Astro-Constants

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AUTHOR_NOTES.md  view on Meta::CPAN

# Author Notes

These are the Author's notes to himself.

# To Do list

* ```precision()``` - make the function aware of the difference between 
absolute and relative uncertainty
* ~~do some benchmarking on the short forms vs the long names~~
* add_constants.pl shouldn't duplicate a constant
* deprecation should be semi-automated
* add symbols and sources to PhysicalConstants.xml
* check the data/XML_Schema.md file for notes on how to modify the schema
* consider adding Coulomb's constant k = 1/4 PI epsilon_0 for better readability (not speed)

As always check 
[the github repository](https://github.com/duffee/Astro-Constants/issues "Astro::Constants issues")
for current status on issues.

AUTHOR_NOTES.md  view on Meta::CPAN

As a change is made, make copy of PhysicalConstants.xml  to the year and 
upcoming release version of Astro::Constants


## Adding a Constant

There is a script that will add a number of constants to the Constants file
 script/add_constants.pl
assumes the following:
* value in units of MKS
* the uncertainty or precision is given relative to the value

## Modifying a Constant

For now I edit the XML with XML Copy Editor.
Rather than building an editor, I should have a validator.

## Deprecating a Constant

One step per version.  No faster.

ChangeLog  view on Meta::CPAN

* moved constants into main module, Astro::Constants
* removed Astro::Constants::CGS from distribution
* removed short names
* changed `:long` tag to `:all`

v0.14	2020 Apr
====
* updated values to the **2018 CODATA** standard
* build script now produces a Raku module for Astro::Constants
* removed references to CGS in documentation
* added script that fetches constant values and uncertainties from NIST
* added warnings to module when using deprecated constants
* added a script to archive the current PhysicalConstants.xml file
* added dimensions to constants in terms of the SI base units
* values that are established by definition are assigned an relative uncertainty of 0
* clarified definition of critical density parameter, rho_c
* updated PhysicalConstants.xml schema definition
  * changed name of **url** element to **source**
  * added _authority_, _year_ and _reference_ attributes to **source**

v0.13	2018 May
====
* adding symbols to PhysicalConstants.xml definition file
* adding deprecation warning to Astro::Constants::CGS - to be removed from package v0.15
* alternateName element in PhysicalConstants.xml can now take a "type" attribute

data/PhysicalConstants.xml  view on Meta::CPAN

  <timestamp>Sat Apr 18 10:30:23 2020</timestamp>
  <version>v0.14</version>
  <reference_standard>2018 CODATA</reference_standard>
  <link href="http://metacpan.org/pod/Astro::Constants"/>
  <items>
    <PhysicalConstant>
      <name>SPEED_LIGHT</name>
      <alternateName>LIGHT_SPEED</alternateName>
      <description>speed of light in a vacuum</description>
      <value>299792458</value>
      <uncertainty type="defined"/>
      <dimensions length="1" time="-2"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?c" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>BOLTZMANN</name>
      <alternateName/>
      <description>Boltzmann's constant</description>
      <value>1.380649e-23</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions mass="1" length="2" time="-2" temperature="-1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?k" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>GRAVITATIONAL</name>
      <alternateName/>
      <symbol>G</symbol>
      <description>universal gravitational constant</description>
      <value>6.67430e-11</value>
      <uncertainty type="relative">2.2e-5</uncertainty>
      <dimensions length="3" mass="-1" time="-2"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?bg" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>ELECTRON_VOLT</name>
      <alternateName/>
      <description>electron volt</description>
      <value>1.602176634e-19</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions mass="1" length="2" time="-2"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?evj"/>
      <categoryList>
        <category>fundamental</category>
        <category>conversion</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>PLANCK</name>
      <alternateName/>
      <description>Planck constant</description>
      <value>6.62607015e-34</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions mass="1" length="2" time="-1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?h" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>H_BAR</name>
      <alternateName>HBAR</alternateName>
      <description>the reduced Planck constant, Planck's constant (exact) /2pi</description>
      <value>1.0545718176763e-34</value>
      <uncertainty type="relative">1.5e-9</uncertainty>
      <dimensions mass="1" length="2" time="-1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?hbar" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>CHARGE_ELEMENTARY</name>
      <alternateName>ELECTRON_CHARGE</alternateName>
      <description>electron charge (defined positive)</description>
      <value>1.602176634e-19</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions current="1" time="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?e"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>

data/PhysicalConstants.xml  view on Meta::CPAN

      <alternateName/>
      <symbol>
        <symbolRepresentation>
          <latex>\sigma</latex>
          <html>&amp;sigma;</html>
          <unicode>σ</unicode>
        </symbolRepresentation>
      </symbol>
      <description>Stefan-Boltzmann constant</description>
      <value>5.670374419e-8</value>
      <uncertainty type="relative">1.7e-10</uncertainty>
      <dimensions mass="1" time="-3" temperature="-4"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?sigma" authority="2018 CODATA" year="2019"/>
      <source url="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>DENSITY_RADIATION</name>
      <alternateName>A_RAD</alternateName>
      <symbol>a</symbol>
      <description>radiation density constant, 4 * sigma / c</description>
      <value>7.565723e-16</value>
      <uncertainty type="relative">2.3e-6</uncertainty>
      <dimensions mass="1" length="-1" time="-1" temperature="-4"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant"/>
      <source url="http://scienceworld.wolfram.com/physics/RadiationConstant.html"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>WIEN</name>
      <alternateName/>
      <symbol>b</symbol>
      <description>Wien wavelength displacement law constant</description>
      <value>2.897771955e-3</value>
      <uncertainty type="relative">1e-10</uncertainty>
      <dimensions length="1" temperature="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?bwien" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>cosmology</category>
        <category>planetary</category>
        <category>nuclear</category>

data/PhysicalConstants.xml  view on Meta::CPAN

    <PhysicalConstant>
      <name>ALPHA</name>
      <alternateName/>
      <symbol>
        <symbolRepresentation>
          <latex>\alpha</latex>
        </symbolRepresentation>
      </symbol>
      <description>fine structure constant</description>
      <value>7.2973525693e-3</value>
      <uncertainty type="relative">1.5e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?alph" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>

data/PhysicalConstants.xml  view on Meta::CPAN

      <alternateName>VACUUM_IMPEDANCE</alternateName>
      <symbol>
        <symbolRepresentation>
          <latex>Z_{0}</latex>
          <html>Z&lt;sub&gt;0&lt;/sub&gt;</html>
          <unicode>Zâ‚€</unicode>
        </symbolRepresentation>
      </symbol>
      <description>characteristic impedance of vacuum</description>
      <value>376.730313461</value>
      <uncertainty type="relative">1e-50</uncertainty>
      <dimensions mass="1" lenghth="2" time="-3" current="-2"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?z0"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>

data/PhysicalConstants.xml  view on Meta::CPAN

    <PhysicalConstant>
      <name>PERMITIV_FREE_SPACE</name>
      <alternateName>PERMITIVITY_0</alternateName>
      <symbol>
        <symbolRepresentation>
          <latex>\varepsilon_{0}</latex>
        </symbolRepresentation>
      </symbol>
      <description>permittivity of free space, epsilon_0, the electric constant</description>
      <value>8.8541878128e-12</value>
      <uncertainty type="relative">1.5e-10</uncertainty>
      <dimensions time="4" current="2" length="-3" mass="-1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?ep0" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>

data/PhysicalConstants.xml  view on Meta::CPAN

      <name>PERMEABL_FREE_SPACE</name>
      <alternateName>PERMEABILITY_0</alternateName>
      <alternateName>CONSTANT_MAGNETIC</alternateName>
      <symbol>
        <symbolRepresentation>
          <latex>\mu_{0}</latex>
        </symbolRepresentation>
      </symbol>
      <description>permeability of free space, mu_0, the magnetic constant</description>
      <value>1.25663706212e-6</value>
      <uncertainty type="relative">1.5e-10</uncertainty>
      <dimensions mass="1" length="1" time="-2" current="-2"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mu0" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>PI</name>
      <alternateName/>
      <description>trig constant pi</description>
      <value>3.14159265358979324</value>
      <uncertainty type="relative">0.00000000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://oeis.org/search?q=id:A000796&amp;fmt=text"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>FOUR_PI</name>
      <alternateName>FOURPI</alternateName>
      <description>trig constant pi times 4 (shorthand for some calculations)</description>
      <value>12.5663706143592</value>
      <uncertainty type="relative">0.0000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Pi"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>STERADIAN</name>
      <alternateName/>
      <description>a measure of solid angle in square degrees and a SI derived unit</description>
      <value>3282.80635001174</value>
      <uncertainty type="relative">0.00000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Steradian"/>
      <categoryList>
        <category>conversion</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>EXP</name>
      <alternateName/>
      <description>base of natural logarithm</description>
      <value>2.71828182846</value>
      <uncertainty type="relative">0.00000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://oeis.org/search?q=id:A001113&amp;fmt=text"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>ATOMIC_MASS_UNIT</name>
      <alternateName/>
      <symbol>u</symbol>
      <description>unified atomic mass unit, 1 u</description>
      <value>1.66053906660e-27</value>
      <uncertainty type="relative">3.0e-10</uncertainty>
      <dimensions mass="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?ukg" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>conversion</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>PARSEC</name>
      <alternateName/>
      <description>parsec</description>
      <value>3.08567758149e16</value>
      <uncertainty type="relative">1e-11</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Parsec" year="2015"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>ASTRONOMICAL_UNIT</name>
      <alternateName/>
      <description>astronomical unit</description>
      <value>149597870700</value>
      <!-- <value>149_597_870_700</value> -->
      <uncertainty type="relative">0</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://cneos.jpl.nasa.gov/glossary/au.html" authority="IAU"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>LIGHT_YEAR</name>
      <alternateName/>
      <description>the distance that light travels in vacuum in one Julian year</description>
      <value>9460730472580800</value>
      <!-- <value>9_460_730_472_580_800</value> -->
      <uncertainty type="defined"/>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Light-year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>ANGSTROM</name>
      <alternateName/>
      <description>Angstrom</description>
      <value>1e-10</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Angstrom"/>
      <categoryList>
        <category>conversion</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>JANSKY</name>
      <alternateName/>
      <symbol>Jy</symbol>
      <description>Jansky, a unit of flux density</description>
      <value>1e-26</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions mass="1" time="-2"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Jansky" authority="IAU"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>AVOGADRO</name>
      <alternateName/>
      <description>Avogadro's number</description>
      <value>6.02214076e23</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions amountOfSubstance="-1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?na" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>conversion</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>YEAR</name>
      <alternateName>YEAR_JULIAN</alternateName>
      <description>defined as exactly 365.25 days of 86400 SI seconds</description>
      <value>31557600</value>
      <!-- <value>31_557_600</value> -->
      <uncertainty type="relative">0</uncertainty>
      <dimensions time="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Julian_year_(astronomy)"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>YEAR_TROPICAL</name>
      <alternateName/>
      <description>the period of time for the ecliptic longitude of the Sun to increase 360 degrees, approximated by the Gregorian calendar</description>
      <value>31556925.1</value>
      <!-- <value>31_556_925.1</value> -->
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions time="1"/>
      <maxValue>31556959</maxValue>
      <minValue>31556892</minValue>
      <source url="https://en.wikipedia.org/wiki/Tropical_year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>YEAR_SIDEREAL</name>
      <alternateName/>
      <description>the period of revolution of the Earth around the Sun in a fixed reference frame</description>
      <value>31558149.8</value>
      <!-- <value>31_558_149.8</value> -->
      <uncertainty type="absolute">1</uncertainty>
      <dimensions time="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sidereal_year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>YEAR_ANOMALISTIC</name>
      <alternateName/>
      <description>the period between successive passages of the Earth through perihelion</description>
      <value>31558432.6</value>
      <!-- <value>31_558_432.6</value> -->
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions time="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Year#Sidereal,_tropical,_and_anomalistic_years"/>
      <categoryList>
        <category>conversion</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>YEAR_ECLIPSE</name>
      <alternateName/>
      <description>the period between successive passages of the Sun (as seen from the geocenter) through the same lunar node</description>
      <value>29947974.3</value>
      <!-- <value>29_947_974.3</value> -->
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions time="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Year#Draconic_year"/>
      <categoryList>
        <category>conversion</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MASS_SOLAR</name>
      <alternateName>SOLAR_MASS</alternateName>
      <description>solar mass</description>
      <value>1.9884e30</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions mass="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Solar_mass" authority="USNO" year="2014"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>LUMINOSITY_SOLAR</name>
      <alternateName>SOLAR_LUMINOSITY</alternateName>
      <description>solar luminosity</description>
      <value>3.828e26</value>
      <uncertainty type="relative">0.0003</uncertainty>
      <dimensions mass="1" length="2" time="-3"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Solar_luminosity" authority="IAU" year="2015"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>

data/PhysicalConstants.xml  view on Meta::CPAN

        <symbolRepresentation>
          <latex>\frac{\rho_{c}{h^{2}}}</latex>
        </symbolRepresentation>
      </symbol>
      <description>Critical Density parameter expressed in terms of
	      <![CDATA[
	      ρ_c / h² = 3 × (100 km s⁻¹ Mpc⁻¹)² / 8πG
	      ]]>
Multiply by the square of the dimensionless Hubble parameter, h, in your calculations to get the actual value</description>
      <value>1.87834e-26</value>
      <uncertainty type="relative">2.3e-5</uncertainty>
      <dimensions mass="1" length="-3"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Friedmann_equations#Density_parameter"/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>HUBBLE_TIME</name>
      <alternateName/>
      <description>Hubble time *h, the inverse of Hubble's constant valued at 100 km/s/Mpc (DEPRECATED - see ChangeLog)</description>
      <value>3.0853056e17</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions time="1"/>
      <maxValue/>
      <minValue/>
      <source url=""/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
      <deprecated version="0.11" date="2017-04-26"/>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>TEMPERATURE_CMB</name>
      <alternateName>CMB_TEMPERATURE</alternateName>
      <description>cosmic microwave background temperature in Kelvin</description>
      <value>2.72548</value>
      <uncertainty type="absolute">0.00057</uncertainty>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions temperature="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Cosmic_microwave_background" reference="Bibcode:2009ApJ...707..916F" year="2009"/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MAGNITUDE_SOLAR_V</name>
      <alternateName>SOLAR_V_MAG</alternateName>
      <description>visual brightness of the Sun</description>
      <value>-26.74</value>
      <uncertainty type="relative">0.0004</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sun" year="1986"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MAGNITUDE_SOLAR_V_ABSOLUTE</name>
      <alternateName>SOLAR_V_ABS_MAG</alternateName>
      <description>solar absolute V magnitude</description>
      <value>4.83</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>RADIUS_SOLAR</name>
      <alternateName>SOLAR_RADIUS</alternateName>
      <description>solar radius</description>
      <value>6.96e8</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MASS_EARTH</name>
      <alternateName>EARTH_MASS</alternateName>
      <description>mass of Earth</description>
      <value>5.9722e24</value>
      <uncertainty type="absolute">6e20</uncertainty>
      <dimensions mass="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>RADIUS_EARTH</name>
      <alternateName>EARTH_RADIUS</alternateName>
      <description>radius of Earth</description>
      <value>6.3781366e6</value>
      <!-- <value>6.378_136_6e6</value> -->
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>TEMPERATURE_SOLAR_SURFACE</name>
      <alternateName>SOLAR_TEMPERATURE</alternateName>
      <description>surface temperature of sun (photosphere)</description>
      <value>5772</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions temperatur="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sun" authority="NASA" year="2010"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>DENSITY_SOLAR</name>
      <alternateName>SOLAR_DENSITY</alternateName>
      <description>mean solar density</description>
      <value>1408</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions mass="1" length="-3"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sun" authority="NASA" year="2010"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>DENSITY_EARTH</name>
      <alternateName>EARTH_DENSITY</alternateName>
      <description>mean Earth density</description>
      <value>5515</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions mass="1" length="-3"/>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html" authority="NASA" year="2010"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>GRAVITY_SOLAR</name>
      <alternateName>SOLAR_GRAVITY</alternateName>
      <description>solar surface gravity</description>
      <value>274.78</value>
      <uncertainty type="relative">0.0004</uncertainty>
      <dimensions length="1" time="-2"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Surface_gravity"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>GRAVITY_EARTH</name>
      <alternateName>EARTH_GRAVITY</alternateName>
      <description>Earth surface gravity</description>
      <value>9.80665</value>
      <uncertainty type="relative">0.000001</uncertainty>
      <dimensions length="1" time="-2"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Surface_gravity" authority="ISO 80000" year="2019"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>RADIUS_LUNAR</name>
      <alternateName>LUNAR_RADIUS</alternateName>
      <description>lunar radius</description>
      <value>1.7381e6</value>
      <uncertainty type="relative">6e-5</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html" authority="NASA" year="2020"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MASS_LUNAR</name>
      <alternateName>LUNAR_MASS</alternateName>
      <description>lunar mass</description>
      <value>7.346e22</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions mass="kg"/>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html" authority="NASA" year="2020"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>AXIS_SM_LUNAR</name>
      <alternateName>LUNAR_SM_AXIS</alternateName>
      <description>lunar orbital semi-major axis</description>
      <value>3.84402e8</value>
      <uncertainty type="relative">3e-9</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Lunar_distance_(astronomy)" reference="Bibcode:2009PASP..121...29B" year="2009"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>ECCENTRICITY_LUNAR</name>
      <alternateName>LUNAR_ECCENTRICITY</alternateName>
      <description>lunar orbital eccentricity</description>
      <value>0.0549</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Orbit_of_the_Moon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>THOMSON_CROSS_SECTION</name>
      <alternateName>THOMSON_XSECTION</alternateName>
      <symbol>
        <symbolRepresentation>
          <latex>\sigma_{e}</latex>
        </symbolRepresentation>
      </symbol>
      <description>Thomson cross-section</description>
      <value>6.6524587321e-29</value>
      <uncertainty type="relative">9.1e-10</uncertainty>
      <dimensions length="2"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?sigmae" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MASS_ELECTRON</name>
      <alternateName>ELECTRON_MASS</alternateName>
      <description>mass of electron</description>
      <value>9.1093837015e-31</value>
      <uncertainty type="relative">3e-10</uncertainty>
      <dimensions mass="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?me" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MASS_PROTON</name>
      <alternateName>PROTON_MASS</alternateName>
      <description>mass of proton</description>
      <value>1.67262192369e-27</value>
      <uncertainty type="relative">3.1e-10</uncertainty>
      <dimensions mass="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mp" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MASS_NEUTRON</name>
      <alternateName>NEUTRON_MASS</alternateName>
      <description>neutron mass</description>
      <value>1.67492749804e-27</value>
      <uncertainty type="relative">5.7e-10</uncertainty>
      <dimensions mass="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mn" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MASS_HYDROGEN</name>
      <alternateName>HYDROGEN_MASS</alternateName>
      <description>mass of Hydrogen atom --
This value is from the IUPAC and is a little smaller than MASS_PROTON + MASS_ELECTRON, but within the uncertainty given here.  The current value is 1.008u +/- 0.0002 derived from a range of terrestrial materials.  If this is for precision work, you h...
