4 ms·

The label "Many Worlds Interpretation" is a popular label for the theory, but it's not a particularly accurate one. The original paper by Hugh Everett was titl

The label "Many Worlds Interpretation" is a popular label for the theory, but it's not a particularly accurate one. The original paper by Hugh Everett was titled '"Relative State" Formulation of Quantum Mechanics'. The underlying principle of Many Worlds isn't actually that there are many worlds. Is that there is a singular wave function, which is the true reality. The things we refer to as "worlds" are massively-complicated entanglements and superpositions within that wave function, of which we—for some reason—can only observe one position of that superposition.

lisper 7y ago
Everything you say is true. Nonetheless, if you read papers written by self-identified advocates of Everett, they invariably refer to it as "many-worlds" and they talk about "the branching structure of the multiverse" and "copies" or "versions" of yourself. So regardless of what you or I think Everett meant, the present-day advocates of his theory are clearly trying to advance the idea that there are, in point of metaphysical fact, many worlds.
- platz 7y ago
  If you agree on that math/science then this point you're adamant about whether it is or is not a "world" reduces to a semantics/ontology/philosophy question, which we're not going to get further clarity on in a thread about trying to gain a proper or better understanding as laypeople of the scientific theories, unless you want to advance the conversation to the understanding of those scientific theories into a semantic/ontological/philosophic realm.
- ncallaway 7y ago
  Sure, but I would think every one of those advocates would also agree with what I wrote. That the "world" described by many worlds is a convenient short-hand for a single position in a massively entangled system of particles in a complex-superposition. It's the "Many Worlds" is common moniker, and the rhetoric does use the concept of worlds all the time, but whenever you get down to the specifics of the theory there really aren't many worlds. I think it's unfair to hold the shorthand rhetoric against people when they attempt to get to that more precise level. It would be like using the plain english definition of "observation" against someone trying to provide a more rigorous definition of what an "observation" is under the Copenhagen interpretation. Ultimatley, this discussion all stems from the original statement: "MWI insists that experiments have multiple outcomes in point of metaphysical fact." It's a fairly moot point at this point since that statement was removed.
  - lisper 7y ago
    > I would think every one of those advocates would also agree with what I wrote. No, they wouldn't. They don't. See my response to lmm here: https://news.ycombinator.com/item?id=20941803 https://news.ycombinator.com/item?id=20941803 > "MWI insists that experiments have multiple outcomes in point of metaphysical fact." It's a fairly moot point at this point since that statement was removed. I'll stand by that with one minor modification: contemporary advocates of MWI insist that experiments have multiple outcomes in point of metaphysical fact.
    - ncallaway 7y ago
      Sorry for the slow response. Been a busy couple of days :) > No, they wouldn't. They don't. See my response to lmm here I don't think lmm and I disagree. I said "[The underlying principle of Many Worlds] is that there is a singular wave function, which is the true reality". lmm says: "The only thing that MWI demands we take as metaphysically real is the wavefunction". I think this is expressing the same thing in different terms. I said: "The things we refer to as "worlds" are massively-complicated entanglements and superpositions within that wave function". lmm says: "Given a wavefunction like 1/sqrt2(|experimenter who observed a live cat> + |experimenter who observed a dead cat>) ...". Again, I think our descriptions are in fairly close agreement. I think lmm's description is a good summary of how the "worlds" in Many Worlds are viewed by Many Worlds advocates: "in the same way that people who hear a particular pattern of sound might find it convenient to think of it as a chord of two or three notes". The "worlds" aren't actually fundamental to the theory, but rather an emergent phenomena from them. The reason for the label "Many Worlds" is not because they are the fundamental concept. It's because it's the most... interesting element from a pop-sci marketing angle.
crankylinuxuser 7y ago
> "worlds" are massively-complicated entanglements and superpositions within that wave function, of which we—for some reason—can only observe one position of that superposition. Is the collapse of the wave function related to consciousness? How would we construct a test to verify that?

lisper 7y ago

Everything you say is true. Nonetheless, if you read papers written by self-identified advocates of Everett, they invariably refer to it as "many-worlds" and they talk about "the branching structure of the multiverse" and "copies" or "versions" of yourself. So regardless of what you or I think Everett meant, the present-day advocates of his theory are clearly trying to advance the idea that there are, in point of metaphysical fact, many worlds.

platz 7y ago
If you agree on that math/science then this point you're adamant about whether it is or is not a "world" reduces to a semantics/ontology/philosophy question, which we're not going to get further clarity on in a thread about trying to gain a proper or better understanding as laypeople of the scientific theories, unless you want to advance the conversation to the understanding of those scientific theories into a semantic/ontological/philosophic realm.
ncallaway 7y ago
Sure, but I would think every one of those advocates would also agree with what I wrote. That the "world" described by many worlds is a convenient short-hand for a single position in a massively entangled system of particles in a complex-superposition. It's the "Many Worlds" is common moniker, and the rhetoric does use the concept of worlds all the time, but whenever you get down to the specifics of the theory there really aren't many worlds. I think it's unfair to hold the shorthand rhetoric against people when they attempt to get to that more precise level. It would be like using the plain english definition of "observation" against someone trying to provide a more rigorous definition of what an "observation" is under the Copenhagen interpretation. Ultimatley, this discussion all stems from the original statement: "MWI insists that experiments have multiple outcomes in point of metaphysical fact." It's a fairly moot point at this point since that statement was removed.
- lisper 7y ago
  > I would think every one of those advocates would also agree with what I wrote. No, they wouldn't. They don't. See my response to lmm here: https://news.ycombinator.com/item?id=20941803 https://news.ycombinator.com/item?id=20941803 > "MWI insists that experiments have multiple outcomes in point of metaphysical fact." It's a fairly moot point at this point since that statement was removed. I'll stand by that with one minor modification: contemporary advocates of MWI insist that experiments have multiple outcomes in point of metaphysical fact.
  - ncallaway 7y ago
    Sorry for the slow response. Been a busy couple of days :) > No, they wouldn't. They don't. See my response to lmm here I don't think lmm and I disagree. I said "[The underlying principle of Many Worlds] is that there is a singular wave function, which is the true reality". lmm says: "The only thing that MWI demands we take as metaphysically real is the wavefunction". I think this is expressing the same thing in different terms. I said: "The things we refer to as "worlds" are massively-complicated entanglements and superpositions within that wave function". lmm says: "Given a wavefunction like 1/sqrt2(|experimenter who observed a live cat> + |experimenter who observed a dead cat>) ...". Again, I think our descriptions are in fairly close agreement. I think lmm's description is a good summary of how the "worlds" in Many Worlds are viewed by Many Worlds advocates: "in the same way that people who hear a particular pattern of sound might find it convenient to think of it as a chord of two or three notes". The "worlds" aren't actually fundamental to the theory, but rather an emergent phenomena from them. The reason for the label "Many Worlds" is not because they are the fundamental concept. It's because it's the most... interesting element from a pop-sci marketing angle.

crankylinuxuser 7y ago

> "worlds" are massively-complicated entanglements and superpositions within that wave function, of which we—for some reason—can only observe one position of that superposition. Is the collapse of the wave function related to consciousness? How would we construct a test to verify that?