Assume I survive a car/plane crash which we assume could have many different quantum outcomes including me (dead || alive)
Since I was the same person (entire life history) up until the crash/quantum 'branch' - then can't I assume that since there was at least one outcome where I survived, that TO ME I will always survive other such life/death branches?
Furthermore if I witness a crash where someone dies can I assume that the victim will survive in their own "world" so far as at least one quantum branch of survivability seems possible?
Yes, this is Quantum Immortality in a nutshell. If the MWI is correct, it is impossible to die from a subjective point of view.
Survive as what, though? And in what condition? I know from personal experience that one does not always experience oneself in that world-branch in which one is in tip-top shape.
Reminds me of the ancient Greek myth of the goddess whose mortal lover was granted immortality at her request by Zeus, but not eternal youth, because it didn't occur to the goddess to ask Zeus to grant her lover that too. So the lover never died, but grew ever older, more wrinkled & bent, till he became a grasshopper.
Hmm sounds like quantum immorality leaves us all old, crippled and miraculously dodging (typical) eventualities. The version of quantum "self-preservation" I find reasonable is where accidents have an estimated survivability of >~50%. ie, If you get killed by a comet, it's very safe to say that minor quantum events could've moved it a couple feet away. Being born in the 10th century for example and living forever could not have been possible via quantum branches, right? Technological evolution takes time.. Are there any really good arguments out there for QI? (not to bother you - I will research this on my own)