  New concepts from nonequilibrium thermodynamics are used to show that
Landauer's principle can be understood in terms of time asymmetry in the
dynamical randomness generated by the physical process of the erasure of
digital information. In this way, Landauer's principle is generalized, showing
that the dissipation associated with the erasure of a sequence of bits produces
entropy at the rate $k_{{\rm B}}I$ per erased bit, where $I$ is Shannon's
information per bit.
