  BMN Matrix theory admits vacua in the shape of large spherical membranes.
Per- turbing around such vacua, the setup provides for a controlled
computational frame- work for testing information evolution in Matrix black
holes. The theory realizes excitations in the supergravity multiplet as qubits.
These qubits are coupled to matrix degrees of freedom that describe
deformations of the spherical shape of the membrane. Arranging the ripples on
the membrane into a heat bath, we use the qubit system as a probe and compute
the associated Feynman-Vernon density matrix at one loop order. This allows us
to trace the evolution of entanglement in the system and extract the
characteristic scrambling timescale. We find that our numerical analysis is
consistent with this time scaling logarithmically with the entropy of the qubit
system, in tune with suggestions by Sekino and Susskind.
