[ALittleLight]

>Consciousness experiences the reality in which it lives the longest.

That formulation doesn't make sense to me. I would say it as "Consciousness can only experience realities in which it exists." Therefore you won't move into futures in which you don't exist.

[vankessel]

My reasoning behind this was that there can be multiple futures where you could exist and experience, but some of them shorter than others. E.g.

A------B

\ --------C

If you are travelling towards B, once you reach it, you die. But you can't magically jump last second to parallel reality C, you can only branch from the present. Thus you would have needed to branch down to C in advance. Thanks for pointing this out, I will make my reasoning more clear in a future edit.

[ALittleLight]

Two points:

1. Delayed choice quantum eraser experiments suggest to me, unless I've misunderstood them (which is highly possible), that effects can affect causes. https://en.m.wikipedia.org/wiki/Delayed-choice_quantum_erase...

2. Getting shot in the head isn't always fatal. The bullet could deflect off your skull, or even go through your brain and just not hit you. The bullet could experience spontaneous existence failure, or simply fail to interact with the matter in your body and pass through you. My limited understanding of physics says that things like these are possible but massively unlikely at large scale. However, if some set of things are possible but rare, and the only alternative things are impossible, then something rare will happen.

[marcofiset]

That's what I understood based on the gun example. However the same would hold true for any deadly disease you develop, wouldn't it?

[vankessel]

True, the doctor example is really just supposed to be segue into thinking about how a direct message could work. Although, perhaps facing death and recovering turns you into the kind of fellow who will live their life in a vastly different way leading to a longer life?

[saalweachter]

Oh, there's a horrifying contrapositive to that statement.

See, what that statement is really trying to do is assert uniqueness of consciousness within a many-worlds quantum interpretation.

Let's set up your standard quantum deathtrap: radioactive decay triggers the release of a deadly poison. And let's make it a really nasty poison, that is incurable but is going to inflict a good solid day or two of suffering as your organs fully liquify, so we have a nice, meaty, juicy thought experiment.

So many worlds, bam, there are now two (sets of) worlds, one where the particle decayed in the specified time period and your organs are now slowly liquifying and one where you are let out of the death trap, footloose and fancy free, to live a long and happy life, or at least, longer than the you slowly stewing in their own juices.

So what happens to your consciousness?

Well, in a boring materialistic interpretation of the world and consciousness, "you" forked at the same time as the worlds divided, being an aggregate property of the atoms involved, and one of you is blissfully unaware that the other is in horrible agony, perhaps philosophically reassured that there is a version of them not suffering in another quantum universe.

Under the proposition "Consciousness experiences the reality in which it lives the longest.", the you that is slowly liquifying doesn't live the longest, so it isn't conscious. It's a p-zombie, it acts like a conscious person without the underlying "experiencing" of it.

Now, let's carry that on through some more steps.

TV shows and movies like to make it seem like the many-worlds of quantum mechanics are caused by human decisions and the ups and downs of human life. The universe where you chose to go left instead of right, the universe where Hitler's painting career took off, etc etc. But they're caused by quantum events, and there are an uncountably large number of quantum events happening every microsecond as different particles of thorium in the Earth's radioactive core "choose" to decay, let alone what's happening in Betelgeuse.

"Many" in "many-worlds" is an unbelievably large number, and you are only going to live the "longest" in one of them, which means you are a p-zombie in every other one, because your consciousness only experiences the one in which you live the longest.

Now, what are the chances anyone else lives the longest in the same quantum world as you?

Zero. Less than zero. Zero followed by so many zeros it's meaningless.

Under this assumption, everyone you have ever known, everyone you have ever talked to -- me, even -- everyone you have ever loved was a p-zombie the entire time you knew them. Your parents? P-zombies. Your mee-maw? P-zombie. Your children? P-zombies.

Which is ultimately a good thing, I suppose, because then you don't have to feel bad if they die before you, because they're just p-zombies, and you don't have to feel bad about all those times they saw you die in other quantum worlds, because it was mostly just p-zombies watching other p-zombies die.