If they see the message arrive, it has already been sent (and received). Not seeing it get sent yet doesn’t mean it hasn’t happened yet. You’re not accounting for the frame of reference translation involved. Some of the information in your example has travel time. None of that information starts traveling before the things that created that information occurred, though.
mech@feddit.org 9 hours ago
I’m sorry, but all of special relativity disagrees with you.
ParlimentOfDoom@piefed.zip 8 hours ago
The only way that an observer can see a message arrive first before it was sent is if that message was also faster than light.
The propagation of the information that the signal was sent will be travelling before the information of the result starts to propagate. So even if the message is sent equal to light speed, there’s only one point on the two expanding spheres where the cause and effect appear simultaneously. That message you’re observing would have to move quicker than light for any observer to be overlapped by the effect bubble before the cause bubble reaches them. Both of those bubbles expand at the same rate.
How are you beating an ftl signal with your own ftl signal if you’re relying on information that is moving at light speed to react to?