> That shouldn’t detract from making desirable decisions though, because once we make them, we are necessarily in the branch where we made them,
In a branch, surely? While you're thinking for a second or so, there will be numerous nuclear decays in the relevant areas of your brain. Potassium-40 specific activity in the brain human brain is in on the order daBq to hBq kg^-1; there are other radioactive isotopes to be found in the brain, and there are plenty of other branching events. So "there will always be (equally real and existing) branches in which they are made", right?
When thinking of how many worlds in the MWI formalism there are, always think much larger than your intuition tells you, since every quantum outcome is realized. One needs only a small finite fraction of the universe to reach uncountably infinite branches. That should be taken into account when evaluating aesthetic concerns like conceptual clarity particularly for something that requires a weighty set of quantum numbers, like consciousness.
> assuming VMs diverge like the MW branches diverge
You could try to apply this to your VM-forking analogy, by generating a different VM image per bit of VM memory (including registers and memory-mapped I/O devices and the like) per clock cycle, taking the simplifying assumptions that clock-time is uniform for all bits and the clock cycle is the minimum possible time. Then as they say, shrink the lattice, taking clock cycle -> Planck time, bit-layout -> Planck volumes, binary content of each bit -> field content of (continually interacting and self-interacting) 24+ Standard Model fields. And we're still not even fully relativistic.
If I understand correctly, you are arguing that MW is unattractive as an interpretation due to the number of branches. I don’t feel that way. I find MW attractive because it requires less assumptions. It feels natural to me that the physical laws describe a relation (in the mathematical sense) between past and future, rather than a function. I don’t have a problem with uncountable infinity. I mean, the number of possible functions on the natural numbers, a fairly simple thing,
is already uncountable. It shouldn’t be a surprise. We also don’t know whether the universe is actually non-discrete at the base level. It may still turn out that there is really just a countable infinity of possible states of the universe, and thus also just a countable infinity of branches. That’s still humongous — it can accommodate anything you could possibly imagine — but I rather see this as a pro of MW.
In a branch, surely? While you're thinking for a second or so, there will be numerous nuclear decays in the relevant areas of your brain. Potassium-40 specific activity in the brain human brain is in on the order daBq to hBq kg^-1; there are other radioactive isotopes to be found in the brain, and there are plenty of other branching events. So "there will always be (equally real and existing) branches in which they are made", right?
When thinking of how many worlds in the MWI formalism there are, always think much larger than your intuition tells you, since every quantum outcome is realized. One needs only a small finite fraction of the universe to reach uncountably infinite branches. That should be taken into account when evaluating aesthetic concerns like conceptual clarity particularly for something that requires a weighty set of quantum numbers, like consciousness.
> assuming VMs diverge like the MW branches diverge
You could try to apply this to your VM-forking analogy, by generating a different VM image per bit of VM memory (including registers and memory-mapped I/O devices and the like) per clock cycle, taking the simplifying assumptions that clock-time is uniform for all bits and the clock cycle is the minimum possible time. Then as they say, shrink the lattice, taking clock cycle -> Planck time, bit-layout -> Planck volumes, binary content of each bit -> field content of (continually interacting and self-interacting) 24+ Standard Model fields. And we're still not even fully relativistic.
cf. https://en.wikipedia.org/wiki/Quantum_number