That said, I’m using “quantum mechanics” to mean “some generalization of the standard model” in many places.
I think this still has the ambiguity that I am complaining about.
As an analogy, consider the distinction between:
Some population of rabbits that is growing over time due to reproduction
The Fibonacci sequence as a model of the growth dynamics of this population
A computer program computing or mathematician deriving the numbers in or properties of this sequence
The first item in this list is meant to be analogous to the quantum mechanics qua the universe, as in it is some real-world entity that one might hypothesize acts according to certain rules, but exists regardless. The second is a Platonic mathematical object that one might hypothesize matches the rules of the real-world entity. And the third are actual instantiations of this Platonic mathematical object in reality. I would maybe call these “the territory”, “the hypothetical map” and “the actual map”, respectively.
In practice, the actual experimental predictions of the standard model are something like probability distributions over the starting and ending momentum states of particles before and after they interact at the same place at the same time, so I don’t think you can actually run a raw standard model simulation of the solar system which makes sense at all. To make my argument more explicit, I think you could run a lattice simulation of the solar system far above the Planck scale and full of classical particles (with proper masses and proper charges under the standard model) which all interact via general relativity, so at each time slice you move each particle to a new lattice site based on its classical momentum and the gravitational field in the previous time slice. Then you run the standard model at each lattice site which has more than one particle on it to destroy all of the input particles and generate a new set of particles according to the probabilistic predictions of the standard model, and the identities and momenta of the output particles according to a sample of that probability distribution will be applied in the next time slice. I might be making an obvious particle physics mistake, but modulo my own carelessness, almost all lattice sites would have nothing on them, many would have photons, some would have three quarks, fewer would have an electron on them, and some tiny, tiny fraction would have anything else. If you interpreted sets of sites containing the right number of up and down quarks as nucleons, interpreted those nucleons as atoms, used nearby electrons to recognize molecules, interpreted those molecules as objects or substances doing whatever they do in higher levels of abstraction, and sort of ignored anything else until it reached a stable state, then I think you would get a familiar world out of it if you had the utterly unobtainable computing power to do so.
Wouldn’t this fail for metals, quantum computing, the double slit experiment, etc.? By switching back and forth between quantum and classical, it seems like you forbid any superpositions/entanglement/etc. on a scale larger than your classical lattice size. The standard LessWrongian approach is to just bite the bullet on the many worlds interpretation (which I have some philosophical quibbles with, but those quibbles aren’t so relevant to this discussion, I think, so I’m willing to grant the many worlds interpretation if you want).
Anyway, more to the point, this clearly cannot be done with the actual map, and the hypothetical map does not actually exist, so my position is that while this may help one understand the notion that there is an rule that perfectly constrains the world, the thought experiment does not actually work out.
Somewhat adjacently, your approach to this is reductionistic, viewing large entities as being composed of unfathomably many small entities. As part of LDSL I’m trying to wean myself off of reductionism, and instead take large entities to be more fundamental, and treat small entities as something that the large entities can be broken up into.
I think this still has the ambiguity that I am complaining about.
As an analogy, consider the distinction between:
Some population of rabbits that is growing over time due to reproduction
The Fibonacci sequence as a model of the growth dynamics of this population
A computer program computing or mathematician deriving the numbers in or properties of this sequence
The first item in this list is meant to be analogous to the quantum mechanics qua the universe, as in it is some real-world entity that one might hypothesize acts according to certain rules, but exists regardless. The second is a Platonic mathematical object that one might hypothesize matches the rules of the real-world entity. And the third are actual instantiations of this Platonic mathematical object in reality. I would maybe call these “the territory”, “the hypothetical map” and “the actual map”, respectively.
Wouldn’t this fail for metals, quantum computing, the double slit experiment, etc.? By switching back and forth between quantum and classical, it seems like you forbid any superpositions/entanglement/etc. on a scale larger than your classical lattice size. The standard LessWrongian approach is to just bite the bullet on the many worlds interpretation (which I have some philosophical quibbles with, but those quibbles aren’t so relevant to this discussion, I think, so I’m willing to grant the many worlds interpretation if you want).
Anyway, more to the point, this clearly cannot be done with the actual map, and the hypothetical map does not actually exist, so my position is that while this may help one understand the notion that there is an rule that perfectly constrains the world, the thought experiment does not actually work out.
Somewhat adjacently, your approach to this is reductionistic, viewing large entities as being composed of unfathomably many small entities. As part of LDSL I’m trying to wean myself off of reductionism, and instead take large entities to be more fundamental, and treat small entities as something that the large entities can be broken up into.