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Science and MWI

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  • hibbsa
    Deutsch has mentioned that Science has failed to accept MWI where it should have done so, and this has naturally caused me to watch out for glimpses of what
    Message 1 of 9 , Apr 11, 2012
      Deutsch has mentioned that Science has failed to accept MWI where it
      should have done so, and this has naturally caused me to 'watch out' for
      glimpses of what the attidude is toward MWI.

      The perception I have gleaned from this seem to be that actually MWI is
      given a lot of respect. It is regarded very much within the fold of
      science. It is mentioned pretty much whenever QM is discussed if the
      context is 'what does it mean?'. It is also given respectful attention
      in popularizations of science. Also documentary series...for example the
      current series of "Through the Wormhole" on Discovery Science channel,
      dedicates a large fraction of a whole episode to MWI and treats it as if
      it is a major mainstream theory. No talk of interpretations. No time
      given to scientists complaining that the theory is too counter
      intuitive. Significant time given to criticisms of scientists not being
      willing to believe their own equations. And so on.

      So my question to Deutsch, if he's around, would firstly be: what sort
      of acceptance do you have in mind? What would it look like that would be
      different to the way things are at the moment?

      My next question sort of assumes that part of Deutsch's answer to this
      will be in terms of actual scientific time/resources dedicated to MWI
      focused research, and my question about this would be: in your view what
      sort of research isn't being done, that could or should be getting done,
      and how productive would this research promise to be in terms of
      unlocking substantial new testable scientific knowledge about the nature
      of the world?
    • David Deutsch
      ... physicists and philosophers have ... That is true. ... Well, sort of. ... Usually it is presented on a roughly equal footing with several different kinds
      Message 2 of 9 , Apr 11, 2012
        On 11 Apr 2012, at 6:28pm, hibbsa wrote:

        > Deutsch has mentioned that Science has

        physicists and philosophers have

        > failed to accept MWI where it
        > should have done so, and this has naturally caused me to 'watch out' for
        > glimpses of what the attidude is toward MWI.
        >
        > The perception I have gleaned from this seem to be that actually MWI is
        > given a lot of respect. It is regarded very much within the fold of
        > science. It is mentioned pretty much whenever QM is discussed if the
        > context is 'what does it mean?'.

        That is true.

        > It is also given respectful attention
        > in popularizations of science. Also documentary series...

        Well, sort of.

        > for example the
        > current series of "Through the Wormhole" on Discovery Science channel,
        > dedicates a large fraction of a whole episode to MWI and treats it as if
        > it is a major mainstream theory. No talk of interpretations. No time
        > given to scientists complaining that the theory is too counter
        > intuitive. Significant time given to criticisms of scientists not being
        > willing to believe their own equations. And so on.

        Usually it is presented on a roughly equal footing with several different kinds of nonsense. As if you had a documentary about the origin of species that featured a section on evolution and then one of equal length and presented with equal seriousness on young-earth creationism, another on Intelligent Design, another on divinely guided evolution, and so on.
        >
        > So my question to Deutsch, if he's around, would firstly be: what sort
        > of acceptance do you have in mind? What would it look like that would be
        > different to the way things are at the moment?

        For instance, there'd be:

        In theoretical physics: Work on the structure of the multiverse, its implications for the theory of probability, deeper explanations of various quantum algorithms, deeper understanding of the Heisenberg Picture....

        In philosophy: Work on things like personal identity, the relationship between multiple universes and multiple copies in a single universe, morality in the multiverse...

        In theoretical physics, experimental physics and philosophy: Cessation of work whose only interest is in the context of believing nonsensical 'interpretations'...

        In physics teaching: Excision of anti-rational ideologies such as positivism or shut-up-and-calculate from physics classes.

        See also my talk here at the Everett@50 conference: http://vimeo.com/5490979

        > My next question sort of assumes that part of Deutsch's answer to this
        > will be in terms of actual scientific time/resources dedicated to MWI
        > focused research, and my question about this would be: in your view what
        > sort of research isn't being done, that could or should be getting done,
        > and how productive would this research promise to be in terms of
        > unlocking substantial new testable scientific knowledge about the nature
        > of the world?

        One can't predict such things. But wanting to know true explanations is reason enough to pursue them.

