Template:Physical constants/doc
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This template provides easy inclusion of the latest CODATA recommended values of physical constants in articles. It gives the most recent values published, and will be updated when newer values become available, which is typically every four years.
The values have been updated to the CODATA 2018 values. This includes the 2019 redefinition of SI base units, which made the values of several constants exact (e.g. e), whereas some previously exactly defined constants acquired an uncertainty (e.g. μ0).
Usage
Arguments
symbol
- If set to
yes
, the value is preceded by the symbol of the constant, followed by ≈ or = depending on whether or notround
is set. round
- If omitted, the value is shown along with its standard uncertainty. If set to an integer n, the value is rounded to the first n digits after the decimal point (retaining trailing zeros).
unit
- If set to
no
, the unit of measurement is not shown. ref
- If set to
no
, no reference is given. If set toonly
, only the reference is given. after
- Text (e.g. punctuation) to be shown after the constant before the reference.
runc
- If set to
yes
, this will provide only the relative standard uncertainty of the value and its reference.
Available constants
Examples
{{Physical constants|c|unit=no|after= [[metre per second|metres per second]].}}
- 299792458 metres per second.[1]
{{Physical constants|mu0|symbol=yes}}
- μ0 = 1.25663706212(19)×10−6 N⋅A−2[2]
{{Physical constants|G|symbol=yes}}
- G = 6.67430(15)×10−11 m3⋅kg−1⋅s−2[3]
{{Physical constants|hbar|round=2|symbol=yes}}
- ħ ≈ 1.05×10−34 J⋅s[4]
The relative standard uncertainty of ''m''<sub>u</sub> is {{Physical constants|mu|runc=yes|after=.}}
- The relative standard uncertainty of mu is 3.0×10−10.[5]
For the electron mass, {{Physical constants|me|runc=yes|symbol=yes|ref=no}}.
- For the electron mass, ur(me) = 3.0×10−10.
NIST publishes the CODATA value of the [[elementary charge]].{{Physical constants|e|ref=only}}
- NIST publishes the CODATA value of the elementary charge.[6]
See also
{{CODATA2010}}
References
- ↑ "2018 CODATA Value: speed of light in vacuum". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2019-05-20.
{{cite web}}
: Cite has empty unknown parameter:|month=
(help) - ↑ "2018 CODATA Value: vacuum magnetic permeability". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2019-05-20.
- ↑ "2018 CODATA Value: Newtonian constant of gravitation". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2019-05-20.
{{cite web}}
: Cite has empty unknown parameter:|month=
(help) - ↑ "2018 CODATA Value: reduced Planck constant". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2019-08-28.
{{cite web}}
: Cite has empty unknown parameter:|month=
(help) - ↑ "2018 CODATA Value: atomic mass constant". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2019-05-20.
- ↑ "2018 CODATA Value: elementary charge". The NIST Reference on Constants, Units, and Uncertainty. NIST. 20 May 2019. Retrieved 2019-05-20.
{{cite web}}
: Cite has empty unknown parameter:|month=
(help)