I find it highly unlikely that a superintelligence would care to create a medieval simulation with tons of suffering

You are asserting a false duality. Either many-worlds, OR a collapse postulate. You use evidence AGAINST a collapse as evidence FOR many worlds, which is very weak evidence. Here is a third alternative- the wavefunction is not real- merely a mathematical formalism used to calculate probability distributions (this map doesn't have to be the territory). Here is a fourth- collapse is an approximation to a small, non-linear self-coupling in the equation that governs time evolution. Here is a fifth- evolution is governed by both the advanced and retarded Green function solution to the Schroedinger equation, and what appears to be collapse is a sort of beat-resonance between the two. Here is a sixth- there are(non-local) degrees of freedom apart from the wavefunction and 'collapse' occurs because our existing theory is confused about what devices actually measure. I could keep going.

Every one of the above has a huge advantage over many worlds- there is positive evidence to update in their favor. Because they accurately reproduce most of quantum mechanics, all that evidence that we can use to push us to "quantum mechanics is probably right" CAN lead us to any of the above theories.

Many worlds does NOT have Born probabilities, and so IT DOES NOT MAKE PREDICTIONS. No one knows how to use many worlds to do anything at all. So you are doing a very weird sort of Bayesian process- you use Copenhagen or one of the above theories' predictions to update your belief to "quantum mechanics is probably right." Now starting from this new belief, you use other facts to update to "many worlds is probably right." Unfortunately, you didn't notice that in switching to many worlds, all of that evidence that pointed to quantum mechanics is gone.

If you start from an agnostic prior, many world's has no predictions to push you in the direction of "this is the right theory."

Some weird results in that poll... 42% believe Copenhagen is the correct interpretation, but only 30% believe that Bohr's view of QM is correct or will ultimately turn out to be correct. So at least 12% don't think Copenhagen is Bohr's view, which leaves me wondering what they think it is. The natural assumption would be that they think of Copenhagen as an objective collapse theory (in contrast to Bohr's instrumentalism), but that can't be right because "objective collapse" was a separate and much less popular answer. I do notice, though, that the percentages on the interpretation question add up to more than 100, so perhaps some (or all) of the people who chose "objective collapse" also chose "Copenhagen".

Also surprised that while 18% of respondents chose Everett, only 9% believe that the randomness in quantum mechanics is neither fundamental nor irreducible. What the what?

We understand why the evolution of classical systems is governed by classical probabilities---just churn through the quantum mechanics. Decoherence is very simple...

Decoherence isn't actually enough to show why quantum amplitudes show up as classical probabilities- if it were the Born-amplitude problem in many worlds would be solved. You need assumptions to turn "the wavefunction looks like this" into "the wavefunction looks like this so we expect to see result A with probability whatever." Decoherence tells us off-diagonal elements in the density matrix aren't likely to survive interaction with a larger system- thats not enough to connect to experimental values.

You jump straight from decoherence to "experiencing branches" without defining what you mean by "branch. "

Note; The story I originally posted here was true and complete. However the details detract from the main point of the post, which was to indicate material support for life extension causes. Hence the edit.

Owing to a recent financial windfall, I now intend to travel the world working towards life extension. Im starting by pledging donations to the Brain Preservation Fund and the Kim Suozzi fund. Readers will also shortly see my name appearing on the donar list of the aforementioned funds.

I have a blog (link below) where I will soon be writing about my new life as I travel the world working towards life extension.

Happy journeys to us all and see you in the future!

My blog is here: http://zarzuelazen.com/wordpress/

Yes, there are objective facts. Whether a waveunction is made of 2 components or 1 is still not independent of your perspective. No, it's not necessarily nonsense. I am just claiming that the unsolved problems of stuff like "overlap" are not due to a lack of information about quantum mechanics, but due to a lack of information about very complicated things humans do. If it the difficulty of understanding how humans categorize things and revise categories gets attributed to basic quantum mechanics, then we may get some nonsense.

Ah, I see. "Metaphysics."

By which you mean "taking human morality and decision-making, which evolved in a classical world, and figuring out what decisions you should make in a quantum universe."

Would you agree that overlap vs. non-overlap cannot be answered without looking inside humans, and in fact has little to do with the universe apart from a few postulates of quantum mechanics? For some reason I thought we were talking about the universe.

Anyhow, I think Shane Legg had a nice paper on porting utility functions, though of course humans are inconsistent and you immediately run into problems of how to idealize them. The basic idea being that you split up changes into "new things to care about" and "new ways to express old things." Quantum suicide is probably the easiest thing to deal with via this method.

