The object’s length will be perceived as zero when our differential velocity has reached that of light. However, note that the object should have zero mass or convert its rest mass to energy in order to attain the speed of light: δs_r/δt_r = c (δt_r = δs_r ≠ 0), c being but a conversion constant which in this discourse we will hold to unity, i.e. we will not choose any particular unit of measurement to gauge s and t but require that they be measured with the same gauge