  We use the formalisms of Holographic Space-time (HST) and Matrix Theory[11]
to investigate the claim of [1] that old black holes contain a firewall, i.e.
an in-falling detector encounters highly excited states at a time much shorter
than the light crossing time of the Schwarzschild radius. In both formalisms
there is no dramatic change in particle physics inside the horizon until a time
of order the Schwarzschild radius. The Matrix Theory formalism has been shown
to give rise to an S-matrix, which coincides with effective supergravity for an
infinite number of low energy amplitudes. We conclude that the firewall results
from an inappropriate use of quantum effective field theory to describe fine
details of localized events near a black hole horizon. In both HST and Matrix
Theory, the real quantum gravity Hilbert space in a localized region contains
many low energy degrees of freedom that are not captured in QU(antum)
E(ffective) F(ield) T(heory) and omits many of the high energy DOF in QUEFT.