</description>
      <value>1.6738e-27</value>
      <uncertainty type="absolute">3.3e-31</uncertainty>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions mass="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://www.degruyter.com/downloadpdf/j/pac.2016.88.issue-3/pac-2015-0305/pac-2015-0305.pdf" authority="IUPAC"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MASS_ALPHA</name>
      <symbol>
        <symbolRepresentation>
          <latex>m_{\alpha}</latex>
        </symbolRepresentation>
      </symbol>
      <description>mass of alpha particle</description>
      <value>6.6446573357e-27</value>
      <uncertainty type="relative">3.0e-10</uncertainty>
      <dimensions mass="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mal" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>RADIUS_ELECTRON</name>
      <alternateName>ELECTRON_RADIUS</alternateName>
      <symbol>
        <symbolRepresentation>
          <latex>r_{e}</latex>
        </symbolRepresentation>
      </symbol>
      <description>classical electron radius</description>
      <value>2.8179403262e-15</value>
      <uncertainty type="relative">4.5e-10</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?re" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>nuclear</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>RADIUS_BOHR</name>
      <alternateName>BOHR_RADIUS</alternateName>
      <symbol>
        <symbolRepresentation>
          <latex>a_{0}</latex>
        </symbolRepresentation>
      </symbol>
      <description>Bohr radius</description>
      <value>5.29177210903e-11</value>
      <uncertainty type="relative">1.5e-10</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?bohrrada0" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>RADIUS_JUPITER</name>
      <description>Volumetric mean radius of Jupiter</description>
      <value>69911000</value>
      <!-- <value>69_911_000</value> -->
      <uncertainty type="relative">1.5e-5</uncertainty>
      <dimensions length="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name>MASS_JUPITER</name>
      <description>mass of Jupiter</description>
      <value>1.89819e27</value>
      <uncertainty type="relative">5e-6</uncertainty>
      <dimensions mass="1"/>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
  </items>
</Collection>

data/PhysicalConstants.xsd  view on Meta::CPAN

    </xs:complexType>
  </xs:element>
  <xs:element name="PhysicalConstant">
    <xs:complexType>
      <xs:sequence>
        <xs:element ref="name" maxOccurs="unbounded" minOccurs="1"/>
        <xs:element ref="alternateName" minOccurs="0" maxOccurs="unbounded"/>
        <xs:element ref="symbol" minOccurs="0" maxOccurs="unbounded"/>
        <xs:element name="description" type="xs:string"/>
        <xs:element name="value" type="xs:float"/>
        <xs:element ref="uncertainty" maxOccurs="unbounded"/>
        <xs:element name="dimensions" maxOccurs="1"/>
        <xs:element name="maxValue" type="xs:float" default="0"/>
        <xs:element name="minValue" type="xs:float" default="0"/>
        <xs:element ref="source" maxOccurs="unbounded"/>
        <xs:element ref="categoryList"/>
        <xs:element ref="deprecated" minOccurs="0"/>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
  <xs:element name="name">

data/PhysicalConstants.xsd  view on Meta::CPAN

      The symbol element can contain a string of ascii characters
      or uses the symbolRepresentation definition in order to hold more information
    </xs:documentation>
    </xs:annotation>
    <xs:complexType mixed="true">
      <xs:choice>
        <xs:element ref="symbolRepresentation" minOccurs="0"/>
      </xs:choice>
    </xs:complexType>
  </xs:element>
  <xs:element name="uncertainty">
    <xs:complexType mixed="true">
      <xs:attribute name="type" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="dimensions">
    <xs:annotation>
      <xs:documentation xml:lang="en">
	      The seven SI base units and their dimensions
	      as set out under BIPM in 2019
	      s    second    time

data/PhysicalConstants_derived.xsd  view on Meta::CPAN

      </xs:sequence>
    </xs:complexType>
  </xs:element>
  <xs:element name="PhysicalConstant">
    <xs:complexType>
      <xs:sequence>
        <xs:element ref="name" maxOccurs="unbounded"/>
        <xs:element name="alternateName" type="xs:string"/>
        <xs:element name="description" type="xs:string"/>
        <xs:element ref="value" maxOccurs="unbounded"/>
        <xs:element ref="uncertainty" maxOccurs="unbounded"/>
        <xs:element name="dimensions" type="xs:string"/>
        <xs:element name="maxValue" type="xs:string"/>
        <xs:element name="minValue" type="xs:string"/>
        <xs:element ref="url" maxOccurs="unbounded"/>
        <xs:element ref="categoryList"/>
        <xs:element ref="deprecated" minOccurs="0"/>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
  <xs:element name="name">
    <xs:complexType mixed="true">
      <xs:attribute name="type" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="value">
    <xs:complexType mixed="true">
      <xs:attribute name="system" type="xs:string"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="uncertainty">
    <xs:complexType mixed="true">
      <xs:attribute name="type" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="url">
    <xs:complexType>
      <xs:attribute name="href" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
  <xs:element name="categoryList">

data/XML_Schema.md  view on Meta::CPAN


This describes the attributes of one physical constant.
Options are enclosed in [ ]'s and defaults are **bolded**.

* **name**	- the name of the constant as used in your programming language
* **alternateName**	- used for older names, aliases, can be more than one
  - *type*	- attribute which describes how the alternateName is used.  [alias, deprecated]
  - *version* - version of Constants file in which type decided
* **description**	- text to describe the constant
* **value**	- the numerical value of the constant in SI units
* **uncertainty**	- the uncertainty or error in the value
  - *type*	- is the uncertainty in the same units or expressed as a ratio to the value [absolute, relative].
* **dimensions**	- for future use in dimensional analysis,  lists which of the 7 dimensions the constant consists of (e.g. M for mass, L for length, L3 for volume, ML-3 for density)
* **minValue**	- minimum value for the constant, for constants that have values not best described by uncertainty
* **maxValue**	- maximum value for the constant, for constants that have values not best described by uncertainty
* **source**	- a source url for the value of the constant
* **categoryList**	- a list of *category* items that the constant belongs to
* **deprecated**	- used to flag a constant that has been deprecated and will be removed from future versions. 
  - *date*	- date of deprecation decision
  - *version*	- version of PhysicalConstants file when deprecated

### category
I use these to export groups of constants into the namespace.
Add useful categories as required, but try not to over use them.
Keep it useful, not as metadata.

data/old_versions/constants_2015_v0.09.xml  view on Meta::CPAN

  <timestamp>Tue Dec  8 15:38:41 2015</timestamp>
  <version/>
  <link href="http://metacpan.org/pod/Astro::Constants"/>
  <items>
    <constant>
      <name type="long">LIGHT_SPEED</name>
      <name type="short">A_c</name>
      <description>speed of light in a vacuum</description>
      <value system="MKS">2.99792458e8</value>
      <value system="CGS">2.99792458e10</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?c"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">BOLTZMANN</name>
      <name type="short">A_k</name>
      <description>Boltzmann's constant</description>
      <value system="MKS">1.38064852e-23</value>
      <value system="CGS">1.38064852e-16</value>
      <uncertainty type="relative">5.7e-7</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?k"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">GRAVITATIONAL</name>
      <name type="short">A_G</name>
      <description>universal gravitational constant</description>
      <value system="MKS">6.67408e-11</value>
      <value system="CGS">6.67408e-8</value>
      <uncertainty type="relative">4.7e-5</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?G"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">ELECTRON_MASS</name>
      <name type="short">A_me</name>
      <description>mass of electron</description>
      <value system="MKS">9.1093897e-31</value>
      <value system="CGS">9.1093897e-28</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?me"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">PROTON_MASS</name>
      <name type="short">A_mp</name>
      <description>mass of proton</description>
      <value system="MKS">1.672631e-27</value>
      <value system="CGS">1.672631e-24</value>
      <uncertainty type="relative">0.000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?mp"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">ATOMIC_MASS_UNIT</name>
      <name type="short">A_amu</name>
      <description>atomic mass unit</description>
      <value system="MKS">1.6605402e-27</value>
      <value system="CGS">1.6605402e-24</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?amu"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">ELECTRON_VOLT</name>
      <name type="short">A_eV</name>
      <description>electron volt</description>
      <value system="MKS">1.6021772e-19</value>
      <value system="CGS">1.6021772e-12</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?eV"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">PLANCK</name>
      <name type="short">A_h</name>
      <description>Planck's constant</description>
      <value system="MKS">6.6260755e-34</value>
      <value system="CGS">6.6260755e-27</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?h"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">HBAR</name>
      <name type="short">A_hbar</name>
      <description>Planck's constant /2pi</description>
      <value system="MKS">1.0545727e-34</value>
      <value system="CGS">1.0545727e-27</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?hbar"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">ELECTRON_CHARGE</name>
      <name type="short">A_e</name>
      <description>electron charge (defined positive)</description>
      <value system="MKS">1.602e-19</value>
      <value system="CGS">4.8032e-10</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?e"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">NEUTRON_MASS</name>
      <name type="short">A_mn</name>
      <description>neutron mass</description>
      <value system="MKS">1.6749286e-27</value>
      <value system="CGS">1.6749286e-24</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?mn"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">HYDROGEN_MASS</name>
      <name type="short">A_mH</name>
      <description>mass of Hydrogen atom</description>
      <value system="MKS">1.6733e-27</value>
      <value system="CGS">1.6733e-24</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?mH"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">PARSEC</name>
      <name type="short">A_pc</name>
      <description>parsec</description>
      <value system="MKS">3.08567758e16</value>
      <value system="CGS">3.08567758e18</value>
      <uncertainty type="relative">0.00000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?pc"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">SOLAR_MASS</name>
      <name type="short">A_msun</name>
      <description>solar mass</description>
      <value system="MKS">1.99e30</value>
      <value system="CGS">1.99e33</value>
      <uncertainty type="relative">0.01</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?msun"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">SOLAR_RADIUS</name>
      <name type="short">A_rsun</name>
      <description>solar radius</description>
      <value system="MKS">6.96e8</value>
      <value system="CGS">6.96e10</value>
      <uncertainty type="relative">0.01</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?rsun"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">ASTRONOMICAL_UNIT</name>
      <name type="short">A_AU</name>
      <description>astronomical unit</description>
      <value system="MKS">1.496e11</value>
      <value system="CGS">1.496e13</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?AU"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">LIGHT_YEAR</name>
      <name type="short">A_ly</name>
      <description>light year</description>
      <value system="MKS">9.463e15</value>
      <value system="CGS">9.463e17</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?ly"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">SOLAR_LUMINOSITY</name>
      <name type="short">A_Lsun</name>
      <description>solar luminosity</description>
      <value system="MKS">3.9e26</value>
      <value system="CGS">3.9e33</value>
      <uncertainty type="relative">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?Lsun"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">EARTH_MASS</name>
      <name type="short">A_mearth</name>
      <description>mass of Earth</description>
      <value system="MKS">5.976e24</value>
      <value system="CGS">5.976e27</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?mearth"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">EARTH_RADIUS</name>
      <name type="short">A_rearth</name>
      <description>radius of Earth</description>
      <value system="MKS">6.378e6</value>
      <value system="CGS">6.378e8</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?rearth"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">ANGSTROM</name>
      <name type="short">A_AA</name>
      <description>Angstrom</description>
      <value system="MKS">1e-10</value>
      <value system="CGS">1e-8</value>
      <uncertainty type="relative">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?AA"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">JANSKY</name>
      <name type="short">A_Jy</name>
      <description>Jansky</description>
      <value system="MKS">1e-26</value>
      <value system="CGS">1e-23</value>
      <uncertainty type="relative">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?Jy"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">RHO_C</name>
      <name type="short">A_rhoc</name>
      <description>critical density /h^2</description>
      <value system="MKS">1.8791e-26</value>
      <value system="CGS">1.8791e-29</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?rhoc"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">STEFAN_BOLTZMANN</name>
      <name type="short">A_sigma</name>
      <description>Stefan-Boltzmann constant</description>
      <value system="MKS">5.67040e-8</value>
      <value system="CGS">5.67040e-5</value>
      <uncertainty type="relative">0.00001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?sigma"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">A_RAD</name>
      <name type="short">A_arad</name>
      <description>radiation density constant</description>
      <value system="MKS">7.5646e-16</value>
      <value system="CGS">7.5646e-15</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?arad"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">THOMSON_XSECTION</name>
      <name type="short">A_sigmaT</name>
      <description>Thomson cross-section</description>
      <value system="MKS">6.6524585e-29</value>
      <value system="CGS">6.6524585e-25</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?sigmaT"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">ELECTRON_RADIUS</name>
      <name type="short">A_re</name>
      <description>classical electron radius</description>
      <value system="MKS">2.817941e-15</value>
      <value system="CGS">2.817941e-13</value>
      <uncertainty type="relative">0.000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?re"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">BOHR_RADIUS</name>
      <name type="short">A_a0</name>
      <description>Bohr radius</description>
      <value system="MKS">5.29177208e-11</value>
      <value system="CGS">5.29177208e-9</value>
      <uncertainty type="relative">0.00000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?a0"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">WIEN</name>
      <name type="short">A_Wien</name>
      <description>Wien displacement law constant</description>
      <value system="MKS">2.897769e-3</value>
      <value system="CGS">2.897769e-1</value>
      <uncertainty type="relative">0.000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?Wien"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">ALPHA</name>
      <name type="short">A_alpha</name>
      <description>fine structure constant</description>
      <value>(1.0/137.03599)</value>
      <uncertainty type="relative">?</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?alpha"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">AVOGADRO</name>
      <name type="short">A_NA</name>
      <description>Avogadro's number</description>
      <value>6.0221367e23</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?NA"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">YEAR</name>
      <name type="short">A_yr</name>
      <description>year</description>
      <value>3.156e7</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?yr"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">HUBBLE_TIME</name>
      <name type="short">A_tH</name>
      <description>Hubble time *h</description>
      <value>3.0853056e17</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?tH"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">SOLAR_TEMPERATURE</name>
      <name type="short">A_Tsun</name>
      <description>surface temperature of sun</description>
      <value>5780</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?Tsun"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">CMB_TEMPERATURE</name>
      <name type="short">A_TCMB</name>
      <description>cosmic microwave background temperature</description>
      <value>2.726</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?TCMB"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">PI</name>
      <name type="short">A_pi</name>
      <description>trig constant pi</description>
      <value>3.14159265358979324</value>
      <uncertainty type="relative">0.00000000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?pi"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">EXP</name>
      <name type="short">A_exp</name>
      <description>base of natural logarithm</description>
      <value>2.71828182846</value>
      <uncertainty type="relative">0.00000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?exp"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">SOLAR_DENSITY</name>
      <name type="short">A_dsun</name>
      <description>mean solar density</description>
      <value system="MKS">1408</value>
      <value system="CGS">1.408</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?dsun"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">EARTH_DENSITY</name>
      <name type="short">A_dearth</name>
      <description>mean Earth density</description>
      <value system="MKS">5515</value>
      <value system="CGS">5.515</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?dearth"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">SOLAR_GRAVITY</name>
      <name type="short">A_gsun</name>
      <description>solar surface gravity</description>
      <value system="MKS">274</value>
      <value system="CGS">27400</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?gsun"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">EARTH_GRAVITY</name>
      <name type="short">A_gearth</name>
      <description>Earth surface gravity</description>
      <value system="MKS">9.78</value>
      <value system="CGS">978</value>
      <uncertainty type="relative">0.01</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?gearth"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">SOLAR_V_MAG</name>
      <name type="short">A_Vsun</name>
      <description>solar V magnitude</description>
      <value>-26.74</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?Vsun"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">SOLAR_V_ABS_MAG</name>
      <name type="short">A_MVsun</name>
      <description>solar absolute V magnitude</description>
      <value>4.83</value>
      <uncertainty type="relative">0.01</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?MVsun"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">VACUUM_IMPEDANCE</name>
      <name type="short">A_Z0</name>
      <description>characteristic impedance of vacuum</description>
      <value>376.730313461</value>
      <uncertainty type="relative">0.00000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?Z0"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">PERMITIV_FREE_SPACE</name>
      <name type="short">A_eps0</name>
      <description>permittivity of free space</description>
      <value system="MKS">8.854187817e-12</value>
      <value system="CGS">1</value>
      <uncertainty type="relative">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?eps0"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">PERMEABL_FREE_SPACE</name>
      <name type="short">A_mu0</name>
      <description>permeability of free space</description>
      <value system="MKS">1.256637061e-6</value>
      <value system="CGS">1</value>
      <uncertainty type="relative">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?mu0"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">LUNAR_RADIUS</name>
      <name type="short">A_rmoon</name>
      <description>lunar radius</description>
      <value system="MKS">1738e3</value>
      <value system="CGS">1738e5</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?rmoon"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">LUNAR_MASS</name>
      <name type="short">A_mmoon</name>
      <description>lunar mass</description>
      <value system="MKS">7.348e22</value>
      <value system="CGS">7.348e25</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?mmoon"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">LUNAR_SM_AXIS</name>
      <name type="short">A_amoon</name>
      <description>lunar orbital semi-major axis</description>
      <value system="MKS">3.844e8</value>
      <value system="CGS">3.844e10</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?amoon"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
    <constant>
      <name type="long">LUNAR_ECCENTRICITY</name>
      <name type="short">A_emoon</name>
      <description>lunar orbital eccentricity</description>
      <value>0.0549</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <link href="http://physics.nist.gov/cgi-bin/cuu/Value?emoon"/>
      <url/>
      <categoryList>
        <category/>
      </categoryList>
    </constant>
  </items>

data/old_versions/constants_2017_v0.12.xml  view on Meta::CPAN

    <source>2014 CODATA</source>
    <link href="http://metacpan.org/pod/Astro::Constants" />
    <items>
        <PhysicalConstant>
            <name type="long">SPEED_LIGHT</name>
            <name type="short">A_c</name>
            <alternateName>LIGHT_SPEED</alternateName>
            <description>speed of light in a vacuum</description>
            <value system="MKS">2.99792458e8</value>
            <value system="CGS">2.99792458e10</value>
            <uncertainty type="relative">0</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?c" />
            <categoryList>
                <category>fundamental</category>
                <category>cosmology</category>
                <category>electromagnetic</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">BOLTZMANN</name>
            <name type="short">A_k</name>
            <alternateName />
            <description>Boltzmann's constant</description>
            <value system="MKS">1.38064852e-23</value>
            <value system="CGS">1.38064852e-16</value>
            <uncertainty type="relative">5.7e-7</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?k" />
            <categoryList>
                <category>fundamental</category>
                <category>electromagnetic</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">GRAVITATIONAL</name>
            <name type="short">A_G</name>
            <alternateName />
            <description>universal gravitational constant</description>
            <value system="MKS">6.67408e-11</value>
            <value system="CGS">6.67408e-8</value>
            <uncertainty type="relative">4.7e-5</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?bg" />
            <categoryList>
                <category>fundamental</category>
                <category>cosmology</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">ELECTRON_VOLT</name>
            <name type="short">A_eV</name>
            <alternateName />
