(3) The computation outside the sphere

    The velocity redshift is the same with in the sphere

    Substituting

into formula (12), we have

                       (23)

where Λ₀ ，M  and  a  is obtain from the outmost layer.

    The total redshift is formula (13).

    When  Z_v=1 , the total redshift is  Z_max ,  and the distance  r_s  corresponding to  Z_max  is just the limit of sight, that is, the limiting distance of observation.