Douma, and S. Kotochigova. Available: http://physics.nist.gov/constants [Thursday, 02-Jun-2011 21:00:12 EDT]. National Institute of Standards and Technology, Gaithersburg, MD 20899.</ref> (satuan [[SI]])
!Ketidakpastian standar relatif
|-
|[[konstanta magnetik]] (permeabilitas vakum)
|<math> \mu_0 \,</math>
|4π × 10<sup>−7</sup> N·A<sup>−2</sup> = 1.256 637 061... × 10<sup>−6</sup> N·A<sup>−2</sup>
|terdefinisi
|-
|[[konstanta listrik]] (permitivitas vakum)
|<math> \varepsilon_0 = 1/\mu_0 c^2 \,</math>
|8.854 187 817... × 10<sup>−12</sup> F·m<sup>−1</sup>
|terdefinisi
|-
|[[impedansi ruang hampa]]
|<math>Z_0 = \mu_0 c \,</math>
|376.730 313 461... Ω
|terdefinisi
|-
|[[konstanta Coulomb]]
|<math>k_{\mathrm{e}} = 1 / 4\pi\varepsilon_0 \,</math>
|8.987 551 787... × 10<sup>9</sup> N·m<sup>2</sup>·C<sup>−2</sup>
|terdefinisi
|-
|[[muatan elementer]]
|<math>e
\,</math>
|1.602 176 565(35) × 10<sup>−19</sup> C
|2.2 × 10<sup>−8</sup>
|- 
|[[magneton Bohr]]
|<math>\mu_{\mathrm{B}} = e \hbar / 2 m_\mathrm{e}</math>
|9.274 009 68(20) × 10<sup>−24</sup> J·T<sup>−1</sup>
|2.2 × 10<sup>−8</sup>
|-
|[[kuantum konduktansi]]
|<math>G_0 = 2 e^2 / h \,</math>
|7.748 091 7346(25) × 10<sup>−5</sup> S
|3.2 × 10<sup>−10</sup>
|-
|invers [[kuantum konduktansi]]
|<math>G_0^{-1} = h / 2 e^2 \,</math>
|12 906.403 7217(42) Ω
|3.2 × 10<sup>−10</sup>
|-
|[[konstanta Josephson]]
|<math>K_{\mathrm{J}} = 2 e / h \,</math>
|4.835 978 70(11) × 10<sup>14</sup> Hz·V<sup>−1</sup>
|2.2 × 10<sup>−8</sup>
|-
|[[kuantum fluks magnetik]]
|<math>\phi_0 = h / 2 e \,</math>
|2.067 833 758(46) × 10<sup>−15</sup> Wb
|2.2 × 10<sup>−8</sup>
|-
|[[magneton nuklir]]
|<math>\mu_{\mathrm{N}} = e \hbar / 2 m_\mathrm{p}</math>
|5.050 783 53(11) × 10<sup>−27</sup> J·T<sup>−1</sup>
|2.2 × 10<sup>−8</sup>
|-
|[[konstanta von Klitzing]]
|<math>R_{\mathrm{K}} = h / e^2 \,</math>
|25 812.807 4434(84) Ω
|3.2 × 10<sup>−10</sup>
|-
|}

