  Based on the work of Gao-Jafferis-Wall and Maldacena-Stanford-Yang, we
observe that the time-shifted thermofield states of two entangled CFTs can be
made traversable by an appropriate coupling of the two CFTs, or alternatively
by the application of a modified quantum teleportation protocol. This provides
evidence for the smoothness of the horizon for a large class of entangled
states related to the thermofield by time-translations. The smoothness of these
states has some relevance for the firewall paradox and the proposal that some
observables in quantum gravity may be state-dependent. We notice that quantum
teleportation through these entangled states could be used in a laboratory
setup to implement a time-machine, which allows the observer to travel far in
the future.
