The fact that the multiple worlds cannot currently, and probably never will be able to, interact in any significant way, makes it such that the moral worth of an action in one world out of many is exactly the same as what it would be if there was only one world.
This is actually a reasonably lay-friendly way of summarizing the case of the quantum-mechanical independence axiom. In non-interacting cases you should just do what you think is best for your own future (or past, but that’s a decision theory feature :P ), treating the quantum-mechanical amplitude-squared as a probability.
But I think the main reason why this time loop stuff sounds bad is just because all this extra time loop “measure” has no causal connection to outside. It breaks the normal laws of physics, so of course you get abnormal results.
This is actually a reasonably lay-friendly way of summarizing the case of the quantum-mechanical independence axiom. In non-interacting cases you should just do what you think is best for your own future (or past, but that’s a decision theory feature :P ), treating the quantum-mechanical amplitude-squared as a probability.
But I think the main reason why this time loop stuff sounds bad is just because all this extra time loop “measure” has no causal connection to outside. It breaks the normal laws of physics, so of course you get abnormal results.