  The description of the dynamics of closed quantum systems, governed by the
Schroedinger equation at first sight seems incompatible with the Lindblad
equation describing open ones. By analyzing closed dynamics of a spin-1/2 chain
we reconstruct exponential decays characteristic for the latter model. We
identify all necessary ingredients to efficiently model this behavior, such as
an infinitely large environment and the coupling to the system weak in
comparison to the internal couplings in the bath.
