Ftl means there's one global reference frame most likely the cmbr one. The reason relativity predicts weird effects like time travel is because it doesn't allo

Ftl means there's one global reference frame most likely the cmbr one. The reason relativity predicts weird effects like time travel is because it doesn't allow ftl as an assumption, so the only way to hack ftl into it is negative time. It's baffling how many people seriously argue about consequences of something that completely disproves the theory itself while still using it to generate predictions.