            <description>electron volt</description>
            <value system="MKS">1.6021766208e-19</value>
            <value system="CGS">1.6021766208e-12</value>
            <uncertainty type="relative">6.1e-9</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?tevj" />
            <categoryList>
                <category>fundamental</category>
                <category>conversion</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">PLANCK</name>
            <name type="short">A_h</name>
            <alternateName />
            <description>Planck constant</description>
            <value system="MKS">6.626070040e-34</value>
            <value system="CGS">6.626070040e-27</value>
            <uncertainty type="relative">1.2e-8</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?h" />
            <categoryList>
                <category>fundamental</category>
                <category>cosmology</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">H_BAR</name>
            <name type="short">A_hbar</name>
            <alternateName>HBAR</alternateName>
            <description>Planck's constant /2pi</description>
            <value system="MKS">1.054571800e-34</value>
            <value system="CGS">1.054571800e-27</value>
            <uncertainty type="relative">1.2e-8</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?hbar" />
            <categoryList>
                <category>fundamental</category>
                <category>cosmology</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">ELECTRON_CHARGE</name>
            <name type="short">A_e</name>
            <alternateName>CHARGE_ELEMENTARY</alternateName>
            <description>electron charge (defined positive)</description>
            <value system="MKS">1.6021766208e-19</value>
            <value system="CGS">4.8032046729e-10</value>
            <uncertainty type="relative">6.1e-9</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?e" />
            <categoryList>
                <category>fundamental</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">STEFAN_BOLTZMANN</name>
            <name type="short">A_sigma</name>
            <alternateName />
            <description>Stefan-Boltzmann constant</description>
            <value system="MKS">5.670367e-8</value>
            <value system="CGS">5.670367e-5</value>
            <uncertainty type="relative">2.3e-6</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?sigma" />
            <url href="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant" />
            <categoryList>
                <category>fundamental</category>
                <category>cosmology</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">DENSITY_RADIATION</name>
            <name type="short">A_arad</name>
            <alternateName>A_RAD</alternateName>
            <description>radiation density constant, 4 * sigma / c</description>
            <value system="MKS">7.565723e-16</value>
            <value system="CGS">7.565723e-15</value>
            <uncertainty type="relative">2.3e-6</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant" />
            <categoryList>
                <category>fundamental</category>
                <category>cosmology</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">WIEN</name>
            <name type="short">A_Wien</name>
            <alternateName />
            <description>Wien wavelength displacement law constant</description>
            <value system="MKS">2.8977729e-3</value>
            <value system="CGS">2.8977729e-1</value>
            <uncertainty type="relative">5.7e-7</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?bwien" />
            <categoryList>
                <category>fundamental</category>
                <category>electromagnetic</category>
                <category>cosmology</category>
                <category>planetary</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">ALPHA</name>
            <name type="short">A_alpha</name>
            <alternateName />
            <description>fine structure constant</description>
            <value system="MKS">7.2973525664e-3</value>
            <value system="CGS">7.2973525664e-3</value>
            <uncertainty type="relative">2.3e-10</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?alph" />
            <categoryList>
                <category>fundamental</category>
                <category>cosmology</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">IMPEDANCE_VACUUM</name>
            <name type="short">A_Z0</name>
            <alternateName>VACUUM_IMPEDANCE</alternateName>
            <description>characteristic impedance of vacuum</description>
            <value>376.730313461</value>
            <uncertainty type="relative">1e-50</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Z0" />
            <categoryList>
                <category>fundamental</category>
                <category>cosmology</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">PERMITIV_FREE_SPACE</name>
            <name type="short">A_eps0</name>
            <alternateName>PERMITIVITY_0</alternateName>
            <description>permittivity of free space, epsilon_0, the electric constant</description>
            <value system="MKS">8.854187817e-12</value>
            <value system="CGS">1</value>
            <uncertainty type="relative">1e-30</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?ep0" />
            <categoryList>
                <category>fundamental</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">PERMEABL_FREE_SPACE</name>
            <name type="short">A_mu0</name>
            <alternateName>PERMEABILITY_0</alternateName>
            <alternateName>CONSTANT_MAGNETIC</alternateName>
            <description>permeability of free space, mu_0, the magnetic constant</description>
            <value system="MKS">1.2566370614e-6</value>
            <value system="CGS">1</value>
            <uncertainty type="relative">1e-10</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mu0" />
            <categoryList>
                <category>fundamental</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">PI</name>
            <name type="short">A_pi</name>
            <alternateName />
            <description>trig constant pi</description>
            <value>3.14159265358979324</value>
            <uncertainty type="relative">0.00000000000000001</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?pi" />
            <categoryList>
                <category>mathematical</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">FOUR_PI</name>
            <name type="short">A_4pi</name>
            <alternateName>FOURPI</alternateName>
            <description>trig constant pi times 4 (shorthand for some calculations)</description>
            <value>12.5663706143592</value>
            <uncertainty type="relative">0.0000000000001</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?pi" />
            <categoryList>
                <category>mathematical</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">STERADIAN</name>
            <name type="short">A_ster</name>
            <alternateName />
            <description>a measure of solid angle in square degrees</description>
            <value>57.2957795130823</value>
            <uncertainty type="relative">0.00000000000001</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?pi" />
            <categoryList>
                <category>conversion</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">EXP</name>
            <name type="short">A_exp</name>
            <alternateName />
            <description>base of natural logarithm</description>
            <value>2.71828182846</value>
            <uncertainty type="relative">0.00000000001</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?exp" />
            <categoryList>
                <category>mathematical</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">ATOMIC_MASS_UNIT</name>
            <name type="short">A_amu</name>
            <alternateName />
            <description>atomic mass unit, 1 u</description>
            <value system="MKS">1.660539040e-27</value>
            <value system="CGS">1.660539040e-24</value>
            <uncertainty type="relative">1.2e-8</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?ukg" />
            <categoryList>
                <category>conversion</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">PARSEC</name>
            <name type="short">A_pc</name>
            <alternateName />
            <description>parsec</description>
            <value system="MKS">3.08567758149e16</value>
            <value system="CGS">3.08567758149e18</value>
            <uncertainty type="relative">1e-11</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?pc" />
            <categoryList>
                <category>conversion</category>
                <category>cosmology</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">ASTRONOMICAL_UNIT</name>
            <name type="short">A_AU</name>
            <alternateName />
            <description>astronomical unit</description>
            <value system="MKS">149_597_870_700</value>
            <value system="CGS">1.496e13</value>
            <uncertainty type="relative">0</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?AU" />
            <categoryList>
                <category>conversion</category>
                <category>cosmology</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">LIGHT_YEAR</name>
            <name type="short">A_ly</name>
            <alternateName />
            <description>the distance that light travels in vacuum in one Julian year</description>
            <value system="MKS">9_460_730_472_580_800</value>
            <value system="CGS">9.4607304725808e17</value>
            <uncertainty type="relative">0</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?ly" />
            <categoryList>
                <category>conversion</category>
                <category>cosmology</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">ANGSTROM</name>
            <name type="short">A_AA</name>
            <alternateName />
            <description>Angstrom</description>
            <value system="MKS">1e-10</value>
            <value system="CGS">1e-8</value>
            <uncertainty type="relative">0</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?AA" />
            <categoryList>
                <category>conversion</category>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">JANSKY</name>
            <name type="short">A_Jy</name>
            <alternateName />
            <description>Jansky</description>
            <value system="MKS">1e-26</value>
            <value system="CGS">1e-23</value>
            <uncertainty type="relative">0</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Jy" />
            <categoryList>
                <category>conversion</category>
                <category>cosmology</category>
                <category>electromagnetic</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">AVOGADRO</name>
            <name type="short">A_NA</name>
            <alternateName />
            <description>Avogadro's number</description>
            <value>6.022140857e23</value>
            <uncertainty type="relative">1.2e-8</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?na" />
            <categoryList>
                <category>conversion</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">YEAR</name>
            <name type="short">A_yr</name>
            <alternateName>YEAR_JULIAN</alternateName>
            <description>defined as exactly 365.25 days of 86400 SI seconds</description>
            <value>31_557_600</value>
            <uncertainty type="relative">0</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?yr" />
            <categoryList>
                <category>conversion</category>
                <category>cosmology</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">YEAR_TROPICAL</name>
            <alternateName />
            <description>the period of time for the ecliptic longitude of the Sun to increase 360 degrees, approximated by the Gregorian calendar</description>
            <value>31_556_925.1</value>
            <uncertainty type="absolute">0.1</uncertainty>
            <dimensions />
            <maxValue>31556959</maxValue>
            <minValue>31556892</minValue>
            <url href="https://en.wikipedia.org/wiki/Tropical_year" />
            <categoryList>
                <category>conversion</category>
                <category>cosmology</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">YEAR_SIDEREAL</name>
            <alternateName />
            <description>the period of revolution of the Earth around the Sun in a fixed reference frame</description>
            <value>31_558_149.8</value>
            <uncertainty type="absolute">1</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="https://en.wikipedia.org/wiki/Sidereal_year" />
            <categoryList>
                <category>conversion</category>
                <category>cosmology</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">YEAR_ANOMALISTIC</name>
            <alternateName />
            <description>the period between successive passages of the Earth through perihelion</description>
            <value>31_558_432.6</value>
            <uncertainty type="absolute">0.1</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://asa.usno.navy.mil/SecM/Glossary.html" />
            <categoryList>
                <category>conversion</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">YEAR_ECLIPSE</name>
            <alternateName />
            <description>the period between successive passages of the Sun (as seen from the geocenter) through the same lunar node</description>
            <value>29_947_974.3</value>
            <uncertainty type="absolute">0.1</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?yr" />
            <categoryList>
                <category>conversion</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MASS_SOLAR</name>
            <name type="short">A_msun</name>
            <alternateName>SOLAR_MASS</alternateName>
            <description>solar mass</description>
            <value system="MKS">1.9884e30</value>
            <value system="CGS">1.9884e33</value>
            <uncertainty type="relative">0.0001</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?msun" />
            <categoryList>
                <category>cosmology</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">LUMINOSITY_SOLAR</name>
            <name type="short">A_Lsun</name>
            <alternateName>SOLAR_LUMINOSITY</alternateName>
            <description>solar luminosity</description>
            <value system="MKS">3.846e26</value>
            <value system="CGS">3.846e33</value>
            <uncertainty type="relative">0.0003</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Lsun" />
            <categoryList>
                <category>cosmology</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">DENSITY_CRITICAL_RHOc</name>
            <name type="short">A_rhoc</name>
            <alternateName>RHO_C</alternateName>
            <description>critical density /h^2</description>
            <value system="MKS">1.8791e-26</value>
            <value system="CGS">1.8791e-29</value>
            <uncertainty type="relative">0.0001</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?rhoc" />
            <categoryList>
                <category>cosmology</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">HUBBLE_TIME</name>
            <name type="short">A_tH</name>
            <alternateName />
            <description>Hubble time *h, the inverse of Hubble's constant valued at 100 km/s/Mpc (DEPRECATED - see ChangeLog)</description>
            <value>3.0853056e17</value>
            <uncertainty type="relative">0.0000001</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="" />
            <categoryList>
                <category>cosmology</category>
            </categoryList>
            <deprecated version='0.11' date='2017-04-26' />
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">TEMPERATURE_CMB</name>
            <name type="short">A_TCMB</name>
            <alternateName>CMB_TEMPERATURE</alternateName>
            <description>cosmic microwave background temperature in Kelvin</description>
            <value>2.725</value>
            <uncertainty type="relative">0.0007</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?TCMB" />
            <categoryList>
                <category>cosmology</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MAGNITUDE_SOLAR_V</name>
            <name type="short">A_Vsun</name>
            <alternateName>SOLAR_V_MAG</alternateName>
            <description>solar V magnitude</description>
            <value>-26.74</value>
            <uncertainty type="relative">0.0004</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Vsun" />
            <categoryList>
                <category>cosmology</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MAGNITUDE_SOLAR_V_ABSOLUTE</name>
            <name type="short">A_MVsun</name>
            <alternateName>SOLAR_V_ABS_MAG</alternateName>
            <description>solar absolute V magnitude</description>
            <value>4.83</value>
            <uncertainty type="relative">0.002</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?MVsun" />
            <categoryList>
                <category>cosmology</category>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">RADIUS_SOLAR</name>
            <name type="short">A_rsun</name>
            <alternateName>SOLAR_RADIUS</alternateName>
            <description>solar radius</description>
            <value system="MKS">6.96e8</value>
            <value system="CGS">6.96e10</value>
            <uncertainty type="relative">0.002</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MASS_EARTH</name>
            <name type="short">A_mearth</name>
            <alternateName>EARTH_MASS</alternateName>
            <description>mass of Earth</description>
            <value system="MKS">5.9722e24</value>
            <value system="CGS">5.9722e27</value>
            <uncertainty type="absolute">6e20</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">RADIUS_EARTH</name>
            <name type="short">A_rearth</name>
            <alternateName>EARTH_RADIUS</alternateName>
            <description>radius of Earth</description>
            <value system="MKS">6.378_136_6e6</value>
            <value system="CGS">6.378_136_6e8</value>
            <uncertainty type="absolute">0.1</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">TEMPERATURE_SOLAR_SURFACE</name>
            <name type="short">A_Tsun</name>
            <alternateName>SOLAR_TEMPERATURE</alternateName>
            <description>surface temperature of sun</description>
            <value>5778</value>
            <uncertainty type="relative">0.0002</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Tsun" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">DENSITY_SOLAR</name>
            <name type="short">A_dsun</name>
            <alternateName>SOLAR_DENSITY</alternateName>
            <description>mean solar density</description>
            <value system="MKS">1408</value>
            <value system="CGS">1.408</value>
            <uncertainty type="relative">0.001</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?dsun" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">DENSITY_EARTH</name>
            <name type="short">A_dearth</name>
            <alternateName>EARTH_DENSITY</alternateName>
            <description>mean Earth density</description>
            <value system="MKS">5514</value>
            <value system="CGS">5.514</value>
            <uncertainty type="relative">0.0002</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?dearth" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">GRAVITY_SOLAR</name>
            <name type="short">A_gsun</name>
            <alternateName>SOLAR_GRAVITY</alternateName>
            <description>solar surface gravity</description>
            <value system="MKS">274.0</value>
            <value system="CGS">27400</value>
            <uncertainty type="relative">0.0004</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?gsun" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">GRAVITY_EARTH</name>
            <name type="short">A_gearth</name>
            <alternateName>EARTH_GRAVITY</alternateName>
            <description>Earth surface gravity</description>
            <value system="MKS">9.78</value>
            <value system="CGS">978</value>
            <uncertainty type="relative">0.001</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?gearth" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">RADIUS_LUNAR</name>
            <name type="short">A_rmoon</name>
            <alternateName>LUNAR_RADIUS</alternateName>
            <description>lunar radius</description>
            <value system="MKS">1.7381e6</value>
            <value system="CGS">1.7381e8</value>
            <uncertainty type="relative">6e-5</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?rmoon" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MASS_LUNAR</name>
            <name type="short">A_mmoon</name>
            <alternateName>LUNAR_MASS</alternateName>
            <description>lunar mass</description>
            <value system="MKS">7.342e22</value>
            <value system="CGS">7.342e25</value>
            <uncertainty type="relative">0.0002</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mmoon" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">AXIS_SM_LUNAR</name>
            <name type="short">A_amoon</name>
            <alternateName>LUNAR_SM_AXIS</alternateName>
            <description>lunar orbital semi-major axis</description>
            <value system="MKS">3.844e8</value>
            <value system="CGS">3.844e10</value>
            <uncertainty type="relative">0.0003</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?amoon" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">ECCENTRICITY_LUNAR</name>
            <name type="short">A_emoon</name>
            <alternateName>LUNAR_ECCENTRICITY</alternateName>
            <description>lunar orbital eccentricity</description>
            <value>0.0549</value>
            <uncertainty type="relative">0.002</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?emoon" />
            <categoryList>
                <category>planetary</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">THOMSON_CROSS_SECTION</name>
            <name type="short">A_sigmaT</name>
            <alternateName>THOMSON_XSECTION</alternateName>
            <description>Thomson cross-section</description>
            <value system="MKS">6.6524587158e-29</value>
            <value system="CGS">6.6524587158e-25</value>
            <uncertainty type="relative">1.4e-9</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?sigmae" />
            <categoryList>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MASS_ELECTRON</name>
            <name type="short">A_me</name>
            <alternateName>ELECTRON_MASS</alternateName>
            <description>mass of electron</description>
            <value system="MKS">9.10938356e-31</value>
            <value system="CGS">9.10938356e-28</value>
            <uncertainty type="relative">1.2e-8</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?me" />
            <categoryList>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MASS_PROTON</name>
            <name type="short">A_mp</name>
            <alternateName>PROTON_MASS</alternateName>
            <description>mass of proton</description>
            <value system="MKS">1.672621898e-27</value>
            <value system="CGS">1.672621898e-24</value>
            <uncertainty type="relative">1.2e-8</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mp" />
            <categoryList>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MASS_NEUTRON</name>
            <name type="short">A_mn</name>
            <alternateName>NEUTRON_MASS</alternateName>
            <description>neutron mass</description>
            <value system="MKS">1.674927471e-27</value>
            <value system="CGS">1.674927471e-24</value>
            <uncertainty type="relative">1.2e-8</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mn" />
            <categoryList>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MASS_HYDROGEN</name>
            <name type="short">A_mH</name>
            <alternateName>HYDROGEN_MASS</alternateName>
            <description>mass of Hydrogen atom --   
This value is from the IUPAC and is a little smaller than MASS_PROTON + MASS_ELECTRON, but within the uncertainty given here.  The current value is 1.008u +/- 0.0002 derived from a range of terrestrial materials.  If this is for precision work, you h...
