  A new condition for the linear dissipative instability of the strong plane
shock wave in an arbitrary medium is obtained. The instability of the shock is
realized due to the flow instability behind its front, which is similar to the
known dissipative instability in the boundary layer for the
Tollmien-Schlichting waves. It is found that within the limit of low viscosity
the one-dimensional longitudinal disturbances grow much faster than the
two-dimensional corrugation ones. It points to a better correspondence to
experiment of the new condition for the absolute instability of the shock in
comparison with theory, which does not take viscosity into account.
