Origin of measurement uncertainty

[Loren Booda]

Does quantum measurement uncertainty result from observer, object or both?

[vanesch]

It depends upon the interpretation you give to the quantum formalism, but the different potential answers have no operational effect.

As quantum theory is operationally a theory which allows you to calculate probabilities of outcomes of observations, one shouldn't be surprised to find "uncertainties" (in other words, non-trivial probability distributions).

And as the mental image one has of what "happens behind the screens" is totally interpretation-dependent, the answer to your question is so, too. But it doesn't change anything to what's actually possible with the theory.

[Loren Booda]

Thank you for responding, vanesch. What probabilistic interpretations are expressed in terms of the observer alone, though?

[vanesch]

Thank you for responding, vanesch. What probabilistic interpretations are expressed in terms of the observer alone, though?

Many worlds views. The probability is in which world you see, not what happens to the world.

This in contrast to Copenhagen-style views, where something random happens 'for real'.

[koantum]

Does quantum measurement uncertainty result from observer, object or both?
If only Heisenberg's term Unschärfe were correctly translated into FUZZINESS instead of incorrectly into "uncertainty". :grumpy: The stability of atoms (and everything made of atoms) rests on the objective fuzziness of their internal relative positions and momenta, not on our uncertainty about the exact values of these quantities.