</description>
            <value>1.6738e-27</value>
            <uncertainty type="absolute">3.3e-31</uncertainty>
            <uncertainty type="relative">0.0002</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="https://www.degruyter.com/downloadpdf/j/pac.2016.88.issue-3/pac-2015-0305/pac-2015-0305.pdf" />
            <categoryList>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">MASS_ALPHA</name>
            <name type="short">A_ma</name>
            <description>mass of alpha particle</description>
            <value>6.644_657_230e-27</value>
            <uncertainty type="relative">1.2e-8</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mal" />
            <categoryList>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">RADIUS_ELECTRON</name>
            <name type="short">A_re</name>
            <alternateName>ELECTRON_RADIUS</alternateName>
            <description>classical electron radius</description>
            <value system="MKS">2.8179403227e-15</value>
            <value system="CGS">2.8179403227e-13</value>
            <uncertainty type="relative">6.8e-10</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?re" />
            <categoryList>
                <category>nuclear</category>
                <category>electromagnetic</category>
            </categoryList>
        </PhysicalConstant>
        <PhysicalConstant>
            <name type="long">RADIUS_BOHR</name>
            <name type="short">A_a0</name>
            <alternateName>BOHR_RADIUS</alternateName>
            <description>Bohr radius</description>
            <value system="MKS">5.2917721067e-11</value>
            <value system="CGS">5.2917721067e-9</value>
            <uncertainty type="relative">2.3e-10</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?bohrrada0" />
            <categoryList>
                <category>electromagnetic</category>
                <category>nuclear</category>
            </categoryList>
        </PhysicalConstant>
    </items>

data/old_versions/constants_2018_v0.13.xml  view on Meta::CPAN

  <source>2014 CODATA</source>
  <link href="http://metacpan.org/pod/Astro::Constants"/>
  <items>
    <PhysicalConstant>
      <name type="long">SPEED_LIGHT</name>
      <name type="short">A_c</name>
      <alternateName>LIGHT_SPEED</alternateName>
      <description>speed of light in a vacuum</description>
      <value system="MKS">2.99792458e8</value>
      <value system="CGS">2.99792458e10</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?c"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">BOLTZMANN</name>
      <name type="short">A_k</name>
      <alternateName/>
      <description>Boltzmann's constant</description>
      <value system="MKS">1.38064852e-23</value>
      <value system="CGS">1.38064852e-16</value>
      <uncertainty type="relative">5.7e-7</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?k"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">GRAVITATIONAL</name>
      <name type="short">A_G</name>
      <alternateName/>
      <description>universal gravitational constant</description>
      <value system="MKS">6.67408e-11</value>
      <value system="CGS">6.67408e-8</value>
      <uncertainty type="relative">4.7e-5</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?bg"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ELECTRON_VOLT</name>
      <name type="short">A_eV</name>
      <alternateName/>
      <description>electron volt</description>
      <value system="MKS">1.6021766208e-19</value>
      <value system="CGS">1.6021766208e-12</value>
      <uncertainty type="relative">6.1e-9</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?tevj"/>
      <categoryList>
        <category>fundamental</category>
        <category>conversion</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PLANCK</name>
      <name type="short">A_h</name>
      <alternateName/>
      <description>Planck constant</description>
      <value system="MKS">6.626070040e-34</value>
      <value system="CGS">6.626070040e-27</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?h"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">H_BAR</name>
      <name type="short">A_hbar</name>
      <alternateName>HBAR</alternateName>
      <description>Planck's constant /2pi</description>
      <value system="MKS">1.054571800e-34</value>
      <value system="CGS">1.054571800e-27</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?hbar"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ELECTRON_CHARGE</name>
      <name type="short">A_e</name>
      <alternateName>CHARGE_ELEMENTARY</alternateName>
      <description>electron charge (defined positive)</description>
      <value system="MKS">1.6021766208e-19</value>
      <value system="CGS">4.8032046729e-10</value>
      <uncertainty type="relative">6.1e-9</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?e"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">STEFAN_BOLTZMANN</name>
      <name type="short">A_sigma</name>
      <alternateName/>
      <description>Stefan-Boltzmann constant</description>
      <value system="MKS">5.670367e-8</value>
      <value system="CGS">5.670367e-5</value>
      <uncertainty type="relative">2.3e-6</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?sigma"/>
      <url href="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_RADIATION</name>
      <name type="short">A_arad</name>
      <alternateName>A_RAD</alternateName>
      <description>radiation density constant, 4 * sigma / c</description>
      <value system="MKS">7.565723e-16</value>
      <value system="CGS">7.565723e-15</value>
      <uncertainty type="relative">2.3e-6</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">WIEN</name>
      <name type="short">A_Wien</name>
      <alternateName/>
      <description>Wien wavelength displacement law constant</description>
      <value system="MKS">2.8977729e-3</value>
      <value system="CGS">2.8977729e-1</value>
      <uncertainty type="relative">5.7e-7</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?bwien"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>cosmology</category>
        <category>planetary</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ALPHA</name>
      <name type="short">A_alpha</name>
      <alternateName/>
      <description>fine structure constant</description>
      <value system="MKS">7.2973525664e-3</value>
      <value system="CGS">7.2973525664e-3</value>
      <uncertainty type="relative">2.3e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?alph"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">IMPEDANCE_VACUUM</name>
      <name type="short">A_Z0</name>
      <alternateName>VACUUM_IMPEDANCE</alternateName>
      <description>characteristic impedance of vacuum</description>
      <value>376.730313461</value>
      <uncertainty type="relative">1e-50</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Z0"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PERMITIV_FREE_SPACE</name>
      <name type="short">A_eps0</name>
      <alternateName>PERMITIVITY_0</alternateName>
      <description>permittivity of free space, epsilon_0, the electric constant</description>
      <value system="MKS">8.854187817e-12</value>
      <value system="CGS">1</value>
      <uncertainty type="relative">1e-30</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?ep0"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PERMEABL_FREE_SPACE</name>
      <name type="short">A_mu0</name>
      <alternateName>PERMEABILITY_0</alternateName>
      <alternateName>CONSTANT_MAGNETIC</alternateName>
      <description>permeability of free space, mu_0, the magnetic constant</description>
      <value system="MKS">1.2566370614e-6</value>
      <value system="CGS">1</value>
      <uncertainty type="relative">1e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mu0"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PI</name>
      <name type="short">A_pi</name>
      <alternateName/>
      <description>trig constant pi</description>
      <value>3.14159265358979324</value>
      <uncertainty type="relative">0.00000000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?pi"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">FOUR_PI</name>
      <name type="short">A_4pi</name>
      <alternateName>FOURPI</alternateName>
      <description>trig constant pi times 4 (shorthand for some calculations)</description>
      <value>12.5663706143592</value>
      <uncertainty type="relative">0.0000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?pi"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">STERADIAN</name>
      <name type="short">A_ster</name>
      <alternateName/>
      <description>a measure of solid angle in square degrees</description>
      <value>57.2957795130823</value>
      <uncertainty type="relative">0.00000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?pi"/>
      <categoryList>
        <category>conversion</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">EXP</name>
      <name type="short">A_exp</name>
      <alternateName/>
      <description>base of natural logarithm</description>
      <value>2.71828182846</value>
      <uncertainty type="relative">0.00000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?exp"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ATOMIC_MASS_UNIT</name>
      <name type="short">A_amu</name>
      <alternateName/>
      <description>atomic mass unit, 1 u</description>
      <value system="MKS">1.660539040e-27</value>
      <value system="CGS">1.660539040e-24</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?ukg"/>
      <categoryList>
        <category>conversion</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PARSEC</name>
      <name type="short">A_pc</name>
      <alternateName/>
      <description>parsec</description>
      <value system="MKS">3.08567758149e16</value>
      <value system="CGS">3.08567758149e18</value>
      <uncertainty type="relative">1e-11</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?pc"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ASTRONOMICAL_UNIT</name>
      <name type="short">A_AU</name>
      <alternateName/>
      <description>astronomical unit</description>
      <value system="MKS">149_597_870_700</value>
      <value system="CGS">1.496e13</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="https://cneos.jpl.nasa.gov/glossary/au.html"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">LIGHT_YEAR</name>
      <name type="short">A_ly</name>
      <alternateName/>
      <description>the distance that light travels in vacuum in one Julian year</description>
      <value system="MKS">9_460_730_472_580_800</value>
      <value system="CGS">9.4607304725808e17</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?ly"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ANGSTROM</name>
      <name type="short">A_AA</name>
      <alternateName/>
      <description>Angstrom</description>
      <value system="MKS">1e-10</value>
      <value system="CGS">1e-8</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?AA"/>
      <categoryList>
        <category>conversion</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">JANSKY</name>
      <name type="short">A_Jy</name>
      <alternateName/>
      <description>Jansky</description>
      <value system="MKS">1e-26</value>
      <value system="CGS">1e-23</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Jy"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">AVOGADRO</name>
      <name type="short">A_NA</name>
      <alternateName/>
      <description>Avogadro's number</description>
      <value>6.022140857e23</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?na"/>
      <categoryList>
        <category>conversion</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR</name>
      <name type="short">A_yr</name>
      <alternateName>YEAR_JULIAN</alternateName>
      <description>defined as exactly 365.25 days of 86400 SI seconds</description>
      <value>31_557_600</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?yr"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_TROPICAL</name>
      <alternateName/>
      <description>the period of time for the ecliptic longitude of the Sun to increase 360 degrees, approximated by the Gregorian calendar</description>
      <value>31_556_925.1</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue>31556959</maxValue>
      <minValue>31556892</minValue>
      <url href="https://en.wikipedia.org/wiki/Tropical_year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_SIDEREAL</name>
      <alternateName/>
      <description>the period of revolution of the Earth around the Sun in a fixed reference frame</description>
      <value>31_558_149.8</value>
      <uncertainty type="absolute">1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="https://en.wikipedia.org/wiki/Sidereal_year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_ANOMALISTIC</name>
      <alternateName/>
      <description>the period between successive passages of the Earth through perihelion</description>
      <value>31_558_432.6</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://asa.usno.navy.mil/SecM/Glossary.html"/>
      <categoryList>
        <category>conversion</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_ECLIPSE</name>
      <alternateName/>
      <description>the period between successive passages of the Sun (as seen from the geocenter) through the same lunar node</description>
      <value>29_947_974.3</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?yr"/>
      <categoryList>
        <category>conversion</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_SOLAR</name>
      <name type="short">A_msun</name>
      <alternateName>SOLAR_MASS</alternateName>
      <description>solar mass</description>
      <value system="MKS">1.9884e30</value>
      <value system="CGS">1.9884e33</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?msun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">LUMINOSITY_SOLAR</name>
      <name type="short">A_Lsun</name>
      <alternateName>SOLAR_LUMINOSITY</alternateName>
      <description>solar luminosity</description>
      <value system="MKS">3.846e26</value>
      <value system="CGS">3.846e33</value>
      <uncertainty type="relative">0.0003</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Lsun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_CRITICAL_RHOc</name>
      <name type="short">A_rhoc</name>
      <alternateName>RHO_C</alternateName>
      <description>critical density /h^2</description>
      <value system="MKS">1.8791e-26</value>
      <value system="CGS">1.8791e-29</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?rhoc"/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">HUBBLE_TIME</name>
      <name type="short">A_tH</name>
      <alternateName/>
      <description>Hubble time *h, the inverse of Hubble's constant valued at 100 km/s/Mpc (DEPRECATED - see ChangeLog)</description>
      <value>3.0853056e17</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href=""/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
      <deprecated version="0.11" date="2017-04-26"/>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">TEMPERATURE_CMB</name>
      <name type="short">A_TCMB</name>
      <alternateName>CMB_TEMPERATURE</alternateName>
      <description>cosmic microwave background temperature in Kelvin</description>
      <value>2.725</value>
      <uncertainty type="relative">0.0007</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?TCMB"/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MAGNITUDE_SOLAR_V</name>
      <name type="short">A_Vsun</name>
      <alternateName>SOLAR_V_MAG</alternateName>
      <description>solar V magnitude</description>
      <value>-26.74</value>
      <uncertainty type="relative">0.0004</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Vsun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MAGNITUDE_SOLAR_V_ABSOLUTE</name>
      <name type="short">A_MVsun</name>
      <alternateName>SOLAR_V_ABS_MAG</alternateName>
      <description>solar absolute V magnitude</description>
      <value>4.83</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?MVsun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_SOLAR</name>
      <name type="short">A_rsun</name>
      <alternateName>SOLAR_RADIUS</alternateName>
      <description>solar radius</description>
      <value system="MKS">6.96e8</value>
      <value system="CGS">6.96e10</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_EARTH</name>
      <name type="short">A_mearth</name>
      <alternateName>EARTH_MASS</alternateName>
      <description>mass of Earth</description>
      <value system="MKS">5.9722e24</value>
      <value system="CGS">5.9722e27</value>
      <uncertainty type="absolute">6e20</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_EARTH</name>
      <name type="short">A_rearth</name>
      <alternateName>EARTH_RADIUS</alternateName>
      <description>radius of Earth</description>
      <value system="MKS">6.378_136_6e6</value>
      <value system="CGS">6.378_136_6e8</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">TEMPERATURE_SOLAR_SURFACE</name>
      <name type="short">A_Tsun</name>
      <alternateName>SOLAR_TEMPERATURE</alternateName>
      <description>surface temperature of sun</description>
      <value>5778</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?Tsun"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_SOLAR</name>
      <name type="short">A_dsun</name>
      <alternateName>SOLAR_DENSITY</alternateName>
      <description>mean solar density</description>
      <value system="MKS">1408</value>
      <value system="CGS">1.408</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?dsun"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_EARTH</name>
      <name type="short">A_dearth</name>
      <alternateName>EARTH_DENSITY</alternateName>
      <description>mean Earth density</description>
      <value system="MKS">5514</value>
      <value system="CGS">5.514</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?dearth"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">GRAVITY_SOLAR</name>
      <name type="short">A_gsun</name>
      <alternateName>SOLAR_GRAVITY</alternateName>
      <description>solar surface gravity</description>
      <value system="MKS">274.0</value>
      <value system="CGS">27400</value>
      <uncertainty type="relative">0.0004</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?gsun"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">GRAVITY_EARTH</name>
      <name type="short">A_gearth</name>
      <alternateName>EARTH_GRAVITY</alternateName>
      <description>Earth surface gravity</description>
      <value system="MKS">9.78</value>
      <value system="CGS">978</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?gearth"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_LUNAR</name>
      <name type="short">A_rmoon</name>
      <alternateName>LUNAR_RADIUS</alternateName>
      <description>lunar radius</description>
      <value system="MKS">1.7381e6</value>
      <value system="CGS">1.7381e8</value>
      <uncertainty type="relative">6e-5</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?rmoon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_LUNAR</name>
      <name type="short">A_mmoon</name>
      <alternateName>LUNAR_MASS</alternateName>
      <description>lunar mass</description>
      <value system="MKS">7.342e22</value>
      <value system="CGS">7.342e25</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mmoon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">AXIS_SM_LUNAR</name>
      <name type="short">A_amoon</name>
      <alternateName>LUNAR_SM_AXIS</alternateName>
      <description>lunar orbital semi-major axis</description>
      <value system="MKS">3.844e8</value>
      <value system="CGS">3.844e10</value>
      <uncertainty type="relative">0.0003</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?amoon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ECCENTRICITY_LUNAR</name>
      <name type="short">A_emoon</name>
      <alternateName>LUNAR_ECCENTRICITY</alternateName>
      <description>lunar orbital eccentricity</description>
      <value>0.0549</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?emoon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">THOMSON_CROSS_SECTION</name>
      <name type="short">A_sigmaT</name>
      <alternateName>THOMSON_XSECTION</alternateName>
      <description>Thomson cross-section</description>
      <value system="MKS">6.6524587158e-29</value>
      <value system="CGS">6.6524587158e-25</value>
      <uncertainty type="relative">1.4e-9</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?sigmae"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_ELECTRON</name>
      <name type="short">A_me</name>
      <alternateName>ELECTRON_MASS</alternateName>
      <description>mass of electron</description>
      <value system="MKS">9.10938356e-31</value>
      <value system="CGS">9.10938356e-28</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?me"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_PROTON</name>
      <name type="short">A_mp</name>
      <alternateName>PROTON_MASS</alternateName>
      <description>mass of proton</description>
      <value system="MKS">1.672621898e-27</value>
      <value system="CGS">1.672621898e-24</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mp"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_NEUTRON</name>
      <name type="short">A_mn</name>
      <alternateName>NEUTRON_MASS</alternateName>
      <description>neutron mass</description>
      <value system="MKS">1.674927471e-27</value>
      <value system="CGS">1.674927471e-24</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mn"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_HYDROGEN</name>
      <name type="short">A_mH</name>
      <alternateName>HYDROGEN_MASS</alternateName>
      <description>mass of Hydrogen atom --   
This value is from the IUPAC and is a little smaller than MASS_PROTON + MASS_ELECTRON, but within the uncertainty given here.  The current value is 1.008u +/- 0.0002 derived from a range of terrestrial materials.  If this is for precision work, you h...
