Absolute measurement: is it really possible?

[Loren Booda]

Heisenberg uncertainty forbids measuring exactly and simultaneously complementary dynamic observables, but can even compatible quantum numbers ever be precisely determined? Chaos disturbs consecutive measurement, but can one measure perfectly properties of singular events in those classical systems? In the physical limit, is absolute measurement ever possible?

[Arcon]

Originally posted by Loren Booda
Heisenberg uncertainty forbids measuring exactly and simultaneously complementary dynamic observables, but can even compatible quantum numbers ever be precisely determined? Chaos disturbs consecutive measurement, but can one measure perfectly properties of singular events in those classical systems? In the physical limit, is absolute measurement ever possible?

In principle quantum numbers can be precisely determined. For example: when you send a single electron through a Stern-Gerlag device it is deflected in either of two directions, up or down. The direction is very measurable and thus the z-component of spin, a quantum number, is detectable too.