I understand what you are saying, which I think my last post showed quite clearly

Maybe you're just used to talking with people who are better at interpreting you, or people who are more similar to you. Clearly understandable to people you talk with every day isn't always clearly understandable to me, as we've seen.

What you are saying really amounts to saying that "realism and solipsism are the same", because we cannot really distinguish either through science, all we can do is use logic and metaphysical "reasoning".

Could you explain this? Is this a metaphor, or are have you interpreted my statements about vectors to actually bear on realism vs. solipsism? Perhaps we have been talking about two different things.

Obviously both overlap and non-overlap cannot be true, they are ontologically different

Ah. See, this is the sort of thing I was trying to illustrate with the example of the diagonal line. A line being made of one component is ontologically different from a line being made of two components. Does this matter?

What happens if a one-componenter runs into a two-componenter? Do they argue? Does the first say "because of [insert convincing component-ist argument here], it's ONE component!" Are there valid component-ist arguments? How can the two-componenter respond?

I think it would go more like this: the first one says "hey, if you describe lines in terms of plus and minus diagonals, this one is clearly just a plus diagonal, so why say it has two components?" And the second says "Oh, huh, you're right. But there are lots of horizontal and vertical lines out there, so two-components is more useful." And the first says "yeah, that makes sense, unless you were building a ramp or something." "Well then, cheerio." "Toodles."

The reason this was so anticlimactic is because each participant could frame their ontology in a universal language (vectors!), and the ontologies were lossless transformations of each other - in this case the transformation was as simple as tilting your head. This clarity of the situation leaves no room for appeals to componentism. Arguments are for when both people are uncertain. When people know what's going on, there's simply a difference.

Have you read any of the papers that outline this? Alastair Wilson have written several: http://www.alastairwilson.org/

Could you point me to an example? Similar to how we are potentially talking about two different things, Alastair Wilson seemed to be talking about something other than physics in the papers I skimmed. The phrase "the most appropriate metaphysics to underwrite the semantics renders Everettian quantum mechanics a theory of non-overlapping worlds" exemplifies this for me.

What I am saying is that if one person says "all the worlds have always existed" and another says "the worlds spread out from one world," it's possible that both of them are being consistent, but then they are using two different definitions of "world." I am also saying that there is no basis that is "more real" than the others - only that some are more useful, and it's okay that people use different definitions as long as they're clear about it.

And yes, both pictures can describe the same thing. Have you worked with Bell states at all? Or am I misinterpreting your name and you actually haven't taken a class on quantum mechanics before?

The quantum world is like a diagonal line. One person comes up to it and says "Ah! Here is a diagonal line! It has just as much horizontal as it does vertical, therefore it is a mixture between horizontal and vertical." Another person comes up to it and says "Ah! Here is a diagonal line! It is a perfect rising diagonal, and is not even a little biased towards the falling diagonal." Will these two people argue over whether the line is made of two components or one?

Are all the worlds in the wavefunction from the beginning of time or do they somehow spring out from one world? This is called overlap vs non-overlap (first discussed by David Lewis).

So, by "world" in this post I'll mean "basis sate for the universe." The basis is arbitrary, so what "world" means will still depend on how I'm choosing what "worlds" are - there's the energy basis, for instance, where nothing ever changes if you look at just one of those "worlds." But you can have animals or computers in your basis states if you want - they aren't energy eigenstates, so they change with time.

Anyhow, currently the universe is spread out over a very wide variety of energy eigenstates, which is a fancy way of saying that lots of stuff changes. If we only allow quantum mechanics (that is, strictly follow MWI), this spread over "energy-worlds" is how the universe has been since the beginning of time. But if we look at the exact same state a different way, you could just call the initial state of the universe a basis state, and then, lo and behold, the universe would have sprung from one world, and the distribution of worlds then changed over time. This way of looking at things is probably pretty useful for cosmology. Or you could use worlds that change over time but don't include the original state of the universe, giving you overlap again. This is what we do unintentionally when we choose worlds that have humans in them, which is also pretty useful :)

For overlap vs. non-overlap to get more complicated than "both are valid pictures," you'd need some model where there weren't any static worlds to talk about - this would be a change to QM though. Also, this does raise the interesting question of how complicated that initial world (if we look at it that way) was. It doesn't have to be too complicated before we see interesting stuff.

Anyhow, it's pretty likely I was too hasty in my mistake-detection. But meh, I rarely regret putting off reading things. And I only occasionally regret putting my foot in my mouth :)