</description>
      <value>1.6738e-27</value>
      <uncertainty type="absolute">3.3e-31</uncertainty>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="https://www.degruyter.com/downloadpdf/j/pac.2016.88.issue-3/pac-2015-0305/pac-2015-0305.pdf"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_ALPHA</name>
      <name type="short">A_ma</name>
      <description>mass of alpha particle</description>
      <value>6.644_657_230e-27</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?mal"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_ELECTRON</name>
      <name type="short">A_re</name>
      <alternateName>ELECTRON_RADIUS</alternateName>
      <description>classical electron radius</description>
      <value system="MKS">2.8179403227e-15</value>
      <value system="CGS">2.8179403227e-13</value>
      <uncertainty type="relative">6.8e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?re"/>
      <categoryList>
        <category>nuclear</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_BOHR</name>
      <name type="short">A_a0</name>
      <alternateName>BOHR_RADIUS</alternateName>
      <description>Bohr radius</description>
      <value system="MKS">5.2917721067e-11</value>
      <value system="CGS">5.2917721067e-9</value>
      <uncertainty type="relative">2.3e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <url href="http://physics.nist.gov/cgi-bin/cuu/Value?bohrrada0"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_JUPITER</name>
      <name type="short">A_rjup</name>
      <description>Volumetric mean radius of Jupiter</description>
      <value system="MKS">69_911_000</value>
      <uncertainty type="relative">1.5e-5</uncertainty>
      <dimensions>length</dimensions>
      <maxValue/>
      <minValue/>
      <url href="https://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_JUPITER</name>
      <name type="short">A_mjup</name>
      <description>mass of Jupiter</description>
      <value system="MKS">1.89819e27</value>
      <uncertainty type="relative">5e-6</uncertainty>
      <dimensions>mass</dimensions>
      <maxValue/>
      <minValue/>
      <url href="https://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
  </items>
</Collection>

data/old_versions/constants_2019_v0.13.xml  view on Meta::CPAN

  <reference_standard>2014 CODATA</reference_standard>
  <link href="http://metacpan.org/pod/Astro::Constants"/>
  <items>
    <PhysicalConstant>
      <name type="long">SPEED_LIGHT</name>
      <name type="short">A_c</name>
      <alternateName>LIGHT_SPEED</alternateName>
      <description>speed of light in a vacuum</description>
      <value system="MKS">2.99792458e8</value>
      <value system="CGS">2.99792458e10</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?c"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">BOLTZMANN</name>
      <name type="short">A_k</name>
      <alternateName/>
      <description>Boltzmann's constant</description>
      <value system="MKS">1.38064852e-23</value>
      <value system="CGS">1.38064852e-16</value>
      <uncertainty type="relative">5.7e-7</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?k"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">GRAVITATIONAL</name>
      <name type="short">A_G</name>
      <alternateName/>
      <description>universal gravitational constant</description>
      <value system="MKS">6.67408e-11</value>
      <value system="CGS">6.67408e-8</value>
      <uncertainty type="relative">4.7e-5</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?bg"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ELECTRON_VOLT</name>
      <name type="short">A_eV</name>
      <alternateName/>
      <description>electron volt</description>
      <value system="MKS">1.6021766208e-19</value>
      <value system="CGS">1.6021766208e-12</value>
      <uncertainty type="relative">6.1e-9</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?tevj"/>
      <categoryList>
        <category>fundamental</category>
        <category>conversion</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PLANCK</name>
      <name type="short">A_h</name>
      <alternateName/>
      <description>Planck constant</description>
      <value system="MKS">6.626070040e-34</value>
      <value system="CGS">6.626070040e-27</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?h"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">H_BAR</name>
      <name type="short">A_hbar</name>
      <alternateName>HBAR</alternateName>
      <description>Planck's constant /2pi</description>
      <value system="MKS">1.054571800e-34</value>
      <value system="CGS">1.054571800e-27</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?hbar"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">CHARGE_ELEMENTARY</name>
      <name type="short">A_e</name>
      <alternateName>ELECTRON_CHARGE</alternateName>
      <description>electron charge (defined positive)</description>
      <value system="MKS">1.6021766208e-19</value>
      <value system="CGS">4.8032046729e-10</value>
      <uncertainty type="relative">6.1e-9</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?e"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">STEFAN_BOLTZMANN</name>
      <name type="short">A_sigma</name>
      <alternateName/>
      <description>Stefan-Boltzmann constant</description>
      <value system="MKS">5.670367e-8</value>
      <value system="CGS">5.670367e-5</value>
      <uncertainty type="relative">2.3e-6</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?sigma"/>
      <source url="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_RADIATION</name>
      <name type="short">A_arad</name>
      <alternateName>A_RAD</alternateName>
      <description>radiation density constant, 4 * sigma / c</description>
      <value system="MKS">7.565723e-16</value>
      <value system="CGS">7.565723e-15</value>
      <uncertainty type="relative">2.3e-6</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">WIEN</name>
      <name type="short">A_Wien</name>
      <alternateName/>
      <description>Wien wavelength displacement law constant</description>
      <value system="MKS">2.8977729e-3</value>
      <value system="CGS">2.8977729e-1</value>
      <uncertainty type="relative">5.7e-7</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?bwien"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>cosmology</category>
        <category>planetary</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ALPHA</name>
      <name type="short">A_alpha</name>
      <alternateName/>
      <description>fine structure constant</description>
      <value system="MKS">7.2973525664e-3</value>
      <value system="CGS">7.2973525664e-3</value>
      <uncertainty type="relative">2.3e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?alph"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">IMPEDANCE_VACUUM</name>
      <name type="short">A_Z0</name>
      <alternateName>VACUUM_IMPEDANCE</alternateName>
      <description>characteristic impedance of vacuum</description>
      <value>376.730313461</value>
      <uncertainty type="relative">1e-50</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?Z0"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PERMITIV_FREE_SPACE</name>
      <name type="short">A_eps0</name>
      <alternateName>PERMITIVITY_0</alternateName>
      <description>permittivity of free space, epsilon_0, the electric constant</description>
      <value system="MKS">8.854187817e-12</value>
      <value system="CGS">1</value>
      <uncertainty type="relative">1e-30</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?ep0"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PERMEABL_FREE_SPACE</name>
      <name type="short">A_mu0</name>
      <alternateName>PERMEABILITY_0</alternateName>
      <alternateName>CONSTANT_MAGNETIC</alternateName>
      <description>permeability of free space, mu_0, the magnetic constant</description>
      <value system="MKS">1.2566370614e-6</value>
      <value system="CGS">1</value>
      <uncertainty type="relative">1e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mu0"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PI</name>
      <name type="short">A_pi</name>
      <alternateName/>
      <description>trig constant pi</description>
      <value>3.14159265358979324</value>
      <uncertainty type="relative">0.00000000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?pi"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">FOUR_PI</name>
      <name type="short">A_4pi</name>
      <alternateName>FOURPI</alternateName>
      <description>trig constant pi times 4 (shorthand for some calculations)</description>
      <value>12.5663706143592</value>
      <uncertainty type="relative">0.0000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?pi"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">STERADIAN</name>
      <name type="short">A_ster</name>
      <alternateName/>
      <description>a measure of solid angle in square degrees</description>
      <value>57.2957795130823</value>
      <uncertainty type="relative">0.00000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?pi"/>
      <categoryList>
        <category>conversion</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">EXP</name>
      <name type="short">A_exp</name>
      <alternateName/>
      <description>base of natural logarithm</description>
      <value>2.71828182846</value>
      <uncertainty type="relative">0.00000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?exp"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ATOMIC_MASS_UNIT</name>
      <name type="short">A_amu</name>
      <alternateName/>
      <description>atomic mass unit, 1 u</description>
      <value system="MKS">1.660539040e-27</value>
      <value system="CGS">1.660539040e-24</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?ukg"/>
      <categoryList>
        <category>conversion</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PARSEC</name>
      <name type="short">A_pc</name>
      <alternateName/>
      <description>parsec</description>
      <value system="MKS">3.08567758149e16</value>
      <value system="CGS">3.08567758149e18</value>
      <uncertainty type="relative">1e-11</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?pc"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ASTRONOMICAL_UNIT</name>
      <name type="short">A_AU</name>
      <alternateName/>
      <description>astronomical unit</description>
      <value system="MKS">149_597_870_700</value>
      <value system="CGS">1.496e13</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://cneos.jpl.nasa.gov/glossary/au.html"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">LIGHT_YEAR</name>
      <name type="short">A_ly</name>
      <alternateName/>
      <description>the distance that light travels in vacuum in one Julian year</description>
      <value system="MKS">9_460_730_472_580_800</value>
      <value system="CGS">9.4607304725808e17</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?ly"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ANGSTROM</name>
      <name type="short">A_AA</name>
      <alternateName/>
      <description>Angstrom</description>
      <value system="MKS">1e-10</value>
      <value system="CGS">1e-8</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?AA"/>
      <categoryList>
        <category>conversion</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">JANSKY</name>
      <name type="short">A_Jy</name>
      <alternateName/>
      <description>Jansky</description>
      <value system="MKS">1e-26</value>
      <value system="CGS">1e-23</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?Jy"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">AVOGADRO</name>
      <name type="short">A_NA</name>
      <alternateName/>
      <description>Avogadro's number</description>
      <value>6.022140857e23</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?na"/>
      <categoryList>
        <category>conversion</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR</name>
      <name type="short">A_yr</name>
      <alternateName>YEAR_JULIAN</alternateName>
      <description>defined as exactly 365.25 days of 86400 SI seconds</description>
      <value>31_557_600</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?yr"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_TROPICAL</name>
      <alternateName/>
      <description>the period of time for the ecliptic longitude of the Sun to increase 360 degrees, approximated by the Gregorian calendar</description>
      <value>31_556_925.1</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue>31556959</maxValue>
      <minValue>31556892</minValue>
      <source url="https://en.wikipedia.org/wiki/Tropical_year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_SIDEREAL</name>
      <alternateName/>
      <description>the period of revolution of the Earth around the Sun in a fixed reference frame</description>
      <value>31_558_149.8</value>
      <uncertainty type="absolute">1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sidereal_year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_ANOMALISTIC</name>
      <alternateName/>
      <description>the period between successive passages of the Earth through perihelion</description>
      <value>31_558_432.6</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/SecM/Glossary.html"/>
      <categoryList>
        <category>conversion</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_ECLIPSE</name>
      <alternateName/>
      <description>the period between successive passages of the Sun (as seen from the geocenter) through the same lunar node</description>
      <value>29_947_974.3</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?yr"/>
      <categoryList>
        <category>conversion</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_SOLAR</name>
      <name type="short">A_msun</name>
      <alternateName>SOLAR_MASS</alternateName>
      <description>solar mass</description>
      <value system="MKS">1.9884e30</value>
      <value system="CGS">1.9884e33</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?msun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">LUMINOSITY_SOLAR</name>
      <name type="short">A_Lsun</name>
      <alternateName>SOLAR_LUMINOSITY</alternateName>
      <description>solar luminosity</description>
      <value system="MKS">3.846e26</value>
      <value system="CGS">3.846e33</value>
      <uncertainty type="relative">0.0003</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?Lsun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_CRITICAL_RHOc</name>
      <name type="short">A_rhoc</name>
      <alternateName>RHO_C</alternateName>
      <description>critical density /h^2</description>
      <value system="MKS">1.8791e-26</value>
      <value system="CGS">1.8791e-29</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?rhoc"/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">HUBBLE_TIME</name>
      <name type="short">A_tH</name>
      <alternateName/>
      <description>Hubble time *h, the inverse of Hubble's constant valued at 100 km/s/Mpc (DEPRECATED - see ChangeLog)</description>
      <value>3.0853056e17</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url=""/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
      <deprecated version="0.11" date="2017-04-26"/>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">TEMPERATURE_CMB</name>
      <name type="short">A_TCMB</name>
      <alternateName>CMB_TEMPERATURE</alternateName>
      <description>cosmic microwave background temperature in Kelvin</description>
      <value>2.725</value>
      <uncertainty type="relative">0.0007</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?TCMB"/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MAGNITUDE_SOLAR_V</name>
      <name type="short">A_Vsun</name>
      <alternateName>SOLAR_V_MAG</alternateName>
      <description>solar V magnitude</description>
      <value>-26.74</value>
      <uncertainty type="relative">0.0004</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?Vsun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MAGNITUDE_SOLAR_V_ABSOLUTE</name>
      <name type="short">A_MVsun</name>
      <alternateName>SOLAR_V_ABS_MAG</alternateName>
      <description>solar absolute V magnitude</description>
      <value>4.83</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?MVsun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_SOLAR</name>
      <name type="short">A_rsun</name>
      <alternateName>SOLAR_RADIUS</alternateName>
      <description>solar radius</description>
      <value system="MKS">6.96e8</value>
      <value system="CGS">6.96e10</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_EARTH</name>
      <name type="short">A_mearth</name>
      <alternateName>EARTH_MASS</alternateName>
      <description>mass of Earth</description>
      <value system="MKS">5.9722e24</value>
      <value system="CGS">5.9722e27</value>
      <uncertainty type="absolute">6e20</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_EARTH</name>
      <name type="short">A_rearth</name>
      <alternateName>EARTH_RADIUS</alternateName>
      <description>radius of Earth</description>
      <value system="MKS">6.378_136_6e6</value>
      <value system="CGS">6.378_136_6e8</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">TEMPERATURE_SOLAR_SURFACE</name>
      <name type="short">A_Tsun</name>
      <alternateName>SOLAR_TEMPERATURE</alternateName>
      <description>surface temperature of sun</description>
      <value>5778</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?Tsun"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_SOLAR</name>
      <name type="short">A_dsun</name>
      <alternateName>SOLAR_DENSITY</alternateName>
      <description>mean solar density</description>
      <value system="MKS">1408</value>
      <value system="CGS">1.408</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?dsun"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_EARTH</name>
      <name type="short">A_dearth</name>
      <alternateName>EARTH_DENSITY</alternateName>
      <description>mean Earth density</description>
      <value system="MKS">5514</value>
      <value system="CGS">5.514</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?dearth"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">GRAVITY_SOLAR</name>
      <name type="short">A_gsun</name>
      <alternateName>SOLAR_GRAVITY</alternateName>
      <description>solar surface gravity</description>
      <value system="MKS">274.0</value>
      <value system="CGS">27400</value>
      <uncertainty type="relative">0.0004</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?gsun"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">GRAVITY_EARTH</name>
      <name type="short">A_gearth</name>
      <alternateName>EARTH_GRAVITY</alternateName>
      <description>Earth surface gravity</description>
      <value system="MKS">9.78</value>
      <value system="CGS">978</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?gearth"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_LUNAR</name>
      <name type="short">A_rmoon</name>
      <alternateName>LUNAR_RADIUS</alternateName>
      <description>lunar radius</description>
      <value system="MKS">1.7381e6</value>
      <value system="CGS">1.7381e8</value>
      <uncertainty type="relative">6e-5</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?rmoon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_LUNAR</name>
      <name type="short">A_mmoon</name>
      <alternateName>LUNAR_MASS</alternateName>
      <description>lunar mass</description>
      <value system="MKS">7.342e22</value>
      <value system="CGS">7.342e25</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mmoon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">AXIS_SM_LUNAR</name>
      <name type="short">A_amoon</name>
      <alternateName>LUNAR_SM_AXIS</alternateName>
      <description>lunar orbital semi-major axis</description>
      <value system="MKS">3.844e8</value>
      <value system="CGS">3.844e10</value>
      <uncertainty type="relative">0.0003</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?amoon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ECCENTRICITY_LUNAR</name>
      <name type="short">A_emoon</name>
      <alternateName>LUNAR_ECCENTRICITY</alternateName>
      <description>lunar orbital eccentricity</description>
      <value>0.0549</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?emoon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">THOMSON_CROSS_SECTION</name>
      <name type="short">A_sigmaT</name>
      <alternateName>THOMSON_XSECTION</alternateName>
      <description>Thomson cross-section</description>
      <value system="MKS">6.6524587158e-29</value>
      <value system="CGS">6.6524587158e-25</value>
      <uncertainty type="relative">1.4e-9</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?sigmae"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_ELECTRON</name>
      <name type="short">A_me</name>
      <alternateName>ELECTRON_MASS</alternateName>
      <description>mass of electron</description>
      <value system="MKS">9.10938356e-31</value>
      <value system="CGS">9.10938356e-28</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?me"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_PROTON</name>
      <name type="short">A_mp</name>
      <alternateName>PROTON_MASS</alternateName>
      <description>mass of proton</description>
      <value system="MKS">1.672621898e-27</value>
      <value system="CGS">1.672621898e-24</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mp"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_NEUTRON</name>
      <name type="short">A_mn</name>
      <alternateName>NEUTRON_MASS</alternateName>
      <description>neutron mass</description>
      <value system="MKS">1.674927471e-27</value>
      <value system="CGS">1.674927471e-24</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mn"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_HYDROGEN</name>
      <name type="short">A_mH</name>
      <alternateName>HYDROGEN_MASS</alternateName>
      <description>mass of Hydrogen atom --   
This value is from the IUPAC and is a little smaller than MASS_PROTON + MASS_ELECTRON, but within the uncertainty given here.  The current value is 1.008u +/- 0.0002 derived from a range of terrestrial materials.  If this is for precision work, you h...