== Tabel konstanta atom dan nuklir ==
{| class="wikitable"
|-
! colspan="2"|{{tnavbar-header|Quantity|Template:Table of atomic and nuclear constants}}
!Simbol
!Nilai<ref name="concise"/><ref name="2010 CODATA"/> (satuan [[SI]])
!Ketidakpastian standar relatif
|- 
| colspan=2 |[[radius Bohr]]
|<math>a_0 = \alpha / 4 \pi R_\infin \,</math>
|5.291 772 1092(17) × 10<sup>−11</sup> m
|3.2 × 10<sup>−9</sup>
|-
| colspan=2 |[[radius elektron klasik]]
|<math>r_{\mathrm{e}} = e^2 / 4\pi\varepsilon_0 m_\mathrm{e} c^2\,</math>
|2.817 940 3267(27) × 10<sup>−15</sup> m
|9.7 × 10<sup>−10</sup>
|-
| colspan=2 |[[elektron|massa elektron]]
|<math>m_{\mathrm{e}} \,</math>
| 9.109 382 91(40) × 10<sup>−31</sup> kg
|4.4 × 10<sup>−8</sup>
|-
|colspan=2| [[konstanta berpasangan Fermi]]
|<math>G_{\mathrm{F}} / (\hbar c)^3</math>
|1.166 364(5) × 10<sup>−5</sup> GeV<sup>−2</sup>
|4.3 × 10<sup>−6</sup>
|-
|colspan=2 |[[konstanta struktur-halus]]
|<math>\alpha = \mu_0 e^2 c / 2 h = e^2 / 4 \pi \varepsilon_0 \hbar c \,</math>
|7.297 352 5698(24) × 10<sup>−3</sup>
|3.2 × 10<sup>−10</sup>
|-
|colspan=2 |[[Energi Hartree]]
|<math>E_{\mathrm{h}} = 2 R_\infin h c \,</math>
|4.359 744 34(19) × 10<sup>−18</sup> J
|4.4 × 10<sup>−8</sup>
|-
|colspan=2 |[[proton|massa proton]]
|<math>m_{\mathrm{p}} \,</math>
| 1.672 621 777(74) × 10<sup>−27</sup> kg
|4.4 × 10<sup>−8</sup>
|-
|colspan=2 |kuantum sirkulasi
|<math>h / 2 m_{\mathrm{e}} \,</math>
|3.636 947 5520(24) × 10<sup>−4</sup> m<sup>2</sup> s<sup>−1</sup>
|6.5 × 10<sup>−10</sup>
|-
|colspan=2 |[[konstanta Rydberg]]
|<math>R_\infin = \alpha^2 m_{\mathrm{e}} c / 2 h \,</math>
|10 973 731.568 539(55) m<sup>−1</sup>
|5.0 × 10<sup>−12</sup>
|-
|colspan=2 |Thomson [[cross section (physics)|cross section]]
|<math>(8 \pi / 3)r_{\mathrm{e}}^2</math>
|6.652 458 734(13) × 10<sup>−29</sup> m<sup>2</sup>
|1.9 × 10<sup>−9</sup>
|-
|colspan=2 |[[sudut Weinberg|sudut campur lemah]]
|<math>\sin^2 \theta_{\mathrm{W}} = 1 - (m_{\mathrm{W}} / m_{\mathrm{Z}})^2 \,</math>
|0.2223(21)</td>
<td>9.5 × 10<sup>−3</sup>
|-
|colspan=2 |[[keadaan Efimov|faktor Efimov]]
|<math></math>
|22.7</td>
<td>
|-
|}

== Tabel konstanta fisika-kimia ==
{{Table of physico-chemical constants}}

== Tabel nilai yang diadopsi ==
{| class="wikitable"
|-
!colspan=2|Besaran
!Simbol
!Nilai (satuan [[SI]])
!Ketidakpastian standar relatif
|-
|colspan=2|nilai konvensional [[konstanta Josephson]]<ref name="volt">This is the value adopted internationally for realizing representations of the [[volt]] using the [[Josephson effect]].<br /></ref>
|<math>K_{\mathrm{J-90}} \,</math>
|4.835 979 × 10<sup>14</sup> Hz·V<sup>−1</sup>
|terdefinisi
|-
|colspan=2|nilai konvensional [[konstanta von Klitzing]]<ref name="vonKlitzing">This is the value adopted internationally for realizing representations of the [[Ohm (satuan)|ohm]] using the [[efek kuantum Hall]].</ref>
|<math>R_{\mathrm{K-90}} \,</math>
|25 812.807 Ω
|terdefinisi
|-
|rowspan=2 align="center"|[[massa molar]]
|[[konstanta massa molar|konstanta]]
|<math>M_{\mathrm{u}} = M({}^{12}\mathrm{C}) / 12 \,</math>
|1 × 10<sup>−3</sup> kg·mol<sup>−1</sup>
|terdefinisi
|-
|[[karbon-12]]
|<math>M({}^{12}\mathrm{C}) = N_{\mathrm{A}} m({}^{12}\mathrm{C}) \,</math>
|1.2 × 10<sup>−2</sup> kg·mol<sup>−1</sup>
|terdefinisi
|-
|colspan=2|percepatan [[gravitasi]] standar ([[jatuh bebas]] di bumi)
|<math>g_{\mathrm{n}} \,\!</math>
|9.806 65 m·s<sup>−2</sup>
|terdefinisi
|-
|colspan=2|[[Atmosfer (satuan)|atmosfer standar]]
|<math> \mathrm{atm} \,</math>
|101 325 Pa
|terdefinisi
|-
|}

