What you are describing is to first compute the answer using Many Worlds, and then figure out where to apply the collapse in Copenhagen to not affect anything.
What I am saying is to compute the answer using quantum mechanics.
The way to do it correctly, Copenhagen style, is to say “okay, the electron goes through the plate with two holes in it. But since, from the perspective of the electron, it can’t go through two holes, the state of the electron on the other side should be entangled something like |10> + |01>. If we fast-forward to the screen, we get an interference pattern”
The way to do it correctly, MW style, is to say “okay, the electron has equal probability of going through each hole, so let’s split into two worlds with equal phase. The detector will then observe the superposition of the two worlds, something like |10> + |01>, except fast-forwarded to the screen, so there should be an interference pattern.”
If these two approaches look similar, there’s a reason. And it’s not that one is cribbing off the other! As you can see, introducing entanglement in the Copenhagen interpretation was definitely not arbitrary, but it is conceptually trickier than thinking through the same process using the MWI.
Does your understanding of Copenhagen Quantum Mechanics reject the conclusion of Many Worlds, that the universe is in superposition of many states, many of which can contain people, which can’t observe each other?
If not, I think this has become an argument about definitions.
I’m actually pretty sure the Copenhagen Interpretation isn’t complete/coherent enough to actually be turned into a computer program. It just waves it’s hands around the Measurement Problem. The Occam’s Razor justification for people want to make for Many Worlds needs to be made in comparison to the interpretations viable competitors like de Broglie Bohm and company.
I’m actually pretty sure the Copenhagen Interpretation isn’t complete/coherent enough to actually be turned into a computer program. It just waves it’s hands around the Measurement Problem.
I can’t argue with that.
The Occam’s Razor justification for people want to make for Many Worlds needs to be made in comparison to the interpretations viable competitors like de Broglie Bohm and company.
Bohm’s theory is one of those hidden variable theories, which according to EPR must have something like faster than light signaling?
Bohm’s theory is one of those hidden variable theories, which according to EPR must have something like faster than light signaling?
It is a hidden variable theory and as such it is non-local but the non-locality doesn’t imply that we can use it for ftl signalling. The main problems are a.) you need to do weird things to it to make it Lorentz invariant and B.) it is less parsimonious than Many Worlds (as all hidden variable theories probably will be since they add more variables!). On the other hand it returns the Born probabilities (ED: which I guess I would argue makes it parsimonious in a different way since it doesn’t have this added postulate).
I don’t really know enough to make the evaluation for myself. But my sense is that we as a community have done way to much talking about why MWI is better than CI (it obviously is) and not nearly enough thinking about the other alternatives.
Does your understanding of Copenhagen Quantum Mechanics reject the conclusion [...] that the universe is in superposition of many states?
Yes, it does. The Copenhagen interpretation says that when you observe the universe, your observation becomes right, and your model of the world should make a 100% certain retrodiction about what just happened. This is mathematically equivalent to letting the a MWI modeler know which world (or set of worlds with the same eigenstate of the observable) they’re in at some time.
However, in Copenhagen, the universe you observe is all there “is.” If I observe the electron with spin up, there is no other me that observes it with spin down. The probabilities in Copenhagen are more Bayesian than frequentist. Meanwhile in MWI the probabilities are frequencies of “actual” people measuring the electron. But since there is no such thing as an outside observer of the universe (that’s the point), the difference here doesn’t necessarily mean this isn’t an argument about definitions. :P
Your Copenhagen Interpretation looks like starting with Many Worlds, and then rejecting the implied invisible worlds as an additional assumption about reality.
My Copenhagen interpretation (the one I use to demonstrate ideas about the Copenhagen interpretation, not necessarily the interpretation I use when thinking about problems) looks like the Copenhagen Interpretation. And yes, it is close to what you said. But it’s not quite that simple, since all the math is preserved because of stuff like entanglement.
What you are describing is to first compute the answer using Many Worlds, and then figure out where to apply the collapse in Copenhagen to not affect anything.
No.
What I am saying is to compute the answer using quantum mechanics.
The way to do it correctly, Copenhagen style, is to say “okay, the electron goes through the plate with two holes in it. But since, from the perspective of the electron, it can’t go through two holes, the state of the electron on the other side should be entangled something like |10> + |01>. If we fast-forward to the screen, we get an interference pattern”
The way to do it correctly, MW style, is to say “okay, the electron has equal probability of going through each hole, so let’s split into two worlds with equal phase. The detector will then observe the superposition of the two worlds, something like |10> + |01>, except fast-forwarded to the screen, so there should be an interference pattern.”
If these two approaches look similar, there’s a reason. And it’s not that one is cribbing off the other! As you can see, introducing entanglement in the Copenhagen interpretation was definitely not arbitrary, but it is conceptually trickier than thinking through the same process using the MWI.
Does your understanding of Copenhagen Quantum Mechanics reject the conclusion of Many Worlds, that the universe is in superposition of many states, many of which can contain people, which can’t observe each other?
If not, I think this has become an argument about definitions.
I’m actually pretty sure the Copenhagen Interpretation isn’t complete/coherent enough to actually be turned into a computer program. It just waves it’s hands around the Measurement Problem. The Occam’s Razor justification for people want to make for Many Worlds needs to be made in comparison to the interpretations viable competitors like de Broglie Bohm and company.
I can’t argue with that.
Bohm’s theory is one of those hidden variable theories, which according to EPR must have something like faster than light signaling?
It is a hidden variable theory and as such it is non-local but the non-locality doesn’t imply that we can use it for ftl signalling. The main problems are a.) you need to do weird things to it to make it Lorentz invariant and B.) it is less parsimonious than Many Worlds (as all hidden variable theories probably will be since they add more variables!). On the other hand it returns the Born probabilities (ED: which I guess I would argue makes it parsimonious in a different way since it doesn’t have this added postulate).
I don’t really know enough to make the evaluation for myself. But my sense is that we as a community have done way to much talking about why MWI is better than CI (it obviously is) and not nearly enough thinking about the other alternatives.
Yes, it does. The Copenhagen interpretation says that when you observe the universe, your observation becomes right, and your model of the world should make a 100% certain retrodiction about what just happened. This is mathematically equivalent to letting the a MWI modeler know which world (or set of worlds with the same eigenstate of the observable) they’re in at some time.
However, in Copenhagen, the universe you observe is all there “is.” If I observe the electron with spin up, there is no other me that observes it with spin down. The probabilities in Copenhagen are more Bayesian than frequentist. Meanwhile in MWI the probabilities are frequencies of “actual” people measuring the electron. But since there is no such thing as an outside observer of the universe (that’s the point), the difference here doesn’t necessarily mean this isn’t an argument about definitions. :P
Your Copenhagen Interpretation looks like starting with Many Worlds, and then rejecting the implied invisible worlds as an additional assumption about reality.
My Copenhagen interpretation (the one I use to demonstrate ideas about the Copenhagen interpretation, not necessarily the interpretation I use when thinking about problems) looks like the Copenhagen Interpretation. And yes, it is close to what you said. But it’s not quite that simple, since all the math is preserved because of stuff like entanglement.