</description>
      <value>1.6738e-27</value>
      <uncertainty type="absolute">3.3e-31</uncertainty>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://www.degruyter.com/downloadpdf/j/pac.2016.88.issue-3/pac-2015-0305/pac-2015-0305.pdf"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_ALPHA</name>
      <name type="short">A_ma</name>
      <description>mass of alpha particle</description>
      <value>6.644_657_230e-27</value>
      <uncertainty type="relative">1.2e-8</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mal"/>
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_ELECTRON</name>
      <name type="short">A_re</name>
      <alternateName>ELECTRON_RADIUS</alternateName>
      <description>classical electron radius</description>
      <value system="MKS">2.8179403227e-15</value>
      <value system="CGS">2.8179403227e-13</value>
      <uncertainty type="relative">6.8e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?re"/>
      <categoryList>
        <category>nuclear</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_BOHR</name>
      <name type="short">A_a0</name>
      <alternateName>BOHR_RADIUS</alternateName>
      <description>Bohr radius</description>
      <value system="MKS">5.2917721067e-11</value>
      <value system="CGS">5.2917721067e-9</value>
      <uncertainty type="relative">2.3e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?bohrrada0"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_JUPITER</name>
      <name type="short">A_rjup</name>
      <description>Volumetric mean radius of Jupiter</description>
      <value system="MKS">69_911_000</value>
      <uncertainty type="relative">1.5e-5</uncertainty>
      <dimensions>length</dimensions>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_JUPITER</name>
      <name type="short">A_mjup</name>
      <description>mass of Jupiter</description>
      <value system="MKS">1.89819e27</value>
      <uncertainty type="relative">5e-6</uncertainty>
      <dimensions>mass</dimensions>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
  </items>
</Collection>

data/old_versions/constants_2020_v0.14.xml  view on Meta::CPAN

  <reference_standard>2018 CODATA</reference_standard>
  <link href="http://metacpan.org/pod/Astro::Constants"/>
  <items>
    <PhysicalConstant>
      <name type="long">SPEED_LIGHT</name>
      <name type="short">A_c</name>
      <alternateName>LIGHT_SPEED</alternateName>
      <description>speed of light in a vacuum</description>
      <value system="MKS">299792458</value>
      <value system="CGS">2.99792458e10</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?c" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">BOLTZMANN</name>
      <name type="short">A_k</name>
      <alternateName/>
      <description>Boltzmann's constant</description>
      <value system="MKS">1.380649e-23</value>
      <value system="CGS">1.380649e-16</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?k" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">GRAVITATIONAL</name>
      <name type="short">A_G</name>
      <alternateName/>
      <symbol>G</symbol>
      <description>universal gravitational constant</description>
      <value system="MKS">6.67430e-11</value>
      <value system="CGS">6.67430e-8</value>
      <uncertainty type="relative">2.2e-5</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?bg" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ELECTRON_VOLT</name>
      <name type="short">A_eV</name>
      <alternateName/>
      <description>electron volt</description>
      <value system="MKS">1.602176634e-19</value>
      <value system="CGS">1.602176634e-12</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?evj"/>
      <categoryList>
        <category>fundamental</category>
        <category>conversion</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PLANCK</name>
      <name type="short">A_h</name>
      <alternateName/>
      <description>Planck constant</description>
      <value system="MKS">6.62607015e-34</value>
      <value system="CGS">6.62607015e-27</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?h" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">H_BAR</name>
      <name type="short">A_hbar</name>
      <alternateName>HBAR</alternateName>
      <description>the reduced Planck constant, Planck's constant (exact) /2pi</description>
      <value system="MKS">1.0545718176763e-34</value>
      <value system="CGS">1.054571817e-27</value>
      <uncertainty type="relative">1.5e-9</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?hbar" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">CHARGE_ELEMENTARY</name>
      <name type="short">A_e</name>
      <alternateName>ELECTRON_CHARGE</alternateName>
      <description>electron charge (defined positive)</description>
      <value system="MKS">1.602176634e-19</value>
      <value system="CGS">4.8032046729e-10</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?e"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>

data/old_versions/constants_2020_v0.14.xml  view on Meta::CPAN

      <symbol>
	<symbolRepresentation>
	  <latex>\sigma</latex>
	  <html>&amp;sigma;</html>
	  <unicode>σ</unicode>
        </symbolRepresentation>
      </symbol>
      <description>Stefan-Boltzmann constant</description>
      <value system="MKS">5.670374419e-8</value>
      <value system="CGS">5.670367e-5</value>
      <uncertainty type="relative">1.7e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?sigma" authority="2018 CODATA" year="2019" />
      <source url="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_RADIATION</name>
      <name type="short">A_arad</name>
      <alternateName>A_RAD</alternateName>
      <description>radiation density constant, 4 * sigma / c</description>
      <value system="MKS">7.565723e-16</value>
      <value system="CGS">7.565723e-15</value>
      <uncertainty type="relative">2.3e-6</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">WIEN</name>
      <name type="short">A_Wien</name>
      <alternateName/>
      <symbol>b</symbol>
      <description>Wien wavelength displacement law constant</description>
      <value system="MKS">2.897771955e-3</value>
      <value system="CGS">2.897771955e-1</value>
      <uncertainty type="relative">1e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?bwien" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>cosmology</category>
        <category>planetary</category>
        <category>nuclear</category>

data/old_versions/constants_2020_v0.14.xml  view on Meta::CPAN

      <name type="short">A_alpha</name>
      <alternateName/>
      <symbol>
	<symbolRepresentation>
	  <latex>\alpha</latex>
        </symbolRepresentation>
      </symbol>
      <description>fine structure constant</description>
      <value system="MKS">7.2973525693e-3</value>
      <value system="CGS">7.2973525693e-3</value>
      <uncertainty type="relative">1.5e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?alph" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>

data/old_versions/constants_2020_v0.14.xml  view on Meta::CPAN

      <alternateName>VACUUM_IMPEDANCE</alternateName>
      <symbol>
	<symbolRepresentation>
          <latex>Z_{0}</latex>
	  <html>Z&lt;sub&gt;0&lt;/sub&gt;</html>
	  <unicode>Zâ‚€</unicode>
        </symbolRepresentation>
      </symbol>
      <description>characteristic impedance of vacuum</description>
      <value>376.730313461</value>
      <uncertainty type="relative">1e-50</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?z0"/>
      <categoryList>
        <category>fundamental</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>

data/old_versions/constants_2020_v0.14.xml  view on Meta::CPAN

      <name type="short">A_eps0</name>
      <alternateName>PERMITIVITY_0</alternateName>
      <symbol>
	<symbolRepresentation>
	  <latex>\varepsilon_{0}</latex>
        </symbolRepresentation>
      </symbol>
      <description>permittivity of free space, epsilon_0, the electric constant</description>
      <value system="MKS">8.8541878128e-12</value>
      <value system="CGS">1</value>
      <uncertainty type="relative">1.5e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?ep0" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>

data/old_versions/constants_2020_v0.14.xml  view on Meta::CPAN

      <alternateName>PERMEABILITY_0</alternateName>
      <alternateName>CONSTANT_MAGNETIC</alternateName>
      <symbol>
	<symbolRepresentation>
	  <latex>\mu_{0}</latex>
        </symbolRepresentation>
      </symbol>
      <description>permeability of free space, mu_0, the magnetic constant</description>
      <value system="MKS">1.25663706212e-6</value>
      <value system="CGS">1</value>
      <uncertainty type="relative">1.5e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mu0" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>fundamental</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PI</name>
      <name type="short">A_pi</name>
      <alternateName/>
      <description>trig constant pi</description>
      <value>3.14159265358979324</value>
      <uncertainty type="relative">0.00000000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://oeis.org/search?q=id:A000796&amp;fmt=text"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">FOUR_PI</name>
      <name type="short">A_4pi</name>
      <alternateName>FOURPI</alternateName>
      <description>trig constant pi times 4 (shorthand for some calculations)</description>
      <value>12.5663706143592</value>
      <uncertainty type="relative">0.0000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Pi"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">STERADIAN</name>
      <name type="short">A_ster</name>
      <alternateName/>
      <description>a measure of solid angle in square degrees and a SI derived unit</description>
      <value>3282.80635001174</value>
      <uncertainty type="relative">0.00000000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Steradian"/>
      <categoryList>
        <category>conversion</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">EXP</name>
      <name type="short">A_exp</name>
      <alternateName/>
      <description>base of natural logarithm</description>
      <value>2.71828182846</value>
      <uncertainty type="relative">0.00000000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://oeis.org/search?q=id:A001113&amp;fmt=text"/>
      <categoryList>
        <category>mathematical</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ATOMIC_MASS_UNIT</name>
      <name type="short">A_amu</name>
      <alternateName/>
      <symbol>u</symbol>
      <description>unified atomic mass unit, 1 u</description>
      <value system="MKS">1.66053906660e-27</value>
      <value system="CGS">1.66053906660e-24</value>
      <uncertainty type="relative">3.0e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?ukg" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>conversion</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">PARSEC</name>
      <name type="short">A_pc</name>
      <alternateName/>
      <description>parsec</description>
      <value system="MKS">3.08567758149e16</value>
      <value system="CGS">3.08567758149e18</value>
      <uncertainty type="relative">1e-11</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Parsec" year="2015"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ASTRONOMICAL_UNIT</name>
      <name type="short">A_AU</name>
      <alternateName/>
      <description>astronomical unit</description>
      <value system="MKS">149_597_870_700</value>
      <value system="CGS">1.496e13</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://cneos.jpl.nasa.gov/glossary/au.html" authority="IAU" />
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">LIGHT_YEAR</name>
      <name type="short">A_ly</name>
      <alternateName/>
      <description>the distance that light travels in vacuum in one Julian year</description>
      <value system="MKS">9_460_730_472_580_800</value>
      <value system="CGS">9.4607304725808e17</value>
      <uncertainty type="defined"/>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Light-year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ANGSTROM</name>
      <name type="short">A_AA</name>
      <alternateName/>
      <description>Angstrom</description>
      <value system="MKS">1e-10</value>
      <value system="CGS">1e-8</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Angstrom"/>
      <categoryList>
        <category>conversion</category>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">JANSKY</name>
      <name type="short">A_Jy</name>
      <alternateName/>
      <symbol>Jy</symbol>
      <description>Jansky, a unit of flux density</description>
      <value system="MKS">1e-26</value>
      <value system="CGS">1e-23</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Jansky" authority="IAU" />
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">AVOGADRO</name>
      <name type="short">A_NA</name>
      <alternateName/>
      <description>Avogadro's number</description>
      <value>6.02214076e23</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?na" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>conversion</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR</name>
      <name type="short">A_yr</name>
      <alternateName>YEAR_JULIAN</alternateName>
      <description>defined as exactly 365.25 days of 86400 SI seconds</description>
      <value>31_557_600</value>
      <uncertainty type="relative">0</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Julian_year_(astronomy)"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_TROPICAL</name>
      <alternateName/>
      <description>the period of time for the ecliptic longitude of the Sun to increase 360 degrees, approximated by the Gregorian calendar</description>
      <value>31_556_925.1</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue>31556959</maxValue>
      <minValue>31556892</minValue>
      <source url="https://en.wikipedia.org/wiki/Tropical_year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_SIDEREAL</name>
      <alternateName/>
      <description>the period of revolution of the Earth around the Sun in a fixed reference frame</description>
      <value>31_558_149.8</value>
      <uncertainty type="absolute">1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sidereal_year"/>
      <categoryList>
        <category>conversion</category>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_ANOMALISTIC</name>
      <alternateName/>
      <description>the period between successive passages of the Earth through perihelion</description>
      <value>31_558_432.6</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Year#Sidereal,_tropical,_and_anomalistic_years"/>
      <categoryList>
        <category>conversion</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">YEAR_ECLIPSE</name>
      <alternateName/>
      <description>the period between successive passages of the Sun (as seen from the geocenter) through the same lunar node</description>
      <value>29_947_974.3</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Year#Draconic_year"/>
      <categoryList>
        <category>conversion</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_SOLAR</name>
      <name type="short">A_msun</name>
      <alternateName>SOLAR_MASS</alternateName>
      <description>solar mass</description>
      <value system="MKS">1.9884e30</value>
      <value system="CGS">1.9884e33</value>
      <uncertainty type="relative">0.0001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Solar_mass" authority="USNO" year="2014"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">LUMINOSITY_SOLAR</name>
      <name type="short">A_Lsun</name>
      <alternateName>SOLAR_LUMINOSITY</alternateName>
      <description>solar luminosity</description>
      <value system="MKS">3.828e26</value>
      <value system="CGS">3.828e33</value>
      <uncertainty type="relative">0.0003</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Solar_luminosity" authority="IAU" year="2015" />
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>

data/old_versions/constants_2020_v0.14.xml  view on Meta::CPAN

      <name type="short">A_rhoc</name>
      <alternateName>RHO_C</alternateName>
      <symbol>
	<symbolRepresentation>
		<latex>\frac{\rho_{c}{H^{2}}}</latex>
        </symbolRepresentation>
      </symbol>
      <description>normalized critical density $\frac{\rho_{c}}{H^{2}} = \frac{3}{8 pi G}$</description>
      <value system="MKS">1.7885e9</value>
      <value system="CGS">1.7885e12</value>
      <uncertainty type="relative">4.7e-5</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Friedmann_equations#Density_parameter"/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">HUBBLE_TIME</name>
      <name type="short">A_tH</name>
      <alternateName/>
      <description>Hubble time *h, the inverse of Hubble's constant valued at 100 km/s/Mpc (DEPRECATED - see ChangeLog)</description>
      <value>3.0853056e17</value>
      <uncertainty type="relative">0.0000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url=""/>
      <categoryList>
        <category>cosmology</category>
