I’ve always had problems with MWI, but it’s just a gut feeling. I don’t have the necessary specialized knowledge to be able to make a decent argument for or against it. I do concede it one advantage: it’s a Copernican explanation, and so far Copernican explanations have a perfect record of having been right every time. Other than that, I find it irritating, most probably because it’s the laziest plot device in science-fiction.
Technical explanation: the problem with MWI is that it makes the fact that density matrices work seem like a complete epistemological coincidence.
Incidentally, I remember a debate between Eliezer and Scott Aaronson where the former confessed he stopped reading his QM textbook right before the chapter on density matrices.
Half the qubits in jar (1) are in state |0> and the other half are in state |1>.
Half the qubits in jar (2) are in state |+> and the other half are in state |->.
Notice that although from a classical Bayesian MWI perspective the two jars are in very different states, there is no way to tell them apart even in principal.
I’ve never heard the term before, but in context I’d guess it means something like “an explanation that implies we’re less important than the previous explanation did”. Heliocentrism vs. geocentrism, evolution vs. a supernatural creation narrative culminating in people, etc.
Why is MWI more Copernican than the Copenhagen interpretation?
You do realize that an “observer” doesn’t have to be conscious, right? The Copenhagen interpretation doesn’t treat humans specially. If anything, I’d say that the Copenhagen interpretation is more Copernican, since it explains the Born probabilities without requiring anthropics.
My comment was not intended to be an endorsement of polymathwannabe’s analysis. I’m not a QM expert and am not qualified to comment on the details of either interpretation.
The Copernican principle states that there’s nothing special or unique or privileged about our local frame of reference: we’re not at the center of the solar system, we’re not at the center of the galaxy, this is not the only galaxy, and the next logical step would be to posit that this is not the only universe.
I do not believe in reincarnation of any sort. I believe this is my only life.
It has been believed that the Earth was flat. I’m sure at least someone had considered the implication that the Earth goes on forever. This has turned out to be false. The Earth has positive curvature, and thus only finite surface area.
Quite a few people have considered the idea that atoms are little solar systems, which could have their own life. It turns out that electrons are almost certainly fundamental particles. And even if they’re not, the way physics works on a small scale is such that life would be impossible.
Similarly, galaxies do not make up molecules. Even if there are other forces as would be necessary, the light speed limit combined with the expansion of the universe creates a cosmological event horizon. Beyond a certain scale, it is physically impossible for anything to interact.
There are a variety of physical theories that predict other universes. They work in different ways, and tend not to be contradictory. It would be unwise to reject them out of hand, but it would be equally unwise to automatically accept them.
The Copernican principle states that there’s nothing special or unique or privileged about our local frame of reference: we’re not at the center of the solar system, we’re not at the center of the galaxy, this is not the only galaxy, and the next logical step would be to posit that this is not the only universe.
I’ve always had problems with MWI, but it’s just a gut feeling. I don’t have the necessary specialized knowledge to be able to make a decent argument for or against it. I do concede it one advantage: it’s a Copernican explanation, and so far Copernican explanations have a perfect record of having been right every time. Other than that, I find it irritating, most probably because it’s the laziest plot device in science-fiction.
Technical explanation: the problem with MWI is that it makes the fact that density matrices work seem like a complete epistemological coincidence.
Incidentally, I remember a debate between Eliezer and Scott Aaronson where the former confessed he stopped reading his QM textbook right before the chapter on density matrices.
I don’t understand what you mean. Could you explain? I’m familiar with QM, so you don’t need to avoid technicality in your explanation.
Suppose we have two jars of qubits:
Half the qubits in jar (1) are in state |0> and the other half are in state |1>.
Half the qubits in jar (2) are in state |+> and the other half are in state |->.
Notice that although from a classical Bayesian MWI perspective the two jars are in very different states, there is no way to tell them apart even in principal.
BTW, that’s the only reason why I’m not fully convinced by realist interpretations of QM.
Against Many Worlds
Broken link, but files 9703089 and 9704039 appear to be the relevant ones.
Thanks. Fixed. Doing links on a tablet is a nightmare.
What’s a Copernican explanation?
I’ve never heard the term before, but in context I’d guess it means something like “an explanation that implies we’re less important than the previous explanation did”. Heliocentrism vs. geocentrism, evolution vs. a supernatural creation narrative culminating in people, etc.
Freud’s psychoanalysis has been often put in the same category of “Copernican” things as heliocentrism and evolution.
Why is MWI more Copernican than the Copenhagen interpretation?
You do realize that an “observer” doesn’t have to be conscious, right? The Copenhagen interpretation doesn’t treat humans specially. If anything, I’d say that the Copenhagen interpretation is more Copernican, since it explains the Born probabilities without requiring anthropics.
My comment was not intended to be an endorsement of polymathwannabe’s analysis. I’m not a QM expert and am not qualified to comment on the details of either interpretation.
The Copernican principle states that there’s nothing special or unique or privileged about our local frame of reference: we’re not at the center of the solar system, we’re not at the center of the galaxy, this is not the only galaxy, and the next logical step would be to posit that this is not the only universe.
I do not believe in reincarnation of any sort. I believe this is my only life.
It has been believed that the Earth was flat. I’m sure at least someone had considered the implication that the Earth goes on forever. This has turned out to be false. The Earth has positive curvature, and thus only finite surface area.
Quite a few people have considered the idea that atoms are little solar systems, which could have their own life. It turns out that electrons are almost certainly fundamental particles. And even if they’re not, the way physics works on a small scale is such that life would be impossible.
Similarly, galaxies do not make up molecules. Even if there are other forces as would be necessary, the light speed limit combined with the expansion of the universe creates a cosmological event horizon. Beyond a certain scale, it is physically impossible for anything to interact.
There are a variety of physical theories that predict other universes. They work in different ways, and tend not to be contradictory. It would be unwise to reject them out of hand, but it would be equally unwise to automatically accept them.
The Copernican principle states that there’s nothing special or unique or privileged about our local frame of reference: we’re not at the center of the solar system, we’re not at the center of the galaxy, this is not the only galaxy, and the next logical step would be to posit that this is not the only universe.