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Thread: many-worlds and changing physical constants

  1. #1 many-worlds and changing physical constants 
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    Wikipedia claims that constants can change in the MWI-style universe, however given my understanding this is not so, and wikipedia is the only source that claims so.

    When the electrons split in the double-slit experiment, all the physical constants are the same for the electrons in superposition, right?

    So if you are only assuming the MWI style universe is true, and assuming all other types of multi-verses are false, then wouldn't it mean that all the physical constants in all the possible different realities/universes are the same?


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  3. #2 Re: many-worlds and changing physical constants 
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    Quote Originally Posted by VitalOne
    Wikipedia claims that constants can change in the MWI-style universe, however given my understanding this is not so, and wikipedia is the only source that claims so.

    When the electrons split in the double-slit experiment, all the physical constants are the same for the electrons in superposition, right?

    So if you are only assuming the MWI style universe is true, and assuming all other types of multi-verses are false, then wouldn't it mean that all the physical constants in all the possible different realities/universes are the same?
    The many worlds interpretation of QM is just that, an interpretation. It produces precisely the same predictions as does QM with the Copenhagen interpretation.

    Forget about what happens in some other world. The question has no meaning.

    Wiki is generally useful but it is not always authoritative. Don't make any bets based on some weird Wiki statement.


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  4. #3 Re: many-worlds and changing physical constants 
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    Quote Originally Posted by DrRocket
    Quote Originally Posted by VitalOne
    Wikipedia claims that constants can change in the MWI-style universe, however given my understanding this is not so, and wikipedia is the only source that claims so.

    When the electrons split in the double-slit experiment, all the physical constants are the same for the electrons in superposition, right?

    So if you are only assuming the MWI style universe is true, and assuming all other types of multi-verses are false, then wouldn't it mean that all the physical constants in all the possible different realities/universes are the same?
    The many worlds interpretation of QM is just that, an interpretation. It produces precisely the same predictions as does QM with the Copenhagen interpretation.

    Forget about what happens in some other world. The question has no meaning.

    Wiki is generally useful but it is not always authoritative. Don't make any bets based on some weird Wiki statement.
    Although all the interpretations are based off the same observations and mathematics, they have different implications.

    What happens in alternate timelines is relevant, if it could answer the anthropic/fine-tuning question. But I'm pretty confident that physical constants would not change in a MWI style multiverse, only in the other type of multiverses like the chaotic inflation style.
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  5. #4  
    Forum Radioactive Isotope MagiMaster's Avatar
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    No, the reason they're labeled interpretations (rather than theories or hypotheses) is because there are no different physical implications. Sure, they may have some philosophical differences, but that's it.
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  6. #5  
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    There is no reason to assume that physical constants don't have a probability cloud. We can't know, because our brain would only be able to exists in a very small range of that cloud.

    There is also no reason to assume they have. (Except, as MagiMaster notes, to make god utterly unnecessary and humble our ego)
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  7. #6  
    Moderator Moderator Dishmaster's Avatar
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    There has been some discussion, whether the finestructure constant may be not so constant at all. Here is a link describing, what is known about it:
    http://www.technologyreview.com/blog/arxiv/23397/
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  8. #7  
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    Quote Originally Posted by MagiMaster
    No, the reason they're labeled interpretations (rather than theories or hypotheses) is because there are no different physical implications. Sure, they may have some philosophical differences, but that's it.
    But they do have different physical implications, the MWI implying that there are physically other timelines/universes besides this one splitting at each moment, while other interpretations don't involve multiple timelines. This would have different physical implications like time travel, etc..

    What do you mean when you say they have philosophical differences but not different physical implications?
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  9. #8  
    Forum Radioactive Isotope MagiMaster's Avatar
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    I mean that there is no (known) measurement that can be made from within this universe that could distinguish one interpretation from another. If time travel is possible, it also will not distinguish one from the other. Philosophically, you feel there must be some difference, but physically, there isn't.
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  10. #9  
    . DrRocket's Avatar
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    Quote Originally Posted by MagiMaster
    I mean that there is no (known) measurement that can be made from within this universe that could distinguish one interpretation from another. If time travel is possible, it also will not distinguish one from the other. Philosophically, you feel there must be some difference, but physically, there isn't.
    It is not a questoin of known measurements. The two theories produce exactly the same predictions. There is no way to distinguish the mutiverse from the Copenhagen interpretation even in principle.

    That is why they are interpretations, They are the same theory.

    Philosophy is just a word game if you can't tell the difference between the two theories with any physical means.
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  11. #10  
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    Quote Originally Posted by MagiMaster
    I mean that there is no (known) measurement that can be made from within this universe that could distinguish one interpretation from another. If time travel is possible, it also will not distinguish one from the other. Philosophically, you feel there must be some difference, but physically, there isn't.
    I think what you mean is that there's no way to empirically distinguish which is true from which is false

    But physically there is a difference, if alternate timelines physically exist, or if the observer plays a role, etc...physically there are different implications, like if the universe physically exists in superposition until observed would have different implications than no observer role
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  12. #11  
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    Quote Originally Posted by VitalOne
    Quote Originally Posted by MagiMaster
    I mean that there is no (known) measurement that can be made from within this universe that could distinguish one interpretation from another. If time travel is possible, it also will not distinguish one from the other. Philosophically, you feel there must be some difference, but physically, there isn't.
    I think what you mean is that there's no way to empirically distinguish which is true from which is false

    But physically there is a difference, if alternate timelines physically exist, or if the observer plays a role, etc...physically there are different implications, like if the universe physically exists in superposition until observed would have different implications than no observer role
    That is just a word game. If it is in principle impossible to distinguish between two theories empirically they are the same theory. There are no different meaningful implications. Philosophers can argue the question of how many angels can dance on the head of a pin, but scientists have no time for such nonsense.
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