== Satuan natural ==
{{main|Satuan natural}}
Dengan menggunakan [[analisis dimensional]], dimungkinkan untuk menggabungkan konstanta fisika universal untuk mendefinisikan sistem [[satuan pengukuran]] yang tidak memiliki acuan ke konstruksi manusia manapun. Bergantung dari pemilihan dan penataan konstanta yang digunakan, satuan natural yang dihasilkan mungkin dapat memiliki makna fisika yang berarti. Contohnya, [[satuan Planck]], dibawah ini, menggunakan [[kecepatan cahaya|''c'']], [[konstanta gravitasi|''G'']], [[konstanta Planck|''ħ'']], [[konstanta listrik|''ε''<sub>0</sub>]] dan [[konstanta Boltzmann|''k<sub>B</sub>'']] untuk menyatukan berbagai teori seperti [[gravitasi kuantum]].
{| class="wikitable"
!colspan=4| {{tnavbar-header|'''Base Planck units'''|Template:Base Planck units}}
|-
! Nama
! Dimensi
! Dinyatakan
! Nilai<ref name="CODATA">[http://physics.nist.gov/cuu/Constants/index.html Fundamental Physical Constants from NIST]</ref> ([[SI]] units)
|- style="text-align:left;"
| '''[[panjang Planck]]'''
| [[Panjang]] (L)
| <math>l_\text{P} = \sqrt{\frac{\hbar G}{c^3}}</math>
| {{nowrap|1.616 199(97) × 10<sup>−35</sup> [[meter|m]]}}<ref>[http://physics.nist.gov/cgi-bin/cuu/Value?plkl CODATA — Planck length]</ref>
|-
| '''[[massa Planck]]'''
| [[Massa]] (M)
| <math>m_\text{P} = \sqrt{\frac{\hbar c}{G}}</math>
| {{nowrap|2.176 51(13) × 10<sup>−8</sup> [[kilogram|kg]]}}<ref>[http://physics.nist.gov/cgi-bin/cuu/Value?plkm CODATA — Planck mass]</ref>
|-
| '''[[waktu Planck]]'''
| [[Waktu]] (T)
| <math>t_\text{P} = \frac{l_\text{P}}{c} = \frac{\hbar}{m_\text{P}c^2} = \sqrt{\frac{\hbar G}{c^5}} </math>
| {{nowrap|5.391 06(32) × 10<sup>−44</sup> [[detik|s]]}}<ref>[http://physics.nist.gov/cgi-bin/cuu/Value?plkt CODATA — Planck time]</ref>
|-
| '''[[muatan Planck]]'''
| [[muatan listrik]] (Q)
| <math>q_\text{P} = \sqrt{4 \pi \varepsilon_0 \hbar c} </math>
| {{nowrap|1.875 545 956(41) × 10<sup>−18</sup> [[Coulomb|C]]}}<ref>[http://physics.nist.gov/cgi-bin/cuu/Value?ep0 CODATA — electric constant]</ref><ref>[http://physics.nist.gov/cgi-bin/cuu/Value?hbar CODATA — Planck constant over 2 pi]</ref><ref>[http://physics.nist.gov/cgi-bin/cuu/Value?c CODATA — speed of light in vacuum]</ref>
|-
| '''[[temperatur Planck]]'''
| [[Temperatur]] (Θ)
| <math>T_\text{P} = \frac{m_\text{P} c^2}{k_\text{B}} = \sqrt{\frac{\hbar c^5}{G k_\text{B}^2}}</math>
| {{nowrap|1.416 833(85) × 10<sup>32</sup> [[kelvin|K]]}}<ref>[http://physics.nist.gov/cgi-bin/cuu/Value?plktmp CODATA — Planck temperature]</ref>
|}

== Referensi ==
{{reflist}}
* {{CODATA2006}}
* {{citation|authorlink= John D. Barrow|last=Barrow |first= John D. |title =The Constants of Nature; From Alpha to Omega - The Numbers that Encode the Deepest Secrets of the Universe| publisher=Pantheon Books| year=2002 | isbn=0-375-42221-8}}.
== Pranala luar ==
* [http://www.sixtysymbols.com/# Sixty Symbols], University of Nottingham
* [http://goldbook.iupac.org/list_goldbook_phys_constants_defs.html IUPAC - Gold Book]

{{Authority control}}

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