Trope-a-Day: Time Travel

Time Travel: Present in very limited forms: the kind you can do with wormhole shortcuts and relativistic travel (whose primary usage is permitting physics grad students to actually observe local causality violations), and the kind that lets transcendent AIs whisper to themselves from the future via acausal logic.  In both cases, subject to Chronological Consistency Protection, as they’re operating in a block universe.  (See Temporal Paradox.)