In quantum mechanics, the uncertainty principle is any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle—complimentary variables—can be known.
Kisuke Urahara has spent more than one human lifetime focusing almost entirely on the big picture. His mind is a network of entailments and connections and possibility. But as he draws closer to understanding one thing, he sometimes finds himself with dwindling grasp on another. Comprehension is not merely knowledge, and it is never unbounded. Sometimes, what he inadvertently loses his grip on is something he should not have let go.
In which someone strikes Urahara where it hurts the most—his heart.
- Part 7 of Chaos Theory