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There's a certain amount of intuition and taste involved when assigning theoretical costs, but that's no reason not to do it. We have general principles with so

There's a certain amount of intuition and taste involved when assigning theoretical costs, but that's no reason not to do it. We have general principles with some rational justification for preferring certain features of theories over others. Simplicity in terms of "not multiplying entities without need" is one such principle. A discernible state is an entity. More discernible states requires more entities or more discernible features of an entity. This is the only way to make the concept of discernible state intelligible. To deny this is just to engage in magical thinking. But each posit has a cost associated with it. We don't know what that cost is exactly (relative to other theories with different features). But we do know that an exponential growth in discernible states overshadows the theoretical cost of the whole regardless of how we quantify the cost of any individual posit. MWI is almost maximally profligate; any empirically adequate theory without this cost should be preferred.

whimsicalism 2y ago
to me, this is like saying germ theory of disease has higher theoretical burden than miasma theory of disease because it posits all of these individual viruses and bacteria around us everywhere. "sure, we can observe bacteria and viruses in the lab individually - but when we move to the physical world disease spread is described by miasma which is simpler and thus this is the more parsimonious theory." there are fewer entities in miasma - but you still have to posit this additional thing (the miasma) on top of the already observed viruses and bacteria. similarly, i don't agree that 'count of entities' is the correct criterion for what makes a theory more or less parsimonious/occam's razor preferred. it is about the number of rules even if there is a single rule that creates exponential entities. Copenhagen would also predict this 'exponential branching' in the system under observation - it just proposes that it collapses when measured by the apparatus: an additional rule that makes it less parsimonious than many worlds
- hackinthebochs 2y ago
  It's hard to compare theories that don't have well-developed mechanisms. If we're naive theorists comparing miasma vs tiny organisms, but you have no sense of how those organisms operate, its functionally just a comparison between one miasma and many miasmas, i.e. one vs. many nebulous non-mechanistic effects. In that case one miasma would be preferable. But that's not a demerit to the concept of minimizing entities as a theoretical virtue. >i don't agree that 'count of entities' is the correct criterion for what makes a theory more or less parsimonious/occam's razor preferred. I mean, its literally in the original formulation of Occam's razor: "plurality should not be posited without necessity". But there are many ways to justify this. My preferred argument is that fewer entities means fewer resources with which to "bake in" the explananda into the theory. The more knobs to turn to generate your empirically adequate theory, the less likely your theory will capture reality. >[Copenhagen] just proposes that it collapses when measured by the apparatus Measurement isn't limited to an "apparatus". Collapse of superposition is a feature of large scale interactions. While there is branching, in practice it is bounded because interactions tend to cause collapse.

whimsicalism 2y ago

to me, this is like saying germ theory of disease has higher theoretical burden than miasma theory of disease because it posits all of these individual viruses and bacteria around us everywhere. "sure, we can observe bacteria and viruses in the lab individually - but when we move to the physical world disease spread is described by miasma which is simpler and thus this is the more parsimonious theory." there are fewer entities in miasma - but you still have to posit this additional thing (the miasma) on top of the already observed viruses and bacteria. similarly, i don't agree that 'count of entities' is the correct criterion for what makes a theory more or less parsimonious/occam's razor preferred. it is about the number of rules even if there is a single rule that creates exponential entities. Copenhagen would also predict this 'exponential branching' in the system under observation - it just proposes that it collapses when measured by the apparatus: an additional rule that makes it less parsimonious than many worlds

hackinthebochs 2y ago
It's hard to compare theories that don't have well-developed mechanisms. If we're naive theorists comparing miasma vs tiny organisms, but you have no sense of how those organisms operate, its functionally just a comparison between one miasma and many miasmas, i.e. one vs. many nebulous non-mechanistic effects. In that case one miasma would be preferable. But that's not a demerit to the concept of minimizing entities as a theoretical virtue. >i don't agree that 'count of entities' is the correct criterion for what makes a theory more or less parsimonious/occam's razor preferred. I mean, its literally in the original formulation of Occam's razor: "plurality should not be posited without necessity". But there are many ways to justify this. My preferred argument is that fewer entities means fewer resources with which to "bake in" the explananda into the theory. The more knobs to turn to generate your empirically adequate theory, the less likely your theory will capture reality. >[Copenhagen] just proposes that it collapses when measured by the apparatus Measurement isn't limited to an "apparatus". Collapse of superposition is a feature of large scale interactions. While there is branching, in practice it is bounded because interactions tend to cause collapse.