3 ms·

It's simpler (as in fewer rules; not that it results in a "simpler" smaller world) than a lot of other interpretations: it doesn't need to specify an explicit c

It's simpler (as in fewer rules; not that it results in a "simpler" smaller world) than a lot of other interpretations: it doesn't need to specify an explicit concept of wave collapse.

semi-extrinsic 7y ago
Instead it does have to specify the explicit concept of how these many worlds fork off from each other. MWI is a lot more mind-boggling if you truly think about it.
- GoblinSlayer 7y ago
  The forking obeys the Schrodinger equation. The collapse was artificially added to evade this forking that naturally follows from the equation.
yyyk 7y ago
But it has no good explanation for why the Born rule applies at all. The current attempts are IMHO very unconvincing, since I see no reason why rational choice theory should apply at all. A much more detailed way of saying about the same thing as the above sentence: https://backreaction.blogspot.com/2019/09/the-trouble-with-many-worlds.html https://backreaction.blogspot.com/2019/09/the-trouble-with-m...
- lmm 7y ago
  > it has no good explanation for why the Born rule applies at all. Indeed it doesn't, but the Born rule is much smaller and simpler than the notion of collapse that other approaches rely on. > A much more detailed way of saying about the same thing as the above sentence: https://backreaction.blogspot.com/2019/09/the-trouble-with-m.. https://backreaction.blogspot.com/2019/09/the-trouble-with-m.... This post doesn't seem to understand many-worlds. There is no concept of a privileged "detector". All that many-worlds postulates is that detectors, experimenters, and anything else you might measure with obeys the normal rules of physics, and can be put into an entangled superposition just like anything else.
  - yyyk 7y ago
    >Indeed it doesn't, but the Born rule is much smaller and simpler than the notion of collapse that other approaches rely on. First, not all of the other approaches have a collapse. e.g. Bohm and a few lesser known others don't have it. Second, it's not clear Born is 'smaller and simpler' than the collapse of some other interpretations. e.g. in QBism collapse arises naturally from the theory and it would be weird if collapse didn't happen. " This post doesn't seem to understand many-worlds... anything else you might measure with obeys the normal rules of physics" Her point is that what MWI tries to derive everything from the Schrödinger equation alone, but it still needs to solve its equivalent of the measurement problem (why can we only get certain results on the evolution of this branch?), but that can't be done since Schrödinger is linear and the equivalent problem is not.
    - lmm 7y ago
      > e.g. Bohm and a few lesser known others don't have it. Bohm is just MWI with a bunch of extra epicycles. > Second, it's not clear Born is 'smaller and simpler' than the collapse of some other interpretations. e.g. in QBism collapse arises naturally from the theory and it would be weird if collapse didn't happen. I'd be interested in hearing more, but from a quick look I'd argue that the notion of an agent who should evaluate subjective probabilities is more complex than objective probability numbers. > Her point is that what MWI tries to derive everything from the Schrödinger equation alone, but it still needs to solve its equivalent of the measurement problem (why can we only get certain results on the evolution of this branch?) That's not true though. The branching behaviour is inherent in the Schrödinger equation.
      - yyyk 7y ago
        "Bohm is just MWI with a bunch of extra epicycles." Heh. I've heard MWI is just an hidden variable theory with the other branches being the hidden information. Slightly more seriously, the two did develop independently. "I'd be interested in hearing more..." IMHO, QBism is relatively intuitive if/once you accept the subjective probability premise (which means probability one isn't same as 'true'!), but I'm far from qualified to explain it well... "The branching behaviour is inherent in the Schrödinger equation." The point is not the branching per se, but what happens in the current branch's evolution. There are only some branches that are 'legal' or 'likely', and it appears the limits/probabilities aren't deductible from Schrödinger alone. Almost like MWI needs a little extra something to be a complete theory. P.S. That downvote wasn't mine.

It's simpler (as in fewer rules; not that it results in a "simpler" smaller world) than a lot of other interpretations: it doesn't need to specify an explicit concept of wave collapse.

semi-extrinsic 7y ago

Instead it does have to specify the explicit concept of how these many worlds fork off from each other. MWI is a lot more mind-boggling if you truly think about it.

GoblinSlayer 7y ago
The forking obeys the Schrodinger equation. The collapse was artificially added to evade this forking that naturally follows from the equation.

yyyk 7y ago

But it has no good explanation for why the Born rule applies at all. The current attempts are IMHO very unconvincing, since I see no reason why rational choice theory should apply at all. A much more detailed way of saying about the same thing as the above sentence: https://backreaction.blogspot.com/2019/09/the-trouble-with-many-worlds.html https://backreaction.blogspot.com/2019/09/the-trouble-with-m...

lmm 7y ago
> it has no good explanation for why the Born rule applies at all. Indeed it doesn't, but the Born rule is much smaller and simpler than the notion of collapse that other approaches rely on. > A much more detailed way of saying about the same thing as the above sentence: https://backreaction.blogspot.com/2019/09/the-trouble-with-m.. https://backreaction.blogspot.com/2019/09/the-trouble-with-m.... This post doesn't seem to understand many-worlds. There is no concept of a privileged "detector". All that many-worlds postulates is that detectors, experimenters, and anything else you might measure with obeys the normal rules of physics, and can be put into an entangled superposition just like anything else.
- yyyk 7y ago
  >Indeed it doesn't, but the Born rule is much smaller and simpler than the notion of collapse that other approaches rely on. First, not all of the other approaches have a collapse. e.g. Bohm and a few lesser known others don't have it. Second, it's not clear Born is 'smaller and simpler' than the collapse of some other interpretations. e.g. in QBism collapse arises naturally from the theory and it would be weird if collapse didn't happen. " This post doesn't seem to understand many-worlds... anything else you might measure with obeys the normal rules of physics" Her point is that what MWI tries to derive everything from the Schrödinger equation alone, but it still needs to solve its equivalent of the measurement problem (why can we only get certain results on the evolution of this branch?), but that can't be done since Schrödinger is linear and the equivalent problem is not.
  - lmm 7y ago
    > e.g. Bohm and a few lesser known others don't have it. Bohm is just MWI with a bunch of extra epicycles. > Second, it's not clear Born is 'smaller and simpler' than the collapse of some other interpretations. e.g. in QBism collapse arises naturally from the theory and it would be weird if collapse didn't happen. I'd be interested in hearing more, but from a quick look I'd argue that the notion of an agent who should evaluate subjective probabilities is more complex than objective probability numbers. > Her point is that what MWI tries to derive everything from the Schrödinger equation alone, but it still needs to solve its equivalent of the measurement problem (why can we only get certain results on the evolution of this branch?) That's not true though. The branching behaviour is inherent in the Schrödinger equation.
    - yyyk 7y ago
      "Bohm is just MWI with a bunch of extra epicycles." Heh. I've heard MWI is just an hidden variable theory with the other branches being the hidden information. Slightly more seriously, the two did develop independently. "I'd be interested in hearing more..." IMHO, QBism is relatively intuitive if/once you accept the subjective probability premise (which means probability one isn't same as 'true'!), but I'm far from qualified to explain it well... "The branching behaviour is inherent in the Schrödinger equation." The point is not the branching per se, but what happens in the current branch's evolution. There are only some branches that are 'legal' or 'likely', and it appears the limits/probabilities aren't deductible from Schrödinger alone. Almost like MWI needs a little extra something to be a complete theory. P.S. That downvote wasn't mine.