  We discuss, from a quantum information perspective, recent proposals of
Maldacena, Ryu, Takayanagi, van Raamsdonk, Swingle, and Susskind that spacetime
is an emergent property of the quantum entanglement of an associated boundary
quantum system. We review the idea that the informational principle of minimal
complexity determines a dual holographic bulk spacetime from a minimal quantum
circuit U preparing a given boundary state from a trivial reference state. We
describe how this idea may be extended to determine the relationship between
the fluctuations of the bulk holographic geometry and the fluctuations of the
boundary low-energy subspace. In this way we obtain, for every quantum system,
an Einstein-like equation of motion for what might be interpreted as a bulk
gravity theory dual to the boundary system.
