> This allows different observers to reasonably disagree about which came first. Basic relativity. that happens all the time. Lets set aside the Earth being cu

> This allows different observers to reasonably disagree about which came first. Basic relativity. that happens all the time. Lets set aside the Earth being curved for a moment - I'll use real cities but these could be asteroids floating in intergalactic space at the same distance. I'm in London, I see an event happen in London, Moscow, New York and LA all at the same time, at 12:00:00.500 UTC according to me. London-Moscow 9ms London-NY 66ms London-LA 103ms Lets imagine they are in a straight line too and all in the same reference pane. The events actually occurred in the follow order, at the following milliseconds past 12:00:00 UTC, according to our NTP synced clocks. LA: 397ms NY: 434ms Moscow: 491ms London: 500ms From LA's point of view they would see LA: 397ms NY: 471ms London: 603ms Moscow: 603ms From Moscow's POV Moscow: 491ms London: 509ms NY: 509ms LA: 509ms From NY's POV LA: 434ms NY: 434ms London: 566ms Moscow: 566ms So LA thinks LA was first, NY was second, London and Moscow co-timed third. NY thinks LA and NY were co-timed first, then London and Moscow co-timed third. Moscow thinks Moscow was first, everywhere else was second. London thinks everywhere was first So we disagree. So what. Now sure, if your wormholes are in different reference frames you can get confusions, but why would a wormhole with two ends fixed in the same reference frame and neither end accelerating allow passing information backwards in time? I know relativity says there is no universal clock everyone agrees on, but isn't that only applicable for points in different reference planes (and even then you can surely adjust if you know your relative velocity to the universal point)? Back to cosmic scales. Point A, B, C, D, all 10 light years apart, same reference frame Point A event happens at t+0 B sees at t+10, C and t+20, D at t+30. D also has a wormhole to A, so sees the event in the wormhole at t+0, and causes a separate event (light up a sign saying "A event just happend") C would see that D is flagging the event at t+10, but have to wait until t+20 to see it. Why is that bad? How would D get a signal back to A before t+0. I guess a spaceship in a different reference frame (say v=0.99c) at D could see (old fashioned looking out the window) the "event just happened" message, then use a separate wormhole to send a message to a spaceship at A travelling in the same reference frame as spaceship D. Spaceship A could then light up a message, which planet A could see, but would planet A see that before t+0 on their local clock?