CODATA recommended values of physical constants.

See <>.

All CODATA recommended values are defined as a constant and as a
function.  The function returns three values, the value of the
constant, the standard uncertainty, and the relative standard
uncertainty.  Floating-point numbers are of the type `long-float'.
Please note that some of the constants have values which can not be
represented as IEEE 754 single precision floating-point numbers.


     (ql:quickload :codata-recommended-values)

     (defun E (m)
       (symbol-macrolet ((c codata-recommended-values:speed-of-light-in-vacuum))
         (* m c c)))

The latest values are available via the `codata-recommended-values'
package.  If you need a previously issued value, append the year to
the package name, for example, `codata-recommended-values-2010'.
Ralph Schleicher <>
Modified BSD License