Yeah, this is the part of the proposal that’s hardest for me to buy. Chaos theory means that small variations in initial conditions lead to massive differences pretty rapidly; and we can’t even measure an approximation of initial conditions. The whole “let’s calculate the universe from the start” approach seems to leave way too much scope to end up with something completely unexpected.
It’s not actually calculating the universe from the start. The formalism is intended to be specified such that identifying the universe to arbitrarily high precision ought to still converge; I’m still skeptical, but it does work to simply infer backwards in time, which ought to be a lot more tractable than forward in time (I think? maybe.) but is still not friendly, and see above about apple making contact with newton’s scalp. It’s definitely a key weak point, I have some ideas how to fix it and need to talk them over in a lot more depth with @carado.
Inferring backwards would significantly reduce my concern since your starting from a point we have information about.
I suppose that maybe we could calculate the Kolmogorov score of worlds close to us by backchaining, although that doesn’t really seem to be compatible with the calculation at each step being a formal mathematical expression.
Yeah, this is the part of the proposal that’s hardest for me to buy. Chaos theory means that small variations in initial conditions lead to massive differences pretty rapidly; and we can’t even measure an approximation of initial conditions. The whole “let’s calculate the universe from the start” approach seems to leave way too much scope to end up with something completely unexpected.
It’s not actually calculating the universe from the start. The formalism is intended to be specified such that identifying the universe to arbitrarily high precision ought to still converge; I’m still skeptical, but it does work to simply infer backwards in time, which ought to be a lot more tractable than forward in time (I think? maybe.) but is still not friendly, and see above about apple making contact with newton’s scalp. It’s definitely a key weak point, I have some ideas how to fix it and need to talk them over in a lot more depth with @carado.
Inferring backwards would significantly reduce my concern since your starting from a point we have information about.
I suppose that maybe we could calculate the Kolmogorov score of worlds close to us by backchaining, although that doesn’t really seem to be compatible with the calculation at each step being a formal mathematical expression.