      </categoryList>
      <deprecated version="0.11" date="2017-04-26"/>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">TEMPERATURE_CMB</name>
      <name type="short">A_TCMB</name>
      <alternateName>CMB_TEMPERATURE</alternateName>
      <description>cosmic microwave background temperature in Kelvin</description>
      <value>2.72548</value>
      <uncertainty type="absolute">0.00057</uncertainty>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Cosmic_microwave_background" reference="Bibcode:2009ApJ...707..916F" year="2009" />
      <categoryList>
        <category>cosmology</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MAGNITUDE_SOLAR_V</name>
      <name type="short">A_Vsun</name>
      <alternateName>SOLAR_V_MAG</alternateName>
      <description>visual brightness of the Sun</description>
      <value>-26.74</value>
      <uncertainty type="relative">0.0004</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sun" year="1986"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MAGNITUDE_SOLAR_V_ABSOLUTE</name>
      <name type="short">A_MVsun</name>
      <alternateName>SOLAR_V_ABS_MAG</alternateName>
      <description>solar absolute V magnitude</description>
      <value>4.83</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sun"/>
      <categoryList>
        <category>cosmology</category>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_SOLAR</name>
      <name type="short">A_rsun</name>
      <alternateName>SOLAR_RADIUS</alternateName>
      <description>solar radius</description>
      <value system="MKS">6.96e8</value>
      <value system="CGS">6.96e10</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_EARTH</name>
      <name type="short">A_mearth</name>
      <alternateName>EARTH_MASS</alternateName>
      <description>mass of Earth</description>
      <value system="MKS">5.9722e24</value>
      <value system="CGS">5.9722e27</value>
      <uncertainty type="absolute">6e20</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_EARTH</name>
      <name type="short">A_rearth</name>
      <alternateName>EARTH_RADIUS</alternateName>
      <description>radius of Earth</description>
      <value system="MKS">6.378_136_6e6</value>
      <value system="CGS">6.378_136_6e8</value>
      <uncertainty type="absolute">0.1</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://asa.usno.navy.mil/static/files/2016/Astronomical_Constants_2016.pdf"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">TEMPERATURE_SOLAR_SURFACE</name>
      <name type="short">A_Tsun</name>
      <alternateName>SOLAR_TEMPERATURE</alternateName>
      <description>surface temperature of sun (photosphere)</description>
      <value>5772</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sun" authority="NASA" year="2010"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_SOLAR</name>
      <name type="short">A_dsun</name>
      <alternateName>SOLAR_DENSITY</alternateName>
      <description>mean solar density</description>
      <value system="MKS">1408</value>
      <value system="CGS">1.408</value>
      <uncertainty type="relative">0.001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Sun" authority="NASA" year="2010"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">DENSITY_EARTH</name>
      <name type="short">A_dearth</name>
      <alternateName>EARTH_DENSITY</alternateName>
      <description>mean Earth density</description>
      <value system="MKS">5515</value>
      <value system="CGS">5.515</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html" authority="NASA" year="2010"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">GRAVITY_SOLAR</name>
      <name type="short">A_gsun</name>
      <alternateName>SOLAR_GRAVITY</alternateName>
      <description>solar surface gravity</description>
      <value system="MKS">274.78</value>
      <value system="CGS">27478</value>
      <uncertainty type="relative">0.0004</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Surface_gravity"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">GRAVITY_EARTH</name>
      <name type="short">A_gearth</name>
      <alternateName>EARTH_GRAVITY</alternateName>
      <description>Earth surface gravity</description>
      <value system="MKS">9.80665</value>
      <value system="CGS">980.665</value>
      <uncertainty type="relative">0.000001</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Surface_gravity" authority="ISO 80000" year="2019"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_LUNAR</name>
      <name type="short">A_rmoon</name>
      <alternateName>LUNAR_RADIUS</alternateName>
      <description>lunar radius</description>
      <value system="MKS">1.7381e6</value>
      <value system="CGS">1.7381e8</value>
      <uncertainty type="relative">6e-5</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html" authority="NASA" year="2020"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_LUNAR</name>
      <name type="short">A_mmoon</name>
      <alternateName>LUNAR_MASS</alternateName>
      <description>lunar mass</description>
      <value system="MKS">7.346e22</value>
      <value system="CGS">7.346e25</value>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html" authority="NASA" year="2020"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">AXIS_SM_LUNAR</name>
      <name type="short">A_amoon</name>
      <alternateName>LUNAR_SM_AXIS</alternateName>
      <description>lunar orbital semi-major axis</description>
      <value system="MKS">3.84402e8</value>
      <value system="CGS">3.84402e10</value>
      <uncertainty type="relative">3e-9</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Lunar_distance_(astronomy)" reference="Bibcode:2009PASP..121...29B" year="2009"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">ECCENTRICITY_LUNAR</name>
      <name type="short">A_emoon</name>
      <alternateName>LUNAR_ECCENTRICITY</alternateName>
      <description>lunar orbital eccentricity</description>
      <value>0.0549</value>
      <uncertainty type="relative">0.002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://en.wikipedia.org/wiki/Orbit_of_the_Moon"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">THOMSON_CROSS_SECTION</name>
      <name type="short">A_sigmaT</name>
      <alternateName>THOMSON_XSECTION</alternateName>
      <symbol>
	<symbolRepresentation>
          <latex>\sigma_{e}</latex>
        </symbolRepresentation>
      </symbol>
      <description>Thomson cross-section</description>
      <value system="MKS">6.6524587321e-29</value>
      <value system="CGS">6.6524587321e-25</value>
      <uncertainty type="relative">9.1e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?sigmae" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_ELECTRON</name>
      <name type="short">A_me</name>
      <alternateName>ELECTRON_MASS</alternateName>
      <description>mass of electron</description>
      <value system="MKS">9.1093837015e-31</value>
      <value system="CGS">9.1093837015e-28</value>
      <uncertainty type="relative">3e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?me" authority="2018 CODATA" year="2019"/>
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_PROTON</name>
      <name type="short">A_mp</name>
      <alternateName>PROTON_MASS</alternateName>
      <description>mass of proton</description>
      <value system="MKS">1.67262192369e-27</value>
      <value system="CGS">1.67262192369e-24</value>
      <uncertainty type="relative">3.1e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mp" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_NEUTRON</name>
      <name type="short">A_mn</name>
      <alternateName>NEUTRON_MASS</alternateName>
      <description>neutron mass</description>
      <value system="MKS">1.67492749804e-27</value>
      <value system="CGS">1.67492749804e-24</value>
      <uncertainty type="relative">5.7e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mn" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_HYDROGEN</name>
      <name type="short">A_mH</name>
      <alternateName>HYDROGEN_MASS</alternateName>
      <description>mass of Hydrogen atom --   
This value is from the IUPAC and is a little smaller than MASS_PROTON + MASS_ELECTRON, but within the uncertainty given here.  The current value is 1.008u +/- 0.0002 derived from a range of terrestrial materials.  If this is for precision work, you h...
</description>
      <value>1.6738e-27</value>
      <uncertainty type="absolute">3.3e-31</uncertainty>
      <uncertainty type="relative">0.0002</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="https://www.degruyter.com/downloadpdf/j/pac.2016.88.issue-3/pac-2015-0305/pac-2015-0305.pdf" authority="IUPAC" />
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_ALPHA</name>
      <name type="short">A_ma</name>
      <symbol>
	<symbolRepresentation>
	  <latex>m_{\alpha}</latex>
        </symbolRepresentation>
      </symbol>
      <description>mass of alpha particle</description>
      <value>6.6446573357e-27</value>
      <uncertainty type="relative">3.0e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?mal" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_ELECTRON</name>
      <name type="short">A_re</name>
      <alternateName>ELECTRON_RADIUS</alternateName>
      <symbol>
	<symbolRepresentation>
	  <latex>r_{e}</latex>
        </symbolRepresentation>
      </symbol>
      <description>classical electron radius</description>
      <value system="MKS">2.8179403262e-15</value>
      <value system="CGS">2.8179403262e-13</value>
      <uncertainty type="relative">4.5e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?re" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>nuclear</category>
        <category>electromagnetic</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>

data/old_versions/constants_2020_v0.14.xml  view on Meta::CPAN

      <name type="short">A_a0</name>
      <alternateName>BOHR_RADIUS</alternateName>
      <symbol>
	<symbolRepresentation>
	  <latex>a_{0}</latex>
        </symbolRepresentation>
      </symbol>
      <description>Bohr radius</description>
      <value system="MKS">5.29177210903e-11</value>
      <value system="CGS">5.29177210903e-9</value>
      <uncertainty type="relative">1.5e-10</uncertainty>
      <dimensions/>
      <maxValue/>
      <minValue/>
      <source url="http://physics.nist.gov/cgi-bin/cuu/Value?bohrrada0" authority="2018 CODATA" year="2019" />
      <categoryList>
        <category>electromagnetic</category>
        <category>nuclear</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">RADIUS_JUPITER</name>
      <name type="short">A_rjup</name>
      <description>Volumetric mean radius of Jupiter</description>
      <value system="MKS">69_911_000</value>
      <uncertainty type="relative">1.5e-5</uncertainty>
      <dimensions>length</dimensions>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
    <PhysicalConstant>
      <name type="long">MASS_JUPITER</name>
      <name type="short">A_mjup</name>
      <description>mass of Jupiter</description>
      <value system="MKS">1.89819e27</value>
      <uncertainty type="relative">5e-6</uncertainty>
      <dimensions>mass</dimensions>
      <maxValue/>
      <minValue/>
      <source url="https://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html"/>
      <categoryList>
        <category>planetary</category>
      </categoryList>
    </PhysicalConstant>
  </items>
</Collection>

lib/Astro/Constants.pm  view on Meta::CPAN

neutron mass

This constant is also available using the alternate name C<NEUTRON_MASS>
(imported using the :alternate tag for backwards compatibility)

=head2 MASS_HYDROGEN

    1.6738e-27

mass of Hydrogen atom --
This value is from the IUPAC and is a little smaller than MASS_PROTON + MASS_ELECTRON, but within the uncertainty given here.  The current value is 1.008u +/- 0.0002 derived from a range of terrestrial materials.  If this is for precision work, you h...

This constant is also available using the alternate name C<HYDROGEN_MASS>
(imported using the :alternate tag for backwards compatibility)

=head2 MASS_ALPHA

    6.6446573357e-27

mass of alpha particle

lib/Astro/Constants.pm  view on Meta::CPAN

=back

=head1 FUNCTIONS

=head2 pretty

This is a helper function that rounds a value or list of values to 5 significant figures.

=head2 precision

Give this method the string of the constant and it returns the precision or uncertainty
listed.

  $rel_precision = precision('GRAVITATIONAL');
  $abs_precision = precision('MASS_EARTH');

At the moment you need to know whether the uncertainty is relative or absolute.
Looking to fix this in future versions.

=head2 Deprecated functions

I've gotten rid of C<list_constants> and C<describe_constants> because they are now in
the documentation.  Use C<perldoc Astro::Constants> for that information.

=head1 SEE ALSO

=over 4

lib/Astro/Constants.pm6  view on Meta::CPAN


=end pod

our constant MASS_NEUTRON is export(:nuclear) = 1.67492749804e-27;

=head3 MASS_HYDROGEN

    1.6738e-27

mass of Hydrogen atom --   
This value is from the IUPAC and is a little smaller than MASS_PROTON + MASS_ELECTRON, but within the uncertainty given here.  The current value is 1.008u +/- 0.0002 derived from a range of terrestrial materials.  If this is for precision work, you h...

This constant is also available using the alternate name C<HYDROGEN_MASS> (imported using the :alternate tag for backwards compatibility)

=end pod

our constant MASS_HYDROGEN is export(:nuclear) = 1.6738e-27;

=head3 MASS_ALPHA

    6.6446573357e-27

lib/Astro/Constants.pm6  view on Meta::CPAN


our constant MASS_JUPITER is export(:planetary) = 1.89819e27;
=begin pod

=head3 pretty

This is a helper function that rounds a value or list of values to 5 significant figures.

=head3 precision

Give this method the string of the constant and it returns the precision or uncertainty
listed.

  $rel_precision = precision('GRAVITATIONAL');
  $abs_precision = precision('MASS_EARTH');

At the moment you need to know whether the uncertainty is relative or absolute.
Looking to fix this in future versions.

=head2 Deprecated functions

I've gotten rid of C<list_constants> and C<describe_constants> because they are now in
the documentation.  Use C<perldoc Astro::Constants> for that information.

=head1 SEE ALSO

=item L<Astro::Cosmology>

lib/Astro/Constants/2019.pm  view on Meta::CPAN

neutron mass

This constant is also available using the alternate name C<NEUTRON_MASS>
(imported using the :alternate tag for backwards compatibility)

=head2 MASS_HYDROGEN

    1.6738e-27

mass of Hydrogen atom --
This value is from the IUPAC and is a little smaller than MASS_PROTON + MASS_ELECTRON, but within the uncertainty given here.  The current value is 1.008u +/- 0.0002 derived from a range of terrestrial materials.  If this is for precision work, you h...

This constant is also available using the alternate name C<HYDROGEN_MASS>
(imported using the :alternate tag for backwards compatibility)

=head2 MASS_ALPHA

    6.6446573357e-27

mass of alpha particle

lib/Astro/Constants/2019.pm  view on Meta::CPAN

=back

=head1 FUNCTIONS

=head2 pretty

This is a helper function that rounds a value or list of values to 5 significant figures.

=head2 precision

Give this method the string of the constant and it returns the precision or uncertainty
listed.

  $rel_precision = precision('GRAVITATIONAL');
  $abs_precision = precision('MASS_EARTH');

At the moment you need to know whether the uncertainty is relative or absolute.
Looking to fix this in future versions.

=head2 Deprecated functions

I've gotten rid of C<list_constants> and C<describe_constants> because they are now in
the documentation.  Use C<perldoc Astro::Constants> for that information.

=head1 SEE ALSO

=over 4

script/add_constant.pl  view on Meta::CPAN

        my $e = XML::LibXML::Element->new('description');
        $e->appendText( $description );
        $new_constant->addChild($e);
    }
    if (defined $value) {
        my $e = XML::LibXML::Element->new('value');
        $e->appendText( $value );
        $new_constant->addChild($e);
    }
    if (defined $precision) {
        my $e = XML::LibXML::Element->new('uncertainty');
        $e->setAttribute( 'type', 'relative' );
        $e->appendText( $precision );
        $new_constant->addChild($e);
    }
    if ($dimensions) {
        my $e = XML::LibXML::Element->new('dimensions');
        $e->appendText( $dimensions );
        $new_constant->addChild($e);
    }
	else {

script/build_module.pl  view on Meta::CPAN

% my $tags = shift;

=head1 FUNCTIONS

=head2 pretty

This is a helper function that rounds a value or list of values to 5 significant figures.

=head2 precision

Give this method the string of the constant and it returns the precision or uncertainty
listed.

  $rel_precision = precision('GRAVITATIONAL');
  $abs_precision = precision('MASS_EARTH');

At the moment you need to know whether the uncertainty is relative or absolute.
Looking to fix this in future versions.

=head2 Deprecated functions

I've gotten rid of C<list_constants> and C<describe_constants> because they are now in
the documentation.  Use C<perldoc Astro::Constants> for that information.

