2 ms·

Postulate what? The Born rule doesn't hold with absolute certainty in any interpretation, it holds only with asymptotic certainty, and the latter is a quantitat

Postulate what? The Born rule doesn't hold with absolute certainty in any interpretation, it holds only with asymptotic certainty, and the latter is a quantitative observable computable property, and it computes the same way in any interpretation, otherwise interpretations would be quantitatively different.

tsimionescu 2y ago
Some people claim that the MWI doesn't need the Born rule as a postulate, that it can be deduced from the Schrodinger equation if we just assume that entire universe is described by a universal wavefunction. This is generally why some claim that the MWI is actually the "most serious" interpretation, since it supposedly only has one postulate (that the wavefunction describes the universe), while other interpretations require at least two postulates (the one above, plus the Born rule). I believe that this is the claim that evanb was making at the beginning of this thread: that you don't need the Born rule, that decoherence (which is to some extent a consequence of the Schrodinger equation, not an extra postulate) is enough to explain how the classical physics we observe in day to day life emerge from the wavefunction description of the universe in QM.
- GoblinSlayer 2y ago
  He answered a question about collapse, not Born rule, it's two different phenomena. Decoherence replaces collapse and explains why you observe one result, Born rule is replaced by the law of big numbers. Born rule is an abductive explanation for empirically observed statistics, and as abduction allows alternative explanations, it's empirical observation that needs to be explained, not postulates. Ironically, the law of big numbers is calculated MWI style: it considers all outcomes equally as if they all happen somehow even though they are mutually exclusive, but they all add up to the final statistics of statistics. The Schrodinger equation gives your state, you project it to the Born rule basis and see the projection asymptotically approaches 1. What's left after that is how to interpret asymptotic certainty, but that looks easy.

tsimionescu 2y ago

Some people claim that the MWI doesn't need the Born rule as a postulate, that it can be deduced from the Schrodinger equation if we just assume that entire universe is described by a universal wavefunction. This is generally why some claim that the MWI is actually the "most serious" interpretation, since it supposedly only has one postulate (that the wavefunction describes the universe), while other interpretations require at least two postulates (the one above, plus the Born rule). I believe that this is the claim that evanb was making at the beginning of this thread: that you don't need the Born rule, that decoherence (which is to some extent a consequence of the Schrodinger equation, not an extra postulate) is enough to explain how the classical physics we observe in day to day life emerge from the wavefunction description of the universe in QM.

GoblinSlayer 2y ago
He answered a question about collapse, not Born rule, it's two different phenomena. Decoherence replaces collapse and explains why you observe one result, Born rule is replaced by the law of big numbers. Born rule is an abductive explanation for empirically observed statistics, and as abduction allows alternative explanations, it's empirical observation that needs to be explained, not postulates. Ironically, the law of big numbers is calculated MWI style: it considers all outcomes equally as if they all happen somehow even though they are mutually exclusive, but they all add up to the final statistics of statistics. The Schrodinger equation gives your state, you project it to the Born rule basis and see the projection asymptotically approaches 1. What's left after that is how to interpret asymptotic certainty, but that looks easy.