        -- David Deutsch
      • tomegalovlito
        ... What you say about the theory of probability doeesn t sound right. Just because a coin is fair , it doesn t mean that when I toss it in a specific
        Message 3 of 9 , Apr 12, 2012
          --- In Fabric-of-Reality@yahoogroups.com, David Deutsch <david.deutsch@...> wrote:
          >
          > On 11 Apr 2012, at 6:28pm, hibbsa wrote:
          >
          > For instance, there'd be:
          >
          > In theoretical physics: Work on the structure of the multiverse, its implications for the theory of probability, deeper explanations of various quantum algorithms, deeper understanding of the Heisenberg Picture....
          >

          What you say about the theory of probability doeesn't sound right. Just because a coin is "fair", it doesn't mean that when I toss it in a specific instance it will come up heads in 50% of the universes. That depends on the details of my movement, which are practically unknowable to me, but probably don't change much for each universe in the particular instance we're considering. The "infinite tosses" definition of probability would be the correct one, because over many *different* tosses, we'd get heads 50% of the time.
        • Elliot Temple
          ... There is no such thing as what the result would be of doing something physically impossible. You can t flip a coin infinitely many times. We judge what
          Message 4 of 9 , Apr 12, 2012
            On Apr 12, 2012, at 9:42 AM, tomegalovlito wrote:

            >
            >
            > --- In Fabric-of-Reality@yahoogroups.com, David Deutsch <david.deutsch@...> wrote:
            >>
            >> On 11 Apr 2012, at 6:28pm, hibbsa wrote:
            >>
            >> For instance, there'd be:
            >>
            >> In theoretical physics: Work on the structure of the multiverse, its implications for the theory of probability, deeper explanations of various quantum algorithms, deeper understanding of the Heisenberg Picture....
            >>
            >
            > What you say about the theory of probability doeesn't sound right. Just because a coin is "fair", it doesn't mean that when I toss it in a specific instance it will come up heads in 50% of the universes. That depends on the details of my movement, which are practically unknowable to me, but probably don't change much for each universe in the particular instance we're considering. The "infinite tosses" definition of probability would be the correct one, because over many *different* tosses, we'd get heads 50% of the time.

            There is no such thing as what the result would be of doing something physically impossible.

            You can't flip a coin infinitely many times. We judge what *would* happen in hypotheticals using the laws of physics. But the laws of physics don't cover the very cases they tell us are physically impossible. The laws of physics offer no guidance about what would happen if they were violated.

            -- Elliot Temple
            http://fallibleideas.com/
          • tomegalovlito
            ... Okay, fine. If I were to toss the coin very many times, then I would get heads around 50% of the time.
            Message 5 of 9 , Apr 12, 2012
              --- In Fabric-of-Reality@yahoogroups.com, Elliot Temple <curi@...> wrote:
              >
              >
              > On Apr 12, 2012, at 9:42 AM, tomegalovlito wrote:
              >
              > >
              > >
              > > --- In Fabric-of-Reality@yahoogroups.com, David Deutsch <david.deutsch@> wrote:
              > >>
              > >> On 11 Apr 2012, at 6:28pm, hibbsa wrote:
              > >>
              > >> For instance, there'd be:
              > >>
              > >> In theoretical physics: Work on the structure of the multiverse, its implications for the theory of probability, deeper explanations of various quantum algorithms, deeper understanding of the Heisenberg Picture....
              > >>
              > >
              > > What you say about the theory of probability doeesn't sound right. Just because a coin is "fair", it doesn't mean that when I toss it in a specific instance it will come up heads in 50% of the universes. That depends on the details of my movement, which are practically unknowable to me, but probably don't change much for each universe in the particular instance we're considering. The "infinite tosses" definition of probability would be the correct one, because over many *different* tosses, we'd get heads 50% of the time.
              >
              > There is no such thing as what the result would be of doing something physically impossible.
              >
              > You can't flip a coin infinitely many times. We judge what *would* happen in hypotheticals using the laws of physics. But the laws of physics don't cover the very cases they tell us are physically impossible. The laws of physics offer no guidance about what would happen if they were violated.
              >
              > -- Elliot Temple
              > http://fallibleideas.com/
              >

              Okay, fine. If I were to toss the coin "very many" times, then I would get heads "around" 50% of the time.
            • hibbsa
              ... I get that MWI raises huge questions, but for me the question is, does MWI actually open up research avenues for how to go about any of this? What are the
              Message 6 of 9 , Apr 15, 2012
                --- In Fabric-of-Reality@yahoogroups.com, David Deutsch <david.deutsch@...> wrote:
                >
                > On 11 Apr 2012, at 6:28pm, hibbsa wrote:
                > > So my question to Deutsch, if he's around,
                > > would firstly be: what sort
                > > of acceptance do you have in mind?
                > > What would it look like that would be
                > > different to the way things are at the moment?


                > For instance, there'd be:
                >
                > In theoretical physics: Work on the
                > structure of the multiverse, its
                > implications for the theory of probability,
                > deeper explanations of various quantum
                > algorithms, deeper understanding of the
                > Heisenberg Picture....

                I get that MWI raises huge questions, but for me the question is, does MWI actually open up research avenues for how to go about any of this? What are the leads...what are the approaches...how can these questions be progressed?
                So in summary I guess I am meaning to ask something like "Is MWI productive, or potentially productive?"