=head1 SEE ALSO

=for :list

script/build_module.pl  view on Meta::CPAN

	$constant->{deprecated} = 1 if $element->getChildrenByTagName('deprecated');

    my @categories;
    for my $cat_node ( $element->getElementsByTagName('category') ) {
		my $category =	$cat_node->textContent();
		next unless $category;
		push @categories, $category;
	}
    $constant->{categories} = \@categories if @categories;

	my $precision = $element->getChildrenByTagName('uncertainty')->shift();
	store_precision($name,
		$precision->textContent(),
		$precision->getAttribute('type'));

    return $constant;
}

script/dat_to_xml.pl  view on Meta::CPAN


	if (! defined $mks ) {
		# Unitless constant
		$writer->dataElement('value', $cgs );
	}
	else {
		$writer->dataElement('value', $mks, system => 'MKS');
		$writer->dataElement('value', $cgs, system => 'CGS');
	}

	$writer->dataElement('uncertainty', $precision, type => 'relative');		# absolute|relative
	$writer->emptyTag('dimensions');	# mass^1, length^-3, time|luminosity
	$writer->emptyTag('maxValue');
	$writer->emptyTag('minValue');

	my $search_term = $short =~ s/A_//r;
	$writer->emptyTag('url', 'href' => "http://physics.nist.gov/cgi-bin/cuu/Value?$search_term");

	$writer->startTag('categoryList');
	$writer->dataElement('category', $category);
	$writer->endTag();

script/fetch_constant_values.pl  view on Meta::CPAN


#die "Usage: $0 infile outfile" unless @ARGV == 1;

my $TESTING = 1;
my $ONLINE = 1;
my $SLEEP = 0;

my $ua = Mojo::UserAgent->new;
$ua->max_redirects(2);

my ($n, @values_parsed, @uncertainties_parsed, );
my ($td_flag, $font_flag, $text_flag, $uncertainty_flag) = 0;

my $xml = XML::LibXML->load_xml(location => "$Bin/../data/PhysicalConstants.xml");

=pod

my $nist_parser = HTML::Parser->new(
	start_h => [\&start_nist, "self, tagname, attr"],
	end_h => [\&end_nist, "tagname, attr"],
	text_h => [\&text, "text"],
);

script/fetch_constant_values.pl  view on Meta::CPAN

		if ( $value->hasAttribute('system') ) {
			$old_value = $value->textContent() if $value->getAttribute('system') eq 'MKS';
		}
		else {
			$old_value = $value->textContent();
			next;
		}
		$old_value =~ tr/_//;
	}

	my $precision = $constant->getChildrenByTagName('uncertainty')->shift();
	my $precision_type = $precision->getAttribute('type');
	$precision = $precision->textContent();
	my $source = $constant->getChildrenByTagName('source')->shift();
	my $source_url = $source->getAttribute('url');

	say <<CONST;
$name\t$old_value\t$precision\t$precision_type
$description
$source_url
CONST
	next unless $source_url =~ /physics\.nist\.gov/;
	next if $source_url =~ /wikipedia|jupiterfact/;

	print "Fetch page? [Ynq] ";
	my $ans = <STDIN>;
	next if $ans =~ /n/i;
	last if $ans =~ /q/i;

	my ($new_value, $new_uncertainty) = get_constant_value($source);
	if ( ! defined $new_value ) {
		warn "Couldn't get value for $long_name from $source_url";
	}
	elsif ( $new_value == $old_value ) {
			say "No change";
	}
	else {
        $new_uncertainty //= '';
		print <<"E";
UPDATE: $old_value \t($precision)
    TO: $new_value \t($new_uncertainty)
E
	}
	last if $TESTING && $TESTING <= ++$n;
	sleep $SLEEP if $SLEEP;
}


exit;

####

sub get_constant_value {
	my ($source) = @_;
	(@values_parsed, @uncertainties_parsed ) = ();

	my $url = $source->getAttribute('url');
	my $selector = $source->getAttribute('selector');
	if ( $url =~ /\.pdf$/ ) {
		warn "Can't scrape PDF documents yet\n";
		return;
	}
	say "Getting $url";
	return 0 unless $ONLINE;
    $DB::single = 1;

script/fetch_constant_values.pl  view on Meta::CPAN

	return unless $tx;

	if ( $url =~ /oeis\.org/ ) {
		my ($value) = $tx->content =~ /\%e \s \w+ \s (\d+\.?\d*)/x;
		print /(\%e.+)/ if /\%e/ && $TESTING;
		return $value;
	}
	elsif ( $url =~ /nist\.gov/ ) {
		mojo_parse($tx->result);
		return extract_value( @values_parsed ),
			extract_value( @uncertainties_parsed );
	}
	else {
		print $tx->result;
	}
}

sub start_nist {
	my ($self, $tag, $attr) = @_;
	$td_flag = 1 if $tag eq 'td';
	$font_flag = 1 if $tag eq 'font';
	return unless $td_flag && $font_flag;
	return if $font_flag && ! $attr->{color} || $attr->{color} ne 'red';
	$text_flag = 1;
}

sub end_nist {
	my ($tag) = @_;
	if ($tag eq 'tr') {
		$uncertainty_flag = 0;
	}
	return unless $tag eq 'td' || $tag eq 'font';
	$td_flag = 0 if $tag eq 'font';
	$font_flag = 0 if $tag eq 'font';
	$text_flag = 0;
}

sub text {
	my ($text, $attr) = @_;
	if ($text_flag) {
		push @values_parsed, $text;
		say "I found $text" if $TESTING;
	}
	if ($uncertainty_flag) {
		push @uncertainties_parsed, $text;
	}
	elsif (@values_parsed && $text =~ /Relative standard uncertainty/) {
		$uncertainty_flag = 1;
	}
	if ($uncertainty_flag) {
		say "TG: $text";
	}
}

sub configure_parsers {
	#$nist_parser->ignore_tags('tt', 'b', 'sup');
}

sub extract_value {
	my ($digits, $power, $units) = grep /\w/, @_;

script/update_constant_values.pl  view on Meta::CPAN

use LWP::Simple;
use List::Util qw/shuffle/;
use XML::LibXML;

#die "Usage: $0 infile outfile" unless @ARGV == 1;

my $TESTING = 0;
my $ONLINE = 1;
my $SLEEP = 0;

my ($n, @values_parsed, @uncertainties_parsed, );
my ($td_flag, $font_flag, $text_flag, $uncertainty_flag) = 0;

my $xml = XML::LibXML->load_xml(location => "$Bin/../data/PhysicalConstants.xml");
my $nist_parser = HTML::Parser->new(
	start_h => [\&start_nist, "self, tagname, attr"],
	end_h => [\&end_nist, "tagname, attr"],
	text_h => [\&text, "text"],
);

configure_parsers();

script/update_constant_values.pl  view on Meta::CPAN

		if ( $value->hasAttribute('system') ) {
			$old_value = $value->textContent() if $value->getAttribute('system') eq 'MKS';
		}
		else {
			$old_value = $value->textContent();
			next;
		}
		$old_value =~ tr/_//;
	}

	my $precision = $constant->getChildrenByTagName('uncertainty')->shift();
	my $precision_type = $precision->getAttribute('type');
	$precision = $precision->textContent();
	my $source = $constant->getChildrenByTagName('source')->shift();
	my $source_url = $source->getAttribute('url');

	say <<CONST;
$long_name\t$old_value\t$precision\t$precision_type
$description
$source_url
CONST
	#next unless $source_url =~ /physics\.nist\.gov/;
	next if $source_url =~ /wikipedia|jupiterfact/;

	print "Fetch page? [Ynq] ";
	my $ans = <STDIN>;
	next if $ans =~ /n/i;
	last if $ans =~ /q/i;

	my ($new_value, $new_uncertainty) = get_constant_value($source);
	if ( ! defined $new_value ) {
		warn "Couldn't get value for $long_name from $source_url";
	}
	elsif ( $new_value == $old_value ) {
			say "No change";
	}
	else {
    	$new_uncertainty //= '';
		print <<"E";
UPDATE: $old_value \t($precision)
    TO: $new_value \t($new_uncertainty)
E
	}
	last if $TESTING && $TESTING <= ++$n;
	sleep $SLEEP if $SLEEP;
}


exit;

####

sub get_constant_value {
	my ($source) = @_; 
	(@values_parsed, @uncertainties_parsed ) = ();
	
	my $url = $source->getAttribute('url');
	my $selector = $source->getAttribute('selector');
	if ( $url =~ /\.pdf$/ ) {
		warn "Can't scrape PDF documents yet\n";
		return;
	}
	say "Getting $url";
	return 0 unless $ONLINE;
	my $content = get($url);
	return unless $content;

	if ( $url =~ /oeis\.org/ ) {
		my ($value) = $content =~ /\%e \s \w+ \s (\d+\.?\d*)/x;
		print /(\%e.+)/ if /\%e/ && $TESTING;
		return $value;
	}
	elsif ( $url =~ /nist\.gov/ ) {
		$nist_parser->parse($content);
		return extract_value( @values_parsed ),
			extract_value( @uncertainties_parsed );
	}
	else {
		print $content;
	}
}

sub start_nist {
	my ($self, $tag, $attr) = @_;
	$td_flag = 1 if $tag eq 'td';
	$font_flag = 1 if $tag eq 'font';
	return unless $td_flag && $font_flag;
	return if $font_flag && ! $attr->{color} || $attr->{color} ne 'red';
	$text_flag = 1;
}

sub end_nist {
	my ($tag) = @_;
	if ($tag eq 'tr') {
		$uncertainty_flag = 0;
	}
	return unless $tag eq 'td' || $tag eq 'font';
	$td_flag = 0 if $tag eq 'font';
	$font_flag = 0 if $tag eq 'font';
	$text_flag = 0;
}

sub text {
	my ($text, $attr) = @_;
	if ($text_flag) {
		push @values_parsed, $text;
		say "I found $text" if $TESTING;
	}
	if ($uncertainty_flag) {
		push @uncertainties_parsed, $text;
	}
	elsif (@values_parsed && $text =~ /Relative standard uncertainty/) {
		$uncertainty_flag = 1;
	}
	if ($uncertainty_flag) {
		say "TG: $text";
	}
}

sub configure_parsers {
	$nist_parser->ignore_tags('tt', 'b', 'sup');
}

sub extract_value {
	my ($digits, $power, $units) = grep /\w/, @_;

script/xml_to_pm.pl  view on Meta::CPAN

	push @{$tagname->{all}}, $name if $name;
		

	for my $cat_node ( $constant->getElementsByTagName('category') ) {
		my $category =	$cat_node->textContent();
		next unless $category;
		push @{$tagname->{$category}}, $name;
		push @{$tagname->{$category}}, $alternate if $alternate;
	}

	my $precision = $constant->getChildrenByTagName('uncertainty')->shift();
	store_precision($name,
		$precision->textContent(), 
		$precision->getAttribute('type'));
}

write_pod_footer($ac_fh);
write_module_footer($ac_fh, $tagname);

exit;

script/xml_to_pm.pl  view on Meta::CPAN

    say $fh @pod; # delayed writing pod until after the code.
	say $fh <<'POD';
=head1 FUNCTIONS

=head2 pretty

This is a helper function that rounds a value or list of values to 5 significant figures.

=head2 precision

Give this method the string of the constant and it returns the precision or uncertainty
listed.

  \$rel_precision = precision('GRAVITATIONAL');
  \$abs_precision = precision('MASS_EARTH');

At the moment you need to know whether the uncertainty is relative or absolute.
Looking to fix this in future versions.

=head2 Deprecated functions

I've gotten rid of C<list_constants> and C<describe_constants> because they are now in
the documentation.  Use C<perldoc Astro::Constants> for that information.

=head1 SEE ALSO

=for :list

script/xml_to_raku.pl  view on Meta::CPAN

			#write_constant($ac_fh, ($values->{mks} || $values->{value}), $alternate) if $values->{mks} || $values->{value};
		}
	}

	#### write to the module files
	write_method_pod($ac_fh, $long_name, $short_name, $description, $values, \@alternates);
	write_constant($ac_fh, ($values->{mks} || $values->{value}), $long_name, $short_name, \@categories) 
			if $values->{mks} || $values->{value};


	my $precision = $constant->getChildrenByTagName('uncertainty')->shift();
	#store_precision($long_name, $precision->textContent(), $precision->getAttribute('type'));
}

write_pod_footer($ac_fh);
write_module_footer($ac_fh, $tagname);

exit;

#### HEADER ####
sub write_module_header {

script/xml_to_raku.pl  view on Meta::CPAN


	say $fh <<POD;
=begin pod

$dzil_methodtag pretty

This is a helper function that rounds a value or list of values to 5 significant figures.

$dzil_methodtag precision

Give this method the string of the constant and it returns the precision or uncertainty
listed.

  \$rel_precision = precision('GRAVITATIONAL');
  \$abs_precision = precision('MASS_EARTH');

At the moment you need to know whether the uncertainty is relative or absolute.
Looking to fix this in future versions.

=head2 Deprecated functions

I've gotten rid of C<list_constants> and C<describe_constants> because they are now in
the documentation.  Use C<perldoc Astro::Constants> for that information.

=head1 SEE ALSO

=item L<Astro::Cosmology>

t/functions.t  view on Meta::CPAN

use Test::More;
use Astro::Constants qw( :all pretty precision );

can_ok('Astro::Constants', qw/pretty precision/);

like( pretty(SPEED_LIGHT), qr/\d\.\d{2,5}([Ee][+-]?\d+)?$/, 'SPEED_LIGHT to 3 sig figs');
like( pretty(BOLTZMANN), qr/\d\.\d{2,5}([Ee][+-]?\d+)?$/, 'BOLTZMANN to 3 sig figs');
is( pretty(GRAVITATIONAL), 6.674e-11, 'GRAVITATIONAL rounded to 3 sig figs');
is( pretty(ELECTRON_VOLT), 1.602e-19, 'ELECTRON_VOLT rounded to 3 sig figs');

is( precision('GRAVITATIONAL'), 2.2e-5, 'relative uncertainty in GRAVITATIONAL');
is( precision('MASS_EARTH'), 6e20, 'absolute uncertainty in MASS_EARTH');

TODO: {
	local $todo = q/need to descern between absolute and relative precision/;

	is( precision('GRAVITATIONAL'), 2.2e-5, 'relative uncertainty in GRAVITATIONAL');
	is( precision('MASS_EARTH'), 6e20, 'absolute uncertainty in MASS_EARTH');

}

done_testing();

t/nuclear.t  view on Meta::CPAN

	is(MASS_ELECTRON, 9.1093837015e-31, 'MASS_ELECTRON');
	is(MASS_PROTON, 1.67262192369e-27, 'MASS_PROTON');
	is(MASS_NEUTRON, 1.67492749804e-27, 'MASS_NEUTRON');
	is(RADIUS_ELECTRON, 2.8179403262e-15, 'RADIUS_ELECTRON');
	is(RADIUS_BOHR, 5.29177210903e-11, 'RADIUS_BOHR');

	is(MASS_ALPHA, 6.6446573357e-27, 'MASS_ALPHA');

diag "MASS_HYDROGEN is from IUPAC 2013";
TODO: {
	local $TODO = "haven't implemented 'relative' uncertainties in method yet";

	cmp_ok(precision('MASS_HYDROGEN', 'relative'), '==', 0.0002, 
		'relative uncertainty of H mass');
};
cmp_ok(precision('MASS_HYDROGEN'), '==', 3.3e-31, 
	'absolute uncertainty of H mass');

my $h_abs = precision('MASS_HYDROGEN');
my $p_plus_e = MASS_PROTON + MASS_ELECTRON;
cmp_ok($p_plus_e, '<', MASS_HYDROGEN + $h_abs, 
	'Is proton + electron less than the upper bound on mass hydrogen');
cmp_ok($p_plus_e, '>', MASS_HYDROGEN - $h_abs, 
	'Is proton + electron greater than the lower bound on mass hydrogen');

done_testing();

xt/author/xml/test.xml  view on Meta::CPAN

    <source>2014 CODATA</source>
    <link href="http://metacpan.org/pod/Astro::Constants" />
    <items>
        <PhysicalConstant>
            <name type="long">SPEED_LIGHT</name>
            <name type="short">A_c</name>
            <alternateName>LIGHT_SPEED</alternateName>
            <description>speed of light in a vacuum</description>
            <value system="MKS">2.99792458e8</value>
            <value system="CGS">2.99792458e10</value>
            <uncertainty type="relative">0</uncertainty>
            <dimensions />
            <maxValue />
            <minValue />
            <url href="http://physics.nist.gov/cgi-bin/cuu/Value?c" />
            <categoryList>
                <category>fundamental</category>
                <category>cosmology</category>
                <category>electromagnetic</category>
            </categoryList>
        </PhysicalConstant>



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