# Re: What are wavefunctions?

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On 02 Jan 2014, at 22:06, John Clark wrote:```
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On Thu, Jan 2, 2014 at 1:07 PM, Jason Resch <jasonre...@gmail.com> wrote:
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>>> The wave function says everything there is to be said about how something is right now.
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>> The wave function says nothing about where the electron is right now, the square of the wave function (I'm not being pedantic the distinction is important) does tell you something but not enough, it can only give you probable locations of the electron but it could be anywhere.
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> Up above, you were saying MWI implies a single definite result.

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Forget MWI forget theory forget interpretations, whenever you perform a experiment with photons you always get a single definite result, and the photon always leaves a specific clearcut dot on the photographic plate and never a grey smudge.
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> (which it does in the third person perspective), but here you are using the uncertainty in the first person perspective.
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As many pointed out, Everett's theory uses this and that point is capital to understand comp generalization of it.
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You have not answered my last posts. I don't see how you can make sense of Everett without the 1p/3p distinction, still less computationalism, indeed.
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Bruno

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> You should stick to one or the other, or at least be explicit when you switch between them.
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And you are using MWI and "the wave function" as if they were interchangeable, they are not. If a electron hits a photographic plate and you see a dot on the plate right there then you know which branch in the multiverse you're in, the branch where the electron hit right there. But you still don't know what the probability distribution was so you don't know what the wave function squared was. And even if you did know the function squared you still wouldn't know what the wave function itself was because it contains imaginary numbers and so when squared 2 very different wave functions can yield identical probability distributions.
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> There are other reasons to prefer it besides it's answer to the measurement problem without magical observers, including:
```- Fewer assumptions

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Fewer assumptions but more universes. Which are more expensive? I think assumptions are probably more expensive so MWI is more economical, but I could be wrong.
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> Explains how quantum computers work

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Other interpretations could do that too but I think Many Worlds does it in a way that is simpler for humans to understand. That's why I think if quantum computers ever become common Many Worlds will become the standard interpretation, programing a quantum computer would just be too complicated if you thought about it in other ways.
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> Fully mathematical theory (no fuzziness, or loose definitions)

I agree.

>No faster-than-light influences

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If that were true (and if MWI were realistic, and it is) then from experiment we'd know for certain that MWI is dead wrong, we can never know for certain that a theory is right but we can know for certain that it's wrong. But it isn't true.
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John K Clark

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