een included in the conversion tables. Unit names appear in curly braces.</p><pre>              {'c'}                  the speed of light in a vacuum
              {'g'}                  acceleration due to gravity
              {'e'}                  charge on an electron
              {'me'}                 mass of an electron
              {'mp'}                 mass of a proton
              {'Planck','h'}         energy expended over time
              {'alpha'}              fine structure constant
   