> ro=(8*pi*h*c)/(l**5)*(1/(exp(h*c/(l*k*T))-1)) > > Anyway, this produces a "OverflowError: integer pow()" which can be quite > misleading when there is no pow() on the line (** instead). Just as division should normally trigger a floating-point operation, so also exponentiation should trigger a floating-point operation. This shouldn't be an error. Bruce Sherwood