I've been pre-occupied with Heisenberg's uncertainty principle for around four years now, and I've come to fabricate a lot of questions. The most pressing one, however, is as follows: To me, the uncertainty principle seems to reference our (relatively) poorly controlled methods to measure a particle's momentum and position rather than being some special quantum phenomenon. Is this how it was intended? If I measure a coffee mug's position using a crowbar, I change the coffee mug's momentum by measuring it. I do not, however, change its momentum simply by having knowledge of the coffee mug's position. This is how I think of the uncertainty principle, but was it meant this way? If it was, then doesn't that screw up multiple other concepts such as entanglement and electron configuration around nuclei? Or did Heisenberg believe in some phenomenon that changed one of the particle's traits merely because we observed it?