[Durus]

I'm not sure that particle wave duality is an example of how "the quantum world is nothing like the classic world" as much as it is an example of a difference.

Regardless my point is that there are those that suggest that because observation changes the observed that there are things that are ultimately unknowable. I reject this concept and it related philosophies.

[Cboldt]

-- Regardless my point is that there are those that suggest that because observation changes the observed that there are things that are ultimately unknowable. --

Quantum mechanics just says that what is knowable, is probabilities; and that certainty (or near certainty) in one atomic/quantum (small) observation makes for much uncertainty in another.

Many of the issues that people have with quantum mechanics have their roots in the thought experiment explanations. Action on a small scale defies being described in terms that reflect our ability to intuit. "Wave / Particle duality" being one such thought experiment, Schroedinger's cat being another.