  The emergent nature of spacetime geometry and black holes can be directly
probed in simple holographic duals of higher spin gravity and tensionless
string theory. To this end, we study time dependent thermal correlation
functions of gauge invariant observables in suitably chosen free large N gauge
theories. At low temperature and on short time scales the correlation functions
encode propagation through an approximate AdS spacetime while interesting
departures emerge at high temperature and on longer time scales. This includes
the existence of evanescent modes and the exponential decay of time dependent
boundary correlations, both of which are well known indicators of bulk black
holes in AdS/CFT. In addition, a new time scale emerges after which the
correlation functions return to a bulk thermal AdS form up to an overall
temperature dependent normalization. A corresponding length scale was seen in
equal time correlation functions in the same models in our earlier work.
