Quantum mechanical amplitudes are almost exactly as mathematically simple as classical probabilities. (Despite the fact that we developed math while observing classical probabilities but not quantum amplitudes! That seems like pretty robust evidence.)
A theory that gets rid of quantum mechanical amplitudes and replaces them by classical probability doesn’t get simpler, it just gets more like human experience. We are already pretty certain that particle physics does obey quantum probability, and we see pretty well how humans’ experience of classical probability emerges from the picture (modulo the hard problem of consciousness), so we know that humans’ experience of classical probability is irrelevant as evidence about the underlying physical facts (as are the metaphysical intuitions derived from this experience).
(I mention these considerations both as evidence against the prospects of clean physical theories based on classical probability, and as arguments against the worldview according to which such theories are metaphysically attractive, which seems to run through your writing much more generally.)
At any rate, superposition already doesn’t need to be regarded as fundamental, if you are happy on giving up on notions like “locality.” There is room for interesting math here, but I don’t see the metaphysical relevance.
At any rate, superposition already doesn’t need to be regarded as fundamental, if you are happy on giving up on notions like “locality.”
Locality is implicit in special relativity- in a sense being happy “giving up notions like “locality”″ is the same as “if you are happy ignoring the way that all modern physical theories work” (relativity and quantum field theory.)
Quantum mechanical amplitudes are almost exactly as mathematically simple as classical probabilities.
Yes, but this is about physics- the big question isn’t about whether things are mathematically simple. The big question is why do quantum amplitudes show up in our experiments only as classical probabilities? Answering that question would almost certainly revolutionize our understanding of physics.
Yes, my point was that giving up on locality is fairly ridiculous, but is necessary to get rid of superposition.
We understand why the evolution of classical systems is governed by classical probabilities—just churn through the quantum mechanics. Decoherence is very simple (e.g., if you make your reversible computation irreversible by creating heat, the computer looks like it is governed by classical probabilities). As to why we experience branches with high L2 mass, or why we experience anything at all, indeed that looks like a hard question (though I strenuously object to finding “high L2 mass” more surprising than “high probability,” since that is quite clearly an artifact of human intuitions).
We understand why the evolution of classical systems is governed by classical probabilities—just churn through the quantum mechanics. Decoherence is very simple...
Decoherence isn’t actually enough to show why quantum amplitudes show up as classical probabilities- if it were the Born-amplitude problem in many worlds would be solved. You need assumptions to turn “the wavefunction looks like this” into “the wavefunction looks like this so we expect to see result A with probability whatever.” Decoherence tells us off-diagonal elements in the density matrix aren’t likely to survive interaction with a larger system- thats not enough to connect to experimental values.
You jump straight from decoherence to “experiencing branches” without defining what you mean by “branch. ”
My point was that we have no uncertainty about any physical processes involved, only about why we experience what we do. We aren’t uncertain about why classical computers are classical, or why L2-typical observers would experience classical probabilities.
The fact that you experience the outcomes of physical experiments at all requires explanation. I don’t see why that explanation is easier if you use probabilities or counting measure (especially given an infinite universe) rather than amplitude. It seems like bad form to absorb confusion about the hard problem of consciousness into confusion about physics, given that I at least cannot imagine any physics that would resolve my confusion about consciousness.
Quantum mechanical amplitudes are almost exactly as mathematically simple as classical probabilities. (Despite the fact that we developed math while observing classical probabilities but not quantum amplitudes! That seems like pretty robust evidence.)
A theory that gets rid of quantum mechanical amplitudes and replaces them by classical probability doesn’t get simpler, it just gets more like human experience. We are already pretty certain that particle physics does obey quantum probability, and we see pretty well how humans’ experience of classical probability emerges from the picture (modulo the hard problem of consciousness), so we know that humans’ experience of classical probability is irrelevant as evidence about the underlying physical facts (as are the metaphysical intuitions derived from this experience).
(I mention these considerations both as evidence against the prospects of clean physical theories based on classical probability, and as arguments against the worldview according to which such theories are metaphysically attractive, which seems to run through your writing much more generally.)
At any rate, superposition already doesn’t need to be regarded as fundamental, if you are happy on giving up on notions like “locality.” There is room for interesting math here, but I don’t see the metaphysical relevance.
Locality is implicit in special relativity- in a sense being happy “giving up notions like “locality”″ is the same as “if you are happy ignoring the way that all modern physical theories work” (relativity and quantum field theory.)
Yes, but this is about physics- the big question isn’t about whether things are mathematically simple. The big question is why do quantum amplitudes show up in our experiments only as classical probabilities? Answering that question would almost certainly revolutionize our understanding of physics.
Yes, my point was that giving up on locality is fairly ridiculous, but is necessary to get rid of superposition.
We understand why the evolution of classical systems is governed by classical probabilities—just churn through the quantum mechanics. Decoherence is very simple (e.g., if you make your reversible computation irreversible by creating heat, the computer looks like it is governed by classical probabilities). As to why we experience branches with high L2 mass, or why we experience anything at all, indeed that looks like a hard question (though I strenuously object to finding “high L2 mass” more surprising than “high probability,” since that is quite clearly an artifact of human intuitions).
Decoherence isn’t actually enough to show why quantum amplitudes show up as classical probabilities- if it were the Born-amplitude problem in many worlds would be solved. You need assumptions to turn “the wavefunction looks like this” into “the wavefunction looks like this so we expect to see result A with probability whatever.” Decoherence tells us off-diagonal elements in the density matrix aren’t likely to survive interaction with a larger system- thats not enough to connect to experimental values.
You jump straight from decoherence to “experiencing branches” without defining what you mean by “branch. ”
My point was that we have no uncertainty about any physical processes involved, only about why we experience what we do. We aren’t uncertain about why classical computers are classical, or why L2-typical observers would experience classical probabilities.
The fact that you experience the outcomes of physical experiments at all requires explanation. I don’t see why that explanation is easier if you use probabilities or counting measure (especially given an infinite universe) rather than amplitude. It seems like bad form to absorb confusion about the hard problem of consciousness into confusion about physics, given that I at least cannot imagine any physics that would resolve my confusion about consciousness.
So it’s enough to establish a quasi-classical preferred basis, but you still have the Born Rule problem? But one is solved ?