I think it’s quite reasonable for “survive past time T” to mean that “at time T+1 there will exist a living human that has psychological and physical continuity from the state of the human at T-1″. In the MW interpretation that sort of survival is guaranteed. In the Copenhagen interpretation it has tiny probability.
The real problem is that conservation of expected evidence does not hold for Bob. There is no observation he can make that is in favour of Copenhagen over MW.
This can be seen as a variant of the Sleeping Beauty problem. A coin is flipped, and the universe is started with either MW or Copenhagen rules. If it’s MW then Alice is woken up on 10,000 days with no memory of any previous awakenings, and Bob is awakened on only one of those days. If it’s Copenhagen then with 0.01% probability, Bob is awakened on all those days (with no memory) otherwise awakened on none of them.
Assuming Bob wakes up, what credence should he have that the coin flip resulted in MW?
The real problem is that conservation of expected evidence does not hold for Bob. There is no observation he can make that is in favour of Copenhagen over MW.
That argument proves too much. E.g. consider Russian roulette and the proposition “the next chamber contains a bullet”. This will only ever be (subjectively) disproved, and not proved.
For a many worlder “exist” conditions trigger if they are fullfilled in brother timelines that did not take place.
And even so, one can imagine holding your stomach having been mortally wounded by the machine. All of that person is going to die, that person won’t survive. It probably does not warm to know that the person from 10 seconds ago is going to survive. “Bob” is ambigious over these individuals.
I think it’s quite reasonable for “survive past time T” to mean that “at time T+1 there will exist a living human that has psychological and physical continuity from the state of the human at T-1″. In the MW interpretation that sort of survival is guaranteed. In the Copenhagen interpretation it has tiny probability.
The real problem is that conservation of expected evidence does not hold for Bob. There is no observation he can make that is in favour of Copenhagen over MW.
This can be seen as a variant of the Sleeping Beauty problem. A coin is flipped, and the universe is started with either MW or Copenhagen rules. If it’s MW then Alice is woken up on 10,000 days with no memory of any previous awakenings, and Bob is awakened on only one of those days. If it’s Copenhagen then with 0.01% probability, Bob is awakened on all those days (with no memory) otherwise awakened on none of them.
Assuming Bob wakes up, what credence should he have that the coin flip resulted in MW?
That argument proves too much. E.g. consider Russian roulette and the proposition “the next chamber contains a bullet”. This will only ever be (subjectively) disproved, and not proved.
For a many worlder “exist” conditions trigger if they are fullfilled in brother timelines that did not take place.
And even so, one can imagine holding your stomach having been mortally wounded by the machine. All of that person is going to die, that person won’t survive. It probably does not warm to know that the person from 10 seconds ago is going to survive. “Bob” is ambigious over these individuals.