  We claim that the dynamics of noncritical string theories in two dimensions
is related to an underlying noncritical version of M-theory, which we define in
terms of a double-scaled nonrelativistic Fermi liquid in 2+1 dimensions. After
reproducing Type 0A and 0B string theories as solutions, we study the natural
M-theory vacuum. The vacuum energy of this solution can be evaluated exactly,
its form suggesting a duality to the Debye model of phonons in a melting solid,
and a possible topological nature of the theory. The physical spacetime is
emergent in this theory, only for states that admit a hydrodynamic description.
Among the solutions of the hydrodynamic equations of motion for the Fermi
surface, we find families describing the decay of one two-dimensional string
theory into another via an intermediate M-theory phase.
