                                      pi     3.1415926535897931E+00
                                    ln10     2.3025850929940459E+00
                             boltz_sigma     5.6703999999999998E-05
                           boltz_sigma*4     2.2681599999999999E-04
                    boltz_sigma*4/clight     7.5657673816464059E-15
                      boltz_sigma/clight     1.8914418454116015E-15
                                    crad     7.5657673816464059E-15
