 Milne developed this model independent of general relativity but with awareness of special relativity.As he initially described it, the model has no expansion of space, so all of the redshift (except that caused by peculiar velocities) is explained by a recessional velocity associated with the hypothetical "explosion".However, the mathematical equivalence of the zero energy density (formula_5) version of the FLRW metric to Milne's model implies that a full general relativistic treatment using Milne's assumptions would result in an increasing scale factor and associated metric expansion of space with the unique feature of a linearly increasing scale factor for all time since the deceleration parameter is uniquely zero for such a model.