drgo on Nostr: If travel backwards in time were possible, then the present would be the subject of ...

If travel backwards in time were possible, then the present would be the subject of warring future factions trying to guarantee their eventual existence.

How so? If party A needs event a to happen in order to exist but party B can only exist if event b happens instead of a, then A and B will travel back in time to fight each other to ensure event a or b happen.