                > In philosophy: Work on things like personal
                > identity, the relationship between multiple
                > universes and multiple copies in a single universe,
                > morality in the multiverse...


                > In theoretical physics, experimental physics
                > and philosophy: Cessation of work whose only
                > interest is in the context of believing > nonsensical 'interpretations'...



                > In physics teaching: Excision of anti-rational
                > ideologies such as positivism or shut-up-and-calculate
                > from physics classes.


                > See also my talk here at the Everett@50 conference: http://vimeo.com/5490979

                Will do - and thanks for the reply.
              • Brett Hall
                ... The video linked to below is brilliant for a number of reasons - not least of which, the exposition of precisely how taking seriously Schrodinger s wave
                Message 7 of 9 , Apr 15, 2012
                  On 16/04/2012, at 6:07 AM, "hibbsa" <asbbih@...> wrote:

                  >
                  >
                  > --- In Fabric-of-Reality@yahoogroups.com, David Deutsch <david.deutsch@...> wrote:
                  > >
                  > > On 11 Apr 2012, at 6:28pm, hibbsa wrote:
                  > > > So my question to Deutsch, if he's around,
                  > > > would firstly be: what sort
                  > > > of acceptance do you have in mind?
                  > > > What would it look like that would be
                  > > > different to the way things are at the moment?
                  >
                  > > For instance, there'd be:
                  > >
                  > > In theoretical physics: Work on the
                  > > structure of the multiverse, its
                  > > implications for the theory of probability,
                  > > deeper explanations of various quantum
                  > > algorithms, deeper understanding of the
                  > > Heisenberg Picture....
                  >
                  > I get that MWI raises huge questions, but for me the question is, does MWI actually open up research avenues for how to go about any of this? What are the leads...what are the approaches...how can these questions be progressed?
                  > So in summary I guess I am meaning to ask something like "Is MWI productive, or potentially productive?"
                  >
                  The video linked to below is brilliant for a number of reasons - not least of which, the exposition of precisely how taking seriously Schrodinger's wave equation as a literal description of reality opens up many new avenues of research not currently being pursued because people don't believe in the multiverse for philosophical reasons. David covers the fact that the multiverse thought of as a huge number of parallel universes is merely a crude approximation - and so we can do a lot better than this. (I think this is why, for example the chapter in BoI on the multiverse looked so much different to "Shadows" in FoR).

                  In elementary particle physics he talks about how physicists know that particles are quantum objects and yet they construct theories which are explicitly single universe theories. He talks about physicists constructing classical theories they know to be false and then enact a ritual of "quantisation" to try and make progress *rather* than taking the multiverse seriously. They do this because it has worked in the past (it worked for Feynman) but there's no reason that it should work again. So progress is being stymied there by people refusing to believe in the truth of quantum theory. I like when he compares this state of affairs to what might have been the case if progress in Newtonian physics had been hampered by people thinking that Keplarisation had to be done - that somehow classical mechanics had to be all about conic sections.

                  David explains in this video how probability statements can be properly understood in physical reality. If we want to know the probability of a thing occurring in the next instance then speaking about what would happen in an infinite number of experiments no longer speaks about reality. Instead probability statements can be understood in reality in terms of observers bifurcating - and someone else who knows more might want to correct me here - but this means speaking about a measure of observers witnessing particular outcomes and this then is what we mean when we speak about a probability as being 50% or whatever.

                  About 40 minutes in he puts up a list of all the promising avenues of research that are possible only with a multiverse view and not without. For real progress I wonder how we can expect to have the so-called theory of everything where general relativity is unified with quantum theory if people are not taking the multiverse seriously. This is first on the list by the way. Other stuff there about quantum computation and the philosophy of physics and personal identity are all going to require a multiverse view if we are to continue to make progress by taking this particular theory seriously...as David reiterates below.

                  Brett
                  >
                  > > In philosophy: Work on things like personal
                  > > identity, the relationship between multiple
                  > > universes and multiple copies in a single universe,
                  > > morality in the multiverse...
                  >
                  > > In theoretical physics, experimental physics
                  > > and philosophy: Cessation of work whose only
                  > > interest is in the context of believing > nonsensical 'interpretations'...
                  >
                  > > In physics teaching: Excision of anti-rational
                  > > ideologies such as positivism or shut-up-and-calculate
                  > > from physics classes.
                  >
                  > > See also my talk here at the Everett@50 conference: http://vimeo.com/5490979
                  >
                  > Will do - and thanks for the reply
                  >
                  >


