  IF Aviendha saw a mutable future generated from accessing mirror worlds, the hardware for accessing Mirror Worlds MUST be present in the Columns ter'angreal. Everything we've seen prior to ToM suggests that the columns have nothing to do with Mirror Worlds and everything to do with Blood Memory.  The basic technology for accessing the Mirror Worlds was already present and functional, why duplicate that hardware in addition to whatever is required for the ancestral search function.  W