On Wednesday, January 8, 2003, at 10:58 AM, George Levy wrote:
In the original verision of Quantum Suicide (QS), as understood in this list, the experimenter sets up a suicide machine that kills him if the world does not conform to his wishes. Hence, in the branching many-worlds, his consciousness is erased in those worlds, and remains intact in the worlds that do satisfy him.Hawking had a good line: "When I hear about Schrodinger's Cat, I reach for my gun."
Is it possible to perform such a feat without suicide? What is the minimum "attrition" that is required and still get the effect of suicide?
Slightly modify the QS conditions in another direction: instead of dying immediately, one goes onto death row to await execution. Or one is locked in a box with the air running out. And so on.
This removes the security blanket of saying "Suicide is painless, and in all the worlds you have not died in, you are rich!" In 99.9999...99% of all worlds, you sit in the box waiting for the air to run out.
I don't know if there are other worlds in the DeWitt/Graham sense (there is no reason to believe Everett ever thought in these terms), but if they "exist" they appear to be either unreachable by us, or inaccessible beyond short times and distances (coherence issues).
In particular, it seems to me there's a "causal decision theory" argument which says that one should make decisions based on the maximization of the payout. And based on everything we observe in the world around us, which is overwhelmingly classical at the scales we interact in, this means the QS outlook is deprecated.
Consider this thought experiment: Alice is facing her quantum mechanics exam at Berkeley. She sees two main approaches to take. First, study hard and try to answer all of the questions as if they mattered. Second, take the lessons of her QS readings and simply _guess_, or write gibberish, killing herself if she fails to get an "A." (Or, as above, facing execution, torture, running out of air, etc., just to repudiate the "suicide is painless" aspect of some people's argument.)
From rationality, or causal decision theory, which option should she pick?
All indications are that there are virtually no worlds in which random guessers do well. (The odds are readily calcuable, given the type of exam, grading details, etc. We can fairly easily see that a random guesser in the SATs will score around 550-600 combined, but that a random guesser in a non-multiple-choice QM exam will flunk with ovewhelming likelihood.)
What should one do? What did all of you actually do? What did Moravec do, what did I do, what did Tegmark do?