4 ms·
Because you can construct experiments where the proton from source A ends up at location B, and the proton from source C ends up at location D, or A ends up at
by wizzwizz4 5y ago
Because you can construct experiments where the proton from source A ends up at location B, and the proton from source C ends up at location D, or A ends up at D and B ends up at C. (Or some other possibilities.) You find that the A→B, C→D possibility's amplitude sums with the A→D, B→C possibility: i.e., that they're the same indistinguishable final state.
If swapping two things around gives a result indistinguishable from not swapping them, that's fungibility.
- whatshisface 5y agoPhotons of different polarizations are nonidentical, but if this argument is true, it would also prove that horizontally and vertically polarized photons were identical... in an experiment insensitive to polarization. I do not believe this answers the original question.
- wizzwizz4 5y agoTwo coins aren't identical, but they're fungible. Is "identical" even well-defined on fundamental-ish particles?
- whatshisface 5y agoIdentical means that either bosonic or fermionic conditions are applied to the joint tensor-product'd wavefunctions of multi-particle systems. It's well defined, and although I was hoping this thread would offer a more grounded definition I am not sure if it succeeded.