Testing the Many-Worlds Interpretation

[spudtater]

(For those not entirely familiar with it, the "Many-worlds interpretation" is a view where every random event causes a new universe to split off — see the "parallel universes" so beloved by cheesy sci-fi.)

"One good example of this is the Quantum Suicide "experiment" that some proponents of the Many-Worlds Interpretation claim (I think jokingly) could actually be used to test the MWI. The way it works is, you basically run the Schrödinger's Cat thought experiment on yourself– you set up an apparatus whereby an atom has a 50% chance of decaying each second, and there's a detector which waits for the atom to decay. When the detector goes off, it triggers a gun, which shoots you in the head and kills you. So all you have to do is set up this experiment, and sit in front of it for awhile. If after sixty seconds you find you are still alive, then the many-worlds interpretation is true, because there is only about a one in 10¹⁸ chance of surviving in front of the Quantum Suicide machine for a full minute, so the only plausible explanation for your survival is that the MWI is true and you just happen to be the one universe where the atom's 50% chance of decay turned up "no" sixty times in a row."

Super Mario World vs. the Many-Worlds Interpretation of Quantum Physics, Mechanically Separated Meat, 3 Feb 2008

(The Super Mario World video is quite good, as well.)

Comments

[spudtater.livejournal.com]

Yeah. Ignore gominokouhai's thread above, as it's tangential. The generally accepted idea is that millions of alternate yous have millions of alternate, but equally valid, consciousnesses.

That's the point of the experiment in the post — for each 2⁶⁰ yous that carry out the experiment, (2⁶⁰ − 1) of them die and thus reach no conclusion. But the lucky one comes through unscathed, and concludes that the odds of such a thing happening are so incredibly remote that the many-worlds interpretation can be the only reason he is still alive.

[xenophanean.livejournal.com]

That's true, for the one that survived it would be remarkably unlikely, a telling experiment. That doesn't mean that he'll be identically continuous with you (i.e. be you in an identity sense), you'll almost certainly be one of the 20^60 to have died.

That is, unless you specifically stipulate that you're assuming that the universe can only go forward to one where you're alive. Which is just solipsism and doesnt need a many worlds theory. If you assume that it's inconsistent that you can move forward into a universe where you're not alive, you've just stated "I cannot die" regardless of whether there are many future universes, or only one.

I think this weird problem arises purely from human inability to concieve of our own non-existence.

[xenophanean.livejournal.com]

I should say, you've stated, "I cannot die, while the universe remains in existence".

[gominokouhai]

Good point: the anthropic principle applies, so no proof is gained.

[spudtater.livejournal.com]

In (2⁶⁰ - 1) of the universes, I die. By definition, these universes are not observable to me and hence to me they do not and cannot exist. For every continuous thread of consciousness I continue to exist. I will not die during the experiment.

This isn't sollipsism, but it is somewhat idealism-flavoured.

Of course, I will not deny that others have equally valid consciousnesses, which is why I would never actually conduct the experiment, even if I were 100% convinced that the MWI were correct. To the external observer I would almost certainly die, and I would not do that to (2⁶⁰ - 1) galaxy_girl00s. And, you know, all you lot.

(Addendum: that's the downside of this experiment — even if it produces a positive result, you can hardly consider this result to be communicable to other people. To some, that would disqualify it as a scientific experiment. YMMV.)

[xenophanean.livejournal.com]

Hmm, think that makes it a bit naff, if we're allowing that threads of consciousness could be cut, as you seem to be, yes there would be a thread of consciousness alive at the end, but there's no guarantee it's you. The assumption appears to remain that your consciousness can't move into a space where it's dead. If that's true, you can't die under any circumstances.

Here's another example. Imagine the universe splits only once, when you decide whether to stay in Edinburgh or move to Glasgow. In both streams, you live in your respective city for 10 years, however, then, in the Glasgow stream, you are killed by a falling filing cabinet. What happens then? Does your consciousness never go down the Glasgow route, does it skip to Edinburgh? Or do you just die?

[spudtater.livejournal.com]

> but there's no guarantee it's you

Who the hell else would it be if it isn't me?   8^)

I'm saying all future branches of me are, themselves, me. "I" am not a single pre-determined thread of experience from birth to death, I am the space of all potential paths from now on.

In answer to your question, my consciousness goes down both the Edinburgh route and the Glasgow route. Both Edinburgh me and Glasgow me are me. (Though Edinburgh me is not Glasgow me, nor vice versa — intransitivity yay). So I might say that in five years' time, I will be in both Edinburgh and Glasgow, but in 15 years' time, I will merely be in Edinburgh — I won't be dead in Glasgow because I cannot possibly be in an observable state where I am dead.

(If you ask Glasgow me, then I will cease to exist in another five years… there's no way for Glasgow me to become Edinburgh me. In fact, in Glasgow me's universe, Edinburgh me arguably does not even exist.)

[gominokouhai]

Been thinking about this. When we can upload our consciousnesses into the cybermatrix metanet, the consciousness that goes there is going to be a copy, a backup. Meanwhile, you and your body are going to continue to live and die in the humdrum meatspace world, while some damn copy of you is living it up in a universe constructed of pure dreams.

Assuming that it takes nonzero effort to upload one's consciousness, and the net gain to oneself remains at zero, it would be a complete waste of time to upload. You don't get any of the benefits. Somebody else gets to have all the fun, and they also get to call themselves `you' while they're doing it.

I suspect that Charlie has probably already addressed this, but I could never finish Accelerando.

``Humdrum Meatspace World'' wbaenfarb.

[spudtater.livejournal.com]

But again, the metanet me is also me. Regarding the meatspace me as more 'me' is pure anthropomorphic bias.

(I'll just have to accept the fact that one of the resultant mes will end up jealous and bitter).