Hmmm. Would you be happier if I changed my last line to read ”… we need to discard the whole Si concept as inappropriate to our imperfectly-observed universe.”?
I don’t think so. Solomonoff induction applies to streams. The most common application is to streams of sense data. There is no pretense of somehow observing the whole of the universe in the first place.
You are correct that my comments are missing the mark. Still, there is a sense in which the kinds of non-determinism represented by Born probabilities present problems for Si. I agree that Si definitely does not pretend to generate its predictions based on observation of the whole universe. And it does not pretend to predict everything about the universe. But it does seem to pretend that it is doing something better than making predictions that apply to only one of many randomly selected “worlds”.
Can anyone else—Cousin_it perhaps—explain why deterministic evolution of the wave function seems to be insufficient to place Si on solid ground?
You are correct that my comments are missing the mark. Still, there is a sense in which the kinds of non-determinism represented by Born probabilities present problems for Si.
They would represent problems for determinism—if they were “real” probabailities. However the idea around here is that probabilities are in the mind.
It is a commonly heard statement that probabilities calculated within a pure state have a different character than the probabilities with which different pure states appear in a mixture, or density matrix. As Pauli put it, the former represents “Eine prinzipielle Unbestimmtheit, nicht nur Unbekanntheit” *. But this viewpoint leads to so many paradoxes and mysteries that we explore the consequences of the unified view, that all probability signifies only incomplete human information.
[*] Translation: “A fundamental uncertainty, not only obscurity”
Hmmm. Would you be happier if I changed my last line to read ”… we need to discard the whole Si concept as inappropriate to our imperfectly-observed universe.”?
I don’t think so. Solomonoff induction applies to streams. The most common application is to streams of sense data. There is no pretense of somehow observing the whole of the universe in the first place.
You are correct that my comments are missing the mark. Still, there is a sense in which the kinds of non-determinism represented by Born probabilities present problems for Si. I agree that Si definitely does not pretend to generate its predictions based on observation of the whole universe. And it does not pretend to predict everything about the universe. But it does seem to pretend that it is doing something better than making predictions that apply to only one of many randomly selected “worlds”.
Can anyone else—Cousin_it perhaps—explain why deterministic evolution of the wave function seems to be insufficient to place Si on solid ground?
They would represent problems for determinism—if they were “real” probabailities. However the idea around here is that probabilities are in the mind.
Here is E T Jaynes on the topic:
[*] Translation: “A fundamental uncertainty, not only obscurity”