I take it that the theory doesn’t tell us determinately that any given particle absolutely lacks any more fundamental structure. How could it, even in principle?
Paul N., you’re right that QM can’t rule out the electron having a more fundamental structure—but it can tell us that whatever that structure might be, it’s the same from one electron to the next! Why? Because we’re talking about a theory in which whether two states of the universe are “the same” or “different” is a primitive with testable consequences, and this is true not because of some “add-on law” that physicists made up but because of the theory’s structure. In particular, if two electrons had some definite property that differed even in the hundredth decimal place, then you wouldn’t get an interference pattern when you switched the electrons, but as a matter of fact you do. I know Eliezer doesn’t want people to see QM as “bizarre,” but if thinking of it that way helps you accept this as a fact, go ahead!
I take it that the theory doesn’t tell us determinately that any given particle absolutely lacks any more fundamental structure. How could it, even in principle?
Paul N., you’re right that QM can’t rule out the electron having a more fundamental structure—but it can tell us that whatever that structure might be, it’s the same from one electron to the next! Why? Because we’re talking about a theory in which whether two states of the universe are “the same” or “different” is a primitive with testable consequences, and this is true not because of some “add-on law” that physicists made up but because of the theory’s structure. In particular, if two electrons had some definite property that differed even in the hundredth decimal place, then you wouldn’t get an interference pattern when you switched the electrons, but as a matter of fact you do. I know Eliezer doesn’t want people to see QM as “bizarre,” but if thinking of it that way helps you accept this as a fact, go ahead!