5 ms·
But any aliens' frame of reference is almost certain to be non-inertial with respect to our own :) That kills any notion of simultaneity.
by akkartik 7y ago
But any aliens' frame of reference is almost certain to be non-inertial with respect to our own :) That kills any notion of simultaneity.
- flingo 7y agoYou can still line them up with many points of reference. Would be pretty hard on a human timeline though.
- a1369209993 7y ago> That kills any notion of simultaneity. That's not actually true. Assuming there's a distinguished "initial" event [the big bang], and your universe does not contain any closed timelike curves [citation needed], you can define a Longest Proper Time from the initial event to any other event as the (obviously) longest proper time that any object or test particle could experience along a (timelike) path from the initial event to the later event. Simultaneous events have equal LPTs and are always spacelike-separated (if there was a timelike path from A to B then B.lpt (>)= A.lpt + len(path) > A.lpt, so B.lpt!=A.lpt and they aren't actually simultaneous).