                  [Non-text portions of this message have been removed]
                • Elliot Temple
                  ... Can you provide details regarding it working for Feynman?
                  Message 8 of 9 , Apr 17, 2012
                    On Apr 15, 2012, at 4:11 PM, Brett Hall wrote:

                    > On 16/04/2012, at 6:07 AM, "hibbsa" <asbbih@...> wrote:
                    >
                    >>
                    >>
                    >> --- In Fabric-of-Reality@yahoogroups.com, David Deutsch <david.deutsch@...> wrote:
                    >>>
                    >>> On 11 Apr 2012, at 6:28pm, hibbsa wrote:
                    >>>> So my question to Deutsch, if he's around,
                    >>>> would firstly be: what sort
                    >>>> of acceptance do you have in mind?
                    >>>> What would it look like that would be
                    >>>> different to the way things are at the moment?
                    >>
                    >>> For instance, there'd be:
                    >>>
                    >>> In theoretical physics: Work on the
                    >>> structure of the multiverse, its
                    >>> implications for the theory of probability,
                    >>> deeper explanations of various quantum
                    >>> algorithms, deeper understanding of the
                    >>> Heisenberg Picture....
                    >>
                    >> I get that MWI raises huge questions, but for me the question is, does MWI actually open up research avenues for how to go about any of this? What are the leads...what are the approaches...how can these questions be progressed?
                    >> So in summary I guess I am meaning to ask something like "Is MWI productive, or potentially productive?"
                    >>
                    > The video linked to below is brilliant for a number of reasons - not least of which, the exposition of precisely how taking seriously Schrodinger's wave equation as a literal description of reality opens up many new avenues of research not currently being pursued because people don't believe in the multiverse for philosophical reasons. David covers the fact that the multiverse thought of as a huge number of parallel universes is merely a crude approximation - and so we can do a lot better than this. (I think this is why, for example the chapter in BoI on the multiverse looked so much different to "Shadows" in FoR).
                    >
                    > In elementary particle physics he talks about how physicists know that particles are quantum objects and yet they construct theories which are explicitly single universe theories. He talks about physicists constructing classical theories they know to be false and then enact a ritual of "quantisation" to try and make progress *rather* than taking the multiverse seriously. They do this because it has worked in the past (it worked for Feynman)

                    Can you provide details regarding it working for Feynman?
                  • Elliot Temple
                    ... This is wrong. If you toss a coin a trillion times, you might get near 50% heads (say, +/- 2%). Or you might not. Either can happen. To say you *would* get
                    Message 9 of 9 , Apr 17, 2012
                      On Apr 12, 2012, at 11:22 AM, tomegalovlito wrote:

                      >
                      >
                      > --- In Fabric-of-Reality@yahoogroups.com, Elliot Temple <curi@...> wrote:
                      >>
                      >>
                      >> On Apr 12, 2012, at 9:42 AM, tomegalovlito wrote:
                      >>
                      >>>
                      >>>
                      >>> --- In Fabric-of-Reality@yahoogroups.com, David Deutsch <david.deutsch@> wrote:
                      >>>>
                      >>>> On 11 Apr 2012, at 6:28pm, hibbsa wrote:
                      >>>>
                      >>>> For instance, there'd be:
                      >>>>
                      >>>> In theoretical physics: Work on the structure of the multiverse, its implications for the theory of probability, deeper explanations of various quantum algorithms, deeper understanding of the Heisenberg Picture....
                      >>>>
                      >>>
                      >>> What you say about the theory of probability doeesn't sound right. Just because a coin is "fair", it doesn't mean that when I toss it in a specific instance it will come up heads in 50% of the universes. That depends on the details of my movement, which are practically unknowable to me, but probably don't change much for each universe in the particular instance we're considering. The "infinite tosses" definition of probability would be the correct one, because over many *different* tosses, we'd get heads 50% of the time.
                      >>
                      >> There is no such thing as what the result would be of doing something physically impossible.
                      >>
                      >> You can't flip a coin infinitely many times. We judge what *would* happen in hypotheticals using the laws of physics. But the laws of physics don't cover the very cases they tell us are physically impossible. The laws of physics offer no guidance about what would happen if they were violated.
                      >>
                      >> -- Elliot Temple
                      >> http://fallibleideas.com/
                      >>
                      >
                      > Okay, fine. If I were to toss the coin "very many" times, then I would get heads "around" 50% of the time.

                      This is wrong.

                      If you toss a coin a trillion times, you might get near 50% heads (say, +/- 2%). Or you might not. Either can happen.

                      To say you *would* get near 50% heads is simply false. The laws of physics allow it to go either way.

                      Will you "probably" get near 50% heads? You can't say that when the topic at issue is a theory of probability. It'd be circular to use probability as a premise in one's theory of probability.

                      So this whole way of thinking about probability does not work. But Deutsch's way does work.
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