Your whole “paradoxical” setup works just as well if the randomizing device in the grenade is classical rather than quantum. But in the classical case our feelings are just the same, though no copies exist! The moral of the story is, I certainly do care about probability-branches of myself (the probabilities could be classical or quantum, no difference), but you haven’t yet persuaded me to care about arbitrary copies of myself elsewhere in the universe that aren’t connected to my “main tree”, so to speak.
In the classical case we could convert the probability into indexical uncertainty. That is, the random choices were made at the beginning of time. There’s no tree, there are just independent copies marching in lock-step until they behave differently.
No, it doesn’t, if by classical you mean “pseudorandom”. The pseudorandom grenade that sly holds “could” really have killed him, whereas the quantum grenade that he holds never stood any chance of killing the sly that holds it, but it certainly killed his quantum twin who he professes not to care about.
I think you mean “might have”. If the grenade is pseudorandom and it didn’t kill him, it just means that deterministically it couldn’t kill him. It’s perfectly equivalent to a fake grenade that you don’t know is fake.
It can’t kill you (it’s physically impossible for it to explode), but it might kill you (you don’t know that it’s physically impossible etc. etc.).
Your whole “paradoxical” setup works just as well if the randomizing device in the grenade is classical rather than quantum. But in the classical case our feelings are just the same, though no copies exist! The moral of the story is, I certainly do care about probability-branches of myself (the probabilities could be classical or quantum, no difference), but you haven’t yet persuaded me to care about arbitrary copies of myself elsewhere in the universe that aren’t connected to my “main tree”, so to speak.
What do you mean by “classical”? Do you mean “pseudorandom”, like a digit of pi?
In the classical case we could convert the probability into indexical uncertainty. That is, the random choices were made at the beginning of time. There’s no tree, there are just independent copies marching in lock-step until they behave differently.
Ditto in the quantum case.
No, it doesn’t, if by classical you mean “pseudorandom”. The pseudorandom grenade that sly holds “could” really have killed him, whereas the quantum grenade that he holds never stood any chance of killing the sly that holds it, but it certainly killed his quantum twin who he professes not to care about.
I think you mean “might have”. If the grenade is pseudorandom and it didn’t kill him, it just means that deterministically it couldn’t kill him. It’s perfectly equivalent to a fake grenade that you don’t know is fake.
It can’t kill you (it’s physically impossible for it to explode), but it might kill you (you don’t know that it’s physically impossible etc. etc.).
:-P
Sure. I agree, but for charging someone with attempted murder, it is the “might” that matters.
Nice—I think you got across exactly what I was struggling to say but with about 1⁄4 of the words!